MSc Digital Dental Technology

MSc Digital Dental Technology

DDT7001

Dental Research Project

MODULE GUIDE

2021/2022

Semester 3

Level HE7

Contents

TOC o "1-3" h z u 1. Key Information PAGEREF _Toc105253177 h 22. Learning and Teaching PAGEREF _Toc105253178 h 23. Module Communications PAGEREF _Toc105253179 h 24. Module Description PAGEREF _Toc105253180 h 25. Learning Outcomes and Assessments PAGEREF _Toc105253181 h 36. Assessment Deadlines PAGEREF _Toc105253182 h 37. Assessment Feedback PAGEREF _Toc105253183 h 48. Module Calendar PAGEREF _Toc105253184 h 49. Formative Assessment PAGEREF _Toc105253185 h 510. Indicative Reading PAGEREF _Toc105253186 h 511. Guidelines for the Preparation and Submission of Written Assessments PAGEREF _Toc105253187 h 612. Procedures for Other Assessments PAGEREF _Toc105253188 h 1113. Academic Misconduct PAGEREF _Toc105253189 h 1114. Assessments PAGEREF _Toc105253190 h 1215. General Assessment Guidelines for Written Assessments PAGEREF _Toc105253191 h 19

1. Key Information

Module Tutor Dr Nikolaos Poulis (Module Leader)

Dr Abdurahman Salem

Email N.Poulis@bolton.ac.ukA.Salem@bolton.ac.uk

Availability and Contact Method(s) Scheduled drop in hours available for support - on campus and/or online

Weblink to Moodle Class https://moodle.bolton.ac.uk/course/view.php?id=22279

Weblink to Module Specification http://modules.bolton.ac.uk/DDT7001

2. Learning and Teaching

This module utilises a blended learning approach and requires you to work independently and is primarily dependent on self-directed studying. The research area of interest will be linked, as far as is possible, to the expertise and existing research projects of the supervisor. An induction to the module will take place by the module leader, where all expectations and the rationale of the module delivery will be thoroughly explained. The module leader will provide targeted seminar activities, coupled with your initial supervisor meetings will take place using either face to face or remote communication platforms. This will support you to complete your research proposals with the agreement of your supervisor and the module leader. The module leader seminar series will be based on group activity and peer-support. Upon the allocation of your supervisor, one-to-one supervision sessions will be provided to support and guide you during the research being conducted, but also with the production of your Dissertation. There will be 32 hours supervision/sessions/tutorials over 15 weeks.

3. Module CommunicationsThe Module Tutors contact details are provided at the top of this page. You must check your University of Bolton email address and the Moodle area dedicated to this module regularly as many module communications are channelled through these media.

Your Module Tutor will normally aim to respond to your email messages within 2 full working days of receipt. However responses will be longer in holiday periods.

4. Module DescriptionThe aim of this module is to provide you with an opportunity to undertake an independent, substantial and in-depth investigation on a research topic of a particular interest. This module is ideally suited to an experimental research dissertation approach. Further activities will develop your critical thinking, critical analysis and problem-solving skills, as well as your working independence. You will develop your abilities to identify and set the correct research questions, aims, objectives and research hypotheses for a research study of interest. The knowledge acquired from the taught MSc Digital Dental Technology modules will aid in developing your research methodology, collecting and analysing the data, as well as interpreting and justifying your results, leading into your conclusions. You will receive the required support and guidance from your supervisor and the module leader in order to complete your research and produce your Dissertation. If your research is of suitable quality, you will be invited to re-format your project into an academic paper suitable for publication in an academic journal.

5. Learning Outcomes and AssessmentsModule Learning Outcomes Assessment

No. and Type

LO1: Critically appraise and evaluate the literature in order to construct relevant research questions and appropriate aims and objectives. Assessment 1:

Dissertation

LO2: Critically analyse, evaluate and review appropriate literature from a wide range of relevant sources. Assessment 1:

Dissertation

LO3: Critically examine a range of data collection methods, exploring limitations, in order to propose and justify an appropriate methodological approach to address the aims and objectives of a research study. Assessment 1:

Dissertation

LO4: Plan and implement a structured research project, demonstrating effective data collection methods and data analysis, whilst conforming with ethical and research governance requirements. Assessment 1:

Dissertation

LO5: Critically analyse, interpret and model data, elucidating coherent findings and conclusions which respond to the research question, whilst synthesising recommendations which recognise the limitations of your own study. Assessment 1:

Dissertation

LO6: Defend findings and demonstrate critical reflection in an effective and structured manner. Assessment 2:

Oral Assessment

6. Assessment DeadlinesAssessment item

Due Date Weight

1

Dissertation

Coursework 12,000 - 15,000 words Week 14

4/9/2021 90%

2

Oral assessment

Oral/Poster presentation - Professional Discussion - 30 Minutes Week 15

(w/c 5/9/2021) 10%

7. Assessment FeedbackFeedback on items of assessment can be formal (such as on a signed feedback form) or informal (such as advice from a tutor in a tutorial). Feedback is therefore not just your grade or the comments written on your feedback form, it is advice you get from your tutor and sometimes your peers about how your work is progressing, how well you have done, what further actions you might take.

We recognise the value of prompt feedback on work submitted. Other than in exceptional circumstances (such as might be caused by staff illness), you can expect your work to be marked and feedback provided not more than 15 working days from the deadline date. However, please note that that such feedback will be provisional and unconfirmed until the Assessment Board has met and may therefore be subject to change.

Please take time to read or listen to your assessment feedback. This can be very useful in determining your strengths and key areas for development, and can therefore help you improve on future grades.

8. Module CalendarSession No. Date or Week Commencing Topics Covered Planned Delivery Method*

1 30/05/2022 Tutorial: Introduction to the module in a tutorial held by the module leader. Guidance from the module leader and the supervisors on the proposed research proposals. On campus

2 06/06/2022 Tutorial: Submission of Research Proposal. Feedback on the submitted research proposals. On campus

3 13/06/2022 Tutorial/Workshop: Guidance from the supervisor and feedback. On campus

4 20/06/2022 Tutorial/Workshop: Guidance from the supervisor and feedback. On campus

5 27/06/2022 Tutorial/Workshop: Guidance from the supervisor and feedback. On campus

6 04/07/2022 Tutorial/Workshop: Guidance from the supervisor and feedback. On campus

7 11/07/2022 Tutorial/Workshop: Guidance from the supervisor and feedback. On campus

8 18/07/2022 Tutorial/Workshop: Guidance from the supervisor and feedback. On campus

9 25/07/2022 Tutorial: Guidance from the supervisor and feedback. On campus

10 01/08/2022 Tutorial: Guidance from the supervisor and feedback. Zoom / On campus

11 08/08/2022 Tutorial: Guidance from the supervisor and feedback. Zoom / On campus

12 15/08/2022 Tutorial: Guidance from the supervisor and feedback. Zoom / On campus

13 22/08/2022 Tutorial: Guidance from the supervisor and feedback. Zoom / On campus

14 29/08/2022 Tutorial: Dissertation Submission week (4/9/22) On campus

15 05/09/2022 Oral/Poster Presentation On campus

* Subject to change in the event of any campus restrictions

9. Formative AssessmentFormative assessment is employed throughout the initial preparatory stages of research development, the research being conducted and the Dissertation being produced. During the sessions with your supervisor, you will receive valuable feedback on the development of your research project, as well as on drafts of your Dissertation.

10. Indicative Reading

Bell, J. (2014) Doing your Research Project: A Guide for First-time Researchers. 6th ed. Berkshire: Open University Press.

Berg, K., Latin, R. (2008) Essentials of research methods in health, physical education, exercise science, and recreation. 3rd ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams and Wilkins.

Biggam, J. (2017) Succeeding with your Master's Dissertation: A step-by-step handbook. 4th ed. London: Open University Press.

Booth, A., Sutton, A. and Papaioannou, D. (2012) Systematic approaches to a successful literature review. London: SAGE.

Brunette, D.M. (2020) Critical thinking: Understanding and evaluating dental research. 3rd ed. Batavia, IL: Quintessence Publishing Co., Inc.

Dawson, C. (2009) Introduction to research methods: a practical guide for anyone undertaking a research project. 4th ed. Oxford: How To Books.

Field, A. (2017) Discovering statistics using IBM SPSS. 5th ed. London: SAGE.

Fink, A. (2005) Conducting research literature reviews: from the Internet to paper. 2nd ed. Thousand Oaks: SAGE.

Gastel, B. and Day, R. (2016) How to write and publish a scientific paper. Santa Barbara: Greenwood Press.

Gray, D. (2014) Doing research in the real world. 3rd ed. Los Angeles: SAGE.

Jesson, J., Matheson, L. and Lacey, F. (2011) Doing your literature review: traditional and systematic techniques. London: SAGE.

Kumar, R. (2014) Research methodology: a step-by-step guide for beginners. 4th ed. Los Angeles: SAGE.

Levenstein, S.D. (2012) Encyclopedia of Dentistry Research. NY: Nova Science Publishers.

Murray, N. & Beglar, D. (2009) Inside Track to Writing Dissertations and Theses [Paperback] London: Pearson Longman.

Neville, C. (2007) The complete guide to referencing and avoiding plagiarism. Maidenhead: McGraw Hill/Open University Press.

Pears, R. and Shields, G. (2010) Cite them right: the essential referencing guide. 8th ed. Basingstoke: Palgrave Macmillan.

Ridley, D. (2012) The literature review: a step-by-step guide for students. 2nd ed. London: SAGE.

Rudestam K E., Newton, R.R. (2014) Surviving Your Dissertation. A Comprehensive Guide To Content And Process. (4th Ed.). London: SAGE.

Smeeton, N.C. (2016) Dental statistics made easy. 3rd ed. Boca Raton, FL: CRC Press LLC

Tabachnick, B.G. and Fidell, L.S. (2013) Using multivariate statistics. 6th Ed. Harlow, England: Pearson Education UK.

Von Fraunhofer, J.A. (2010) Research writing in Dentistry. Iowa: Wiley-Blackwell.

Wallace, M. and Wray, A. (2016). Critical reading and writing for postgraduates. Los Angeles: SAGE.

Siegel, S. and Castellan, N. (1988) Nonparametric Statistics for the Behavioral Sciences. London: McGraw-Hill.

Some of the most useful online databases that you are expected to use to find relevant scientific research articles are the following:

1. Pubmed

2. Sciencedirect

3. Scopus

11. Guidelines for the Preparation and Submission of Written Assessments

Written assessments should be word-processed in Arial or Calibri Light font size 12. There should be double-spacing and each page should be numbered.

There should be a title page identifying the programme name, module title, assessment title, your student number, your marking tutor and the date of submission.

You should include a word-count at the end of the assessment (excluding references, figures, tables and appendices).

Where a word limit is specified, the following penalty systems applies:

Up to 10% over the specified word length = no penalty

10 20% over the specified indicative word length = 5 marks subtracted (but if the assessment would normally gain a pass mark, then the final mark to be no lower than the pass mark for the assessment).

More than 20% over the indicative word length = if the assessment would normally gain a pass mark or more, then the final mark will capped at the pass mark for the assessment.

All written work should be referenced using the standard University of Bolton referencing style see: https://libguides.bolton.ac.uk/resources/referencing/Unless otherwise notified by your Module Tutor, electronic copies of assignments should be saved as word documents and uploaded into Turnitin via the Moodle class area. If you experience problems in uploading your work, then you must send an electronic copy of your assessment to your Module Tutor via email BEFORE the due date/time.

Please note that when you submit your work to Moodle, it will automatically be checked for matches against other electronic information. The individual percentage text matches may be used as evidence in an academic misconduct investigation (see Section 13).

Late work will be subject to the penalties:

Up to 7 calendar days late = 10 marks subtracted but if the assignment would normally gain a pass mark, then the final mark to be no lower than the pass mark for the assignment.

More than 7 calendar days late = This will be counted as non-submission and no marks will be recorded.

Late submission of assessments on refer and those which are graded Pass/Fail only, is not permitted. Students may request an extension to the original published deadline date as described below.

In the case of exceptional and unforeseen circumstances, an extension of up to 14 days after the assessment deadline may be granted. This must be agreed by your Programme Leader, following a discussion the Module Tutor. You should complete an Extension Request Form available from your Tutor and attach documentary evidence of your circumstances, prior to the published submission deadline.

Extensions over 14 calendar days should be requested using the Mitigating Circumstances procedure, with the exception of extensions for individual projects and artefacts which, at the discretion of the Programme Leader, may be longer than 14 days.

Requests for extensions which take a submission date past the end of the module (normally week 15) must be made using the Mitigating Circumstances procedures.

Some students with registered disabilities will be eligible for revised submission deadlines. Revised submission deadlines do not require the completion extension request paperwork.

Hard Copy Binding

You must submit two coloured hard copies of you Dissertation that must be thermally bound.

10. Ethics

You are required to fill in the RE1 Ethics form (available in the Moodle area) even if your research does not involve human participants, human data or human materials.

Your Supervisor / Module Leader can assist you with the completion of the RE1 Ethics form and any other Ethical issues that may arise regarding your project. There must be a separate subsection in your Materials and Methods section of your Dissertation regarding the Ethical considerations and actions taken before commencing your project. The completed RE1 Ethics form must be submitted to the module leader who will liaise with the School Research Ethics Officer. A copy of this form must be submitted with the dissertation (bound in at the beginning).

11. Laboratory Risk Assessment Checklist

You are required to fill in the Laboratory Risk Assessment Checklist (available in the Moodle area). You must find the corresponding Risk Assessment forms related to your research project provided in the Risk Assessment archive (available in the Moodle area) and populate them in the Laboratory Risk Assessment Checklist. The Laboratory Risk Assessment Checklist must be completed, signed off by the supervisor and submitted to the module leader. If a Risk Assessment regarding the nature of work undertaken during your experiments is not available, this must be completed by yourself and submitted to the module leader for approval. Risk assessment form templates are available in the Moodle area.

12. COSHH Assessments

You are required to provide the COSHH assessment forms that correspond to the substances being used in the research project that you will be carrying out. The completed COSHH assessments must be assessed by the supervisor and submitted to the module leader. Risk assessment form templates are available in the Moodle area.

13. Research Diary

You are required to keep a hardbound research diary in which you will keep a full informal record of your daily activity. All related experimental information must be incorporated in the research diary, e.g., materials (including LOT numbers) and equipment being used, methodology, results, etc. Everything that might be important in the future, even in terms of thoughts or ideas during the experiments, must be recorded. It is not unusual to experience difficulties in successfully repeating an experiment, if methodology details are missing from the research diary. In every meeting that you have with your supervisor or module leader every week, you must bring the research diary, present it and evidence your attendance by obtaining a signature. The performance of the student, apart from the marking criteria will be considered by the content of the research diary.

Please note that the failure of data storage systems is not considered to be a valid reason for an extension. It is therefore important that you keep multiple copies of your work on different storage devices before submitting it.

1547222-15258500

Faculty of Health and Wellbeing

Centre for Dental Sciences

Dental Technology Dissertation Project

MSc Digital Dental Technology

Title

Name

A report submitted in the part fulfilment for the degree of Master of Science in Digital Dental Technology

Date (Month and Year)

Name:

Student number:

Title:

Supervisor:

Submission Date:

Declaration

This dissertation project is original work carried out solely by me and it has been accurately referenced and acknowledged, complying with the University of Boltons guidelines regarding plagiarism (Student Handbook).

Signature

12. Procedures for Other Assessments

Oral/Poster Presentation - Professional Discussion 30 Minutes

The Oral Presentation of the Poster Professional Discussion will take place at the Social Learning Zone at Queens Campus.

The PowerPoint Poster must be submitted via Turnitin (after being converted to a PDF) before the first students presentation commences.

The Oral Presentation of the Poster Professional Discussion will be recorded for external moderation purposes. The second marker will be taking part in the professional discussion together with the supervisor.

13. Academic MisconductAcademic misconduct may be defined as any attempt by a student to gain an unfair advantage in any assessment. This includes plagiarism, collusion, commissioning (contract cheating) amongst other offences. In order to avoid these types of academic misconduct, you should ensure that all your work is your own and that sources are attributed using the correct referencing techniques. You can also check originality through Turnitin.

Please note that penalties apply if academic misconduct is proven. See the following link for further details:

https://www.bolton.ac.uk/student-policy-zone/student-policy-zone-2021-2022

14. Assessments

Assessment Number 1

Assessment Type (and weighting) Dissertation (90%)

Assessment Name Title to be chosen by the student in collaboration with the module leader and the supervisor

Assessment Submission Date 4/9/2022

Learning Outcomes Assessed:

LO1: Critically appraise and evaluate the literature in order to construct relevant research questions and appropriate aims and objectives.

LO2: Critically analyse, evaluate and review appropriate literature from a wide range of relevant sources.

LO3: Critically examine a range of data collection methods, exploring limitations, in order to propose and justify an appropriate methodological approach to address the aims and objectives of a research study.

LO4: Plan and implement a structured research project, demonstrating effective data collection methods and data analysis, whilst conforming with ethical and research governance requirements.

LO5: Critically analyse, interpret and model data, elucidating coherent findings and conclusions which respond to the research question, whilst synthesising recommendations which recognise the limitations of your own study.

Dissertation Brief and Structure

Produce an Experimental Dissertation of 12,000-15,000 words in which you critically evaluate the outcomes of your research regarding a topic of interest in Dental Technology (the topic will be allocated to you in collaboration with your supervisor and the approval from the Module Leader).

Dissertation Structure

Section number Section

N/A Title page

Declaration page

Abstract

Acknowledgments

Table of Contents

List of Figures

List of Tables

1 Introduction

2 Materials and Methods

3 Results

4 Discussion

5 Conclusions

6 References

7 Appendices

8 Supplemental Documents

Title page

A title page template is available in this module guide.

Declaration page

A declaration page template is available in this module guide.

Abstract

Provide a 250-300 word abstract divided in the following subsections:

Introduction

The aim and hypothesis must be clearly stated in the last sentence of this section.

Materials and Methods

Results

Conclusions

The abstract must be written after the completion of your Dissertation as it provides a concise form of the corresponding parts of your Dissertation.

Acknowledgments

Express your sincere thanks to all those that helped you with your project.

Table of Contents

In the table of contents, all headings and subheadings of the Dissertation must be listed and clearly defined as numbered sections. The page numbering of all sections preceding the Introduction must be in Roman numerals. The page numbering of all sections following the Introduction must change to standard Arabic numerals.

The indentation of all subheadings must be such that similar levels of subheadings are aligned.

List of Figures

In the list of figures, all figures must be clearly numbered and paginated in the order they are found in the manuscript. The figure legends must be the same as the ones below the figures in the manuscript.

The figures must be numbered according to the heading / subheading section they appear in. For example, the first figure found in section 2.1.2 must be numbered as Figure 2.1.2.1, whereas the fourth figure found in the same section must be numbered as Figure 2.1.2.4.

List of Tables

In the list of tables, all tables must be clearly numbered and paginated in the order they are found in the manuscript. The table legends must be the same as the ones above the tables in the manuscript.

The tables must be numbered according to the heading / subheading section they appear in. For example, the first table found in section 4.3.2.2 must be numbered as Table 4.3.2.2.1, whereas the third table found in the same section must be numbered as Table 4.3.2.2.3.

Introduction

This section provides an in-depth literature review presenting a background on the topic of the Dissertation to help the reader understand what the current gaps in the literature are and why this piece of work is important. It must include all the relevant information on the subject area based on published research from credible sources (mainly textbooks and scientific journals). In this section, basic principles of the subject matter must also be included (e.g., for a dissertation regarding dental implants, the incorporation of a section which in depth explains what osseointegration is). Similarly, basic principles of equipment and materials used in the Materials and Methods section can also be presented for the reader to be able to understand their function. Subsections must be used to obtain a defined structure. The aims and objectives of the project, as well as the research hypothesis, must be clearly defined in a separate paragraph (the last of the Introduction part) leading to the next section.

Materials and Methods

Describe in detail the materials and methods that were implemented in your experiments. Subsections must be used to obtain a defined structure and a clear methodology rationale. The whole experimental methodology must be presented in such detail, that if another researcher wants to repeat the experiments, the same results must be obtained. The materials and equipment used must be clearly described providing manufacturing information in brackets (product name, manufacturer, city, country). The groups of specimens and the corresponding sample size must be clearly described. The reasons behind selecting the particular methodology must not be discussed in this section. The statistical analysis implemented in your research must be included at the end of this section.

Results

Present the results of your research in the experimental order described in the Materials and Methods section. Provide any relevant data tables, graphs, figures, etc. and briefly describe them. There must be no interpretation of the results in this section, but only their description. Statistically significant findings must be incorporated in the corresponding graphs or tables. The raw data are not needed in this section (these can be provided in the appendices, if needed).

Discussion

In this section, you must interpret your results and associate them to the relevant literature supporting or rejecting your research hypothesis. It is a substantial section of your Dissertation, as you have the chance to discuss the results of your experiments, leading to the acceptance or rejection of the research hypothesis (set by you at the end of the Introduction). You must present your intellectual critical analysis skills in interpreting and evaluating your research results in a logical order and in accordance with the relevant literature. Comparison of the findings from your research with those of other researchers work (from published articles) is mandatory. Similarities or differences must be thoroughly discussed and substantiated through possible explanations and theories, based on relevant literature. This section gives you the opportunity to additionally discuss other issues that are vital for the reader to understand your research project, e.g., the concept behind the methodology chosen. Lastly, limitations of the research carried out must be stated, as well as suggestive points for future work.

Conclusions

This is the section where you state your conclusions from the research. This is not the Results or the Discussion section. The conclusions are linked to the aims and objectives defined in the Introduction section of your Dissertation and provide concise outcomes from the research carried out. There must be no new information in this section.

References

Present your reference list according to the University of Bolton Referencing format (Harvard style) and use only credible sources (textbooks and peer-reviewed scientific journals being the most credible). There is a minimum requirement of 20 references (fifteen refereed academic journals and five academic books).

Appendices

Provide the relevant to the research project you carried out supplemental information, e.g., raw data.

Supplemental Documents

Do not include this section in the Table of Contents (thus there will be no pagination on these documents).

RE1 Ethics Form (this must be bound in at the beginning of the Dissertation)

Laboratory Risk Assessment Checklist

COSHH Forms

(Instructions for the Figures and Tables)

The figures and tables in the text must be clearly numbered. The numbering relates to the heading / subheading section that the figures and tables appear in. For example, the first figure found in section 2.1.2 must be numbered as Figure 2.1.2.1, whereas the fourth figure found in the same section must be numbered as Figure 2.1.2.4. The tables are numbered in the same manner.

The legends must be clear explaining the subject matter accurately (as standalone titles). Table legends stand above the tables, whereas figure legends stand below the figures. All figures and tables must be cited in the text.

Minimum Secondary Research Source Requirements:

Level HE7 - It is expected that the Reference List will contain between fifteen to twenty sources. As a MINIMUM the Reference List should include four refereed academic journals and five academic books.

Specific Assessment Criteria:

(Please note that the General Assessment Criteria will also apply. Please see Section 15).

Distinction (70% and above)

Students will provide an in-depth understanding of the subject matter showing high levels of intellectual critical analysis skills in interpreting and evaluating the research results in a logical order and in accordance with the relevant literature. The dissertation structure and presentation will be excellent. Each section will accurately adhere to the requirements of the sections structure presented above. The reference list format, as well as the citations in the report, will follow the exact format provided by the University of Bolton (Harvard). Presentation of figures and tables will be of a high standard. Academic writing (proof-reading) will be exceptional, as well as the communication with the supervisor and the module leader.

Merit (60% -69%)

Students will provide a comprehensive understanding of the subject matter showing good levels of intellectual critical analysis skills in interpreting and evaluating the research results in a logical order and in accordance with the relevant literature. The dissertation structure and presentation will be good. Each section will adhere to most of the requirements of the sections structure presented above. The reference list format, as well as the citations in the report, will adequately follow the format provided by the University of Bolton (Harvard). Presentation of figures and tables will be of a good standard. Academic writing (proof-reading) will be good, as well as the communication with the supervisor and the module leader.

Pass (50%-59%)

Students will provide a satisfactory understanding of the subject matter showing fair levels of intellectual critical analysis skills in interpreting and evaluating the research results in a logical order and in accordance with the relevant literature. The dissertation structure and presentation will be fair. Each section will fairly adhere to the requirements of the sections structure presented above. The reference list format, as well as the citations in the report, will fairly follow the format provided by the University of Bolton (Harvard). Presentation of figures and tables will be of a lower standard. Academic writing (proof-reading) will be fair, as well as the communication with the supervisor and the module leader.

Fail (Below 50%): Students who do not meet the requirements of the Pass criteria will not successfully complete the assessment activity.

Assessment Number 2

Assessment Type (and weighting) Oral/Poster presentation - Professional Discussion - 30 Minutes (10%)

Assessment Name Title to be chosen by the student in collaboration with the module leader and the supervisor

Assessment Submission Date w/c 5/9/2022

Learning Outcomes Assessed:

LO6: Defend findings and demonstrate critical reflection in an effective and structured manner.

Assessment Brief

A poster will be prepared and presented to the supervisor and a 2nd marker. The presentation combined with a professional discussion will have a duration of 30 minutes. The structure of the poster must present the following sections: Introduction, Materials and Methods, Results, Discussion, Conclusions, References.

Specific Assessment Criteria:

(Please note that the General Assessment Criteria will also apply. Please see Section 15).

Distinction (70% and above)

The structure of the poster will be excellent. The font size and style will be such that is easily readable to the audience. The amount of text will be such that clearly helps the presenter remember what he / she talks about, whereas the audience can also read it fast. The figures and tables presented in the poster will be of utmost importance. The background style and use of colours will clearly not be stressing to the audience. The content of the poster will accurately represent, in a concise form, the work carried out in the research project. The engagement with the audience (visual interaction) will be exceptional. The projection of voice during the presentation will be such that shows a high level of understanding of the subject matter. The time required to present the poster will be 15 minutes. Students will provide an in-depth understanding of the subject matter showing a high level of intellectual critical analysis skills in interpreting and evaluating the research results in a logical order and in accordance to the relevant literature.

Merit (60% -69%)

The structure of the poster will be good. The font size and style will be such that is quite readable to the audience. The amount of text will be such that adequately helps the presenter remember what he / she talks about, whereas the audience can also read it quite fast. The figures and tables presented in the poster will be of importance. The background style and use of colours will not be

stressing to the audience. The content of the poster will represent, in a concise form, the work carried out in the research project. The engagement with the audience (visual interaction) will be good. The projection of voice during the presentation will be such that shows a good level of understanding of the subject matter. The time required to present the poster will be slightly over-exceeded. Students will provide a comprehensive understanding of the subject matter showing a good level of intellectual critical analysis skills in interpreting and evaluating the research results in a logical order and in accordance to the relevant literature.

Pass (50%-59%)

The structure of the poster will be fair. The font size and style will be such that is fairly readable to the audience. The amount of text will be such that moderately helps the presenter remember what he / she talks about, whereas the audience can also read it. The figures and tables presented in the poster will be fairly important. The background style and use of colours will not be too stressing to the audience. The content of the poster will adequately represent, in a concise form, the work carried out in the research project. The engagement with the audience (visual interaction) will be fair. The projection of voice during the presentation will be such that shows a level of understanding of the subject matter. The time required to present the poster will be moderately over-exceeded. Students will provide a satisfactory understanding of the subject matter showing a level of intellectual critical analysis skills in interpreting and evaluating the research results in a logical order and in accordance to the relevant literature.

Fail (Below 50%): Students who do not meet the requirements of the Pass criteria will not successfully complete the assessment activity.

15. General Assessment Guidelines for Written Assessments Level HE7% Relevance Knowledge Argument/Analysis Structure Presentation Written English Research/Referencing

DISTINCTION Exceptional Quality 85-100% Directly relevant to title/brief.

Expertly addresses the assumptions of the title and/or the requirements of the brief.

Demonstrates an exceptional knowledge of theory and practice for this level.

Insightfully interprets appropriate concepts and theoretical models.

Demonstrates originality in conceptual understanding. Presents an exceptional critique of key research material resulting in clear, original and illuminating conclusions.

Demonstrates distinctive, insightful and creative solutions to complex problems.

Produces exceptional work that makes a contribution to the development of knowledge and understanding in the subject area. Coherently articulated and logically structured.

An appropriate format is used. Exceptional presentational style & layout, appropriate to the type of assignment.

Effective inclusion of figures, tables, plates (FTP).

Exceptionally well writtenanswer with standard spelling and grammar.

Style is clear, resourceful and academic.

Sources accurately cited in the text.

An extensive range of contemporary and relevant references cited in the reference list in the correct style.

Excellent Quality 70-84% Directly relevant to title/brief.

Expertly addresses the assumptions of the title and/or the requirements of the brief.

Demonstrates an excellent knowledge of theory and practice for this level.

Expertly interprets appropriate concepts and theoretical models.

Demonstrates originality in conceptual understanding. Presents an excellent critique of key research material resulting in clear, original and illuminating conclusions.

Demonstrates insightful and creative thinking solutions to complex problems.

Produces excellent work that makes a contribution to the development of knowledge and understanding in the subject area. Coherently articulated and logically structured.

An appropriate format is used. Excellent presentational style & layout, appropriate to the type of assignment.

Effective inclusion of figures, tables, plates (FTP).

Excellently writtenanswer with standard spelling and grammar.

Style is clear, resourceful and academic.

Sources accurately cited in the text.

A wide range of contemporary and relevant references cited in the reference list in the correct style.

MERIT Good Quality 60-69% Directly relevant to title/brief.

Addresses the assumptions of the title and/or the requirements of the brief well. Demonstrates a sound knowledge of theory and practice for this level.

Comprehensively interprets appropriate concepts and theoretical models.

Demonstrates originality in conceptual understanding Presents a cohesive critique of key research material resulting in clear and original conclusions.

Demonstrates creative solutions to complex problems.

Produces superior work that makes a contribution to the development of knowledge and understanding in the subject area For the most part coherently articulated and logically constructed.

An appropriate format is used. Very good presentational style & layout, appropriate to the type of assignment.

Effective inclusion of FTP. Well written withstandard spelling and grammar. Style is clear and academic.

Sources accurately cited in the text.

A range of contemporary and relevant references cited in the reference list in the correct style.

PASS Satisfactory Quality 50-59% Generally addresses the assumptions of the title and/or the requirements of the brief.

Minor irrelevance in places. Demonstrates an adequate knowledge of theory and practice for this level. Some minor omissions.

Satisfactorily interprets some appropriate concepts and theoretical models.

Demonstrates some originality in conceptual understanding. Presents some critique of key research material resulting in original conclusions. Loss of focus in places.

Demonstrates some creativity in solving complex problems.

Produces satisfactory work that makes some contribution to the development of knowledge and understanding in the subject area. Adequate attempt at articulation and logical structure.

An acceptable format is used. The presentational style & layout is largely correct for the type of assignment.

Inclusion of FTP but lacks selectivity. Competently written with minor lapses in spelling and grammar.

Style is legible and mainly academic.

Key contemporary and relevant academic sources are drawn upon.

Most sources are accurately cited in the text and reference list/bibliography.

Minor weaknesses evident.

FAIL Borderline Fail 45-49% Some implications of issues explored.

Some irrelevant and/or superficial arguments.

Some omissions evident in knowledge of theory and practice at this level.

Insufficient understanding of appropriate concepts and theoretical models.

Demonstrates some conceptual understanding in places. A limited amount of critique of key research material with description in places. Lacks creativity. Some original conclusions.

Limited attempt at articulation and problems with structure.

Some formatting errors. Some weaknesses in the presentational style & layout.

Some inappropriate use of FTP. Intermittent lapses in grammar and spelling.

Style hinders clarity in places and is not academic throughout. Limited number of contemporary and relevant sources cited. Weaknesses in referencing technique.

Fail 30-44%

Significant degree of irrelevance to the title and/or brief.

Issues are addressed at a superficial level and in unchallenging terms. Demonstrates weaknesses in knowledge of theory and practice for this level.

Limited understanding and application of concepts. A basic argument is presented, but too descriptive or narrative in style.

Limited originality and creativity.

Conclusions are not clearly stated. Poorly structured. Lack of articulation.

Format deficient. For the type of assignment the presentational style &/or layout is lacking.

FTP ignored in text or not used where clearly needed. Deficiencies in spelling and grammar make reading difficult in places.

Simplistic or repetitious style impairs clarity. Inappropriate sources and poor referencing technique.

<30%

Relevance to the title and/or brief is intermittent or missing.

The topic is reduced to its vaguest and least challenging terms. Demonstrates a lack of basic knowledge of either theory or practice for this level, with little evidence of conceptual understanding. Severely limited arguments. Descriptive or narrative in style with no evidence of critique and originality or creativity.

Conclusions are sparse. Unstructured.

Lack of articulation.

Format deficient. For the type of assignment the presentational style &/or layout is lacking.

FTP as above. Poorly written with numerous deficiencies in grammar, spelling, expression and style. An absence of academic sources and poor referencing technique.

Table of Contents

TOC o "1-3" h z u Introduction PAGEREF _Toc107154499 h 31.1PMMA (polymethyl methacrylate) PAGEREF _Toc107154500 h 31.1.1 Background and development PAGEREF _Toc107154501 h 31.1.2 Chemistry and types of PMMA PAGEREF _Toc107154502 h 41.1.3 Properties of PMMA PAGEREF _Toc107154503 h 6

1.1.4 Application of PMMA in dentistry PAGEREF _Toc107154504 h 7Carbon Nanotubes PAGEREF _Toc107154506 h 121.2.1 Historical background and development PAGEREF _Toc107154507 h 121.2.2 Properties of Carbon nanotubes additives PAGEREF _Toc107154508 h 131.2.3 Applications of Carbon Nanotubes Additives in Dentistry PAGEREF _Toc107154509 h 141.4 drawbacks of using PMMA as denture base materials PAGEREF _Toc107154510 h 151.5 Aim and research hypothesis PAGEREF _Toc107154512 h 16References PAGEREF _Toc107154513 h 16

Introduction

1.1 PMMA (polymethyl methacrylate)

In clinical dentistry, a wide variety of polymers are frequently employed for various applications. Among these, poly methyl methacrylate (PMMA) is one of the polymers that is most frequently used in dental laboratories (to create orthodontic retainers and dentures and for repair), dental clinics (to reline dentures and temporary crowns), and industry (such as fabrication of artificial teeth). PMMA is typically sold as a liquid-powder solution. The powder comprises a transparent polymer (PMMA), but additives like pigments and synthetic fibres made of nylon or acrylic are utilised to change the powder's physical characteristics and appearance to resemble oral tissues. A methyl methacrylate monomer, cross-linking agents, and inhibitors are present in the liquid component. PMMA has significant downsides, including the potential for denture fracture owing to water sorption and weak impact and flexural strength, but continuous research has led to a number of modifications that have helped to mitigate these issues and further enhance the material's characteristics (such as conductivity, water sorption, solubility, impact, and flexural strengths). For instance, some research claimed that adding different fibres to PMMA composites increased their performance. (Zafar, 2020).

1.1.1 Background and development

Otto Rohm invented PMMA in 1902, and it is a solid glass-like material with good biocompatibility. Kulzer demonstrated in 1936 that by combining PMMA powder and a liquid monomer, a dough material could be created that cured when benzoyl peroxide (BPO) was added and the mixture was heated to 100C. In 1938, PMMA was used for the first time in a clinical setting to repair cranial defects in monkeys. As surgeons gained a better understanding of the PMMA system, they began to use it in human reconstructive surgery. Following that, the heat curing polymer Paladon 65 (Heraeus Kulzer, Hanau, Germany) was used to repair cranial defects in humans by fabricating plates in the laboratory (Revell, 2014).

Poly methyl methacrylate resins have been used to make the majority of denture bases since the mid-1940s. These resins are tough plastics made by joining multiple methyl methacrylate molecules, or "mers". One distinct advantage of poly(methyl methacrylate) as a denture base material is its ease of processing. Poly(methyl methacrylate) denture base material is typically supplied in the form of a powder-liquid system. Nonpolymerized methyl methacrylate is present in the liquid. The powder contains small beads of prepolymerized poly(methyl methacrylate) resin. A workable mass is formed when the liquid and powder are mixed in the proper proportions. The material is then polymerized after being introduced into a mould cavity of the desired shape. After the polymerization process is completed, the prosthesis is retrieved and prepared for delivery to the dentist and patient (Phillips and Anusavice, 2003, p. 722).

Denture base polymers are multistage polymer systems composed of MMA monomersand prepolymerized PMMA powder beads. PMMA, an acrylic polymer, was released onto the market as a denture base material in 1937. Previously, denture bases were made from other synthetic (and less convenient) materials including nitrocellulose, phenol formaldehyde, and vulcanite. There are two reaction sites for free radical polymerization if the monomers contain two or more reactive groups - in this case, methacrylate groups. Dimethacrylate monomers are an example of this type of monomer, and polymerization produces a covalently bound cross-linked polymer structure. A thermoset polymer is another name for a cross-linked polymer. Polymerization initiated by blue light results in a certain degree of monomer conversion, i.e., saturation of the carbon-carbon double bonds of the methacrylate groups (c.55%-65%) and creation of covalent bonds between the monomers. However, many methacrylate groups remain unsaturated within the polymer structure, and there are some totally unreacted monomers in the structure, known as residual monomers (Pekka Vallittu and Mutlu Ozcan, 2017).

Since its invention in 1937 by Dr. Walter Wright and the Vernon brothers, heat-polymerized polymethylmethacrylate, more often known as PMMA, has been the material of choice for prostheses. Enhancements have been made to the aesthetics, fit, oral stability, as well as handling and processing. Dentures, maxillofacial prostheses, orthodontic appliances, hybrid implant prostheses, and cranioplasty are among the procedures that can benefit from the utilization of this material. Rowland Hill and John Crawford, both of ICI, were the ones who made the discovery of polymethyl methacrylate in the 1930s (Hashim and Abbas 2019).

1.1.2 Chemistry and types of PMMA

Polymethyl methacrylate (PMMA) is a synthetic resin created by polymerizing methyl methacrylate. PMMA is often used in place of glass in applications such as shatterproof windows, skylights, illuminated signs, and aircraft canopies due to its transparency and durability. You can see it marketed as Plexiglas, Lucite, or Perspex, all of which are trademarked names (Ahangaran et al., 2019).

Acrylic polymers are created through the process of free radical polymerization. Monomers with a carbon-carbon double bond as their reactive group are used in free-radical polymerization. The most common acrylic monomer in dentistry is methyl methacrylate, but hydroxyethyl methacrylate and butyl methacrylate are also used. Methyl methacrylate is a sweet-smelling liquid with a boiling temperature of 100 C. The odour of methyl methacrylate can be found in many dental laboratories, but chronic inhalation should be avoided due to potential liver toxicity. In addition, methyl methacrylate is highly flammable and allergenic. When a free radical (a highly reactive molecule with a free electron) is formed, addition polymerization of methyl methacrylate (PMMA, acrylic) begins. Free radicals can be created in a variety of ways (Figure 13-3). The free radical attacks the monomer's carbon double bond, triggering a chain of monomer addition reactions. As a result, free radicals are often referred to as initiators. The free-radical reaction rapidly adds methyl methacrylate molecules one after the other (thousands per second!). The polymer chain grows in this manner until no more monomer is available. When the available monomer is depleted, the final free radical "terminates" through one of themultiple complex reactions, and polymerization is finished (Powers and Wataha, 2016, p. 171).

Acrylic resin dentures are created through the process of free radical addition polymerization of poly methyl methacrylate (PMMA). Methyl methacrylate (MMA) is the monomer.The normal sequence of activation, initiation, propagation, and termination is used in the conversion of a monomer to a polymer. The resins are available in both heat-cured and cold-cured varieties. According to polymerization activation there are three types of acrylic resin: heat cured, light cured and cold cured. Heat-cured resins are made up of a powder and a liquid that are heated to form a rigid solid. Table 3.2.2 lists the components of the powder and liquid (Richard Van Noort, 2013, pp. 175176).

As an ester of methacrylic acid (CH2=C[CH3]CO2H), poly(methyl methacrylate [PMMA] is a frequently used resin. Current production relies mostly on propylene, a chemical extracted from the lighter parts of crude oil. Cumene, also known as isopropyl benzene, is created when propylene and benzene react; cumene hydroperoxide is produced when cumene hydroperoxide is treated with acid; and acetone is converted to volatile methyl methacrylate (CH2=C[CH3]CO2CH3) in a three-step process. Polymerization (linking together in large numbers) of liquid methyl methacrylate molecules or water-based microdroplets occurs in the presence of free-radical initiators to form solid PMMA (Zafar, 2020).The basic unit of a polymer is the following:

Figure 1. SEQ Figure * ARABIC 1.2.1: Types Of PMMA

1.1.3 Properties of PMMA

Acrylic resins typically have tensile strengths of no more than 50 MPa.The elastic modulus is low, and the flexural modulus is in the 2200-2500 MPa range. It is perhaps not surprising that dentures are prone to fracture when combined with a lack of fracture toughness. Midline fractures, which are most common in upper dentures, account for 30% of denture repairs performed by dental laboratories. The thermal expansion coefficient is approximately 80 ppm/C , this is quite high. In general, this is not a problem, except that porcelain teeth set in denture base resin may slowly loosen and fall out because of differential expansion and contraction. PMMA may absorb water due to the polar nature of the resin molecules. Water absorption is typically in the range of 1.0-2.0% by weight. In practise, this compensates for minor processing shrinkage. However, due to the slow rate of water diffusion through the resin, the denture would require several weeks of continuous immersion in water to achieve a stable weight. Although PMMA is soluble in most solvents, it is virtually insoluble in most of the fluids that it may come into contact with in the mouth due to its light cross-linking. However, some weight loss will occur as a result of theleaching of the monomer, as well as potentially some of the pigments. In general, PMMA is highly biocompatible, and patients experience few complications. Nonetheless, some patients will experience an allergic reaction. This is most likely due to the denture's various leachable components, such as any residual monomer or benzoic acid. Because of their higher residual monomer content, cold-cured resin dentures are more likely to cause an allergic reaction almost immediately. It is sometimes possible to overcome this problem by subjecting the denture to an additional curing cycle, but there is a risk that the denture will distort as internal processing stresses are relieved (Richard Van Noort, 2013, pp. 178179).

Many factors influence the strength of an individual denture base resin.These factors include the resin's composition, processing technique, and the conditions presented by the oral environment. Denture base resins must meet or exceed the standards outlined in ANSI/ADA Specification No. 12 in order to provide acceptable physical properties. A transverse test is used to assess the relationship between applied load and resultant deflection in a resin specimen with specific dimensions (Phillips and Anusavice, 2003, p. 745).

PMMA has a 92% light transmission rate, which is higher than that of glass and plastic combined. Because of its clarity and environmental friendliness, it is also much more suited and desired than polystyrene and polyethenes. Due to its high strength and lightweight nature, it is far more scratch and weather resistant than the majority of other transparent acrylates, including polycarbonate. This material is resistant to UV rays and weather because of its exceptional mechanical and optical properties. PMMA possesses all of these qualities, in addition to biocompatibility and antimicrobial properties, which can be improved by adding co-polymers and additives, making it a perfect material for use in dentistry (Kaur and Thakur, 2022).

1.1.4.0 Application of PMMA in dentistry

PMMA, also known as poly(methyl methacrylate), was initially sold in 1928 under the brand name Plexiglas. Since then, PMMA has been utilised for a plethora of purposes, such as the bodies of electric guitars, transparent glass alternatives for windows, and semiconductor research. Due to its high biocompatibility, PMMA is a crucial component of dentures, replacement intraocular lenses, and composite materials used in dental fillings. PMMA bone cement is used in orthopaedic surgery to secure implants and replace missing bone (Khanna and Cernovsky, 2012).

Figure SEQ Figure * ARABIC 2: PMMA in a variety of forms. (Kaur and Thakur, 2022)

1.1.4.1 Bone cement

Bone cement's microscopic composition consists of two components that are adhered to one another. The so-called "pearls" in bone cement are actually tiny, white powdery fragments of pre-polymerized PMMA. The second ingredient is a methyl methacrylate liquid monomer (MMA). After adding a catalyst to start the monomer fluid's polymerization, both ingredients are combined in a theatre. The individual pearls are caught and cemented inside the polymerized monomer's net when the bone cement dries, but there is no chemical bonding between the pearls and the polymerized monomer (Khanna and Cernovsky, 2012).

By mixing phosphate and calcium ions, PMMA bone cements with in vitro bioactivity in apatite deposition have been effectively explored. To achieve modulation in the PMMA/CS hybrid cement, calcium-silicate (CS) cement was blended with PMMA cement. To enhance radiopaque qualities including biocompatibility and osteoconductivity, PMMA-based bone cement was created using hydroxyapatite. To treat vertebral stress fractures, a bioactive composite made of PMMA and collagen derived from minerals is employed. A study assessed the setup time, compressive, tensile strength, adhesion ability, multiplication, and osteogenic distinction of bone-forming stem cells (Kaur and Thakur, 2022)

1.1.4.2 Denture base resins

The most common material used for both complete and partial denture manufacturing is poly methylmethacrylate, or PMMA. Because of its excellent qualities, including aesthetics, biocompatibility, light weight, low cost, ease of manufacture, and repairability, acrylic is a widely utilised material for denture bases (Alzayyat et al., 2020). PMMA has been clinically accepted for more than 70 years. 1-5 Saliva, pH levels, oral bacteria, and the type of oral prosthesis are only a few of the interrelated factors that can lead to situations that reduce the flow of natural saliva, exert mechanical compression, raise warmth, and block light reaching mucosal tissues (An et al., 2021). Nevertheless, it also has some disadvantages, such as poor surface qualities and low mechanical strength. Different strategies have been employed to address these problems, including covering the denture foundation, integrating antifungal agents, and most recently, adding nanoparticles to PMMA denture base materials (Alzayyat et al., 2020).

Candida albicans biofilms are inhibited by grapefruit seed extract (GSE) and PMMA, and these denture base resins can be utilised as denture cleaners . N-acetylcysteine (NAC) was added to PMMA resin, which protected against genotoxicity and caused cell death. This process is useful for creating resin composites with better biocompatibility. PMMA-based resins were created and demonstrated strong antibacterial and protein-repellent action (Kaur and Thakur, 2022). The uses and applications of various denture base resin types are shown in Table 2.

1.1.4.3 Removable orthodontic appliances

Orthodontic treatment has a long history of using removable appliances. They continue to be used for space maintenance, thumb deterrence, tipping teeth, overbite reduction, block movements, and retention despite negative press due to unsatisfactory treatment outcomes. Polymethylmethacrylate is the substance that is most frequently used to make the polymeric component of removable orthodontic equipment (PMMA). In place of vulcanite, this material started to be employed for dentures in the 1930s. These polymers now consist mostly of two component systems, including liquid methylmethacrylate monomer and PMMA powder beads, together with a minor amount of a crosslinking agent (Faltermeier et al., 2007).

Orthodontics is a branch of dentistry that focuses on improving a person's smile and oral health by realigning their teeth and jaws. Various orthodontic appliances come in different varieties. In orthodontics, removable appliances often composed of PMMA, these materials are preferred due to their favourable aesthetics, fast chair-side times, affordability, and ease of oral hygiene (Thaweboon and Thaweboon, 2019).

There is a dizzying array of orthodontic appliances available. They are divided into four categories: removable, fixed, functional, and extra-oral devices. The appliance must be carefully chosen and used correctly, as improper use can exacerbate the malocclusion. Removable appliances can only perform very basic movements, whereas fixed appliances are sophisticated devices that can precisely position the teeth. Functional appliances are used primarily for Class II Division I malocciusions and are useful in difficult cases. Extra-oral devices are used to strengthen anchorage and can help with opening and closing spaces (Roberts-Harry and Sandy, 2004).

1.2.0 Carbon Nanotubes

1.2.1 Historical background and development

Carbon is one of the few elements that can be found in many different structural forms, from carbon black to diamonds, each having its distinct properties and uses. The development of nanotubes is an example of one such scaffold. Carbon nanotubes (CNTs) are nanometer- to micrometer-sized cylinders made up of a hollow hexagonal network of carbon atoms. This material can be produced in a variety of ways, including via electric arc discharge, laser ablation, catalytic hydrocarbon breakdown, electrolysis, synthesis from bulk polymers, and low-temperature solid pyrolysis. Nanotubes are composed of hexagonally-arranged carbon atoms that are completely sp2-hybridized (Fan et al., 2020). The resultant substance is very curvy and has a small diameter. Van der Walls, - stacking, and hydrophobic interactions are all features that contribute to these molecules' wide variety of special behaviors. CNTs can be tailored for certain biological uses by increasing their solubility and/or modulating the incorporation of functional groups (Siwal et al., 2021).

Due to their mechanical (and other) qualities, carbon nanotubes have been the subject of many studies in dentistry during the past two decades. Because of this, they show great promise as a potential reinforcement for dental materials, a scaffold material, and a component in targeted drug delivery systems. Modulating these characteristics improves the clinical performance and overall usefulness of the nanocomposite. While CNTs have many desirable properties, they can only be introduced to a certain extent as a filler or reinforcement in polymers and other materials. The aggregation of CNTs is responsible for this phenomenon (Ghosh and Shetty, 2020). This is a significant barrier to their application, and it is often overcome by chemical functionalization, which improves CNT dispersion and hence reduces clumping. In effect, this increases the matrix's loading capacity, which in turn improves the composite's mechanical characteristics. The goal of optimizing the CNT's loading in the composite matrix is to increase the efficiency with which stress is transferred to the CNT's matrix interface (Gergeroglu, Yildirim, and Ebeoglugil, 2020). The efficiency of the reinforcement is affected by several factors, including but not limited to interfacial stress transmission, aspect ratio, dispersion, alignment, and synthesis type.

1.2.2 Characteristics of Carbon Nanotubes

SWCNTs differ from double-walled carbon nanotubes and multi-walled carbon nanotubes in that they have a single-layer cylindrical sidewall structure, which allows them to have more finely tuned physical and chemical properties for applications than other carbon structures. Because of their ultra-small diameter, high curvature, and large surface area (1315 m2 /g), they have highly reactive surfaces. SWCNT reactive surfaces may provide numerous opportunities for surface modification and have the potential for a wide range of applications. SWCNTs are frequently synthesised using a variety of techniques, including chemical vapour deposition (CVD),laser-ablation,and arc-discharge. To lower the activation energy barriers of the chemical reaction andto regulate the orientation of nanotube growth, various metal particles are used as catalysts in the synthesis formulations. Fe, Ni, Co, Mo, and Yare the most frequently used metals and can consequently be found in samples of recently manufactured nanotubes. Additionally, carbonaceous by-products such asfullerenes, amorphous carbon, and nanocrystalline graphite may be formed. As a result, as-produced SWCNT samples have various contaminants that rely on the synthesis formulas in addition to nanotubes (Gao et al., 2016).

Carbon nanotubes (CNTs), which range in size from a few nanometers to a few microns, are hollow, cylindrical structures made of a network of hexagonal carbon atoms. There are numerous ways to make this material, including electric arc discharge, laser ablation, catalytic hydrocarbon decomposition, electrolysis, synthesis from bulk polymers, and low-temperature solid pyrolysis. Exclusively sp2 hybridised and organised in a hexagonal lattice, carbon atoms in nanotubes. The resulting substance is highly curved, has a tiny diameter, and a high surface area. Through van der Walls, "-" stacking, and hydrophobic interactions, these traits contribute to their numerous distinctive properties. For certain biological applications, CNTs can be changed to improve solubility and adjust the inclusion of functional groups (Castro-Rojas et al., 2021).

1.2.3 Properties of Carbon nanotubes additives

Carbon nanofibers/tubes (CNF/Ts) have been the subject of many studies in the last decade due to their excellent mechanical properties, where they have been used as inclusions in composite materials. Mechanically, CNTs have elastic Young's moduli greater than 1TPa. At only 1/6th the specific gravity, their theoretical strength is 100 times that of steel. Ultimate strength values as high as 60 GPa and ultimate strain values as 6% have been reported. CNTs are also extremely flexible, with the ability to bend in circles and form knots. They, like macroscopic tubes, can buckle or flatten when subjected to appropriate loads. CNTs are extremely small, with diameters typically less than 20 nm. CNFs, on the other hand, are fairly large, with diameters of up to 200 nm (Yazdanbakhsh et al., 2012)

Carbon nanotubes (CNTs) can serve as ideal reinforcing fibers for stronger and tougher cement and concrete materials due to their exceptional mechanical properties and extremely high aspect ratios. Furthermore, these nanoscale materials have the potential to behave as fillers, refining the pore size distribution in the matrix and reducing the porosity of the composite, thereby limiting crack growth and propagation (Azhari and Banthia, 2012).

Carbon nanotubes (CNT) are incredibly strong and electrically efficient. With stated strengths 10 to 100 times greater than steel at a small fraction of the weight, CNTs exhibit excellent mechanical properties. CNTs are durable, strong, and light, and they typically form stable cylinder shapes. Single-walled and multi-walled CNTs are the two basic forms of CNTs with a perfect structure (Fig. 1). A single graphite sheet is flawlessly wound into a cylindrical tube to form single-walled CNTs (SWCNT), and an array of similar nanotubes is nested concentrically to form multiwalled CNTs (MWCNT), which resemble the rings of a tree trunk. CNTs offer outstanding mechanical capabilities (elastic modulus of 1 TPa compared to diamond's 1.2 TPa), as well as superior thermal and electric properties. Carbon fibres are added to a matrix to increase toughness while also giving the material strength and flexibility. 25 The majority of the research on nanotube composites has been on polymer-based CNT materials, which show superior mechanical capabilities over traditional polymer-based composites due to their significantly greater intrinsic strengths and moduli. The efficiency of stress transmission can be up to ten times greater than that of conventional additives. The structure of MWCNTs resembles that of a "Russian nesting doll," which is a collection of patterns made up of the same structure divided into two halves. It contains a number of comparable CNTs stacked one inside the other, each one smaller than the last. Only weak Van der Waals forces connect each constituent tubule to its neighbours. When CNTs are added to some polymer matrices without chemical interaction at the CNTs-polymer interfaces, this could be problematic (Wang et al., 2014).

Figure SEQ Figure * ARABIC 3: single-walled nanotubes and multiwalled carbon nanotubes.

1.2.4 Applications of Carbon Nanotubes Additives in Dentistry

The numerous applications of nanotechnology have resulted in significant improvements in healthcare, particularly in general medicine and dentistry. The development and use of innovative nanomaterials in oral health practises is one aspect that has encouraged new advances in dentistry. Biomimetic nanotechnology, for example, mimics the structure of dental enamel and surrounding tissues to promote and achieve remineralization. The remineralization process focuses on restoring amelogenin-based peptides and hydroxyapatite to restore tooth hardness. These advancements in dentistry include the creation of a toothpaste containing nanosized carbonate apatite, which effectively seals dentin tubules, promoting the management of dental sensitivity. Nanotechnology's goals are to analyse structures, understand physical properties, and create functional constructs by acting directly on the existing framework. The use of nanotechnology in dentistry, known as "nanodentistry," is similar to nanomedicine in that it promotes near-optimal oral health through the use of nanomaterials (including in tissue engineering and drug delivery systems) as integral approaches to dental restorations (Castro-Rojas et al., 2021).

Shape, size, and organization determine CNTs' flexibility. MWCNTs interact with biological membranes and have a high loading capacity, making them suitable for delivery systems. High mechanical and electrical qualities make them bone fillers and scaffolds. Carbon nanotubes as fillers worked effectively at 10 vol percent due to load transfer on interfacial bonding (Castro-Rojas et al., 2021).

Bioactive substances trigger tissue reactions. Antibacterial, tooth-strengthening, and growth-promoting bioactive oral chemicals are needed. Methods reduce inflammation, remineralize teeth, and promote new tissue. Exogenous materials can cover pulp, occlude tubules, provide scaffolding, and induce tooth remineralization. Early caries remineralization increases dentin and enamel biomineralization without affecting adhesion (Ghosh, and Shetty, 2020).

CNTs increase cement paste's mechanical characteristics. Poor CNT-cement interaction. CNTs are hard to diffuse in cement. Researchers distributed CNTs in styrene-acrylic emulsion (SAE). Homo-dispersed CNT-SAE emulsion was added to cement paste. The CNT/SAE hybrid system's mechanical characteristics and microstructure were examined. Cement paste is compared to CNTs and SAE (Adhikary, Rudionis, and Rajapriya, 2020). CNT/SAE network sheets in cement paste may be examined using an FE-SEM (FESEM). Such coatings can conceal fractures and holes in the cement matrix. The CNT/SAE hybrid modifier improves interfacial adhesion and load transmission. CNT/SAE strengthened cement paste. After 28 days, adding 0.1% CNTs and 15% SAE to cement increased flexural strength by 21% and 25%.

Popular yet brittle cement. Cement-based products are brittle and break readily, limiting their durability. Fiber reinforcement prevents cement-based products from breaking. Cementitious fibers can postpone but not prevent microcracks. CNTs increase cement's mechanical characteristics and minimize cracking. CNTs may fill pores. CNTs add durability to cement (drying shrinkage, chloride corrosion, etc.). Cement mortar with 0.1% CNTs had greater flexural strength, Young's modulus, and corrosion resistance (in weight percentage of cement, same as below). Adding 0.3% CNTs to cement mortar increased its flexural and compressive strengths by 23% and 21%. Cement samples lost less strength in freeze-thaw cycles than the standard.

Studies reveal CNTs' utility in cementitious materials, although problems persist. High aspect ratios and van der Waals affinity cluster CNTs. Sonication and a surfactant are used to distribute CNTs in cement. Surfactants reduce cement's mechanical characteristics by entraining air. CNTs won't pass from mixed water to cement matrix, generating geometric clusters. Geometric clusters arise when cement grains exceed inclusion spacing. Complete hydration produces a cement matrix comprising hydration products, space, and CNTs. CNTs fill wetlands. Another problem is repairing large cement matrix cracks. Nanotubes are too tiny to bridge and regulate hydration product cracks, affecting cement matrix mechanical performance. CNTs may be "connected" to transmit stress from tubes to the cement matrix.

According to a study, polymer latex can increase cement's flexural strength and permeability. Latex improves tensile and flexural strength while reducing water absorption and chloride diffusion. Bridge decks, roof waterproofing, anti-corrosive linings, and concrete repair grouts employ polymer-modified cement. Polymer side chains are active. Chemical and physical dispersion creates ideal CNT crystal nuclei. This study employed SAE as latex. SAE has high adhesion, flexibility, and corrosion resistance. It boosts cement concrete's bonding, flexural, and chloride ion resistance. SAE and fiber improve cement's bending and tensile deformation.

1.3 drawbacks of using PMMA as denture base materials

PMMA materials are very suitable for fabricating the denture base, however, it still has some poor mechanical properties. Fractures may occur during use as a result of the inadequate impact and transverse strength. Acrylic resin has notch sensitivity, which can cause midline fractures in the labial frenilum [1-6]. A prominent sutura palatina media or torus, poor occlusal balance, or inaccuracy in denture base fitting may also be a risk factors for fracture. Furthermore, dropping a denture on a hard surface may result in an impact failure (Uzun and Hersek, 2002). Due to the various stresses that these resins may experience, a number of mechanical properties are of interest in resisting the aforementioned complications. For many years, denture bases have been flexed repeatedly during mastication. This can frequently result in prosthesis fatigue failure. The majority of denture fractures occur during use, primarily due to denture resin fatigue. Flexural fatigue occurs when a material is repeatedly flexed; it is a mode of fracture in which a structure eventually fails after being repeatedly subjected to small loads that are not detrimental to the component. Flexural fatigue is a common cause of midline fractures in dentures. The reinforcement of denture base material has piqued the interest of the dental material society (Wang et al., 2014).

Some modifications have been made in recent years to strengthen acrylic resins by using co-polymer, cross-linking agents, and even including a rubber phase in the bead polymer called high-impact resins. Inversion-phase separated polymer beads can be used to create high-impact denture base materials, which improve impact strength (Uzun and Hersek, 2002). A variety of materials, including glass fibres, long carbon fibres, and metal wires, have been incorporated into PMMA to improve its properties (Wang et al., 2014).

1.4 Aim and research hypothesis

According to Wang et al., 2014 MWCNTs can successfully reinforce fracture lines by strengthening the fibrils and bridging voids, thereby improving the polymer's fatigue performance. CNT reinforcement's effects on the mechanical properties of orthodontic resin materials have not been studied. The effect of MWCNT reinforcement on the mechanical properties of a commonly used PMMA denture base material was investigated in some studies.

The aim of the research is to see if there is any effect on the flexural strength of orthodontic resins when adding the carbon nanotube additives materials in different proportions. The null hypothesis was that the addition of MWCNTs by weight would not improve the flexural strength of the orthodontic resin materials.

Control 0.25% 0.50% 0.75%

Flexural strength

Monomer mix

(MPa)

71.818 65.25

60.805

54.105

Flexural strength

Polymer mix

(MPa)

69.1803

58.721

52.279

Results:

The mean flexural strength among the control group, monomer mixed groups, and polymer mixed groups was presented in Table 1. The mean flexural strength of the control group was 71.818MPa, monomer mixed with 0.25% of MWCNTs group was 65.25 MPa, monomer mixed with 0.5% of MWCNTs group was 60.805 MPa, monomer mixed with 0.75% of MWCNTs group was 54.105 MPa, polymer mixed with 0.25% of MWCNTs group was 69.1803 MPa, polymer mixed with 0.5% of MWCNTs group was 58.721 MPa, and polymer mixed with 0.75% of MWCNTs group was 52.279 MPa. In both sample types, it shows a downward trend by enhancing the carbon value, there is an overall reduction in flexural strength. The flexural strength mean value was highest in the case of the polymer mix sample at 0.25% after the control sample in the polymer and monomer mix.

Table 1 shows the consequently decreasing order of the flexural strength values in increasing order of carbon percentage. But in the case of the monomer category, the increasing order of carbon % shows a continuous decrease in flexural strength. This is because there was10.46% reduction in flexural strength during the transition from 0.25% to 0.50% carbon in the polymer mix category. However, there was a 6.44% decrease in flexural strength when the polymer mix made a transition from 0.50% to 0.75%.

Figure 1 shows a bar graph that shows comparative values for monomer and polymer mix samples for a varying percentage of carbon in the samples. The 0.75% carbon values almost identical flexural strength in both monomer and polymer samples. The largest difference exists between the monomer and polymer samples in the case of the 0.25% category. But in the case of 0.5%, there is a slight difference between monomer and polymer samples.

Table 3 shows the one-way ANOVA test analysis along with post-Hoc analysis, majorly considering the flexural strength thus null hypothesis was accepted. Thus population means are not equal. The f-value is 18.375, F-value is very larger than 1 thus, the ratio refers to the variation in means among group means and the difference is very greater. The p-value is 0.000 which is less than 0.05 and it has a significant difference between the groups.

Table 5 shows the post-hoc analysis for the dependent variable. It shows Tukey HSD analysis which shows mean differences in each group are reported. The comparison was not significant in any groups as the difference was greater than the p-value (was greater than 0.05). More precisely there was no significant difference between the P (0.75) and M (0.75) along with P (0.5) as (p>0.05). Furthermore, there is a negative difference between groups such as -17.7 such as between controls along with M (0.75).

Table 6 shows the follow-up of means by the Tukey Honestly significant difference helps in analyzing the minimal differences between the harmonic mean values. This was done as the null hypothesis is accepted. The homogenous subsets are shown with 4 levels of independent variables. Mean are recorded in different subsets. This post-ANOVA analysis shows the significant difference in means for groups in homogenous subsets which utilize harmonic mean sample size. The harmonic mean value for P (0.75) is 52.2797 whereas in the case of the control sample the harmonic mean value is 71.8184.

The results demonstrate a significant difference in flexural strength values amongst the 7 conditions involving the control too, F (6, 77) = 18.375, p=0.000. Pairwise comparisons for the mean utilizing Tukey HSD show that there are significant differences between some groups such as M (0.75) with other categories such as control, M (0.25), P(0.25) as p-value is less than 0.05 whereas with other groups the significant value is higher 0.05. Also, there is a significant difference in the case of comparison between P (0.75) and other groups including the control, M(0.25), M(0.5), and M,(0.25). (p<0.05). Thus, looking at various subsets it is clear that P (0.25) is present only in subset one.

The mean value in the case of M (0.5) and P (0.5) shows significant differences as per the subset

1. But there is no statistically significant difference while making a comparison between P (0.75) and M (0.75). Also, there is no statistically significant difference while making the comparison between M (0.75) and P (0.5). But the results from figure 6 show that there is a statistically significant difference between M (0.25) as well as P (0.25). Furthermore, there is a statically significant difference between M (0.25) and P (0.25) as per a level of variance.

Discussion

3. Materials and methodsMold preparation

Molds were made with dimensions of 64 mm long,(10,0 0,2) mm wide, and (3,3 0,2) mm in height according to ISO 20795-1-2013, the fabrication has done by placing old specimens that had been covered with a thin layer of wax in a metal flask with a surgical plaster material (Figure 1), the halves of the flasks filled with the mixed surgical plaster, and allowed to set. Then, the old specimens were removed using hot water, and the surgical plaster surface was painted with a separating medium.

Figure 1: denture flasks used for sample fabrication.

Sample preparation

PMMA orthodontic test specimens were fabricated with the orthodontic resins, Leocryl Powder Polymer (clear), and Leocryl Liquid Monomer (clear). The multi-wall carbon nanotubes MWCNTs as received from the manufacturer (multi-wall carbon nanotubes) were added to the powder or the liquid according to the subgroups that were made using either mixing the carbon nanotubes with the powder or the liquid (Figures 2 and 3).

Figure 3: carbon nanotubes mixing with polymer in a plastic beaker.

Figure 2: carbon nanotubes mixing with monomer in a glass beaker.

After the fabricating of the control group has been done without adding carbon nanotube materials, the MWCNTs, polymer, and monomer were weighted by an electronic scale (Figure 4), for the first 3 groups that mixed with monomer, the MWCNTs were added to the measured acrylic monomer at 0.25% wt/wt, 0.5% wt/wt, and 0.75% wt/wt, and another 3 groups the MWCNTs were added to the measured polymer at 0.25% wt/wt, 0.5% wt/wt, and 0.75% wt/wt , 12 specimens per group (Figure 5). The carbon nanotubes with monomer liquid were mixed and ultrasonicated for 5 minutes using the ultrasonic machine (Figure 6). The carbon nanotubes were mixed with polymer using the vibration machine for 2 minutes (Figure 7).

Figure 4: The control and the experimental samples.

Figure 5: The electronic scale using for measuring.

Figure 6: carbon nanotubes with monomer in the ultrasonic machine.

Figure 7: Carbon nanotubes were mixed with polymer using the vibration machine.

Figure 8: The pressure pot for polymerization at 40 C with a pressure of 2.5 Atm.

The specimens were made by the sprinkle-on method using a thin homogeneous coating of powder that was spread inside the mold and using a syringe, the liquid was progressively added to completely soak the powder, and the flasks were then placed on a pressure pot for polymerization at 40 C with a pressure of 2.5 Atm for 20 minutes, according to manufacturing instructions (Figure 8).

Figure 9: the metallographic grinding machine.

The specimens were polished with standard metallographic grinding papers, having a grain size of approximately 30 m (P500), 18 m (P1000), and 15 m (P1200) in order to obtain a final sample of the following dimensions: 64 mm long,(10,0 0,2) mm wide, and (3,3 0,2) mm in height according to ISO 20795-1-2013, and to achieve smooth edges as well (Figure 9).

Flexural strength test

The specimens were stored in distilled water at room temperature for 1 week before using the 3-point bending test with a universal testing machine (Figure 10). Before the test, the specimen thickness and width were measured with a Caliper and polished again if necessary. After the test had been done, the flexural strength (FS) was calculated using the formula: FS=3FL/2bd2, where FS is the flexural strength in MPa; F the maximum load (N); L is the specimen span between supports in mm; b is the width of each specimen in mm, and d is the thickness of each specimen in mm. Data on flexural strength from the specimens were evaluated and compared using 1-way ANOVA and the Tukey test to discover any significant differences at (p=0.05).

Figure 10: The universal testing machine.