Science Of Dental Materials Clinical Applications V Shama Bhat

Chủ đề khoa học về vật liệu nha khoa rất quan trọng và không kém phần hấp dẫn đã là một phần không thể thiếu trong chương trình giảng dạy nha khoa của chúng tôi trong vài thập kỷ qua. Môn học, vốn rất đơn giản trong những năm đầu, bao gồm một số ít kim loại và phi kim, đã trải qua những phát triển phi thường, đặc biệt, trong ba thập kỷ qua. Khoa học vật liệu nha khoa ngày nay là một môn học bao gồm thực tế mọi vật liệu kim loại và phi kim loại có thể hình dung được mà các nhà khoa học đã có thể phát triển cho nhiều ứng dụng khác nhau trong công nghiệp và y học. Khi đã lưu ý những điều trên, chúng ta cần tự đặt câu hỏi, liệu chúng ta, những bác sĩ lâm sàng, đã có thể hiểu và đồng hóa vật lý và hóa học của tất cả những vật liệu tuyệt vời này một cách thực tế vào chương trình giảng dạy của mình hay chưa. Câu trả lời trung thực cho câu hỏi này không phải là có tự tin. Một trong những lý do chính của tình trạng này là do thiếu sách giáo khoa phù hợp với đầy đủ các vấn đề cơ bản, bằng một ngôn ngữ và văn phong, đủ đơn giản để hiểu để sử dụng cho các sinh viên BDS đầu tiên của chúng tôi. Nhiều giáo viên đã có nhiều nỗ lực táo bạo trong việc đưa ra sách giáo khoa về môn học này trong thời gian gần đây và tất cả đều được viết bởi các giáo viên, đặc biệt là các chuyên khoa lâm sàng, do đó nội dung vẫn ở trạng thái mất cân đối với sự nhấn mạnh không cân đối. của các khía cạnh lâm sàng của nha khoa với chi phí cơ bản. Những khó khăn trong việc hiểu bản chất hóa học và vật lý phức tạp của các vật liệu mới được phát triển và đưa vào sử dụng đã góp phần làm cho lacuna tồn tại trên thực địa. Giáo sư Shama Bhat, người tiên phong trong nỗ lực làm việc chăm chỉ để đạt được vị thế của một chủ đề độc lập về vật liệu nha khoa, từ kinh nghiệm dày dặn của mình với tư cách là một giáo viên tận tâm về các môn học cho sinh viên BDS, MDS và gần đây đã giới thiệu Thạc sĩ nha khoa tài liệu, đã mạo hiểm để viết một cuốn sách về chủ đề này. Những nỗ lực của anh ấy phần lớn đã thành công và nó sẽ được các sinh viên BDS và cả sinh viên sau đại học quan tâm. Đây là loại sách đầu tiên được giới thiệu ở nước ta vì ông là một nhà khoa học không chuyên về nha khoa đã giảng dạy và nghiên cứu trong ba thập kỷ qua. Tác phẩm có một số đặc điểm nổi bật khiến nó trở nên độc đáo theo nhiều nghĩa. Phong cách trình bày trong mỗi chương có một cách tiếp cận khác biệt rõ ràng làm cho nội dung thú vị và dễ hiểu đối với tất cả mọi người. Tác phẩm này là một bổ sung đáng hoan nghênh cho mảng sách về chủ đề này và nó sẽ đi một chặng đường dài trong việc lấp đầy khoảng trống trong giới học thuật của chúng ta, của thế kỷ này và sẽ được tất cả mọi người chấp nhận. Những nỗ lực chân thành của Giáo sư Shama Bhat và Ông Nandish trong việc tạo ra này là đáng khen ngợi và đóng góp của họ cho khoa học vật liệu nha khoa ở nước ta là rất lớn.

Science of

Dental Materials Clinical Applications

Second Edition

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Science of Dental Materials Clinical Applications

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Disclaimer

Science and technology are constantly changing fields New research and experience broaden the scope of information and knowledge The authors have tried their best in giving information available to them while preparing the material for this book Although, all efforts have been made to ensure optimum accuracy of the material, yet it is quite possible some errors might have been left uncorrected The publisher, the printer and the authors will not be held responsible for any inadvertent errors, omissions or inaccuracies.

eISBN: 978-93-877-4200-0

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dedicated to

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Veena Vidushi, MA (Sociology)

The extraordinarily-abled challenged lady who has excelled in Karnataka classical music, vocal,

Veena and Violin recitals

The first ever blind Veena artist of excellence in India

with B high grade of All India Radio

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Foreword

n the recent years tremendous growth and advancement has taken place inthe basic sciences, especially in the field of material science which hasresulted in numerous innovations and improvements in the clinicalprocedures of dentistry This changed scenario warrants the involvement ofteachers who are specially qualified in material science, in training the dentalstudents Through this, the sound knowledge of dental materials will help thequalified dentists to render better treatment for the patients

As a strong believer of this concept, I wanted to implement this in ourinstitution At that juncture, I was fortunate to get a person like Prof VShama Bhat who has an in-depth knowledge in this field He has contributed

a lot in establishing and developing the Department of Dental Materials alongwith a museum of high standards With his constant perseverance he wasinstrumental in developing a good curriculum for MSc course in dentalmaterials at MAHE, Manipal

Time has come for all of us to establish department of material science inevery institution with specially qualified teachers With our constantencouragement he has come forward to write this book Needless to say, thevast experience of Prof Shama Bhat as a teacher and researcher with greatvision and ideas should reach the teachers and student community at large.This hard work of his at the age of 72 will be fruitful when this happens

I wish all the success to him in this new venture

BH SRIPATHI RAO MDS

EC Member of DCI

Principal Yenepoya Dental College

Mangalore

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Foreword

he very important and equally fascinating subject of science of dentalmaterials has been an integral part of our dental curriculum for the lastseveral decades The subject, which was very simple in the early years,comprising a handful of metals and nonmetals, has undergone phenomenaldevelopments, particularly, in the last three decades Science of dentalmaterials today is a subject that comprises practically every conceivablemetallic and nonmetallic material that the scientists have been able to developfor a wide variety of applications in industry and medicine

Having noted the above, it is pertinent to ask ourselves the question, whether

we, the clinicians, have been able to understand and assimilate the physicsand chemistry of all these wonderful materials in a practical way into ourcurriculum The honest answer to this question is not a confident ‘yes’

One of the main reasons for this state of affairs is the lack of suitabletextbooks with adequate stress on the basics, in one language and style,simple enough to understand for use by our first BDS students Manyteachers have made several bold attempts to bring out textbooks on thissubjects in the recent times and all have been written by teachers, particularly

of clinical specialities, as a result of which the contents have remained in astate of imbalance with disproportionately emphasis in favour of clinicalaspects of dentistry at the cost of basics The difficulties of understanding thecomplicated chemical and physical nature of the newly developed andintroduced materials have contributed to the lacuna existing in the field

Prof Shama Bhat, who is a pioneer in the effort of working hard to achieve astatus of an independent subject to dental materials, from his vast experience

as a dedicated teacher of the subjects to the students of BDS, MDS andrecently introduced MSc in dental materials, has ventured to write a book onthis subject His efforts have been largely successful and it will be of interest

to BDS students and also the postgraduates This book is first of its kindbrought out in our country as he is a non-dental scientist who has beenteaching and researching for the last three decades

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The work has several salient features which make it unique in more than onesense The style of presentation in each chapter has a distinctly differentapproach which makes the contents interesting and readily understood by all.This work is a welcome addition to the array of books on the subject and itwill go a long way in filling the lacuna in our academics, of this century andwill be well accepted by all.

The sincere efforts of Prof Shama Bhat and Mr Nandish in this creation islaudable and their contribution to the science of dental materials in ourcountry is monumental

Preface to Second Edition

e wish to thank all the dental undergraduate and postgraduate studentsand teaching faculty for the encouragement given with appreciationsand feedbacks Accordingly, certain modifications and additions havebeen done Many students have expressed the usefulness of the chapter

‘Orientation to Dentistry’ and the different types of model questions given forevery chapter This has helped them in preparing the answers to long andshort essays and brief (short) questions within the stipulated time

To facilitate faster studies, double-column setting, colour side headings,shaded tables, two-colour diagrams and bold type of keywords have beenfeatured This has reduced the bulk and weight of the book withoutcompromising on quality

We thank Mr Jayaprakash K, Lecturer in our department, for assisting us inbringing out this edition

We hope to receive more constructive feedbacks which will help us to revisefurther in the days to come

V Shama Bhat

BT Nandish

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Acknowledgements

his is a copolymerised work of the long experience in teaching the entiresyllabus to the undergraduate and postgraduate courses, researchpublications since 1976 and deep involvements in the new two-yearMSc course in dental materials in 1999 at Manipal University It is our duty

to acknowledge the persons involved directly or indirectly for their valuablesuggestions and encouragements in bringing out the first edition in 2006 aswell as revised edition now in 2013 this textbook on science of dentalmaterials and clinical applications This is a challenging project as the subject

is very highly cross-linked by interaction with basic sciences, technologiesand dental specialties

Dr BH Sripathi Rao, Principal, and Professor and Head, Department ofMaxillofacial Surgery, earlier Executive Council member of Dental Council

of India, Vice-Chancellor of Yenepoya University, was the main initiator Dr

KS Bhat, ex-Dean, CODS, Manipal, who established the separate department

of dental materials in 1999, has given us continuous support and suggestions.Our dynamic Chancellor Al Haz Abdul Kunhi, Vice Chancellor Dr.Chandramohan, Mr PCM Kunhi, Dr Akhtar Hussain, Prof and HoD ofOrthodontics, Dr Sham S Bhat, Vice Principal, as well as the HoDs of allthe speciality departments are the main sources of inspiration for us

We would like to thank Mr S.K Jain (CMD), Mr Varun Jain (Director),

Mr YN Arjuna (Senior Vice President – Publishing and Editorial), and Mr.Ashish Dixit (Business Head – Digital Publishing, Marketing & Sales) andhis team at CBS Publishers & Distributors Pvt Ltd for their skill,enthusiasm, support, patience and excellent professional approach inproducing and publishing this eBook

Our heartfelt thanks go to Dr Hema Nandish and extraordinarily abledmusician Miss Manipal Aruna Kumari and late Mrs Hemavathi S Bhat whohave really helped in releasing our internal stresses by their encouragement

V Shama Bhat

BT Nandish

About the Book

This is the thoroughly revised and updated edition of the popular textbook aimed at the dental students in providing an in-depth information on the subject of dental materials, with a focus on the clinical applications While planning the content, knowledge of basic sciences of the students admitted to the first year to BDS course has been taken as the base-line Care has been taken to strike a balance between the basic sciences, technologies and adequate orientation to the clinical applications A slightly different approach has been adopted in the organisation of the chapters to make the text more interesting and facts easily understood.

Certain topics like materials used in orthodontia, basic metallurgy, ceramics, etc have been dealt with in greater details which would help the brighter undergraduate students and serve as an introduction to the postgraduate students of the particular specialities.

The salient features include the chapter ‘Orientation to Dentistry’, the usefulness of which has been expressed by many students/readers; and the different types of model questions given at the end of every chapter which have helped them in preparing the answers to long and short

essays and brief (short) answers to questions within the stipulated time To facilitate faster study and longer retention by the students, this edition highlights • double- column text setting • use of colour side-headings, tables and diagrams and • bold printing of keywords.

About the Author

V Shama Bhat

is currently Professor, Department of Dental Materials, Yenepoya Dental College, Mangalore One of the senior- most teachers teaching the subject of dental materials, he completed MSc in physics from Karnataka University, Dharwad in 1957 He was a lecturer in physics at St Joseph’s College, Bangalore (1957–1962); at Manipal Institute of Technology (1962–1969); and Head, Department of Physics, Kasturba Medical College and College of Pharmaceutical Sciences, Manipal (1969– 1976) Later, he took up the challenging position of Professor and Head, Department of Dental Materials, College of Dental Sciences, Manipal, in 1976 and worked hard to establish and develop an independent department and grant status to this subject.

BT Nandish

is currently Assistant Professor, Department of Dental Materials, Yenepoya Dental College, Mangalore He belongs to the first batch of the newly started MSc (DM) course at Manipal Academy of Higher Education, Manipal (1998) After completing his MSc securing first class, he joined this department and helped to develop the

museum and took active part in all the activities He has already conducted research work on gypsum products and introduced new exercise of determination setting time of gypsum products under different parameters for BDS course.

Colour Plate 1

CHAPTER 3: IMPRESSION MATERIALS (AUXILIARY

MATERIALS)

Fig 3.1: Preliminary impression with impression compound

Fig 3.2: Agar-agar duplicating materials

Fig 3.3a: Agar-agar duplicating flasks

Fig 3.3b: Silicone duplicating flasks

Fig 3.4a: Agar-agar duplicating unit

Fig 3.4b: Silicone duplicating unit

Colour Plate 2

Fig 3.5: Duplication and cast

Fig 3.6a: Dust-free alginate

Fig 3.6b: Condensation polysilicone

Fig 3.6c: Add polysilicone’ monophase

Fig 3.6d: Add polysilicone-putty and medium viscosity

Fig 3.7: Elastomer-automixer

Fig 3.8: Syringe and medium viscosity double mix-single impression and

cast

Colour Plate 3

Polysilicone-putty wash two step impression technique

Fig 3.9a: Apply tray adhesive, allow to dry

Fig 3.9b: Needed putty, seated with spacer-preliminary impression

Fig 3.9c: After setting, remove spacer

Fig 3.9d: Provide relief space if required

Fig 3.9e: Load part of syringed material on the tray and apply on teeth

Fig 3.9f: Final impression

Colour Plate 4

CHAPTER 4: GYPSUM PRODUCTS: CAST AND DYE MATERIALS

(AUXILIARY MATERIALS)

Fig 4.1: Type IV Dye stone (NSE = 09%)

Fig 4.2: Synthetic gypsum product

Fig 4.3a: Vacuum mixer bowls

Fig 4.3b: Vacuum hand mixer

Fig 4.4: Vacuum electrical mixer with timer, speed controls

Fig 4.5: Vibrator

Fig 4.6: Cast-base former moulds

Colour Plate 5

Fig 4.7: Vicat penetrometer 300 gm wt., 1 mm wire diameter

Fig 4.8: Supernumerary teeth (peculiar cases)

CHAPTER 6: PROSTHETIC APPLICATIONS OF POLYMER

RESINS

Fig 6.1: Preliminary impression and casts

Fig 6.2: Acrylic special trays

Fig 6.3: Border moulding-tracing

Fig 6.4: ZnOE wash impression and boxing

Colour Plate 6

Fig 6.5: Split cast and split tray

Fig 6.6: Acrylic record bases

Fig 6.7: Wax occlusal rims

Fig 6.8: Bite rims after jaw relating

Fig 6.9: Articulation and teeth setting

Fig 6.10: Flasking and dewaxing

Colour Plate 7

Fig 6.11: Finished partial dentures

Fig 6.12: Finished complete dentures

Injection moulding technique

Fig 6.13: Sprue fitting

Fig 6.14: Flasking

Fig 6.15: Exposing teeth

Fig 6.16: Two-halves after dewaxing

Fig 6.17: Injecting resin dough and then curing

Colour Plate 8

6.18a-j: Denture relining steps

Fig 6.18a: Resorption and clinical condition requiring soft reliner

Fig 6.18b: Denture surface before relining

Fig 6.18c: Relief area for relining

Fig 6.18d: Application of reline primer