BIOMATERIALS SCIENCE: REVISION QUESTIONS
PAST CONTINOUS ASSESSMENT TEST (CAT)
&
UNIVERSITY EXAMINATION QUESTIONS
COMPILED BY Dr B.K. Kisumbi
22
TABLE OF CONTENT PAGES
LEVEL II BDS………………………………………..3
CAT LEVEL II BDS…………………………………3
BDS LEVEL II-C.AT………………………………..4
LEVEL II BDS……………………………………….5
CAT LEVEL II BDS…………………………………6
SELF ASSESSMENT CAT………………………….7
C.A.T FOR BDS LEVEL III………………………...8
BDS LEVEL III……………………………………….9
BDS III SELF ASSESSMENT ……………………...10
LEVEL III BDS………………………………………11
Special Biomaterials CAT……………………………12
SPECIAL BIOMATERIALS CAT………………….13
BIOMATERIALS SELF ASSESSMENT CAT…….13
BDS III - BIOMATERIALS CAT…………………..14
LEVEL III BIOMATERIALS C.A.T……………….15
Biomaterial Science CAT …………………………..16
BIOMATERIALS CAT……………………………...17
LEVEL III BDS ……………………………………...18
EXAMINATIONS……………………………………19- 22
LEVEL II BDS
Date 13/12/2002
SECTION A:
1. Define (a) Modulus of elasticity and describe how it is quantified (3 mks) (b) Hardness & state its importance in a biomaterials for use as a filling (2 mks) (c) Thermal diffusivity (1) (d) Hue & chroma (2) (e) Newtonian & Bingham flow (2 mks)
2. (a) Enumerate the ideal biological requirements of a dental biomaterial (3 marks) (b) What are the characteristic of a metal? (3 marks) (c) Name 2 metal elements constituent in dental materials today (1) (e) Why are metals alloyed? (1)
3. (a) Define polymer and degree of polymerisation (2 ) (b) List the acrylic polymers used in dentistry (2 mks) (c) Describe in detail the setting reaction of dental polymers (5 mks)
4. (a) What roles does visible light with peak wavelength 480m play in dental biomaterials? (1) (b) What are the ideal aesthetic requirements of a dental biomaterial? (3 marks) (c) Name 2 aesthetic materials that are used in modern dentistry. (1)
5. (a) Differentiate between corrosion and tarnish (2 mks) (b) How can corrosion be prevented in the mouth? (1) (c) Describe causes of corrosion as it occurs on biomaterials employed in the oral environment. (5 marks)
SECTION B:
1. With reference to manufacture, classification, formulation, manipulation, properties and application write a concise essay on sulphate dehydrate products.
2. Write a comprehensive essay on mechanical properties of dental material. Highlight how the different parameters are evaluated in-vitro. Using suitable graphical illustrations show how metals, polymers and ceramics under tension.
CAT level II BDS Date: 14th may 2004
SECTION A:
1. (a) Name the catalyst used in the dark reaction, in the Light polymerizing Glass ionomer cements. (1) (b) Briefly describe with the aid of a diagram, Glass- Transition Temperature (Tg) (3 marks)
2. Briefly describe the role of itaconic acid and poly (maleic) acid in Glass ionomer cement setting reaction (3 marks)
3. (a) Compare the compressive strength of Zion oxide eugenol and zinc polycarboxylate
(b) Discuss the properties that make them ideal for specific applications (6 marks)
4. Define and state the significance of; (a) poisons ratio (b) Devitrification (c) Crosslinking (e) Eutectic alloy (4 marks)
5. How do the characteristic properties of ceramic compare with those of a metal? Give a practical example of a dental biomaterial that contains the two. (4 marks)
6. How are alloy microstructure formed? Describe all the possible combination that can occur on alloying 2 or more metals Explain the rationale of alloying metals giving suitable example (6 marks)
7. Write notes on polymerisation processes utilized in dentistry using practical illustrations. (3 marks)
SECTION B: (ESSAY)
1. (a) With reference to ASPA (Aluminosilicate Polyacrylic Acid Cement) describe the advantages and disadvantages of this material in restorative work. Highlight Current Products that attempt to overcome these drawbacks. (10 marks) (b) Make notes on Dental Acrylic Polymers (10 marks)
2. (a) Commencing with definition of working and setting time, describe how you would manipulate each of the dental cements. Write notes on the setting reactions of Dental Cements. (15 marks) (b) Write a critique on Zinc phosphate cement. (5mks)
DATE: 18/3/2005 BDS LEVEL II-C.A.T
SECTION A:
1. (a) Define the co-efficient of viscosity (2) (b) How is plastic flow determined? Give at least four types of evaluation system. (6 mks) (c) What are the units of viscosity (1)
2. (i) What are the characteristics of a metal (4 marks) (ii) Highlight areas where metal find application in their pure form. (2) (iii) Give four alloys applied in dentistry and in two indicate what one of the constituent conferes to the alloy system. (4)
3 (a) using graphic illustration, describe the behavior of the 3 major categories of Biomaterials under tensile stress (6)
(b) Briefly describe the structural processes taking place in one of the materials (3 a) from start of loading until failure (4).
4 Define and state how the working and setting time of Paris are evaluated (4 marks)
5. (a) What is the rationale of alloying Metals? (2) (b) Classify polymerization reaction. (3)
(c) Write short notes on methyl methacrylate and use it to illustrate the polymerization reaction of Heat cured acrylic (6)
6. (a) Define glass transition temperature (Tg) and explain its significance in a biomaterial. (2 mks)
(b) Describe the effects of thermal energy to the structure of silica. (4) (c) What is the product o glass devitrification (1)
7. (a) Define and differentiate plaster of Paris (POP)/ Dental stone and High strength stone. (6) (b) Outline in detail the manipulation of POP.(3) (c) Name four applications of gypsum products.(2)
SECTION B:
1. commencing with a description how the oral environment interacts with biomaterials, write a succinct essay on biocompatibility evaluation of biomaterials. Highlight six potentially bioharzadous biomaterials you know and suggest simple practical precautions dental staff should employ.
2. With reference to formulation, manipulation and applications, write a comprehensive essay on autopolymerising polymethyle metahacrylate (PmmA). Present a critique on the properties of auto (PMMA)
DATE: 10/2/2006 BDS LEVEL II- C.A.T
SECTION A:
1. using a suitable annotated diagram explain the following (a) Stress (b) Toughness
(c) Diamatral strength (d) Delayed recovery (e) Retardation (5marks)
2. (a) With aid of suitable illustration describe (a) The Kelvin body (b) The Voight body (2) (b) what is the relevance of rheologgical behavior in dental applications? (2)
3. With reference to gypsum products, make short notes on: (a) Dead burnt calcium sulphate
(b) Spherullite (c) Hygropscopic expansion (d) Potassium chloride (e) Borax (10)
4. (a) Name four metal alloys applied in dentistry (2) (b) How do the characteristics of metal and polymers compare? (5) (c) Explain the rationale of composite biomaterials (1)
5 (a) Give the structure of methyl methacrylate monomer (2) (b) with aid of the above monomer illustrate free-radical addition polymerization (FRAP) (4) (c) List two dental materials that set via the (FRAP) (1)
6. (a) What are the mandatory properties of a biomaterial for use in dentistry? (3)
(b) How does the oral environment interact with biomaterials?(3)
SECTION B- ESSAY:
1. With reference to the manufacture, properties and applications differentiate Alpha and Beta calcium sulphate hemi hydrate
2. Classify dental acrylic polymer and write a concise essay on the formulation, Manipulation, properties and application of cold-cured acrylic.
LEVEL II BDS
DATE: 24/5/2006
PART A:
1. (a) Describe the rheologgical behavior of toothpastes (3 marks) (b) Define delayed relaxation (1 mark)
2. (a) Differentiate the shape of the Brinell test and that of the Vickers indenter (2) (b) What is the shape of the indentation produced by the knoop’s hardness test?(1)
3. Define and explain the plastic zone of a stree strain graph for a metal wire or spring.(4)
4. Describe two tests you would use to measure impact strength. (2)
5. What would be the endurance limit of any commonly used material? (3 marks)
6. Compare the comparative melting points for the three main building blocks of material used in dentistry (3 marks)
7. (a) Describe the two distinct stage of dehydration of gypsum materials. (2) (b) What is the relevance of each stage? (2 marks)
8. (a) How can the inherent setting reaction of plaster of Paris be accelerated (1) (b) What other accelerant may be used for this purpose. (1) (c) Describe the role of syngenite in the reaction. (1)
9. (a) Define the salt effect in plaster of Paris. (1) (b) What is the need for an anti-expansion solution? (1) (c) Name one such anti-expansion solution. (1)
10. (a) What is critical porosity(1 mark) (b) What is the relevance to the application of dental cements (2 marks) (c) Is the relative strength of plaster and that of Die stone related to pore size or particle size? Explain. (2 marks)
11. (a) Give a classification of Restorative material. (4 marks) (b) State reasons for considering Zinc Oxide Eugenol cement as both an acid-base reaction cement and organochelate reaction cement (2 marks)
12. (a) Make short notes on Acid-based reaction cement giving suitable example and brand names (10 marks) (b) Describe the setting reaction of Zinc Polycarboxylate cements. (3 marks) (c) Briefly describe the role of fillers in dentistry (6 marks)
PARTB:
1. Write a concise essay on polymer ceramic composites using the following subject Headings: (a) Definition (b) Composition (c) Classification (d) Application (e) Advantages (f) disadvantages (20 marks)
2. Classify Impression Materials. Write a comprehensive essay on elastometric impressions making Comparative assessment of the different materials. (20 marks)
22
Level II BDS 6th June 2007
SECTION A:
1. Give a detailed classification of dental cements. Name all the adhesive dental cements applied in modern dental procedures. [ 6 ]
2. Write short notes on Zinc oxide eugenol impression paste. [5]
3. Describe in detail the manipulation of alginate impression material, stating the setting reaction characteristics.[5]
4. Define and describe the method of evaluating; (a) Chroma, of dental amalgam (b) Hardness, of elastometric impression material (c) Impact strength, of acrylic polymer (d) Cytotoxicity potential, of a new biomaterial (e) Degree of polymerization [10]
5. Name two dental materials based on each of the following material categories (a) Alloys (b) Ceramics (c) Polymers (d) Composites [4 ]
SECTION B:
1. (a) Write a concise essay on the historical development of Glass Ionomer cements. (b) give a detailed overview on current advances NB: a comment on nomenclature will help to elucidate the discussion
2. Write a critique on resin composites as restorative material. What are the de merits of dental amalgam today?
CAT LEVEL II BDS: 6th December 2007
Section a:
1. a) Name the catalyst used in the dark reaction, in the light polymerizing Glass ionomer cement (1)(b) Briefly describe with the aid of a diagram, Glass-Transition Temperature (Tg) (3)
2. Brief describe the role of itaconic aid and poly (maleic) acid in Glass ionomer Cement setting reactions. (3 marks)
3. (a) compare the compressive strength of Zinc oxide Eugenol and Zinc polycarboxylate (b) Discuss the properties the make them ideal for specific application. (6 marks)
4. Define and state the significance of; (a) poisons (b) devitrification (c) Crosslinking (d) Eutectic alloy (4 mks)
5. How do the characteristic properties of a ceramic compare with those of a metal? Give a practical example of a dental biomaterial that contains the two. (4 marks)
6. How are alloy microstructures formed? Describe all the possible combinations that can occur on alloying 2 or more metals Explain the rationale of alloying metals giving suitable example (6 marks)
7. Write notes on polymerization processes utilized in dentistry using practical illustrations (3 marks)
SECTION B:
1. (a) With reference to ASPA (Aluminosilicate Polyacrylic Acid Cement) describe the Advantage and disadvantage of this material in restorative work. Highlight Current Product that attempt to overcome these drawbacks. (10 marks) (b) Make notes on Dental Acrylic Polymer (10 marks)
2. (a) commencing with definition of working and setting time, describe how you would manipulate each of the dental cements. Write notes on the setting reactions Of Dental Cement. (15 marks) (b) Write a critique on Zinc phosphate cement. (5)
SELF ASSESSMENT CAT
SECTION A:
1. Define. (a) Dilatant flow (b) Fatigue strength (c) Smear layer (d) Devitrification (e) Glass transition temperature Tg. (5 marks)
2. Describe the ideal biological properties purported for use as an implant. (3 marks)
3. Name 4 potentially bioharzadous element/ compounds constitution in some dental products today. (2 marks)
4. (a)Compare the characteristics of a mental and a ceramic material (6) (b)Give two example of co-application of the two categories of material in (a) above (2)
5. (a) Describes the characteristics of dentine
(b) How do the properties in (i) affect bonding. (5 marks)
6. Compare acid etched enamel and dentine. What is the term used to define Concomitant etching and dentine? (5)
7. How long do you etch normal –enamel/Normal dentine (2)
SECTION B:
1. using suitable illustrate, write a detailed essay on the mechanical behaviour of a metal on application of tensile load. What is the relevance of mechanical properties in clinical performance of biomaterials?
2. Define a polymer. Commencing with characteristics of polymer, write an essay on polymerization reaction types giving practical example in dental materials products.
SELF ASSESSMENT CAT
SECTION A:
1. (a) Classify impression material available in dentistry today (b) Define working time (WT) and setting time (ST) (c) What is the significance of WT and ST in the manipulation of impression material?
2. Briefly describe the biocompatibility properties of each of the impression material category.
3. (a) Classify all Dental cements. (b) Name dental cements that chemical adhere to tissues/substances (c) Describe and illustrate the above chemical interaction.
4. Name cements that are compatible and incompatible with resin composite.
5. What dental material would you select for the following clinical application and why? (a)Luting a porcelain veneer (b)2o impression of a partial denture (c)2o impression of crown and bridge preparation (d)Temporary filling of a hypertensive tooth (e)Multiple class V filling in a patient (d)Atraumatic restorative filling
SECTION B:
1. Write an essay on Zinc oxide eugenol impression paste
2 Write a concise essay on the GIC-PC continuum. Highlight the advantages and disadvantage of GIC’s.
LEVEL II BDS -DATE: 7TH FEBRUARY 2003
SECTION A:
1. Differentiate the following: (a) Elastic and plastic deformation (b) Ductility and malleability (c) Thermal conductivity and thermal expansion (d) Metamerism and value (e) Molecular of a polymer and degree of polymerisation (10 marks)
2. (a) using schematic representation. Describe the microstructure of a solidifying metal (4) (b) Explain why metal conduct heat and electricity. (2) (c) Name NOBLE metal used in dentistry (1)
3. (a) write short notes on free-radical addition polymerisation reactions. (4) (b) What is cross-linking as it applies to polymers (2)
4. (a) Describe how you would select a shade of material to get a matching color. (b) Name one equipment or method used in color measurement. (c) What is glass transition temperature? State its significance. (5 marks)