Overview Of Dentistry And Dental Materials Question And Answers

Overview Of Dentistry And Dental Materials

Question 1. Write a short note on ADA specification no.
Answer:

ADA Introduction:

ADA standard committee for dental products develops specifications for all dental products, instruments, and equipment known as ADA specifications.

ADA specification numbers are the guidelines with definite requirements for physical, chemical, and mechanical properties of dental materials which have clinical significance and development of new materials, instruments, and test methods that are measured in laboratory and laid down by the American Dental Association for Dental Materials.

Read And Learn More: Dental Materials Question And Answers

The ADA’s Council on scientific affairs is responsible for the evaluation of drugs, teeth cleaning agents, teeth whitening agents, therapeutic agents used in dentistry, and dental X-ray films. After the formulation of specifications by ADA, it is submitted to ANSI.

• When a product satisfies ADA specification, the manufacturer label the product as ADA-accepted.
• Each dental material is specified by a specification number as ADA specification.
• The first ADA specification was for amalgam alloy, formulated and reported in 1930.
• Details of the first 25 specifications were included in the book

“American Dental Association Guide to Dental Materials and Devices”.

• A close examination of each of the specifications reveals a general pattern of standardization common to each of the materials.
• Each specification includes information on other applicable specifications.
• Each specification includes information on preparation for delivery with instructions concerning packaging, instructions for use, and marking with a lot of numbers and dates of manufacturers.
• Each specification includes notes that provide additional information on intended uses and references to special items.

Question 2. Write a brief on the aim and scope of dental materials.
Answer:

Aims of Dental Materials:

• To present the basic chemical and physical properties of dental materials.
• To provide sound educational background so that the practice of dentistry emerges from an art into an empirical status of science as more information through further research becomes available.
• Intended to bridge the gap between knowledge obtained in basic courses in material science, chemistry, physics, and dental operatory
• To generate curiosity as to why materials react as they do, why manipulation variables should be observed, and how information is largely limited to material per se and to make the profession an exciting experience?
• To provide the dentist with certain criteria of selection that will enable him to discriminate between fact and propaganda with regard to claims of manufacturers.

Scope of Dental Materials:

There is scarcely a dental procedure that does not make use of dental materials, so dental materials are used in every branch of dentistry.

Following is the scope of dental materials:

• Prosthodontics: In prosthodontics, the dental materials used are impression materials, waxes, prosthetic appliances materials including the base metal, precious and low precious alloys, denture base materials, crown and bridge veneer, implants, and mouth protectors.
• Endodontics: In this dental materials used are pulp paste, root canal filling materials, sealants, and cements.
• Periodontics: Materials used are periodontal packs and periodontal dressings.
• Orthodontics: In orthodontics, materials used are metal and alloys, resin materials.

Question 3. What is dental material science? Describe its aims and objectives including a selection of materials in different patients.
Or
What are the aims and objectives of dental material science? Describe the criteria for the selection of restorative materials.
Answer:

Dental material science is a basic science that deals with the physical, mechanical, and biological properties of dental materials.

Aims of Dental Material Science:

• To present the basic chemical and physical properties of dental materials.
• To provide sound educational background so that the practice of dentistry emerges from an art into an empirical status of science as more information through further research becomes available.
• Intended to bridge the gap between knowledge obtained in basic courses in material science, chemistry, physics, and dental operatory
• To generate curiosity as to why materials react as they do, why manipulation variables should be observed, and how information is largely limited to material per se and to make the profession an exciting experience?
• To provide the dentist with certain criteria of selection that will enable him to discriminate between fact and propaganda with regard to claims of manufacturers.

Objectives of Dental Material Science:

• To understand the evolution and development of the science of dental materials.
• To explain the purpose of the course in dental materials to the person concerned with the profession of dentistry.
• For knowledge of the physical and chemical properties of dental materials.
• For knowledge of biochemical requirements of a physical restorative procedure.
• An intelligent compromise of the conflicting as well as coordinating factors into the desired end results.
• To lay down standards or specifications of various dental materials to guide the manufacturers as well as to help the profession.
• To search for new and better materials which may answer our requirements with greater satisfaction.
• To understand and evaluate the claims made by manufacturers of dental materials.

Criteria for Selection of Restorative Materials in Different Patients:

The selection process is based on consideration of the advantages and disadvantages of each material and will take into account the different requirements of each practitioner according to his/ her skill level, type of practice, cost factors, and other criteria.

• Analysis: Select the material for a particular situation. Incorrect decisions may lead to failure of restoration or appliance.
• Requirements: List the requirement for a material to meet the need for that situation.
• Available materials: The properties of the available materials are compared with requirements at two levels. Previous experience with materials in similar circumstances will be a major factor that influences selection. Newly developed products are to be used to give better results for the same situation to be followed.
• Choice of material: After comparing the properties of available material with the requirements, the final choice of material brand is a matter of personal preference on the part of the dentist. Factors such as ease of handling, availability, and cost may play a part at this stage of the selection process.

Question 4. Define dental material science. Classify dental materials and write a note on preventive dental materials.
Or
Write a short answer on the classification of dental materials.’
Answer:

Dental material science is a basic science that deals with the physical, mechanical, and biological properties of dental materials.

Classification of Dental Materials:

1. Preventive materials.
2. Restorative materials.
3. Auxiliary materials.
4. Prosthetic materials.
5. Appliance materials.
6. Biomaterials.
7. Therapeutic agents.

• Preventive materials: Preventive materials include pit and fissure sealants and other materials used to prevent the onset of dental diseases.
• Restorative materials: Restorative materials include materials used to repair or replace tooth structures. This includes materials like amalgam, composites, ceramics, cast metal structures, and denture materials.
• Auxiliary materials: Auxiliary materials are substances that aid in the fabrication process but do not actually become part of the restoration, appliance or prosthesis. This includes materials like gypsum products, impression materials, casting investments, waxes, etching gels, custom tray materials, etc.
• Prosthetic materials:  Prosthetic materials are materials used to replace missing teeth, oral and maxillofacial structures. These include the alloys, ceramics, and polymers used in fixed and removable partial denture construction and maxillofacial prostheses.
• A biomaterial: A biomaterial is a biological or synthetic substance that can be introduced into body tissue as part of an implanted medical device or used to replace an organ, or bodily function. Although many traditional materials qualify as biomaterials, this term has been introduced to include bone and tissue grafts.
• Therapeutic agents: Therapeutic agents include various chemicals, medicaments, antimicrobials, and other locally applied agents that are capable of producing a specific effect in the area to which it is applied.
• In reality, many materials have dual or multiple uses and so the above categorization is difficult to strictly apply.

Preventive Dental Materials:

• Cement, coating, or restorative material that either seal’s pits and fissures or releases therapeutic agents such as fluoride and/or mineralizing ions to prevent or arrest the demineralization of tooth structure are known as preventive dental materials.
• Preventive dental materials include pit and fissure sealants; sealing agents that prevent leakage; materials used primarily for their antibacterial effects; and liners, bases, cement, and restorative materials such as compomer, hybrid ionomer, and glass ionomer cement that are used primarily because they release fluoride or other therapeutic agents to prevent or inhibit the progression of tooth decay (dental caries).
• In some cases, a preventive material may also serve as a restorative material that may be used for a short-term application (up to several months), for moderately long time periods (1–2 years), or for longer periods (5 years or more).

Question 5. What are the characteristics of ideal dental material?
Or
Write a short note on ideal dental material.
Answer:

The following are the characteristic of ideal dental material:

• It should be biocompatible
• It should be mechanically stable and durable
• It should be resistant to corrosion or chemicals
• It should be dimensionally stable
• It should be minimally conductive both thermally and electrically
• It should be aesthetic
• It should be easy to manipulate
• It should be adherent to tissues
• It should be tasteless and odorless
• It should be cleanable or repairable
• It should be cost-effective.

Question 6. Describe the criteria for the selection of materials used for the restoration of posterior and anterior teeth.
Answer:

• A brittle material is highly susceptible to surface flaws and internal defects when tensile stresses are present.
• Because it cannot plastically deform to reduce stress concentrations and its tensile strength is far lower than its compressive strengths.
• The compressive strength of brittle materials is often reported even though most brittle materials rarely fall under compressive stresses.
• However, when tensile strength values are not available.
• Flexural strength values should be used since they reflect a tensile mode of fracture.
• When tensile strength, flexural strength, or fracture toughness data are not available the compressive strength can be useful for comparisons of the fracture resistance of a similar family of brittle materials such as groups of amalgams, composites, ceramics, or cement.
• The physical properties mentioned above have been obtained using specimen shapes and sizes that are quite different from those of tooth restorations.

So, material products must be selected intuitively on the basis of property comparisons.

• Furthermore, these expected stresses are multiplied by a “safety factor” to ensure that the structure will be able to withstand a certain amount of excess stress.
• However, the tensile strength values reported for restorative materials represent the mean stress values below which 50% of the test specimens have fractured and above which only 50% had survived.
• Because this is an unacceptable failure rate for restorative dentistry, the range of measured values should be known.
• From an ultraconservative viewpoint the lowest 5 or 10% of a strength distribution, not mean values, should be used to design a prosthesis intended to resist fracture at a high level of confidence.
• We can also use the 95% survival stress as determined from Weibull analysis of data
• It is unfortunate that the magnitudes of mastication forces are not known for individual patients to the extent that the dentist can predict the stresses that will be induced in dental restorations.
• However, patients who exhibit evidence of extreme bruxism represent a higher risk population for the fracture of brittle restorative materials.
• The knowledge of the relationships between the properties of restorative materials known to exhibit excellent long-term survival performance is reinforced by clinical experience.
• The best test of a successful restorative material is the test of time under actual clinical conditions.