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Overview of Materials for Dental Applications DMS 7191 Behavioral Objectives Upon completion of this section, you will be able to: 1. Name the combination of sciences that contribute to dental biomateria...

Overview of Materials for Dental Applications DMS 7191 Behavioral Objectives Upon completion of this section, you will be able to: 1. Name the combination of sciences that contribute to dental biomaterials science. 2. Identify different types of restorative dental materials and describe their clinical usage. 3. List the properties expected of an "ideal" restorative dental material. 4. Gain a brief historical perspective about the use of dental biomaterials. 5. Define the term ‘Specification’ and name a synonym for it. 6. Explain the role of various international organizations in establishing specifications for dental biomaterials. 7. Name the organization that was given responsibility for the establishment of specifications and the evaluation of dental biomaterials, instruments and equipment in the U.S.A. 8. Identify the first dental biomaterial to receive an American Dental Association (ADA) Specification number. 9. Describe the role of the American National Standards Institute with regard to Specifications for dental biomaterials in the U.S.A. 10. Describe how dental biomaterials are classified by the U.S. Food and Drug Administration. 11. Name the various units of measurement. List the names and symbols of the seven base SI units from which all SI units are derived. 12. Identify the prefixes used to create multiples and submultiples of SI units. The behavioral objectives listed above are from Chapter 1 and Chapter 18 (pages 387- 389) in the course textbook, and this handout. Fall 2024  DMS 7191 Introductory Principles of Materials Science Fall 2024 Sharukh S. Khajotia, BDS, MS, PhD Associate Dean for Research for Research and Innovation David L. Boren Professor Division of Dental Biomaterials University of Oklahoma College of Dentistry Joint Appointment, OUHSC Graduate College Affiliate Associate Professor of Chemical, Biological and Materials Engineering Course Outline Overview of Materials for Dental Applications DMS 7191 Fall 2024  Biomaterial “any substance, other than a drug, that can be used as part of a system to treat, augment or replace any tissue, organ or function of the body” Dental Biomaterials Science Why should I study Dental Biomaterials? To educate your patients – All materials function in the hostile environment of the oral cavity To assess and treat patients – Recognize all dental materials in the mouth To handle materials properly – Dentistry relies heavily on biomaterials To understand the behavior of materials – Aid in the delivery of patient care – For safety of patient and dental team  Dental Disease 1. Biological causes: – Caries – Periodontal Disease 2. Mechanical causes: – Trauma, attrition, abrasion, bruxism, abfraction 3. Genetic causes  Dental Disease 1. Biological causes: – Caries – Periodontal Disease 2. Mechanical causes: – Trauma, attrition, abrasion, bruxism, abfraction 3. Genetic causes  Terminology Restorative material: Metallic, ceramic, metal- ceramic, or resin-based substance used to replace, repair, or rebuild teeth and/or to enhance esthetics. Direct restorative material: A cement, metal, or resin-based composite that is placed and formed intraorally to restore teeth and/or to enhance esthetics. Indirect restorative material: A ceramic, metal, metal-ceramic, or resin-based composite formed extraorally to produce prostheses, which replace missing teeth, enhance esthetics, and/or restore damaged teeth.  Terminology Temporary restorative material: A cement- or resin-based composite used for a period of a few days to several months to restore or replace missing teeth or tooth structure until a more long-lasting prosthesis or restoration can be placed. Preventive dental material: Cement, coating, or restorative material that either seals pits and fissures or releases a therapeutic agent such as fluoride and/or mineralizing ions to prevent or arrest the demineralization of tooth structure.  Terminology Auxillary restorative material: A substance used in the construction of a dental prosthesis that does not become a part of the prosthesis (e.g., impression materials, gypsum products, waxes, investment materials, finishing/polishing abrasives, matrices, resins for custom trays and bleaching trays). Please see figures 1-9 to 1-13 in Chapter 1 of the textbook. Ideal restorative dental material Biocompatible Bonds permanently to all tooth structures Aesthetically matches teeth and oral tissues Exhibits properties similar to the oral structures it replaces Capable of initiating tissue repair or regeneration Types of Materials Three basic materials Ceramics Inorganic salts Crystalline ceramics Glasses Metals Alloys Intermettalic compounds Polymers Rigid polymers Waxes Elastomers  Force The movement of matter, in the form of a pulling or pushing motion, either external to, or internal to, its structure. Units: Newtons (N), Pound force (Ibf). FIGURE 1-1: Interaction between teeth. A, Natural human dentition of an adult patient showing upper and lower teeth in full-occlusion contact. B, Forces acting on teeth at occlusion. How are materials used in the mouth? Restoration and replacement of lost or damaged oral structures Fillings Fixed Prosthetics Removable Prosthetics - Amalgam - Crowns and bridges: metal, ceramic, resin - Metal partial dentures - Composite resin - Inlays, onlays: metal, ceramic, resin - Resin partial dentures  Current Restorative Materials Before Restoration of fractured incisor with composite resin After Dental Amalgam Composite Resin Restoration  Cavity preparations for Intracoronal restorations: Posterior cast gold inlay A) amalgam, B) inlay A B Extracoronal restorations Cement base under amalgam Metal-ceramic extracoronal restorations FIGURE 1-14  Extracoronal restorations Resin-bonded fixed partial denture Three-unit fixed partial (Maryland bridge) denture (metal-ceramic bridge) Veneer on anterior tooth Endosseous implants Endodontically treated teeth Models Complete Dentures Removable Partial Denture Orthodontic bracket and fixed orthodontic appliance TABLE: Comparative Applications and Durability of Preventive and Restorative Dental Materials  Historical Overview 3000 B.C. Beginning of Dentistry 2500 B.C. Phoenicians 700 B.C. Etruscans 600 A.D. Mayans Figures 1-2 and 1-3 1728 Pierre Fauchard Historical Overview (Father of Modern Dentistry) 1756 Pfaff 1774, 1789 Duchateau and de Chamant 1800’s Porcelain inlay 1816 Taveau 1895 G.V. Black 1897 Philbrook 1907 Taggart 1915 1st observation of fluoridation (Colorado)  Historical Overview 1919 First Specification for a dental material (dental amalgam) by National Institute of Standards and Technology (NIST) 1935 Polymerized acrylic resin denture base 1944 Controlled fluoridation of water (1 ppm) 1976 Medical Device Amendments to U.S. Spherical dental amalgam powder particles Food, Drug and Cosmetic Act  Performance Standards for Dental Materials Specifications are designed to delineate satisfactory materials and rule out unsatisfactory ones. They are also known as Standards, and include laboratory tests of physical, mechanical, chemical and biological properties that result in data to be considered a benchmark for testing commercial products. Please read pages 387-389 of the textbook  Standards Organizations International: International Organization for Standardization (ISO) Federation Dentaire Internationale (FDI) Comité Européen de Normalisation (CEN) American: American National Standards Institute (ANSI)  Standards Organizations ANSI/ADA Specifications: The Council on Scientific Affairs was established in 1966 “to centralize ADA activities in the field of standardization of dental materials, equipment and instruments” The Council studies, evaluates and disseminates information regarding safety, efficacy and promotional claims of dental therapeutic agents, materials, instruments and equipment Specifications are reviewed at least every five years  Standards Organizations ANSI/ADA Specifications (contd.): Specifications for all dental materials, instruments, and equipment except drugs and x- ray films are developed by the ADA Standards Committee on Dental Products; specifications for informatics are developed by the ADA Standards Committee on Dental Informatics Specifications can only be approved as American National Standards by the American National Standards Institute (ANSI) with the designation‘ANSI/ADA Specifications’ Standards Organizations Regulation of Dental Biomaterials U.S. Food and Drug Administration (FDA): Dental materials are devices, which do not have chemical action in the body and are not dependent on being metabolized. Devices only need to show safety and efficacy Drugs (which have chemical action in the body) must show safety, efficacy and usage  Regulation of Dental Biomaterials U.S. Food and Drug Administration (FDA) The FDA has regulatory authority over the safety and efficacy of dental materials, instruments and devices. Most dental materials, equipment and instruments are considered as medical devices since they do not make medicinal or therapeutic claims, and are not required to undergo the stringent evaluation process that new drugs do. Dental materials fall under the purview of the Center for Devices and Radiological Health of the FDA for standardization and evaluation.  Regulation of Dental Biomaterials U.S. Food and Drug Administration (FDA) Through agreement with the FDA, the American Dental Association has the responsibility for providing standards by which dental materials are evaluated The Dental Products Panel of the FDA classifies dental products into three classes depending on relative risk factors: – Class I - low risk – Class II - moderate risk, such as dental amalgams – Class III - high risk, such as dental implants  American Dental Association Seal of Acceptance Program An important symbol of a dental product's safety and effectiveness Helps the public and dental professionals make informed decisions about safe and effective dental products  ADA Seal of Acceptance An assurance for consumers and dentists against misleading or untrue statements concerning a product, its use, safety and effectiveness Strictly voluntary process, covers 300 products, only includes items sold to consumers (toothpastes, dental floss, toothbrushes, mouthrinses) Products prescribed or used by dentists such as restorative materials and drugs are not included (phased out in 2007)  ADA Seal of Acceptance More than 100 consultants, including members of the Council on Scientific Affairs and ADA staff scientists, review and declare oral care products safe, effective and worthy of the ADA Seal. The consultants represent all fields relevant to evaluating dental products, including dental materials, microbiology, pharmacology, toxicology and chemistry  ADA Seal of Acceptance In evaluating products for the Seal, the Council on Scientific Affairs determines whether the product complies with its Provisions for Acceptance. These provisions require that the product meet ANSI/ADA or ISO Specifications. If standards do not exist, the ADA develops official guidelines describing the clinical, biological, and laboratory studies necessary to evaluate safety and effectiveness.  ADA Seal of Acceptance The ADA Seal generally is awarded for a five-year period Manufacturers must reapply to continue using the Seal Whenever the composition of an ‘Accepted’ product changes, the manufacturer must resubmit the product for review and approval before it is marketed with the Seal As long as a product bears the Seal, it must continue to meet these requirements  ADA Seal of Acceptance Qualifying for the ADA Seal: A manufacturer who applies for the Seal must: supply objective data from clinical and/or laboratory studies that support the product's safety, effectiveness and promotional claims prove that manufacturing and laboratory facilities are properly supervised and adequate to assure purity and uniformity of the product, and that the product is manufactured in compliance with Good Manufacturing Practices  ADA Seal of Acceptance Qualifying for the ADA Seal (contd.): A manufacturer who applies for the Seal must: conduct clinical trials as needed in strict compliance with ADA guidelines and procedures submit all advertising, promotional claims and patient education materials for review and approval by the ADA, and be in compliance with the ADA's standards for accuracy and truthfulness in advertising submit composition and other pertinent product information for review and approval  ADA Seal of Acceptance The Professional Product Review program replaced the Seal Program for professional products prescribed or used by dentists in 2006, but was discontinued in 2017 Reviews were published periodically containing Specification-based test results from the ADA laboratories, clinical input from practicing dentists, and a buyer's checklist Examples of preview reports are available online (please see Relevant Websites section in D2L course site) Standards Organizations  Required Reading Restoration Longevity in terms of Mechanical Integrity and Safety of Dental Materials Please read page 11 of the textbook  Measurement Lord Kelvin, the 19th-century English physicist who discovered the second law of thermodynamics, wrote: "When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind."  Systems of Units SI units Metric units English units (US Customary) SI Unit - base quantity Name Symbol length meter m mass kilogram kg electric current ampere A thermodynamic temperature kelvin K amount of substance mole mol luminous intensity candela cd time second s Prefixes of SI Units Factor Name Symbol 1012 tera T 109 giga G 106 mega M 103 kilo k 10-2 centi c 10-3 milli m 10-6 micro µ 10-9 nano n 10-12 pico p Engineers' Lapse Led to Loss of Mars Spacecraft Lockheed Didn't Tally Metric Units By Kathy Sawyer Washington Post Staff Writer Friday, October 1, 1999; Page A01 NASA's Mars Climate Orbiter was lost in space last week because engineers failed to make a simple conversion from English units to metric, an embarrassing lapse that sent the $125 million craft fatally close to the Martian surface, investigators said yesterday. Officials are scrambling to determine whether a similar error is buried in the computer files of two other spacecraft currently cruising through space: the Mars Polar Lander, scheduled to hit the Martian surface on Dec. 3, and the Stardust craft bound for a comet. Baffled NASA officials said they were struggling to figure out how this happened, and bracing themselves for an onslaught of derision. "Our inability to recognize and correct this simple error has had major implications," said JPL director Edward Stone. The initial error was made by contractor Lockheed Martin Astronautics in Colorado, which, like the rest of the U.S. launch industry, traditionally uses English measurements. The JPL navigation team, on the other hand, uses metric measurements in the complex business of figuring out a spacecraft's position relative to moving planets and keeping it on course. The contractor, by agreement, is supposed to convert its measurements to metrics. © Copyright 1999 The Washington Post Company  Dental Materials Research Dental schools Basic science departments Manufacturers laboratories Clinical research "Basic research leads to new knowledge. It provides scientific capital. It creates the fund from which the practical applications of knowledge must be drawn." Vannevar Bush Conventional research Bonding to dentin Bond strength test Universal testing system  Advanced Testing of Properties Atomic force microscope Scanning electron microscope Unpolished Polished Polished resin composite with 6 μm with 0.25 μm diamond diamond Required Reading The Future Need for Dental Biomaterials Pages 12-13 of the textbook Any questions?