Dental materials standards

The formulation of new specifications and the revision or reaffirmation of existing specifications are the responsibiUty of American National Standards Committee MD156 of ANSI for Dental Materials and Devices. This committee coordinates its work closely with Technical Committee 106,... 

A primary responsibility of the Food and Drug Administration (FDA) is the enforcement of the Federal Food, Dmg, and Cosmetic Act of 1938 and its various amendments, eg. May, 1976, in which dental materials, instmments, and equipment are included. Premarketing clearance requirements apply for estabhshing the safety and effectiveness of new products. There is a close Haison between the FDA and the ADA standards and certification programs. 

ANSI/ADA specification no. 14 provides a requirement for removable partial dentures of a combined minimum of 85% by weight of chromium, cobalt, and nickel or, for alloys failing to meet that minimum, at least 20% chromium. Bio-compatibiUty is demonstrated by passing the pertinent criteria of ANSI/ADA specification no. 41, Recommended Standard Practices for Biological Evaluation of Dental Materials. 

Polyelectrolyte-based dental cements or restorative materials include zinc polycarboxylates, glass ionomers, a variety of organic polyelectrolyte adhesives as well as alginate-based impression materials. Dental cements are primarily used as luting (cementing) agents for restorations or orthodontic bands, as thermal insulators under metallic restorations, and as sealents for root canals, pits and fissures. They are also sometimes used as temporary or permanent (anterior) restorations. For further introduction to dental materials the reader is referred to standard texts [122,123]. 

Abrasives - [ALUMINUMCOMPOUNDS - ALUMINIUMOXIDE(ALUMINA) - CALCINED,TABULAR, AND ALUMINATE CEMENTS] (Vol 2) -m automobile polishes [POLISITES] (Vol 19) -for dental materials [DENTAL MATERIALS] (Vol 7) -for enameling [ENAMELS, PORCELAIN OR VITREOUS] (Vol 9) -nitrides as [NITRIDES] (Vol 17) -particle shape classification m [SIZE MEASUREMENT OF PARTICLES] (Vol 22) -phenolic resins PHENOLIC RESINS] (Vol 18) -PVB m [VINYL POLYMERS - VINYL ACETAL POLYMERS] (Vol 24) -silicon carbide m [CARBIDES - SILICONCARBIDE] (Vol 4) -standards and specification [MATERIALS STANDARDS AND SPECIFICATIONS] (Vol 16) -use m cosmetics [COSMETICS] (Vol 7) -use m electroplating cleaning pLECTROPLATING] (Vol 9)... 

W. Souder and G.C. Paffenbarger, Physical Properties of Dental Materials (Natl Bur. Standards (U.S.), Gaithersburg, MD, 1942), Circ. No. C433. 

Ideally, materials for medical and paramedical applications should be tested or evaluated at three level (1) on the ingredients used to make the basic resin, (2) on the final plastic or elastomeric material, and (3) on the final device. Organizations such as the Association for the Advancement of Medical Instrumentation, the U.S.A. Standard Institute, and the American Society for Testing and Materials (F4 Committee) have developed toxicity testing programs for materials used in medical apphcations. The American Dental Association has recommended standard procedures for biological evaluation of dental materials [74]. 

American Dental Association Recommended standard procedures for biological evaluation of dental materials, /. Am. Dent. Assoc., 84, 382, 1972. 

The various dental polymers discussed in this article include impression materials, dentures and denture liners, artificial teeth, crown and bridge materials, mouth protectors, maxillofacial materials, restoratives (consisting of glass polyalkenoates or glass-ionomers and composites), adhesives, and sealants. Specifications and standards for dental materials are also briefly mentioned in the text. 

McLean J.W., "Dental Porcelains" pp. 77-83 in Dental Materials Research, NBS Publication 354. Edited by G. Dickson and JM Cassels. National Bureau of Standards, Washington, DC, 1972. 

A number of important characteristics must be taken into consideration in addition to the efficacy of the products antimicrobial treatment. Biocompatibility is one of those characteristics. According to the International Organization for Standardization (ISO) 10993-1, Biological Testing of Medical and Dental Materials and Devices, all device materials must undergo cytotoxicity, sensitization and irritation testing as a minimum. 

Dental investments are comprised of refractory materials capable of withstanding elevated temperatures. They are used as casting investments and model investments. The compressive strengths, according to International Standards, of the investments and die materials are shown in Table 3. 

The American Society for Testing and Materials (ASTM) F4 Committee on Medical Materials and Devices has developed specifications for chemical composition, mechanical properties, and other factors. Standard test methods also are available from ASTM, 1916 Race Street, Philadelphia. The quaHty of castings is important for dental implants, and standards to define this would be useful. 

Paffenbarger, G. C. (1937). Dental silicate cements. In Judd, D. B. Optical specifications of light scattering materials. Rep>ort No. 1026. Journal of the National Bureau of Standards, 19, 314-16. 

Dental and Medical Materials Group, Polymers Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. 

The dental industry is currently accepting the International Standards Organization (ISO) standard for Polymer-based filling and restorative materials. This standard will require testing of the following properties ... 

From a materials perspective there are two possible reasons why dental enamel shows the large variations in mechanical properties shown in figure 1 firstly, chemical variations in apatite composition and, secondly, changes in enamel structure with position from the occlusal surface to the EDJ. The chemical composition of enamel can be examined with a lateral resolution of 1-10 pm with electron microprobe analysis. Enamel structure can be obtained with SEM. To perform an accurate microprobe analysis, natural and synthetic minerals are used as standards to calibrate the instrument. This is fairly routine for geologists and earth scientists who are able to obtain chemical compositions with an accuracy of <0.1% for a wide range of elements simultaneously (including Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb, Hf, Ta, Pb, Th, U, F and Cl). In enamel only a few of these (Na, Mg, Al, P, K, Ca, Ti, Cl and F) are above the detection limit. The Ti is likely to be an impurity or contaminant rather than a constituent of enamel. This technique does not work for lighter elements such as C, S, O and N which may be present in enamel. 

---