Dental restorative materials

Technology Assessment Conference Statement on Effects and Side Effects of Dental Restorative Materials, National Institute of Dental Research, NIH, Bethesda, Md., Aug. 26-29,1991. 

To achieve such compatibility the primary requisite is that the restorative adheres to tooth material. This concept of adhesion is hardly to be foimd in the literature of the 1920s and 1930s. For that reason we find no attempt at developing tooth adhesives in that period. Adhesion was, apparently, only recognized as a desirable property in the 1950s. It seems for some reason to be associated with the introduction of simple resins as dental restorative materials. Although they were not a great success, attempts were made to bond them to tooth material. 

Goldman, M. (1985). Fracture properties of composite and glass ionomer dental restorative materials. Journal of Biomedical Materials Research, 19, 771-83. 

Tobias, R. S., Browne, R. M. Wilson, C. A. (1985). Antibacterial activity of dental restorative materials. International Dental Research, 18, 161-71. 

Hannah, C. M. Smith, D. C. (1971). Tensile strengths of selected dental restorative materials. Journal of Prosthetic Dentistry, 26, 314-23. 

McComb, D. (1982). Tissue reactions to silicate, silicophosphate, glass ionomer cements and restorative materials. In Smith, D. C. Williams, D. F. (eds.) Biocompatibility of Dental Materials. Volume III. Biocompatibility of Dental Restorative Materials, Chapter 4. Boca Raton CRC Press Inc. 

Matsui, A., Buonocore, M. G., Sayegh, F. Yamaki, M. (1967). Reactions to implants of conventional and new dental restorative materials. Journal of Dentistry for Children, 34, 316-22. 

Updegraff, D. M., Change, R. W. H. Joos, R. W. (1971). Antibacterial activity of dental restorative materials. Journal of Dental Research, 50, 382-7. 

A.J. Preston, E.A. Agalamany, S.M. Fligham, L.FI. Mair, The recharge of aesthetic dental restorative materials with fluoride in vitro—Two year results. Dent. Mater. 19 (2003) 32-37. 

F.C. Eichmiller, W.A. Matjenfoff, Fluoride-releasing dental restorative materials, Oper. Dent. 23 (1998) 213-218. 

Polymers used as dental materials must meet several stringent requirements. Dental restorative materials must be nontoxic, have aesthetic appearance, and good adhesive and mechanical properties. In addition, these materials must exhibit long term stability in the presence of water, enzymes, and various oral fluids, and withstand thermal and load cycles. Finally, a desirable dental restorative materia] should be convenient to work with at the time of application. 

Dental amalgams have been used as dental restorative materials in the United States for the past 160 years and are currently used in approximately 75% of all direct restorations [1]. Of the direct posterior permanent fillings placed in the United States by private practice dentists, 88 % are dental amalgam [2], This material has been considered the preferred material for several reasons. The first is amalgam s history of long term clinical success [3]. The dental amalgam is also easy to place with relatively little technique sensitivity. Dental amalgam is inexpensive to the patient when compared with currently competitive materials... 

The demand for aesthetic dental restorative materials continues to increase and may be the most important criterion for the promising future of the aesthetic polymeric composite resins. As the physical, mechanical, and wear properties of these materials improve, their use in dentistry will expand. The acid-etching of dental enamel [20] and dentin bonding procedures [21] will allow for conservative cavity preparation and the preservation of healthy tooth structure. 

Draughn RA (1985) in Vanherle G, Smith DC (eds) International symposium on posterior composite resin dental restorative materials, 3M Corporation, 299... 

Based upon the limited wear-rate and thermal conductivity data we have, then, it is not surprising that most commercial dental materials are ceramic-based. Some of the commercially available dental restorative materials are listed in Table 8.15. There have been a nnmber of recent wear rate stndies involving these, and other, dental materials [8-12], two of which are of particnlar importance to this case study. In the first study, Al-Hiyasat et al., [8] studied the wear rate of enamel against four dental... 

Table 8.15 Some Commercially Available Dental Restorative Materials...

Figure 8.18 Wear rates for enamel and three dental restoration materials at different loads and pH 1.2. Reprinted from M. Shabanian and L. C. Richards, In vitro wear rates of materials under different loads and varying pH, 7. Prosth. Dent., 87(6), 655. Copyright 2002, with permission from Elsevier.

Work in groups of three. The raw data from reference 8 for the wear rate of enamel after 5000, 15,000, and 20,000 cycles in an experimental device against four dental restorative materials are presented in the table below. 

The results of Figure 8.18 show that most commercially available dental restorative materials have wear rates that are lower (better) than human enamel. All of the materials listed in Table 8.15 have nominal colors equivalent to that of human teeth and are of acceptable biocompatibility. In particular, glass ionomer ceramics have become increasingly popular due to their favorable adhesion to dental tissues, fluoride release, and biocompatibility. 

Polymerizable oligomers, (III), were prepared by Shuhua et al. (4) and used as a component in dental restorative materials. 

Addition polymers consisting of pentaerythritol triallyl ether, (I), and pentaer-ythritolntetrakis(3-mercaptopropionate), (H), were previously prepared by the authors (2) and used in dental restorative materials. Other photosensitive addition polymer mixtures using triallyl l,3,5-triazine-2,4,6-trione, ( ), are also described by the authors (3). 

Cold vapour was generated in acid media to relate the amount of Hg in blood cells with the use of dental restorative material made with amalgams. Robustness of the methodology was studied using fractional factorial designs... 

P.D. Williams and D.C. Smith, Measurement of the tensile strength of dental restorative materials by use of a diametral compressive strength test, J. Dent. Res., 50 (1971) 436-442. 

Wennberg A, Mjor A, Hensten-Petterson A. Biological evaluation of dental restorative materials-a comparison of different test methods. J. Biomed. Mat. Res. 1983 17 23-36. 

Bis(choromethyl) ether (BCME) is primarily used in the synthesis of polymers, ion exchange resins, and plastics. It used as a chemical intermediate for the synthesis of other complex organic alkyl compounds as well as chloromethylating (cross-linking) reaction mixture in anion exchange resins. It is used as a dental restorative material. 

Hannig M Transmission electron microscopic study of in vivo pellicle formation on dental restorative materials. Eur J Oral Sci 1997 105 422-433. 

For testing dental restorative materials, many regimes exist that use similar principles to those described for assessing toothpaste abrasivity. These tests may be conducted under conditions of two-body or three-body wear [25], i.e. focussing either on attrition or abrasion. Two-body tests for restorative materials either use human enamel [26] or a hard material, such as alumina [27] or steatite [28], as the abrader. For three-body tests, an abrasive medium, such as toothpaste slurry [29, 30], or an abrasive food, such as rice or millet seeds [31,32], is typically used. These test methods are usually not truly representative of the oral environment rather, they are designed to assess the wear resistance of restorative materials under extreme conditions. 

McCabe JF, Molyvda S, Rolland SL, Rusby S, Carrick TE Two- and three-body wear of dental restorative materials. Int Dent J 2002 52 406 116. 

Willems G, Celis JP, Lambrechts P, Braem M, Vanherle G Hardness and Young s modulus determined by nanoindentation technique of filler particles of dental restorative materials compared with human enamel. J Biomed Mater Res 1993 27 747-755. 

H. Engqvist et al., Transmittance of a bioceramic dental restorative material based on calcium aluminate. J. Biomed. Mater. Res. B-Appl. Biomater. 69B(1), 94-98 (2004). 

---