Dental restorative materials have the potential both for local toxicity and undesirable systemic side effects through the release of components, reaction intermediates, or degradative products into the biophase. Resin composites are a class of dental restoratives which are now very widely used. There is no evidence that any adverse systematic effects are associated with the resins. However, local effects on dental pulp, including pulpal pain and death, have been widely reported. We seek to clarify whether chemical release from the materials may contribute to these local effects.
The specific aims i n the project period are to quantify the release of resin composite components from a range of materials, and to seek correlation between the amounts released and the toxic effects of individual components and of aqueous eluates of whole resin samples. High performance liquid chromatography will be used to quantify the release. Variations in the pattern of release of these and other components both directly into aqueous solution and through dentin will then be determined for a number of clinically relevant variables. Concentrations of components within dentin immediately adjacent to the odontoblast layer will also be determined in teeth restored with resin composite, both in vitro and in vivo. The longterm goal is to improve safety and effectiveness of dental restorative materials. The proposed work will provide data directly relevant to the future formulation and to the clinical use of dental resin composites. It will also add to concepts and methods which will be applied to the study of other restorative materials as they are developed.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE010331-02
Application #
2131252
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Project Start
1993-09-01
Project End
1996-08-31
Budget Start
1994-09-01
Budget End
1995-08-31
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Dentistry
Type
Schools of Dentistry
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
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Paranjpe, Avina; Cacalano, Nicholas A; Hume, Wyatt R et al. (2007) N-acetylcysteine protects dental pulp stromal cells from HEMA-induced apoptosis by inducing differentiation of the cells. Free Radic Biol Med 43:1394-408
Paranjpe, A; Bordador, L C F; Wang, M-Y et al. (2005) Resin monomer 2-hydroxyethyl methacrylate (HEMA) is a potent inducer of apoptotic cell death in human and mouse cells. J Dent Res 84:172-7
Reichl, F X; Durner, J; Hickel, R et al. (2001) Distribution and excretion of TEGDMA in guinea pigs and mice. J Dent Res 80:1412-5
Hamid, A; Okamoto, A; Iwaku, M et al. (1998) Component release from light-activated glass ionomer and compomer cements. J Oral Rehabil 25:94-9
Hamid, A; Hume, W R (1997) The effect of dentine thickness on diffusion of resin monomers in vitro. J Oral Rehabil 24:20-5
Hamid, A; Hume, W R (1997) A study of component release from resin pit and fissure sealants in vitro. Dent Mater 13:98-102
Hamid, A; Hume, W R (1997) Diffusion of resin monomers through human carious dentin in vitro. Endod Dent Traumatol 13:1-5
Gerzina, T M; Hume, W R (1996) Diffusion of monomers from bonding resin-resin composite combinations through dentine in vitro. J Dent 24:125-8
Hamid, A; Sutton, W; Hume, W R (1996) Variation in phosphoric acid concentration and treatment time and HEMA diffusion through dentin. Am J Dent 9:211-4

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