Cytotoxicity of four categories of dental cements.

Polymerization shrinkage kinetics of dimethacrylate resin-cements.

Tooth slice organ culture and established cell line culture models for cytotoxicity assessment of dental materials

Today, resin-based composites represent one of the most important and most widely used groups of materials in dental practice. Consequently, a large number of products are available on the market. In this chapter, information on the composition, setting reaction and release of substances is provided as the basis for a detailed review of the local and systemic toxicity of resin-based composites. Allergic reaction and topics like estrogenic activity are addressed, which are presently discussed in the media and within government agencies. Information is provided on how to approach and treat patients who claim symptoms deriving from the placement of resin-based composites. The risk of pulpal damage, including postoperative sensitivities and methods to prevent such reactions from occurring, are delineated.

Resin-Based Composites

The agar overlay method was modified and employed in this study to quantitatively evaluate the cytotoxicity of dental materials. The area of fibroblasts affected by the release of toxic substances from tested materials was determined with an image analysis system in order to compare the relative cytotoxicity of amalgams and composite resins. The cytotoxicity of amalgams decreased by 50% or more with aging time. Zinc appeared to be the major contributor to the cytotoxicity of amalgams. The cytotoxicity of chemically cured composite resins was also reduced with hardening time. However, even after 24 hours, the cytotoxicity of all chemically cured composite resins was still apparent. The cytotoxicity of light cured composite resins was dramatically reduced after illumination with the light source. The cytotoxicity of both amalgams and composite resins was strongly dependent upon their hardening process, since aging and curing produced a more stable material which was less likely to release toxic substances into the culture medium. The technique developed in the present study for measuring the area of affected cells to quantitatively evaluate the cytotoxicity of dental materials is simple and reproducible.

Kaga M

Papers

Quantitative evaluation by measuring affected area for cytotoxicity of dental materials