Local and Systemic Responses To Dental Composites and Glass Ionomers

Abstract

For many years, the dental profession worked mainly with rather inert restorative materials that had a limited contact with vital tissue, and the opportunity for local and systemic complications was minimal. However, conditions have changed in recent years where the two leading non-mercury-containing materials, resin composites and glass-ionomer cements, are chemically active compounds and can have detrimental effects on pulp tissue. With the advent of light-curing techniques with incremental layering, resin component formulae that were formerly found to be quite irritating to the pulp have become less so with the elimination of the need for matrices and pressure for good adaptation to be gained. As experience revealed the deficiencies and dangers of ultraviolet-light-curing techniques, visible-light-curing systems were developed that provided greater depth of cure, a higher degree of polymerization with less shrinkage with incremental layers, and less porosity. When glass-ionomer cements (GICs) were first introduced, with just one acid (polyacrylic), pulpal responses were classified as bland. With the addition of many more acids to enhance certain characteristics and reduce the setting time, GICs have become more irritating, especially when used as luting agents in areas where the remaining dentin thickness is 0.5 mm or less. Gold foil and amalgam are inert and innocuous restorative materials but require pressure for condensation which creates an exaggerated inflammatory response. This presentation emphasizes the pulpal responses and side-effects of these non-mercury-containing restorative materials and how to keep them within an acceptable range of biocompatibility. Despite the lack of any substantial appearance of soft tissue and systemic responses to resin composites and GICs, the results of a survey of recent literature are included.

Biocompatibility Evaluation of Dental Luting Cements Using Cytokine Released from Human Oral Fibroblasts and Keratinocytes

“…It has been reported that some dental luting cements are cytotoxic to the dental pulp cells and cause hypersensitivity in animal studies [7]. There have also been numerous biocompatibility studies of dental luting cement using cell culture techniques with various cells, such as gingival fibroblasts [8], dental pulp cells [9,10] and mouse fibroblasts [11].…”

Cytotoxicity of 35 dental resin composite monomers/additives in permanent 3T3 and three human primary fibroblast cultures

“…Stanley reported that the degree of pulpal alterations increases in deeper cavities. 7 Furthermore, it has been determined in vivo that several composite components such as dibenzoyl-peroxide or 2-hydroxy-4-methoxybenzophenone may cause pulp inflammations if protective cavity liners are not used. 8 Genotoxic, mutagenic, or estrogenic effects due to extracts from resin composites, light-curing glassionomer cements, dentin bonding agents, and various composite ingredients have been found in several in vitro studies.…”

Biocompatibility of Resin-Modified Filling Materials

“…It was found that the degree of pulpal alterations induced by those components correlates with cavity depth (Stanley, 1992). Two substances (dibenzoyl peroxide, 2-hydroxy-4-methoxy-benzophenone) caused pulpal inflammation in teeth of monkeys when applied to cavities without a protective lining (Stanley eta (Ferracane, 1995).…”