Long‐term cytotoxicity of resin‐based dental restorative materials

Abstract

SUMMARYSUMMARY Highly ®lled composites, Ormocers (organically modi®ed ceramics) and`smart' materials have been developed to overcome the polymerization shrinkage problems of conventional composite materials. The purpose of the current study was to investigate the effect of longer-term (up to 8 weeks) ageing of these resin-based dental restorative materials and determine the effect of post-curing on cytotoxicity. Twelve discs of each material (Colombus/IDR, De®nite/Degussa, Ariston pHc/Vivadent) were either light-cured (Lc) or light-cured and postcured (Pc). For cytotoxicity testing, the discs were placed in contact with cell culture medium (DMEM) and incubated at 37°C. Extracts from composite materials were collected after 24 h and weekly over a time period of 8 weeks. Cytotoxicity of the eluates to cultured ®broblasts (Balb/c3T3) were measured by the succinic dehydrogenase (SDH) activity (MTT assay) and the results expressed in percentage of negative controls (Te¯on discs). The results showed that ageing signi®cantly in¯uenced the cytotoxicity of the materials. Except for Ariston pHc, materials were less cytotoxic after 8 weeks of ageing than they were in early intervals and post-curing was not generally useful in reducing cytotoxicity. The Ariston pHc was initially moderately toxic, but then become highly cytotoxic for 5 weeks before returning to initial levels. The current study demonstrated the importance of assessing the cytotoxicity of resin composite materials at multiple times.

Cytotoxicity of Composite Materials Polymerized with LED Curing Units

“…[10][11][12][13] However, it is difficult or even impossible to compare the results of different cell culture experiments, because of the many variations in experimental conditions, such as cell type, cell material contact method and exposure time. Although both techniques were used in this experiment, trypan blue exclusion assay and combined acridine orange/ethidium bromide dying, which were used in the cytotoxicity evaluation results, indicated that the number of cells undergoing cell death by necrosis and apoptosis was always higher compared to those incorporating trypan blue.…”

“…[10][11][12][13] The toxicity of a dental material can be evaluated by an in vitro test and through clinical studies in humans. In vitro studies are primarily performed to evaluate the cytotoxicity (cell damage) or genotoxicity (specific DNA damage or chromosomal aberration) of a dental material.…”

Contemporary Methacrylate Resin–based Root Canal Sealers Exhibit Different Degrees of Ex Vivo Cytotoxicity When Cured in Their Self-cured Mode

“…Casual interpretation of the cytotoxicity results of sealer composites polymerized under different/undefined curing conditions may lead to erroneous conclusions (23). It is also anticipated that longer periods will be required (24) to evaluate the cytotoxic responses of sealers that are polymerized in the self-cured mode (25) because the reduced degree of conversion (26) may result in the slow release of toxic, incompletely polymerized resinous components (27). Thus, the objective of this study was to examine the longitudinal cytotoxic behavior of four contemporary methacrylate resin-based sealers that were polymerized in the self-cured mode without adjunctive light curing to enhance the degree of conversion of their resinous components.…”

Heat curing of UTMA-based hybrid resin: effects on the degree of conversion and cytotoxicity

“…In addition, some long-term cytotoxicity studies have been carried out for dental restorative materials containing different dimethacrylates that found that materials became less cytotoxic during aging than they had been in the initial situation. 35 However, as already pointed out in the Introduction, almost all scientific papers published to date have considered dental methacrylate and acrylate composites to have some cytotoxic effects. [5][6][7][8]28,[36][37][38][39] The hybrid resin Estenia used in this study as a newgeneration composite resin has an ultrahigh filler content (92 weight %).…”