ABSTRACT
Objective: The aim of the study was to assess, in vitro, the influence on cytotoxicity of heat treatment applied before photopolymerization,
while mixing three self-adhesive resin cements, in an NIH/3T3 fibroblast cell culture,
based on cell viability measures. Methods: Samples were divided into three groups: (1) no heat treatment while mixing (control),
(2) 37°C, and (3) 60°C heat treatment while mixing. Cements were light-cured immediately
after mixing and immersed in Dulbecco's Modified Eagle Media for the extraction of
possibly uncured products after 24 h and 7 days. Cultures contained 0.5 mL of NIH/3T3
fibroblasts per well at a concentration of 0.4 × 105 cells/mL and specific extracts for each sample. Statistical Analysis Used: Data were statistically analyzed with ANOVA and post hoc Student–Newman–Keuls (significance of 5%). Results: Cement cytotoxicity increased with time, as shown by the higher values observed at
7 days. There was a slight difference in intragroup cytotoxicity levels between 24
h and 7 days. Heat treatment at 60°C was associated with a major decrease in cytotoxicity
levels in all three groups, both at 24 h and at 7 days, with no differences among
the cements. Conclusions: Heat treatment at 60°C should be considered as a strategy to reduce cytotoxicity
of self-adhesive resin cements, as evidenced by the results observed at 24 h and 7
days of analysis.
Key words:
Biocompatibility - dental materials - toxic substances
