Evaluation of the genotoxic effects of formocresol application in vital pulp therapy of primary teeth: a clinical study and meta-analysis.

OBJECTIVES: This in vivo research investigated whether pulp treatments using formocresol for 7 days would cause mutagenic changes in children's lymphocytes. MATERIALS AND METHODS: The mutagenicity was tested in lymphocyte cultures established from the peripheral blood of children living in Brazil. The samples consisted of 2000 cells from teeth undergoing formocresol pulpotomies in which the formocresol pellet was sealed in the primary tooth for 7 days. It was removed on the seventh day, the base was placed, and the tooth was restored. Two venous blood samples (6-8 ml) were collected from each child; the first was prior to pulp therapy, and the second was 7 days later. Two thousand metaphases were analyzed. The level of significance adopted for the statistics was P < 0.05, and a random effects meta-analysis was performed combining this and two previous studies. RESULTS: There was no significant difference found in the metaphase analysis between the blood samples taken before and after the pulpotomy treatment (Wilcoxon signed rank test); however, the meta-analysis showed a significant difference between the combined studies. CONCLUSIONS: This study did not reveal any mutagenic effects, but based on the combined meta-analysis, we recommend the careful use of formocresol. CLINICAL RELEVANCE: This research helps to bring scientific evidence of the safe use of formocresol in deciduous pulpotomy treatments.