Evaluation of the Genotoxicity of Endodontic Materials for Deciduous Teeth Using the Comet Assay

Nilton Cesar Nogueira Dos Santos,Matheus Melo Pithon,João Pedro Pedrosa Cruz,Bruno Marques Soares,Eneida Moraes De Marcílio Cerqueira,Cláudia Do Ó Pessoa,Livia Maria Andrade De Freitas,Maria Emília Santos Pereira Ramos

doi:10.1590/pboci.2021.062

Abstract

Objective: To evaluate genotoxicity of zinc oxide, P. A. calcium hydroxide, mineral trioxide aggregate and an iodoform paste using comet assay on human lymphocytes. Material and Methods: Two positive controls were used: methyl-methanesulfonate for the P.A. calcium hydroxide and mineral trioxide aggregate; and doxorubicin for the iodoform paste and zinc oxide. There were also two negative controls: distilled water for the P.A. calcium hydroxide and mineral trioxide aggregate; and DMSO for the iodoform paste and zinc oxide. Comets were identified using fluorescence microscopy and 100 of them were counted on each of the three slides analyzed per drug test. A damage index was established, taking into consideration the score pattern that had previously been determined from the size and intensity of the comet tail. Analysis of variance, followed by Tukey’s test, was used to compare the means of the DNA damage indices. Results: The DNA damage index observed for mineral trioxide aggregate (7.08 to 8.58) and P.A. calcium hydroxide (6.50 to 8.33), which were similar to negative control index. On the other hand, damage index for zinc oxide (104.7 to 218.50) and iodoform paste (115.7 to 210.7) were similar to positive control index. Conclusion: Iodoform paste and zinc oxide showed genotoxicity at all concentrations used.

Highlights

Dental caries and dentoalveolar trauma can cause irreversible alterations to dental pulp, culminating in necrosis, which can lead to teeth loss
A. calcium hydroxide, mineral trioxide aggregate and an iodoform paste using comet assay on human lymphocytes
The DNA damage index observed for mineral trioxide aggregate (7.08 to 8.58) and P.A. calcium hydroxide (6.50 to 8.33), which were similar to negative control index

Summary

Introduction

Dental caries and dentoalveolar trauma can cause irreversible alterations to dental pulp, culminating in necrosis, which can lead to teeth loss. In view of these changes, pulp therapy is the last resource for deciduous tooth preservation under functional conditions until physiological exfoliation. Pulp therapy of primary teeth is used for many decades, there is no consensus on the filling paste that could be considered as an ideal material. The paste must be resorbable, provide radiopacity, not interfere with the successor tooth germ's development, and be biocompatible with periapical tissue [1,3,4,5]. It is expected that an ideal filling material does not induce genotoxic and/or cytotoxic effects, and there’s no consensus on such effects in the studies [6,7,8,9,10,11,12,13,14,15,16,17]

Methods

Results

Discussion

Conclusion