Caracterização físico-química e avaliação in vitro de diferentes formulações da solução de Carnoy sobre substratos ósseo e dentário humanos

Abstract

The maxillofacial region may be affected by a variety of benign lesions (odontogenic and non-odontogenic), but locally invasive. The use of a conservative treatment can generate high rates of recurrence, whereas a radical approach can lead to aesthetic-functional disorders. The use of Carnoy's solution, as a complementary therapy to surgical treatment, has been described in the literature with the purpose of reducing the recurrence rates of these lesions, in addition to minimizing damages resulting from an aggressive surgical treatment. Thus, the present dissertation is constituted by two chapters that aim, respectively: 1) to characterize the physico-chemical and pharmacological properties of Carnoy's solution with and without chloroform; 2) to evaluate in vitro the effect of different formulations of Carnoy's solution on calcified human substrates. As methodological approaches, laboratory studies were performed. In Chapter 1, the physico-chemical / pharmacological properties and behavior of different formulations of the Carnoy solution used in oral and maxillofacial surgery were evaluated through Raman microspectroscopy, UV / Visible spectrophotometry, among others. The results of this study showed that the Carnoy solution presents acidic pH and, when chloroform is present, it becomes slightly more acidic, as well as giving the solution a higher viscosity. When the solutions were not filtered after preparation, precipitation of iron salts occurred after the seventh day when the chloroform was used in its composition. A study was carried out with 36 lower third molars and 18 mandibular bone fragments, both donated and collected from humans, which were divided into three groups: two groups (Group I = Carnoy solution with chloroform, Group II = Carnoy solution without chloroform) and a control group (saline solution). The samples were evaluated through Raman microspectroscopy, Knoop microhardness test and scanning electron microscopy (SEM) with X-ray dispersive energy spectrum (EDX). There was demineralization / degradation of dental structures in both the mineral matrix / organic matrix and carbonate / phosphate (GI and GII, p <0.05) and in the relationship between the collagen subtypes (GII, p <0.05). In the bone tissue degradation was observed by the reduction in the ratio between the collagen subtypes (GI and GII, p <0.05). The presence of chloroform resulted in a statistically significant reduction in the surface microhardness of dental tissue samples (p = 0.036). In the experimental groups, the MEV / EDX showed significant structural changes in all samples analyzed. As conclusions of both studies, we have: (1) Carnoy's solution is a stable solution when stored at room temperature which, in the presence of chloroform, is prone to precipitation of iron salts, increases its viscosity, And its pH becomes slightly more acidic; (2) both formulations of the Carnoy solution (with or without chloroform) exhibit demineralization ability when applied to calcified human tissues, promoting alteration in both the mineral matrix and the organic matrix; (3) the presence of chloroform in Carnoy's solution provides a greater potential for tissue demineralization and penetrability.