The Influence of Dentin Age and the Presence of Cracks in Removal of the Root Filling Material.

INTRODUCTION: This study evaluated the removal of the filling material during endodontic retreatment considering the presence of cracks and the dentin age. METHODS AND MATERIALS: A total of 20 freshly extracted single-rooted teeth were categorized into the following two groups according to the age of the patients: Group Young (Y; aged 18-30 years) and Group Old (O; aged ≥60 years). Each tooth specimen was scanned by microcomputed tomography (micro-CT) subsequently after endodontic retreatment with the Reciproc instruments (REC). The images were analyzed for differences in the volume of dentin cracks and the presence of the filling material in the middle and apical thirds of the teeth among the groups, according to the dentin age. RESULTS: The micro-CT images showed that after retreatment, there were more cracks in the old root dentin than those in the young root dentin, although the difference was not statistically significant (P>0.05). The greatest reduction in the filling material was achieved when the old root dentin with cracks was retreated when compared with that of the young root dentin with cracks, but the difference was not statistically significant (P>0.05). CONCLUSION: The dentinal age and the presence of cracks were not found to be relevant factors for the removal of the filling material.

Evaluation of inflammatory response of EDTA, EDTA-T, and citric acid in animal model.

INTRODUCTION: The biocompatibility of chelating agents and organic acids have been explained by a variety of methods, and suggestions for use have been based more on clinical observations and physicochemical properties than on biological aspects. The present study aimed to evaluate the inflammatory response of 17% EDTA, 17% EDTA-T, and 10% citric acid in bony defect created in rat jaws. METHODS: Mandibular through and through critical size defects were created bilaterally in 60 rats. Fibrinol (Baldacchi SA, São Paulo, Brazil), a cube-shaped compound of absorbable bovine fibrin foam and sodium chloride, was used as a carrier of the substances. One side had received Fibrinol (control), whereas the opposite side had received Fibrinol soaked with each substance on the 1st, on the 7th, on the 14th, and on the 28th day (n=5 for each day). Hemijaws were prepared for light microscopy, and samples were stained with hematoxylin and eosin. Digitized images were analyzed with a morphometric software (ImageJ; National Institute of Mental Health, Bethesda, MD). to obtain the number of inflammatory cells per area. Comparisons were performed by using the Kruskal-Wallis test (p=0.05). RESULTS: For all days, 10% citric acid and 17% EDTA-T showed, respectively, the lowest and highest number of inflammatory cells per area. All tested substances and controls showed the highest inflammatory cell response on the 14th day. CONCLUSION: Among the tested substances, 10% citric acid proved to be the less aggressive tested solution at 14 days. At 28 days, all solutions were similar, but EDTA-T kept showing the higher number of inflammatory cells.

In vitro evaluation of macrophage viability after incubation in orange oil, eucalyptol, and chloroform.

OBJECTIVE: The aim of this study was to evaluate the cytotoxicity of orange oil, eucalyptol, and chloroform in a cell culture assay by using peritoneal macrophages from Swiss mice. STUDY DESIGN: Control (Dulbecco's modified Eagle's medium [DMEM] plus 1.25% ethyl alcohol) and experimental (orange oil, eucalyptol, and chloroform) groups were studied. Solvents used were tested at 0.025% and 0.050% concentrations in DMEM plus 1.25% ethyl alcohol. RESULTS: Orange oil, eucalyptol, and chloroform were all cytotoxic in comparison to the control group (P < .001). Orange oil showed the least cytotoxicity (P < .001). No significant differences were observed regarding cell viability when comparing the eucalyptol and chloroform groups (P < .05). There were significant differences in the cytotoxicity of eucalyptol and chloroform with an increase in concentration (P < .0001). Nevertheless, this difference was not significant in the orange oil group (P < .05). CONCLUSION: Orange oil was less cytotoxic than eucalyptol and chloroform.