The use of NaOCl in combination with CHX produces cytotoxic product.

OBJECTIVES: The combination of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) yields a "precipitate potentially toxic" (PPT). The aim of this study was to evaluate the tissue response to implanted polyethylene tubes filled with PPT-soaked fibrin sponge. METHODS: Forty rats received four polyethylene tubes each; each tube was filled with fibrin sponge soaked by 2.5 % NaOCl, 2.0 % CHX, PPT (2.5 % NaOCl plus 2.0 % CHX), or not soaked (control). The observation time points were 7, 15, 30, 60, and 90 days. At each time point, eight animals were killed, and the tubes and surrounding tissues were removed, fixed, and prepared for light microscopic analysis by performing glycol methacrylate embedding, serial cutting into 3-µm sections, and hematoxylin-eosin staining. Qualitative and quantitative evaluations of the reactions were performed. Results were statistically analyzed by Kruskal-Wallis test (p < 0.05). RESULTS: All chemical solutions caused moderate reactions at 7 days. On day 30, PPT group was more cytotoxic than the control group and the CHX group (p < 0.05). On days 15 and 60, PPT group was more cytotoxic than the control group (p < 0.05). On day 90, there was no statistically significant difference between the different groups. CONCLUSION: PPT is more cytotoxic than NaOCl and CHX alone, particularly in the short term. CLINICAL SIGNIFICANCE: Protocols which suggest the use of CHX and NaOCl must be revised because this mixture produces cytotoxic product.

Pulpal and periodontal diseases increase triglyceride levels in diabetic rats.

OBJECTIVES: The aim of this study was to evaluate triglyceride and cholesterol levels in diabetic rats and their relationship with pulpal and periodontal diseases. METHODS: Eighty male rats (Rattus norvegicus albinus, Wistar) were divided into the following eight groups comprising ten animals each: normal rats (G1), rats with pulpal diseases (G2), rats with periodontal diseases (G3), rats with both pulpal and periodontal diseases (G4), diabetic rats (G5), diabetic rats with pulpal diseases (G6), diabetic rats with periodontal diseases (G7), and diabetic rats with both periodontal and pulpal diseases (G8). Diabetes was induced by injecting streptozotocin, periapical lesions were induced by exposing pulpal tissue to the oral environment, and periodontal diseases were induced by periodontal ligature. The animals were killed after 30 days, and lipid profile was enzymatically measured using Trinder's method. The total assessed values were statistically analyzed by analysis of variance and Tukey test (p < 0.05). RESULTS: The triglyceride levels of diabetic rats with periodontal disease and of diabetic rats with both periodontal and pulpal diseases were significantly higher than those of normal rats and nondiabetic group rats, respectively. The differences in the cholesterol levels among the groups were not significant. CONCLUSIONS: We found that the association of pulpal and periodontal diseases with diabetes increased triglyceride levels in rats. CLINICAL SIGNIFICANCE: Changes in lipid profile may be related to the presence of oral infections and diabetes.

Blood profile and histology in oral infections associated with diabetes.

INTRODUCTION: We aimed to investigate the relationship between blood profile and histologic findings in both apical periodontitis (AP) and periodontal disease (PD) associated with diabetes. METHODS: Wistar rats (N = 80) were assigned to the following 8 groups: control, AP, PD, AP associated with PD, diabetes, diabetes with AP, diabetes with PD, and diabetes with AP and PD. Diabetes mellitus (DM) was induced with streptozotocin, AP was induced by exposure to the oral environment, and PD was induced using periodontal ligature. After 30 days, blood samples were collected, and the rats were euthanized. Subsequently, the maxillae were processed for light microscopy. Hematologic examinations were conducted to determine the total number of erythrocytes and leukocytes, erythrocyte constant, and blood glucose level. One-way analysis of variance and Kruskal-Wallis tests were used for statistical analysis, and the significance was set at P < .05. RESULTS: A significant correlation was found between the histologic findings and blood parameters. CONCLUSIONS: In conclusion, diabetes accelerated the development and progression of AP and PD in the rats and caused an increase in the average erythrocyte volume as well as the leukocyte and neutrophil counts. Oral infections increase the total number of leukocytes, the number of neutrophils and lymphocytes, and blood glucose concentrations in DM rats.

The number of bleaching sessions influences pulp tissue damage in rat teeth.

INTRODUCTION: Hydrogen peroxide tooth bleaching is claimed to cause alterations in dental tissue structures. This study investigated the influence of the number of bleaching sessions on pulp tissue in rats. METHODS: Male Wistar rats were studied in 5 groups (groups 1S-5S) of 10 each, which differed by the number (1-5) of bleaching sessions. In each session, the animals were anesthetized, and 35% hydrogen peroxide gel was applied to 3 upper right molars. Two days after the experimental period, the animals were killed, and their jaws were processed for light microscope evaluation. Pulp tissue reactions were scored as follows: 1, no or few inflammatory cells and no reaction; 2, <25 cells and a mild reaction; 3, between 25 and 125 cells and a moderate reaction; and 4, 125 or more cells and a severe reaction. Results from each experimental group were compared between groups and within groups to the corresponding unbleached upper left molars and analyzed for significant differences using the Kruskal-Wallis test (P < .05). RESULTS: All tissue sections showed significant bleaching-induced changes in the dental pulp. After 1 bleaching session, necrotic tissue in the pulp horns and underlying inflammatory changes were observed. The extent and intensity of these changes increased with the number of bleaching sessions. After 5 sessions, the changes included necrotic areas in the pulp tissue involving the second third of the radicular pulp and intense inflammation in the apical third. CONCLUSIONS: The number of bleaching sessions directly influenced the extent of pulp damage.