The frequency of sodium hypochlorite extrusion during root canal treatment: an observational clinical study.

BACKGROUND: To determine the frequency of sodium hypochlorite (NaOCl) extrusion and evaluate the outcome of the injury. METHODS: A total of 1123 teeth indicated root canal treatment were included. An open-ended needle was used during/after the instrumentation. Acute burning pain during irrigation was considered as NaOCl extrusion. Negative aspiration was applied for patients with extrusion, and appropriate treatment was planned due to the symptoms. The number of patients who experienced extrusion and symptoms were recorded. Analysis of variance (ANOVA), at P < 0.05, was used to compare the data groups. RESULTS: NaOCl extrusion rate was found at 0.89%, and the injury with swelling that differential diagnosis of NaOCl accident caused by extrusion rate was 0.18%. The most common findings besides acute pain, as a sign of extrusion (n = 10), were accompanying apical bleeding (n = 6) and swelling (n = 2). According to the number of visits, a significant correlation was found between the symptoms (P = 0.010). No serious injury such as a neurological sign, tissue necrosis or trismus occurred in any patient. CONCLUSIONS: Demographic characteristics of the patients and preoperative condition of teeth were not related to NaOCl extrusion. The increasing number of visits may affect the probability of an accident. Negative aspiration immediately may be crucial in preventing severe injuries.

Evaluation of antimicrobial and thermal effects of diode laser on root canal dentin.

OBJECTIVES: The aim of this study was to evaluate the antimicrobial effects of diode laser and temperature rise on the root surface during application. MATERIALS AND METHODS: Thirty-six teeth were chemomechanically prepared and irrigated with 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid, and then autoclaved and incubated with a suspension of Enterococcus faecalis. The specimens were randomly divided into three groups (n = 12): Group 1, irradiated by diode laser at 1.2 W; Group 2, irradiated by diode laser at 2 W; and Group 3, irradiated by diode laser at 3 W. The grown bacteria were counted and the mean numbers of the each test tube were determined. The temperature was measured on the external apical third of the root during laser application. The mean values of results for each group were compared using one-way analysis of variance and Tukey test. RESULTS: No significant difference was obtained among the test groups in terms of the colony counts (P > 0.05). According to the temperature changes, there was a significant difference between groups (P < 0.05). Temperature rises were 16.79°C, 10.20°C, and 6.25°C in Group 3, Group 2, and Group 1, respectively. CONCLUSION: Diode laser irradiation with 1.2 W demonstrated comparable performance with 2 W and 3 W power sets for elimination of E. faecalis from root canal with less temperature rise.

Comparison of ProTaper Next and HyFlex instruments on apical debris extrusion in curved canals.

AIM: To evaluate the amount of apically extruded debris after root canal instrumentation with ProTaper Next and HyFlex instruments in curved root canals. METHODOLOGY: Forty extracted mandibular first molar teeth with curved mesial roots and of similar lengths were instrumented using ProTaper Next or HyFlex instruments. The extruded debris was collected into pre-weighed Eppendorf tubes. The tubes were stored in an incubator at 68 °C for 5 days. The tubes were weighed to obtain the final dry weight of the extruded debris. The weight of the extruded debris was determined by subtracting the initial weight from the final weight. Distribution of data was determined by Shapiro-Wilk test. Continuous variables were compared with the Independent Sample t-test or Mann-Whitney U-test. The significance level was set at P = 0.05. RESULTS: Both instruments were associated with apical debris extrusion. The HyFlex group had significantly less debris extrusion than the ProTaper Next group (P = 0.014). CONCLUSION: HyFlex CM was associated with significantly less apical extrusion than ProTaper Next.

Evaluation of the amount of apically extruded debris during retreatment of root canals filled by different obturation techniques.

OBJECTIVE: To evaluate the amount of apically extruded debris during retreatment (with or without solvent) of root canals filled by two obturation techniques. MATERIALS AND METHODS: Forty-eight root canals were prepared using ProTaper Universal F3 and filled with Gutta-percha and AH 26 sealer using single cone or lateral condensation techniques. The root canal fillings were removed using ProTaper Universal Retreatment system with or without solvent, and the canals were further prepared with ProTaper F4. The operating time was measured. The debris extruded was collected into preweighed Eppendorf tubes. The dry weight of the extruded debris was calculated by subtracting the weight of the empty tube from that of the tube containing debris. Statistical analysis was performed with two-way analysis of variance test, with Bonferroni correction at a 95% confidence level. RESULTS: There was no statistically significant difference in the amount of extruded debris between the two obturation techniques (P=0.332). The mean amount of debris was higher in the nonsolvent groups than the solvent groups, particularly with the single cone technique (P=0.013). There was a significant difference between groups with regard to the retreatment time (P<0.001). Gutta-percha removal took less time in the single cone group than in the lateral condensation group (P<0.001). Gutta-percha removal in the nonsolvent groups took significantly less time than that in the solvent groups (P<0.001). CONCLUSIONS: The amounts of apically extruded debris were similar in both obturation techniques. A greater amount of apically extruded debris was observed in the nonsolvent groups than the solvent groups.

Apical extrusion of debris using ProTaper Universal and ProTaper Next rotary systems.

AIM: To assess and compare the amount of extruded debris after canal preparation using ProTaper Universal and ProTaper Next files. METHODOLOGY: Forty extracted mandibular premolars with single canals and of similar lengths were instrumented using the ProTaper Universal F3 or the ProTaper Next X3. The extruded debris during instrumentation was collected into pre-weighed Eppendorf tubes. The tubes were stored in an incubator for 5 days. The tubes were weighed to obtain the final dry weight of the extruded debris. The amount of apically extruded debris was calculated by subtracting the initial weight of the tube from the final weight. The distribution of the data was examined using the Shapiro-Wilks test. Continuous variables were compared with an independent-samples t-test for two groups. RESULTS: All specimens were associated with apical debris extrusion. The ProTaper Universal group produced a significantly greater amount of debris extrusion (P < 0.001). The lowest and highest amounts of debris for PTU and PTN groups were recorded as 0.00117-0.00165 g and 0.00017-0.00067 g, respectively. CONCLUSION: ProTaper Next files was associated with significantly less extruded apical debris when compared to ProTaper Universal files.