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.

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.

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.

Comparison of hardness of three temporary filling materials cured by two light-curing devices.

AIM: Polymerization ability of light-curing devices can affect the light-cured material hardness. The purpose of the present study was to evaluate and compare the hardness of three temporary filling materials that had been light-cured by either a light emitting diode (LED) or a halogen light-curing unit. METHODS: The temporary filling materials, First Fill, Voco Clip and Bioplic, were placed in wells in a Teflon plate. The 24 specimens of each material were divided into two groups (N.=12/group) for photo-activation by either of the two light-curing units. The LED or halogen device was applied for 40s to the top surface of each specimen. A Knoop hardness test was performed on the top and bottom surface of each specimen, with five measurements per specimen. RESULTS: The highest hardness values for both the LED and halogen treated groups were observed for First Fill and the lowest values were for Voco Clip in top and bottom surfaces. The hardness obtained for the three materials with the halogen unit were significantly higher than the values obtained with the LED unit in both surfaces (P<0.05). CONCLUSION: First Fill light-cured temporary material exhibited the highest hardness values on the top and bottom surfaces than Voco Clip and Bioplic temporary materials. The hardness of light-cured temporary filling materials can be affected by the type of light-curing unit.

An in vitro comparison of working length determination by two motor-driven electronic apex locators.

AIM: The aim of this study was to evaluate the in vitro working length determination of two different apex locator integrated endodontic motors during mechanical preparation. METHODS: A total of 51 maxillary incisors were selected. The access cavities were prepared. The actual working lengths (AWL) were predetermined with a #15 stainless steel file. Specimens were then mounted in an alginate model. RESULTS: Working lengths recorded were VDW Gold (V1), Tri Auto ZX (T1) without using electronic motor and VDW Gold (V2), Tri Auto ZX (T2) by using apex locators in electronic motor operation mode. Data was analyzed by repeated measurements of ANOVA (α=0.01). No difference was found between V1, V2, T1 and T2 (P>0.01). However, statistical analysis found significant differences between AWL and other groups (P<0.01). CONCLUSION: As the values obtained in motor driven mode are equivalent to manual mode measurements, both devices can be safely used without disruption of working length.

Evaluation of residual antimicrobial effects and surface changes of gutta-percha disinfected with different solutions.

AIM: To determine the possible residual antibacterial effects and possible surface changes caused by 5.25% NaOCl, 2.5% NaOCl, 2% CHX and 0.05% Octenisept on in vitro gutta-percha points after different disinfection protocols. MATERIALS AND METHODS: A total of 121 standard # 40, 0.2% gutta-percha cones were cut 10 mm from the tip, sterilized with ethylene oxide. The samples were divided into five groups, and each group was divided into three subgroups according to immersion periods of gutta-percha cones into solutions. One gutta-percha cone from each group was selected for SEM evaluation. RESULTS: All of the tested solutions were effective on the selected microorganisms when compared with the control solution. No surface alterations were detected on the gutta-percha cones. CONCLUSION: In the limits of this study, immersion of gutta-percha into 2% CHX for one minute was found the most effective method to eliminate the selected microorganisms. CLINICAL SIGNIFICANCE: Although gutta-percha points are aseptic in their package, once opened and used, gutta-percha cones may be contaminated. In order to eliminate bacteria and not to cause surface changes on gutta-percha cones, disinfection solution must be selected carefully.