Middle distal canal of mandibular first molar: A case report and literature review.

A successful root canal treatment can only be achieved by gaining adequate access to all root canals, ensuring adequate mechanical preparation, and disinfection as well as placing a three-dimensional impermeable filling in these root canals. Practitioners must be very careful when detecting the root canals in mandibular first molar tooth, because it shows a wide variety of root canal variations and it is the first permanent tooth erupted in the mouth that frequently requires endodontic treatment. Our case report presents the endodontic retreatment of a left permanent mandibular first molar having two roots that consist of three distal canals and two mesial canals (Type XVIII root canal pattern). After all the root canals were identified with endodontic explorer adequate preparation and disinfection were provided, the root canals were filled with calcium hydroxide-based canal sealer and gutta-percha and the crown was restored with resin composite at the second appointment. In addition, a short review of literature for similar cases is presented in this paper.

Catalase activity in healthy and inflamed pulp tissues of permanent teeth in young people.

AIM: To evaluate catalase (CAT, EC 1.11.1.6) activity in healthy and inflamed dental pulp of young patient's teeth and to investigate if an active defense system oxidizing agents is present as a response to bacterial invasion. MATERIALS AND METHODS: Twenty young patients between 15 and 25 ages, who were diagnosed to be healthy, were the source of the pulp tissue. The situation of the dental pulps was evaluated using clinical and radiographic assessments. The patients were divided two groups from healthy, and inflamed pulp tissues were obtained; each participant provided one pulp tissue specimens. The specimens were collected during endodontic treatment or by longitudinally grooving and splitting the teeth (if extracted). Catalase activity was determined through spectrophotometric methods and an independent sample t-test assessed the significance of differences between the groups. RESULTS: There was statistically a difference between healthy pulp tissue and inflamed pulp tissue (P < 0.005, independent sample t-test). The catalase activity of healthy group was significantly lower than inflamed pulp groups. CONCLUSION: The present study has shown that a significant increase in catalase activity is determined in inflamed dental pulps, which is due to pulpitis in comparison to healthy dental pulp.

Quantitative evaluation of apically extruded debris with Twisted File Adaptive instruments in straight root canals: reciprocation with different angles, adaptive motion and continuous rotation.

AIM: To evaluate the influence of movement kinematics when using Twisted File Adaptive instruments (SybronEndo, Orange, CA, USA) (TF Adaptive) on the amount of apically extruded debris. METHODOLOGY: Forty-eight extracted mandibular incisor teeth were selected. The teeth were randomly divided into four groups (n ꞊ 12), and the root canals were instrumented using the following movement kinematics: TF Adaptive motion, 90° clockwise (CW) to 30° counterclockwise (CCW) reciprocating motion, 150°CW to 30°CCW reciprocating motion or continuous rotation. TF Adaptive instruments were used for all groups. Debris extruded apically during instrumentation was collected in pre-weighed Eppendorf tubes, and after drying, the mean weight of the debris was assessed with an electronic balance. The data were analysed statistically using a one-way analysis of variance. RESULTS: The 90° CW to 30° CCW reciprocating motion produced the highest mean extrusion value, and this was significantly greater when compared with continuous rotation (P < 0.05). 150° CW to 30° CCW reciprocating, adaptive and continuous rotation motions produced similar amounts of debris extrusion (P > 0.05). CONCLUSION: Movement kinematics affected the amount of apically extruded debris when using Twisted File Adaptive instruments.

Incidence of dentinal cracks after root canal preparation with ProTaper Gold, Profile Vortex, F360, Reciproc and ProTaper Universal instruments.

AIM: To assess the effect of root canal preparation using ProTaper Gold, Profile Vortex, F360, Reciproc and ProTaper Universal instruments on dentinal crack formation. METHODOLOGY: Ninety mandibular central incisor teeth with mature apices and straight canals (<5° ) were selected and stored in distilled water. Fifteen teeth were left unprepared (control group) and the remaining 75 teeth were assigned to the five root canal shaping groups (n = 15): ProTaper Gold, ProFile Vortex, F360, Reciproc and ProTaper Universal. All the roots were sectioned perpendicular to the long axis at 3, 6 and 9 mm from the apex with a low-speed saw under water cooling. The slices were then viewed through a stereomicroscope at 25×  magnification. The presence of dentinal cracks was determined by photographing all samples using a digital camera. RESULTS: All the experimental groups, except F360, produced significantly more cracks than the control group (P < 0.05). No significant difference was observed amongst the groups at the 6 and 9 mm levels (P > 0.05). The ProTaper Universal group produced significantly more cracks than the control, ProTaper Gold, ProFile Vortex, F360 and Reciproc groups at the apical section (3 mm) (P < 0.05). CONCLUSION: All the systems that were tested produced dentinal cracks. There was no significant difference between the control and F360 groups in terms of dentinal crack formation.