The force required to fracture endodontically roots restored with various materials as intra-orifice barriers.

OBJECTIVE: To evaluate the effect of various materials as intra-orifice barriers on the force required fracture roots. MATERIALS AND METHODS: One hundred-thirty five mandibular premolars were decoronated and prepared up to size #40. The root canals were filled and randomly divided into two control and seven experimental groups (n = 15), as follows: Positive control group (the intra-orifice barrier cavity was not prepared), negative control group (the intra-orifice barrier cavity was prepared, but not filled), filling using glass ionomer cement, nano-hybrid composite resin, short fiber-reinforced composite, bulk-fill flowable composite, MTA Angelus, Micro Mega MTA or Biodentine. A fracture strength test was performed, and the data were analyzed using one-way ANOVA and Tukey's post hoc tests. RESULTS: Nano-hybrid composite, short fiber-reinforced composite, bulk-fill flow able composite, and glass ionomer cement increased the force required fracture the roots compared to the positive and negative control groups (P < 0.05). While MTA groups did not increase the force required fracture the roots compared to the control groups, Biodentine increased significantly. CONCLUSIONS: Within the limitations of the present study, the use of nano-hybrid composite, short fiber-reinforced composite, bulk-fill flowable composite, and glass ionomer cement as an intra-orifice barrier may be useful in reinforcing roots. MTA placement (MTA Angelus or Micro Mega MTA) did not significantly increase the fracture resistance of endodontically treated roots compared to the control groups, however Biodentine did.

Comparison of apically extruded debris after root canal instrumentation using Reciproc(®) instruments with various kinematics.

AIM: To assess the amount of apically extruded debris using Reciproc(®) instruments with different kinematics (150° counter clockwise [CCW]-30° clockwise [CW], 270° CCW-30° CW, 360° CCW-30° CW and continuous rotation). METHODOLOGY: Forty-eight maxillary central incisors were selected and assigned to four root canal shaping groups as follows (n = 12): 150° CCW-30° CW, 270° CCW-30° CW, 360° CCW-30° CW and continuous rotation. Reciproc R25 and R50(®) instruments were used in all groups. Apically extruded debris was collected and dried in preweighed Eppendorf tubes. The weight of extruded debris was assessed with an electronic balance. The data were analysed with one way analysis of variance and LSD post hoc tests (P = 0.05). RESULTS: The 150° CCW-30° CW and 270° CCW-30° CW reciprocating motions extruded significantly less debris than continuous rotation (P < 0.05). However, no significant differences were found between the 360° CCW and 30° CW reciprocating motion and the continuous rotation (P > 0.05). CONCLUSIONS: All instrument movements were associated with apically extruded debris. However, the 150° CCW-30° CW and 270° CCW-30° CW reciprocating motions were associated with less extrusion than continuous rotation.

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.