Comparative evaluation of marginal adaptation of mineral trioxide aggregate, Biodentine, and geristore as a root end filling material: An in vitro scanning electron microscope study.

Aim: The aim of this in vitro study was to measure the quality of marginal adaptation of three root end filling materials by scanning electron microscope (SEM). Methodology: Thirty extracted human permanent single-rooted single canal maxillary anterior teeth with mature apices were prepared up to 60 K-file and obturated. Teeth were resected 3 mm from the apex using a cross-cut fissure bur at 90° angle to the long axis of the tooth. Root end cavities of 3 mm were prepared in each of the teeth with an ultrasonic tip to receive the root end filling material. Group 1 - mineral trioxide aggregate (MTA), Group 2 - Biodentine, and Group 3 - Geristore. The samples were mounted in resin blocks for sectioning with a hard-tissue microtome and sectioned apically at 1 mm and 2 mm levels from the apex. They were gold sputtered and viewed under SEM for evaluating the adaptation of the material to the canal walls. Results: The mean value for Group II (Biodentine) was lower than the mean value for Group I (MTA) and Group III (Geristore) at 1 mm and 2 mm. Conclusion: Biodentine showed significantly better marginal adaptation as compared to MTA and Geristore.

Evaluation of remaining dentin thickness following use of three different rotary nickel-titanium retreatment files: A cone-beam computed tomography study.

AIM: The aim of the study is to measure the amount of remaining dentin thickness (RDT) following retreatment using three different rotary nickel-titanium (NiTi) systems. METHODOLOGY: Mesiobuccal roots of 45 extracted maxillary first molars were prepared up to F2 ProTaper File and obturated. After cone-beam computed tomography (CBCT) imaging, to evaluate the obturation, the samples were randomly assigned to three retreatment groups (n = 15). Group I was retreated with ProTaper Universal retreatment kit, Group II and III with MTWO and D-Race retreatment files, respectively. Postoperatively, all samples were subjected to CBCT imaging and evaluated with AutoCAD software (AutoDesk, Inc.) Mill Valley, California, U.S. to calculate the RDT. Data were statistically analyzed using one-way ANOVA and Tukey's post hoc tests, and the level of significance was set at P = 0.05. RESULTS: The amount of RDT was significantly more in D-Race and MTWO groups when compared to ProTaper group. CONCLUSION: D-Race and MTWO instruments were associated with significantly more RDT than ProTaper.