Guided Endodontics: Volume of Dental Tissue Removed by Guided Access Cavity Preparation-An Ex Vivo Study.

INTRODUCTION: Guided endodontics emerged as an alternative method capable of providing greater precision and accuracy to endodontic treatments. The aim of the present study was to compare the volume of dental tissue removed after guided endodontic access (GEA) and conventional endodontic access (CEA) to mandibular incisors and upper molars. METHODS: Twenty extracted human mandibular incisors and upper molars were selected and submitted to cone-beam computed tomographic (CBCT) examination. They were divided into 2 groups, G1 (mandibular incisors) and G2 (maxillary molars), and subdivided into G1a (CEA), G1b (GEA), G2a (CEA), and G2b (GEA). The Digital Imaging and Communications in Medicine files obtained by examining the CBCT scans were transferred to InVesalius software (Renato Archer Information Technology Center, Campinas, SP, Brazil) to calculate the initial volume of each tooth. G1b and G2b teeth were scanned with a device to plan and print the guides. After gaining endodontic access, new CBCT examinations were performed to calculate the final volume of each sample unit. The Student t test for independent samples compared the volumes among the groups. RESULTS: G1 group had an average volume reduction of 31.667 mm3 (10.62%) using CEA and 26.523 mm3 (10.65%) using GEA with no significant difference among the groups (P = .960). There was an average volume reduction of 62.526 mm3 (5.86%) in the G2 group using CEA and 45.677 mm3 (4.11%) using GEA with a significant difference among the groups (P = .004). CONCLUSIONS: GEA preserved a greater volume of dental tissue in extracted upper human molars than CEA; however, there was no significant difference between CEA and GEA in the volume of dental tissue removed from mandibular incisors.

Effect of different intraradicular posts in the dimensions of root canal computed tomography images.

OBJECTIVES: To evaluate the effect of different intraradicular posts on the dimensions of computed tomography (CT) images in cone-beam and fan-beam equipment. MATERIALS AND METHODS: : A total of 15 root canals of bovine teeth were instrumented up to a file #50 and root-filled by the active lateral condensation technique. The teeth were randomly divided into three groups, according to the type of intraradicular post: 1) tight fiberglass post; 2) anatomical fiberglass post; and 3) metal post. The root canals were desobturated in 10 mm and tomographic images were acquired in two devices, a cone-beam and fan-beam equipment. Then, the intraradicular posts were cemented using an automix self-conditioning and self-adhesive resin cement, and the final acquisitions of the CT images were performed for analysis. The diameter of the canal was compared before and after cementation of the intraradicular posts. The t-test was used between the initial and final measurements of each tomograph and also between the cone-beam and fan-beam tomographs (α = 0.05). RESULTS: The anatomical fiberglass post presented the smallest dimensional change among the initial and final measurements, followed by the tight fiberglass post, with the metal post being the material that showed the most considerable dimensional difference in the cone-beam. CONCLUSION: All of the intraradicular posts used promoted a change in the size of the CT image. The fan-beam scanner promoted greater dimensional change in the images.