RESUMEN
Root canal obliteration is caused by hard tissue apposition and is often associated with teeth with a history of trauma, orthodontic movement, caries reaction, restorative procedures near the pulp chamber, and teeth of elderly patients. Preoperative planning of root canal treatment should be thorough and include an assessment of the patient's signs and symptoms in addition to the evaluation of complementary examinations. In a 27-year-old patient with dyschromia of the lower central incisor, a history of dental trauma, and a positive response to vertical percussion, an initial periapical radiograph was obtained that showed calcification of the canal and presence of a periapical lesion. The patient presented with pain on chewing, a positive response to palpation and a vertical percussion test. The diagnosis was symptomatic apical periodontitis. A cone-beam computed tomography scan was requested and a surface scan was performed to establish a static guide. The root canal was accessed in the middle third of the root and the canal was located using a minimally invasive approach. The root canal was treated conventionally. Results obtained showed the success of the treatment after a 3-year clinical and radiographic follow-up. Therefore, the use of an endodontic guide in cases of calcified canals significantly reduces the clinician's working time and offers a more predictable approach to the treatment of these pathologies.
RESUMEN
PURPOSE: Intraoral scanning subgingival finish lines has been described as challenging. The purpose of this study was to assess the impact of gingival contour around margins of implant stock abutments on marginal fit of Computer-aided Design - Computer-aided Manufacturing (CAD-CAM) zirconia copings. This in-vitro study was conducted on 40 analogues of implant stock abutments that were embedded into individual phantoms composed by a resin block. All 40 phantoms underwent two intraoral scans - one with (test group) and one without artificial gingiva (control group) - using a closed system intraoral scanner. Zirconia copings were then digitally designed and milled, followed by high-speed sintering, before being analyzed for marginal adaptation and internal surface roughness with scanning electron microscopy. Statistically significant differences between groups were assessed with the Mann-Whitney test. Median marginal gap values were 149.78 µm (95% CI: 112.39-216.66) for the test group and 94.90 µm (95% CI: 83.89-107.74) for the control group. A statistically significant difference was found between groups (p=0.0001). However, there were no subjective differences between groups for internal surface roughness. Within the limitations of this study, the present findings suggest that a gingival contour one millimeter higher than the finishing line affects marginal adaptation of CAD-CAM zirconia copings.