Perception of the clinical endodontic practice of Dentistry graduates in their first years in the job market in southern Brazil

Introduction: Knowledge about the clinical endodontic practices of dental school graduates in the first years of their professional life may contribute to the discussions about Dentistry teaching. Methods: An online questionnaire with seven open and closed questions hosted on the Google forms platform was applied to dentists trained in the first half of 2019 in a School of Dentistry in southern Brazil. The questionnaire is structured to analyze how clinical Endodontics has been practiced in the labor market. The data collected in the questionnaires were transferred to an Excel® spreadsheet and analyzed as absolute and relative frequencies for closed questions and descriptions for open questions. Results: Molars and two-rooted teeth are the dental groups most frequently treated endodontically (64.3% and 35.7%). Both retreatment and conservative treatment of the pulp corresponded to up to 25% of all procedures in the graduates' clinical practice. The endodontic protocol learned in their dental school was used by 64.3% of the graduates who provided endodontic treatments, and 42.9% reported the occurrence of at least one accident. The difficulty in access reported by the participants suggests that more training should be provided for this operative stage. Conclusions: After two years in the job market and having faced the initial difficulties existing in any profession, more than half of the graduates still performed endodontics in their dental clinical practice and used the same protocols learned in dental school.

THE POST TRANSFIXED IN THE CORONAL CAVITY INCREASES THE FRACTURE RESISTANCE OF WEAKENED AND DIRECTLY RESTORED TEETH? A SYSTEMATIC REVIEW

Introduction: The objective of this systematic review was to answer the question: Does the intraradicular post transfixed in the dental crown increases the fracture resistance of weakened and directly restored teeth? Methods: Electronic databases (MEDLINE/PubMed, LILACS, SCOPUS, EMBASE, Scientific Electronic Library Online - SCIELO, and Central Register of Controlled Trials - CENTRAL) were searched until March 2021, without language or year restriction. Grey literature was also searched through Google scholar and OpenGrey repository. Only in vitro stud-ies were included that evaluated the influence of the use of intraradicular post trans-fixed in the crown in the buccopalatal/lingual direction in the fracture resistance of the dental crown. Relevant results were summarized and evaluated. The risk of bias was also assessed in the studies. Results: Initial screening of databases resulted in 249 studies, of which 109 were excluded for being duplicates. Of 140 eligible pa-pers, fourteen studies met the inclusion criteria and were selected for full-text read-ing. Of these, two studies were excluded for not having access to the full article. All selected articles were classified as low risk of bias. Conclusion: Based on the studies, it is possible to conclude that the use of a transfixed post in the crown increases the fracture resistance of weakened and directly restored teeth.

Influence of dental crown topography on fracture resistance of premolars with MOD preparation and subjected to different restorative protocols.

To evaluate whether dental crown topography influences the fracture resistance of premolars treated endodontically and with MOD preparation subjected to different restorative protocols. Sixty-four human premolars with one or two roots in equal numerical proportions (n) were selected and randomly divided into four groups (n = 8): (S = single-rooted; D = double-rooted) SS: sound single-rooted; SNR: endodontics (E) + MOD cavity preparation; SR: E + MOD + resin restoration (RS); SP: E + MOD + RS + horizontal zirconia post (ZP); DS: sound double-rooted; DNR: E + MOD; DR: E + MOD + RS; and DP: E + MOD + RS + ZP. After allocation to the groups, the samples were thermocycled and then subjected to the fracture resistance test. Failures after the fracture test were classified as irreparable (with pulp floor fracture) or reparable (without pulp floor fracture). Data were analysed using one-way anova and the Tukey test (α = 0.05). Single-rooted premolars were more resistant to fracture than double-rooted premolars. The restorative treatment using a horizontally transfixed zirconia post improved fracture resistance, resembling that of a healthy tooth.

Influence of access cavity design on fracture strength of endodontically treated lower molars.

To assess whether access cavity design influences the fracture strength of endodontically treated and restored molars. Fifty human lower molars with standard crown dimensions were selected and assigned to the following groups: S - positive control (healthy tooth), ET - negative control (conventional endodontic access (CEA) and no restoration), NI - negative control (minimally invasive endodontic access (MEA) and no restoration), ETR (CEA + restoration with Bulkfill flow) and NIR (MEA + restoration with Bulkfill flow). The specimens were subjected to a compression test. The teeth were inspected for the site of fracture: either pulp floor or cusp. ANOVA, followed by Tukey's multiple comparison test (α = 5%), was used for statistical analysis. The type of access cavity preparation did not increase the fracture strength of endodontically treated teeth. Even with the restoration, all teeth with endodontic access performed had a higher incidence of fractures at the pulp chamber floor level.

Influence of endodontic cavity access on curved root canal preparation with ProDesign Logic rotary instruments.

OBJECTIVE: This study evaluates whether endodontic cavity access into molars influences the chemomechanical preparation of curved root canals. MATERIALS AND METHODS: Twenty mesiobuccal canals of maxillary molars were randomly divided into two experimental groups (n = 10), according to the type of endodontic access analyzed (conventional and minimally invasive). The preparations were made by a single operator, and the canals, after access, were prepared with Logic system (0.25, 0.04 taper) along the working length. Samples were scanned before and after canal preparation (SMX-90CT Plus (Shimadzu® microtomograph operated with 70 kV, 100 uA, FOV (XY) 13.3 mm, FOV (Z) 7.0 mm, and voxel size 0.013 mm/Pix)) to match canal volumes. Images were analyzed to evaluate surface areas, transport, and centralization at 3 mm from the canal entrance and 3 mm from the apex (OnDemand3DTM Dental software). Student's t test with a significance level of 5% was used for the statistical analysis. RESULTS: Regardless of the position of the analyzed canals, there was no difference in the prepared area regarding the transport and centralization of the endodontic instrument between the two types of cavity accesses performed. CONCLUSIONS: The conventional and minimally invasive access did not influence the action of the 0.25 and 0.04 taper instrument during the curved root canal preparation. CLINICAL RELEVANCE: The type of endodontic access did not influence the action of the rotary instrument during the curved root canal preparation.

Strengthening effect of horizontally placed fiberglass posts in endodontically-treated teeth restored with direct resin composite.

PURPOSE: To assess the fracture strength of cavity preparations, directly restored with resin composite, with and without the presence of fiberglass posts with different diameters. METHODS: 84 extracted third molars were embedded in acrylic resin and divided into six groups (n = 14 per group): healthy (H); cavity preparation (P); cavity preparation + endodontic treatment (PE); PE + resin composite (R); PE + R + 2 horizontally transfixed fiberglass posts 1.1 mm in diameter (PERP1); PE + R + 2 fiberglass posts 1.5 mm in diameter (PERP2). The MOD cavity preparations were standardized with their width corresponding to 2/3 of the buccolingual distance and occlusogingival depth of 4 mm, with 2 mm remaining above the cemento-enamel junction. Endodontic treatments were performed in the PE, R, PERP1 and PERP2 groups. The buccal surface received two demarcations to create orifices for placement of the PERP1 and PERP2 posts. Once the fiberglass posts were placed, the teeth were restored with resin composite. In group R, only resin composite was used. After 24 hours, the teeth were subjected to the fracture toughness test on a universal testing machine. A 10 KN load cell and crosshead speed of 1 mm/minute was used until fracture occurred. After testing, the teeth were inspected for the type of fracture classified as: pulpal floor fracture (AP) or cuspal fracture (CP). RESULTS: The data were subjected to ANOVA and Tukey's test (P < 0.05%), demonstrating a statistical difference between groups: H 3830NA; P 778ND; PE 572.93ND; R 1782NC; PERP1 2988NB; PERP2 3100NAB. The fracture pattern was similar between the tested groups, showing 50% of fracture for cusps and pulpal floor.