Impacto do acesso endodôntico ultraconservador e de protocolo de instrumentação minimamente invasivo na espessura de dentina remanescente de molares inferiores

Abstract

Seeking maximum dentin preservation during endodontic treatment, minimally invasive endodontics focuses on the use of new reduced-size access modalities as well as instruments with different designs and heat treatments to be used during canal preparation. The aim of this study was to evaluate, by means of computed microtomography (micro-CT), the remaining dentin thickness and the percentage of dentin removal after performing different accesses (traditional and ultraconservative) and canal preparation with Reciproc systems. and XP-endo Shaper in lower molars. Thirty-two lower molars were scanned by micro-CT and divided into 4 groups based on similar anatomical features (n = 8 per group). The samples were divided according to the type of access: traditional and ultraconservative, and the root canal preparation system: Reciproc and XP-endo Shaper. The teeth were mounted on a dummy and the access cavities were created. In the Reciproc group, the mesial canals were prepared with R25 instruments (size 25, taper .08v) and the distal canal with R25, followed by R40 (size 40, taper .06v). In the XP-endo Shaper group, all root canals were prepared with a size 30 instrument, taper .04v. After root canal preparation, the teeth were scanned again. Post-operative models of the roots were co-registered with their pre-operative dataset, and cross-sections of the roots were used to measure the thinnest thickness of dentin around each canal at 1 mm intervals from the furcation level to 5 mm in the apical direction, on both aspects mesial and distal of the roots. Data were analyzed using Student's t-test and Mann-Whitney test (P < 0.05). Lower dentin thickness values were observed after root canal preparation at all evaluated levels of both groups (P < 0.05). Point differences, without a group predilection, were found in dentin thickness and percentage dentin removal after preparation (P < 0.05). In view of the observed results, it can be concluded that the different access cavity preparations, as well as the different instruments used in the preparation of root canals, obtained similar results in the remaining dentin thickness and the percentage of dentin removal, without presenting clinically significant errors.