Perda de dentina no acesso ao canal e remoção de pinos de fibra para retratamento em molares - análise por tomografia e microtomografia computadorizada

Abstract

Making access cavities for endodontic retreatment in molars and fiber post removal can sacrifice intact tooth structure. The use of flowable resin composites or glass ionomer cement has been proposed to seal the pulp chamber and root canal entrance. For removal of fiber posts, diamond burs, ultrasonic inserts, or even guided access have been indicated. This study has as general objective to evaluate methods of root canal access in teeth restored with composite resin or glass ionomer, and with fiberglass posts depending on their efficiency and effectiveness. This study was divided into three specific objectives: specific objective 1, Evaluate the effect of using a handpiece equipped with white or violet light and the use of glass ionomer or flow resin on the floor in the pulp chamber in the restoration of endodontically treated upper molars in the removal of intact dentin in the endodontic access for retreatment; specific objective 2, Evaluate the effect of the technique of ultrasonic inserts, diamond burs and guide access on the effectiveness and efficiency of removing fiberglass post measuring time consumed, loss of dentin and root canal deviation in maxillary molars; specific objective 3, To present clinical case reports that transfer knowledge obtained in laboratory studies about the fiberglass posts removal, addressing advantages, limitations and the necessity of technical advances in these protocols. Within the limits imposed by the design of these studies, it was possible to conclude that: 1) Access with handpiece equipped with white light, regardless of the restorative material used in the pulp chamber, allowed less dentin loss; 2) The use of glass ionomer cement facilitates access to the root canals with reduced dentin removal from the pulp floor and fewer affected walls; 3) The post removal with guide access results in less work time than the use of ultrasonic and less structural loss than the use of diamond bur and ultrasonic inserts; 4) The post removal with a diamond bur results in greater transposition and widening of the root canal than when performed with ultrasonic and guide access; and 5) Removal of a fiberglass post is a challenge for the clinician and requires technical advancement and effective professional training to generate efficiency and reproducibility of the procedure.