Ti:Sapphire femtosecond laser action on the intraradicular dentine: analysis in electronic scan microscopy / Ação do laser Ti:Sa Femtosegundo sobre a dentina intrarradicular: Análise em Microscopia Eletrônica de Varredura

Abstract

Dental elements with structural loss greater than 50% require the use of root anchorage, characterized by the use of pins. The major obstacles to clinical success of fiber pins are related to adhesion difficulties within the root canal. This work aimed to morphologically evaluate the treatment of the in-root dentinal substrate with Ti:Sapphire Femtosecond laser as a conditioning agent. Human premolars submitted to endodontic treatment were used. Teeth crowns were sectioned and the roots were cleaved and longitudinally separated with diamond discs. The in-root dentin of each specimen was submitted to different surface treatments according to the following groups: G1: only root canal desobturation, G2: root canal desobturation and surface conditioning with 37% phosphoric acid, G3: root canal desobturation and surface conditioning with 37% phosphoric acid and deproteinization with sodium hypochlorite, G4: root canal desobturation and Ti:Sapphire Femtosecond laser application G5: preparation, acid conditioning and Ti:Sapphire Femtosecond application. After the protocols, the roots were submitted to dehydration through successive alcohol baths in concentrations up to 100%, metallized and analyzed in Scanning Electron Microscopy. For G1, the presence of dentin smear layer was observed, in G2 open dentinal tubules were observed, in G3 it was observed the removal of the collagen layer by the action of the hypochlorite, in G4 and G5 groups it was not possible to observe dentinal tubules opening. The Femtosecond Laser Ti:Sapphire was not capable of surface conditioning the in-root dentinal tissue at neither of used strategies.