Ultrasonic techniques to obtain dental pulp from impacted third molars

In the dental clinic impacted teeth are frequent findings, especially upper and lower third molars, leading to their exodontia. Among surgical techniques piezosurgery is advantageous for delicate structures in the oral cavity. Extracted teeth, usually discarded, have been revalued as biological material, providing living tissues with possible applications in regenerative dentistry. The aim was to compare cross-section methods of upper included third molars by ultrasonic piezoelectric technique to obtain dental pulp, with diamond-coated tip (DT) against titanium nitride-coated tip (TN), according to the pulp tissue cell viability and the section surface characteristics.

Patients attending dental consultation were evaluated. Upper third molars (n= 24) were avulsed from 15 patients with exodontia indication, age 18-26 years old, who agreed to participate of the study. Third molars were cross-sectioned at amelocemental junction level with piezoelectric device using DT or TN inserts. Pulps were mechanic and enzymatically treated, and tissue viability determined by Trypan Blue test. Sectioned teeth were visualized using Scanning Electron Microscope (SEM). Ethical principles of biomedical research were respected; all patients gave their informed consent.

Viability of pulp tissue was 84.71% not associated to sex (p= 0.141) nor to teeth position, upper right third molar or upper left third molar (p= 0.580). According to the insert used, pulp tissue viability was 85.21% with TN, similar to 84.00% with DT (p= 0.611). By SEM, cut performed by TN insert showed smooth and uniform surfaces, while DT insert surfaces were irregular, porous, with fissures.

Piezosurgery applied to cross-section upper third molars with both types of inserts showed differences in the cut surfaces but similar effectiveness regarding preservation of pulp tissue with high viability, thus, they could be allocated for further cellular developments. Key words:Impacted teeth, third molars, piezosurgery, regenerative dentistry.