Evaluation of the CO2 laser for endodontic root apex welding

A low-wattage carbon dioxide laser was tested as a means of welding (sealing) the apices of unfilled, endodontically prepared teeth. Thirty-five teeth were filed and lased using a variety of power settings. Apical seals were examined microscopically, radiographically, and mechanically for complete welds. Accurately directed laser exposures of 15 or more watts with a 0.5 second duration will completely seal the apical openings of anterior teeth. The ideal treatment for endodontically compromised teeth has always been a completely sealed tooth apex. Usually amalgam, gutta-percha, or resin sealers are used after a lengthy and tedious preparation of the exposed root area. The carbon dioxide laser is designed for soft tissue dental surgery but is capable of melting enamel and dentin which recrystallizes in a dense solid as it cools (fig. 1). The laser, with its potential for accurately delivering a great quantity of energy to a small, exposed surface, appears to be an excellent tool for quick, direct sealing of open apices. This paper will investigate the practicality and best methods of spot welding root apices.