Efficacy of a new jet nozzle for removal of carious dentin with an air abrasion system

Abstract

A new version of an air abrasion device, which expelled abrasive sodium bicarbonate powder, was fabricated to remove carious tissue. This device had a motor-driven mechanism to control the amount of powder expelled. The purpose of this study was to estimate the abrading efficacy of this device, in particular the new jet nozzle, for removal of carious dentin. Powder was supplied to the handpiece by a rotary gear attached to the powder control motor. Two types of jet nozzles, a cylinder-type and a bugle-type, were fabricated and evaluated. The duct of bugle-type nozzle had an isthmus to increase the air pressure on the powder and to spread it out in a cone-shaped flow. Results obtained showed that the bugle-type jet nozzle exhibited a more prominent abrasive capability. Compared to the cylinder-type nozzle, it was thus more effective in removing the carious dentin which remained in the undercut region of the cavities.

Effectiveness of an actuator-driven pulsed water jet for removal of softened carious dentin

“…As an alternative to conventional mechanical techniques such as steel round burs or hand excavators, which uses impact pressure for caries removal, the air abrasion technique has been introduced. Honda et al 17) in particular, visually evaluated removal of carious dentin using the cylinder-type nozzle and two sizes of the bugle-type nozzle (0.6-1.0 nozzle and 0.8-1.2 nozzle) each on four teeth, and showed that the bugletype nozzles were favorable for the removal of carious dentin. However, air abrasion cannot be used for all patients, such as in cases of severe dust allergy, asthma, chronic obstructive lung disease, recent extraction or other oral surgery, open wounds, advanced periodontal disease, recent placement of orthodontic appliances and oral abrasions, or subgingival caries removal 18) .…”