The maintenance of good oral hygiene in patients with or without prosthesis has been one of the essential parts of the total oral health care. Recently a redesigned air-powder abrasive system was introduced to remove dental plaque and stain from tooth surfaces. This study was designed to evaluate effects of this device on the cementoenamel junction area quantitatively and qualitatively by using the Michigan Computer Graphic Coordinate Measuring system (MCGCMS) and scanning electron microscopy (SEM) after exposure to an air-powder abrasive device. A tooth specimen was exposed to a Cavi-Jet (Dentsply International Inc., York, PA) for 10, 30, 90 seconds intervals. The MCGCMS was utilized before and after treatment of the specimen at each time interval to measure the depth abrasion of the tooth material, and SEM pictures were taken after 90 seconds treatment of the specimen to evaluate surface characteristics. Following conclusions were drawn within the limits the confines of this study. 1. An air-powder abrasive device abrades cementum rapidly and should be used carefully below cementoenamel junction. 2. There was no significant change on the enamel surface quantitatively. 3. The MCGCMS reproduces and measures experimental points accurately.