Root-surface caries formation: effect of in vitro APF treatment.

To determine the effect of one and four-minute acidulated phosphate fluoride, or APF (Oral-B Minute Gel, Oral-B Laboratories) treatments on artificial caries development in root surfaces, an in vitro study was conducted. The authors created a window of exposed root surface on extracted teeth by applying acid-resistant varnish to the remaining surface. APF treatment was administered and followed by a 24-hour deionized-distilled water rinse. A window of sound root surface that had been protected from the APF treatment was exposed and served as a control. Acidified gel was then applied to the exposed root surfaces to create the artificial caries. The authors found that APF treatment significantly enhanced resistance to demineralization of root surfaces from an in vitro acidogenic challenge. However, there was little difference in effectiveness between the one- and four-minute APF treatment times.