This research evaluated the in vivo effects of a periodontal scaling gel used in routine prophylaxis. Fifteen adult patients with moderate to heavy calculus were selected for full mouth hand scaling and prophylaxis using a split mouth design, employing SofScale Scaling Gel in experimental quadrants. Patients and operators were asked to evaluate differences between control and treated quadrants. The following parameters were evaluated during and after treatment: Gingival effects, tooth sensitivity, ease of calculus removal, and overall patient comfort. In addition pre- and post-treatment tooth surfaces were evaluated with scanning electron microscopy using a replicate technique. No tooth sensitivity or soft tissue irritation was observed in any control or experimental quadrants. Calculus removal was independently judged by operators to be easier in the gel treated quadrants when compared to untreated control quadrants. Scanning electron microscopy revealed cleaner enamel and root surfaces with no obvious morphological changes in mineralized tissues. The results of this study demonstrate the safety of the scaling gel and the increased effectiveness of calculus removal during hand scaling of teeth treated with this gel.