The key question is whether scaling and root planing (SRP) followed by one or two doses of photodynamic disinfection using 0.01% MB result in improved outcomes that persist over time in adults with chronic periodontitis when compared with subjects with SRP alone. This study is meant to be pivotal in nature in the evaluation of photodynamic disinfection.
The primary outcome of interest in this study is improvement in or stabilization of clinical attachment level. The clinical attachment level is the distance in mm from the cemento-enamel junction to the base of the sulcus or periodontal pocket as measured with a periodontal probe. In order to prevent study bias all endpoint measurements will be performed by a single examiner throughout the course of the study. A clinically significant difference will be considered as:
1) A measurement difference of 0.4 mm between treatment groups
The secondary objectives are to assess the effects of photodynamic disinfection on clinical symptoms including reductions in probing depth and decreases in bleeding on probing.