Sub-analyses were performed on these outcome variables taking into account the initial Pocket. A pocket was considered moderate if its initial Pocket was between 4 and 6 mm and deep if ≥7 mm. "Risk for disease progression" was defined at patient level. The "need for surgery" outcome measure was calculated. A site was considered as "in need for surgery" if the Pocket was ≥6 mm or 5 mm and Bleeding positive. A tooth was considered in need for surgery if it had at least one site in need for surgery. A patient was considered in need or surgery if at least one tooth was in need for surgery.