Clinical and volumetric analysis of three-wall intrabony defects following open flap debridement

Fourteen defects were treated with flap debridement procedures using the Prichard principle of epithelial exclusion. Six defects were considered to be medium in width (3-4 mm), seven defects were wide (greater than 4 mm), and one defect was narrow (1-2 mm). The parameters studied were changes in gingival and plaque scores, attachment levels, and bone scores. All defects were reentered 9 to 16 months after surgery and changes between the pretreatment and posttreatment bone levels were recorded. The mean gain in probing attachment level was 2.76 mm. The mean amount of defect fill measured from models was 2.56 mm, while the mean defect fill from direct measurements was 3.26 mm. The percentage defect fill measured from study models was 61%. Crestal resorption was 9.7%. The average change in defect volume unadjusted for crestal resorption was 61.8 cu mm. Seven defects had a 50% or greater decrease in defect volume, while seven defects had less than a 50% change. Intrabony defects where calculus is present on the involved tooth surface prior to therapy will repair with substantial amounts of bone as a result of open debridement.