Bioglass particulates were surgically placed in the periodontal osseous defects of 12 patients. The clinical parameters studied were probing depth, attachment level as measured with the Florida Probe, and standardized bitewing radiograph comparisons. Data was collected initially, and at 3-, 6- and 24-month posttreatment intervals. Statistically significant improvements were demonstrated in all clinical parameters studied. There was a mean probing depth reduction of 3.33 mm, a mean attachment gain of 1.92 mm, and a mean radiographic bone fill of 3.47 mm. Results were stable over the 24-month period. Ease of handling and excellent tissue response were characteristic of the material.