GTR THERAPY OF INTRABONY DEFECTS USING 2 DIFFERENT BIORESORBABLE MEMBRANES - 12-MONTH RESULTS

This prospective split-mouth study was designed to compare the clinica l and radiographic healing results in intrabony periodontal defects 12 months after GTR therapy with 2 different bioresorbable barriers. The study comprised 25 healthy patients with one pair of contralaterally located intrabony defects with a probing pocket depth of greater than or equal to 6 mm and radiographic evidence of angular bone loss of gre ater than or equal to 4 mm. The 2 defects of each patient were randomi zed for treatment either with polylactic acid (PLA) membranes or with polyglactin-910 (PG-910) membranes. The patients received systemic dox ycycline (100 mg/d) for 11 days postoperatively. One blinded examiner recorded the following clinical parameters using a pressure calibrated probe at baseline and after 12 months: papillary bleeding index (PBI) , gingival recession (REC), probing pocket depth (PPD), and probing at tachment level (PAL). The vertical relative attachment gain (V-rAG) wa s calculated as a % of the PAL gain related to the maximum possible at tachment gain (expressed by the intraoperatively measured depth of the osseous defect). Geometrically standardized intraoral radiographs wer e quantitatively evaluated for bone changes (density, area) in the def ect region using digital subtraction radiography (DSR). Clinical and r adiographic data were statistically analyzed using the Wilcoxon-signed -rank test (alpha=0.05). Postoperative membrane exposures occurred in 9 PLA and 13 PG-910 treated sites. After 12 months of healing, both ba rrier types provided significant PPD reductions and PAL gain [median ( 25/75 percentile)]: nPPD [PLA: 3.0 (2.0/4.0) mm; PG-910: 3.0 (2.0/4.5) mm]; Delta PAL [PLA: 3.0 (2.5/4.0) mm; PG-910: 2.0 (1.0/4.0) mm]. V-r AG amounted to 60% in PLA sites and 54% in PG-910 sites. DSR revealed significant bone density gain after 12 months. 58.3% of the initial de fect area in PLA sites and 54.0% of the initial defect area in PG-910 sites showed bone density gain. Neither clinical nor radiographic data revealed any significant difference between the 2 barrier types after 12 months. In conclusion, this 12-month study demonstrated that PLA a nd PG-910 membranes provided similar favorable regeneration results in deep intrabony periodontal defects.