A comparative clinical study: the use of human type I collagen with and without the addition of metronidazole in the GTR method of treatment of periodontal disease.

This investigation was undertaken to evaluate cross-linked human type I collagen, with and without added metronidazole, when used as a barrier membrane in the guided tissue regeneration (GTR) principle of treatment for periodontal disease. 16 patients suffering from moderate to severe periodontitis with 78 bilaterally matched periodontal defects underwent similar contralateral surgical flap procedures after preliminary scaling, polishing and oral hygiene instruction. At the experimental sites, which were selected at random, the flap was closed over metronidazole impregnated collagen as a GTR membrane, the contralateral sites receiving a plain collagen barrier as control. The plaque index (PLI), gingival index (GI), bleeding index (BI), probing pocket depth (PPD) and probing attachment level (PAL) were recorded at baseline, 6, 12 and 26 weeks post-operatively. The bony defects were classified and furcation involvement noted. The clinical parameters were recorded by an examiner, other than the surgeon, who had been previously assessed for accurate reproducibility of measurements and was unaware of the experimental sites. PPD and PAL were measured with a constant pressure probe, localised by a soft stent. Post-operative discomfort was evaluated by means of a questionnaire. PLI, GI and BI were significantly improved compared to baseline for both test and control sites at 6, 12 and 26 weeks post surgery (p < 0.001) but there was no significant difference between these sites (p > 0.05). There was a reduction in PPD at 6 weeks which was significant at 12 and 26 weeks post-operatively (p < 0.001) for both test and control sites, but no difference between these sites was evident (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)