The Dynamics of Microbial Colonization of Barrier Membranes for Guided Tissue Regeneration

Abstract

The microbial colonization of expanded polytetrafluoroethylene membrane by putative periodontopathogens at 3 minutes of intraoral manipulation was determined in 42 patients with 42 mandibular posterior two‐ to three‐wall defects. Twenty patients exhibited no periodontal pockets of ≥ 5 mm, other than the study site, and low levels of pathogens (group A). Twenty‐two patients revealed multiple periodontal pockets of 5 mm or more and numerous pathogens (group B). Within the preceding 3 months of regenerative surgery, group A patients had received apically positioned flap surgery with osseous recontouring (except for the study site), and group B patients had been enrolled in a non‐surgical maintenance program. The subgingival microbiota was examined prior to regenerative therapy, and the membrane microbiota was examined at 3 minutes and at the time of removal at 6 weeks by culture, DNA probes, and phasecontrast microscopy. The mean initial defect depth was 7.4 mm for group A and 7.2 mm for group B. At 6 months, the difference in mean clinical attachment gain was statistically significant (P < 0.001; group A: 3.4 mm; group B: 1.4 mm). At 3 minutes, putative pathogens were detected in seven (16.7%) membranes in group B (group Binfected), and the associated sites gained only 0.6 mm in clinical attachment at 6 months. Clinical attachment gain was modeled as a linear function of the explanatory variables (r2 = 86%). The presence of Porphyromonas gingivalis detected by DNA probe at 3 minutes was associated with 1.5 mm less expected gain (P = 0.0002). Total microbial counts and the percentage of Peptostreptococcus micros and Capnocytophaga species at baseline, and of motile rods on the membrane surface facing the gingiva at 6 weeks, were statistically significant negative predictors of clinical attachment. For each week the membrane remained covered, an additional 0.5 mm gain could be expected (P = 0.002); and for every 10 sites that exhibited bleeding on probing, the clinical attachment gain was 0.6 mm less at the site of regeneration (P < 0.0001). The present results showed that putative pathogens may colonize membranes within 3 minutes of intraoral manipulation. The patient group treated with periodontal osseous surgery revealed the lowest levels of periodontal pathogens in the membranes and exhibited the most gain in clinical attachment. J Periodontol 1996;67:694–702.

An evaluation of bovine derived xenograft with and without a bioabsorbable collagen membrane in the treatment of mandibular Class II furcation defects

“…[25][26][27] Microbial colonization of the membranes in GTR studies can deleteriously affect the newly formed cells and decrease the amount of regenerative healing. 32 Membrane exposure has also been in association with gingival recession. 33 In this study however, we did not observe any exposure of the membranes to the oral cavity.…”

Toward guided tissue and bone regeneration: morphology, attachment, proliferation, and migration of cells cultured on collagen barrier membranes. A systematic review

“…However, collagen membranes seem to disintegrate at a high rate when exposed to the oral environment 40 owing to collagenases produced by several oral bacteria, including Porphyromonas gingivalis and Bacteroides melaninogenicus. 41,42 Consequently, some authors advise the use of multiple layers of collagen in cases where primary closure is not achievable or secondary exposure of the membrane is likely to occur. 43 On the defect side of a GTR-treated defect, the population of the membrane's surface with cells promoting regeneration is desirable.…”

“…While osteoblasts were found in only one of the two compartments, fi broblasts could be found on both sides of the membrane (only in GTR). In a series of animal studies, Karring et al were able to show that PDL fi broblasts are able to initiate periodontal regeneration, while this capacity is not found in gingival fi broblasts or bone cells [31][32][33][34][35][36][37][38][39][40][41][42][43][44] (for a review see Karring et al 34 ). Therefore, studies using PDL fi broblasts are reviewed separately at the end of this section.…”

Regeneration of class II furcation defects: determinants of increased success

“…Barrier membranes are at risk of becoming contaminated within 3 min of intraoral membrane manipulation in individuals with multiple deep periodontal pockets, bleeding on probing in other parts of the dentition, and high subgingival levels of putative periodontopathogens. Research has shown a negative correlation between bacterial contamination of the membrane and clinical attachment gain (25).…”