Microbiological profile of molars with advanced furcation defects before and after surgical and non-surgical periodontal treatment: A pilot randomized controlled trial.

OBJECTIVES

To describe the microbiological composition of subgingival dental plaque of class III periodontal furcation-involved defects (FI) after surgical or non-surgical periodontal therapy.

METHODS

Twenty participants contributed with a class III FI and a periodontally healthy site (HS) each. FI molars were randomised either to repeated non-surgical periodontal treatment (NSPT) (10) or surgical treatment (10). Periodontal clinical parameters and subgingival plaque were collected at baseline and 6 months after the treatment from both furcation and healthy sites. Microbial analysis was conducted by sequencing the V3-V4 region of the 16S rRNA gene.

RESULTS

In total, 80 subgingival plaque samples were analysed. Differences in richness, diversity, oxygen metabolism, microbial composition, were observed when comparing class III furcation defects with HS (p < 0.05) both at baseline and 6 months later. At 6-months, significant reduction in PPD (p < 0.01) and increase of REC (p < 0.01) was detected in surgically treated sites (PPD: 3.55 ± 1.4, REC: 3.95 ± 1.7) compared to NSPT sites (PPD: 5.4 ± 1.3, REC: 2.92 ± 0.98). Higher levels of aerobic genera and an increase of Streptococcus mutans, Streptococcus oralis, and Streptococcus gordonii were detected in surgically treated sites compared to NSPT.

CONCLUSIONS

The microbial composition of class III furcation defects after surgical periodontal therapy showed higher level of aerobic and acidogenic microbial flora compared with furcation defects treated with a non-surgical approach.

CLINICAL SIGNIFICANCE: While surgical treatment of class III furcation defects improves pocket depths, it also leads to an increase in acidogenic microflora potentially predisposing to caries.