Treatment of Chronic Periodontitis with 980nm Diode Laser-Microbiomic Results

Objectives: This double-blinded study examined the effects of a 980 nm diode laser in combination with Scaling and Root Planing (SRP) compared to SRP with sham laser treatment on clinical and microbiomic outcomes.
Methods: 15 adult subjects (4- F/ 11- M) aged 32-68 years with moderate to severe chronic periodontitis were recruited from a specialty dental clinic. Exclusions included poorly controlled diabetics (HbA1C > 7.5) or smokers. SRP was completed in 2 visits by experienced hygienists. Subjects were randomized to receive a 980nm diode laser or sham-treatment using the same protocol in 1/2 of the mouth following completion of SRP. Laser energy deployment was accomplished at constant temperature. Subjects were assessed at baseline, 2, 6, and 14 weeks following the laser session. At each visit, subgingival plaque samples from 8 teeth were obtained for microbial analysis, using sterile paper points. Bacterial DNA was extracted and quantified from each paper point sample. 16S rRNA gene libraries were created and sequenced on the Illumina MiSeq. Paired end reads were analyzed with QIIME2. Periodontal assessment (PPD, PAL, GI, and PI) was performed in parallel and outcomes across visits compared.
Results: Improvement in periodontal clinical outcomes (PPD and PAL) changed differentially over time across groups favoring the laser group (p<0.001). Sequencing the oral microbiome yielded 28,501 unique taxonomic assignments, including high abundances of subgingival-associated organisms. Both treatment groups had similar microbiome profiles at baseline and exhibited a reduction in periodontopathic organisms at 6 weeks. The laser treated group had fewer virulent organisms than the sham group at 6 weeks. Both groups trended back toward periodontopathic organisms by 3 months.
Conclusions:
Despite some clinical improvement with laser after SRP, preliminary microbiomic outcomes were similar between post-laser/sham treatment groups at the genus level. Future microbiomic analysis will incorporate detailed species level bacterial analysis using specific amplicons.