Efficacy of photodynamic therapy as an adjunct to scaling and root planing on clinical parameters and microbial composition in subgingival plaque of periodontitis patients: A split-mouth randomized clinical trial.

BACKGROUND: The aim of this study was to assess the efficacy of photodynamic therapy (PDT) as an adjunct to scaling and root planing (SRP) on clinical parameters and microbial composition in subgingival plaque of periodontitis patients. METHODS: Seventeen patients were included in this split-mouth randomized clinical trial. Sites with probing pocket depth (PPD) ≥5 mm in combination with bleeding on probing in different quadrants were randomized into the control group, the group with a single PDT application right after SRP, and the group with three repeated PDT applications 1 week after SRP. The subgingival plaque was collected for 16S rRNA gene sequencing at baseline, Week 2, and Week 8. RESULTS: Seventeen patients with 60 sites completed this 8-week follow-up, and 157 subgingival plaques were successfully analyzed by sequencing. Significant improvements were observed in two primary outcomes: PPD at Week 8 and subgingival microbial composition. Compared to the control group, the repeated-PDT group showed a notable improvement in PPD, substantial alterations in the microbial profile, including a reduction in α-diversity and anaerobic bacteria, and an increase in aerobic bacteria at Week 2. Secondary outcomes, such as clinical attachment level and sulcus bleeding index, also showed improvement at Week 8. Furthermore, both the single- and repeated-PDT groups exhibited a decrease in periodontopathogens and an increase in beneficial bacteria compared with baseline. CONCLUSION: PDT promotes changes in the microbial composition of periodontitis patients' subgingival plaque in a direction favorable to periodontal health, and repeated PDT is a promising adjunctive therapy for periodontal treatment.

DLX3-Dependent Regulation of Ion Transporters and Carbonic Anhydrases is Crucial for Enamel Mineralization.

Patients with tricho-dento-osseous (TDO) syndrome, an ectodermal dysplasia caused by mutations in the homeodomain transcription factor DLX3, exhibit enamel hypoplasia and hypomineralization. Here we used a conditional knockout mouse model to investigate the developmental and molecular consequences of Dlx3 deletion in the dental epithelium in vivo. Dlx3 deletion in the dental epithelium resulted in the formation of chalky hypomineralized enamel in all teeth. Interestingly, transcriptomic analysis revealed that major enamel matrix proteins and proteases known to be involved in enamel secretion and maturation were not affected significantly by Dlx3 deletion in the enamel organ. In contrast, expression of several ion transporters and carbonic anhydrases known to play an important role in enamel pH regulation during maturation was significantly affected in enamel organs lacking DLX3. Most of these affected genes showed binding of DLX3 to their proximal promoter as evidenced by chromatin immunoprecipitation sequencing (ChIP-seq) analysis on rat enamel organ. These molecular findings were consistent with altered pH staining evidenced by disruption of characteristic pH oscillations in the enamel. Taken together, these results show that DLX3 is indispensable for the regulation of ion transporters and carbonic anhydrases during the maturation stage of amelogenesis, exerting a crucial regulatory function on pH oscillations during enamel mineralization. © 2016 American Society for Bone and Mineral Research.