| dc.description.abstract | Introduction. Periodontitis is a chronic multifactorial inflammatory disease associated with dysbiotic plaque biofilms and characterized by progressive destruction of the tooth‐supporting apparatus which when left untreated, it leads to tooth loss. Following non-surgical periodontal therapy, periodontal surgery is recommended for deep periodontal pockets. However, the simultaneous evaluation of clinical, microbiological and molecular changes following different periodontal surgical techniques has not been extensively studied in the literature. Aim This PhD thesis aimed to investigate the clinical, microbiological (metagenomic) and proteomic profile changes at 3 months following of the use of three different treatment modalities of periodontitis in generalized chronic (Stage III-IV). Materials and methods. The study of this was part of a larger randomised controlled clinical trial. The PhD study included 44 otherwise healthy stage III-IV periodontitis patients. All patients had undergone preparatory non-surgical treatment before baseline. Fifteen (15) patients were treated with repeated subgingival debridement (SD), 15 patients treated with simplified papilla preservation flap (SPPF) and 14 with resective surgery (RPFO). Whole saliva and subgingival plaque samples were collected before baseline (BL) and at 3-months post treatment. The efficacy all treatments on severe periodontitis was investigated at a clinical, microbiologic and salivary proteomic level. Changes in the clinical measurements of pocket depth (PPD), recession (REC), clinical attachment level (CAL), full mouth plaque score (FmPS), full mouth bleeding score (FmBS) at 3 months were calculated against the baseline values. Subgingival samples were analysed targeting the 16S rRNA gene, using the next generation Illumina MiSeq Sequencing. LC-MS/MS analysis was performed for saliva samples. Results. At 3-months post treatment it was found that there was a mean PPD reduction of 0.26mm (StD 0.24) for the SD group, followed by 0.68mm (StD. 0.44) for the SPPF group and 1.13mm (StD. 0.38) for RPFO which yielded the highest pocket reduction. A sub-analysis of the areas/sites presenting residual PPD ≥4mm at 3 months following treatment showed that RPFO presented with a reduction of 82.18%followed by SPPF group (64%). The SD group presented a reduction 32.89% of sites with a residual PPD≥4mm. The two surgical approaches were found to be more efficient and comparable between them, in terms of microbial diversity and also more effective in reducing microbiota, when compared to SDS at 3-months. The proteomic analysis revealed proteins expressed at baseline to be involved to immune response, inflammation, and wound healing. At 3 months, there was a clear downregulation of immune/inflammatory pathways which was more pronounced for the surgical groups. Conclusion. All treatments resulted in improvement of clinical measurements. The RPFO was most effective eliminating followed by the SPPF with and lastly from SD with all treatments inducing changes to the subgingival microbiota towards a healthy periodontium with increased diversity. All groups showed a treatment effect on reducing the immune and inflammatory response with the RPFO presenting the higher tendency in reducing inflammatory markers at 3 months. | en_US |
