Adjunctive Effects of a Low-Power Laser on the Healing of Periodontal Tissue

This dissertation, "Adjunctive Effects of a Low-power Laser on the Healing of Periodontal Tissue" by Man-lung, Stanley, Lai, 賴文龍, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract Abstract The aim of this study was to evaluate the adjunctive effect of a low-power laser in non-surgical periodontal treatment of patients with moderate to advanced chronic periodontitis. The study was performed as an intra-individual, longitudinal trial of 9 months duration with a single-blinded, controlled and randomized design. A total of 14 patients, 13 females and 1 male, aged from 33 to 57 years (mean = 43.6) having at least two sites per quadrant with probing pocket depth (PPD) >= 5mm were recruited. Matched sites with PPD of 5mm or above and comparable radiographically detected bone defect were selected on each side of the mouth in each patient. Clinical parameters, including presence of supragingival plaque (PI%), bleeding on probing (BOP%), probing pocket depth (PPD) and probing attachment level (PAL) were recorded at baseline, 3 months, 6 months and 9 months after treatment. Gingival crevicular fluid (GCF) samples and standardized intra-oral radiographs for evaluation of alveolar bone changes by digital subtraction radiography were also taken at the baseline and after 1 month, 3 months, 6 months and 9 months. After initial examination, full-mouth supra- and sub-gingival debridement was performed and oral hygiene instructions were given. Test sites were selected randomly by a coin toss and irradiated by a low-power laser (He-Ne) operating at a wavelength of 632nm and an output power of 0.2mW while control sites received no additional treatment. Laser irradiation was applied directly to the buccal or palatal aspects of the selected sites, each time for ten minutes for a total of eight times in the first 3-month period by a trained operator. The whole-mouth PI% decreased from 83% at baseline to 15% at 9 months while the BOP% decreased i Abstract from 95% to 28%. Statistical significant changes in reductions of PPD and GCF volume, gain in PAL and increase in recession (REC) were seen in both test and control groups of sites at 3-, 6- and 9-month examination when compared to baseline (pThe findings from the present study suggest that the adjunctive use of low-power laser in patients with moderate to severe chronic periodontitis in non-surgical periodontal therapy did not provide additional clinical benefit. ii DOI: 10.5353/th_b3765100 Subjects: Periodontitis - Treatment Lasers in medicine