Evaluation of Antimicrobial Photodynamic Therapy in Multiples Episodes as an Adjunct to Non-surgical Periodontal Treatment in Smokers

MATERIALS AND METHODS

Consent to search - All patients will receive detailed information about experiment (goals, benefits, risks and discomforts) in accordance with a consent form in this research. All procedures will be subject to approval of the Ethics Committee (CEP) of Ribeirão Preto Dental School (FORP), University of São Paulo (USP).

Sample Size Calculation - The sample size was determined to provide 80% power to recognize a significant difference of 1 mm (d) between groups with a 95% confidence interval (a = 0.05) and standard deviation (s) of 1.0 mm. Considering the changes in mean clinical attachment level (CAL) as the primary outcome variable and [Za (1.96) + Zb (0.84)]2 = 7.84. Size calculation was based on the following formula: n = {2[(s)2/(d)2]} · (Za + Zb)2. Therefore, a total of 16 patients were required. However, the number of patients enrolled in this study was 20, considering that some patients could be lost during follow-up.

Experimental Design -The selected subjects will receive specific oral hygiene instruction and supragingival scaling in all teeth, seven days before the start of interventions. The study type will be split mouth with two pairs of contralateral uni-root teeth with proximal periodontal sites presenting probing depth ≥ 5 mm for the clinical, microbiological and immunological assessment. A random number table will be generated by a computer program, each of the selected pairs dental receive the following treatments: SRP or SRP + several aPDT episodes. The clinical, immunological and microbiological parameters will be evaluated at baseline (pre-intervention) and after the completion of non-surgical periodontal therapy. The periodontal clinical examinations (pre and post-intervention) will be performed by a single trained and calibrated examiner, who unknown the experimental groups of this study. Examiners are also blind to study the immunological and microbiological analyzes. SRP procedures and use of the aPDT protocol should be performed by other trained operator for these purposes.

An impression with alginate will be performed in each patient to obtain the models of the dental arches and development of a guide plate on acetate with reference grooves to standardize the insertion and inclination of computerized periodontal probe (Florida Probe System, Florida Probe Corporation , Gainesville, FL, USA). The visible plaque index of each patient, will be assessed dichotomously (O'Leary et al., 1972) and determined by the percentage of tooth surfaces with plaque. In 6 sites of each tooth (mesio-buccal, buccal, distobuccal, mesio- lingual, lingual and disto-lingual) will be assessed clinical periodontal parameters: Probing Depth (mm) that will be measured from the gingival margin to the pocket bottom; relative Clinical Attachment Level (mm) that will be measured from the occlusal plate guide to the pocket bottom; Bleeding on probing, rated dichotomously (Ainamo, Bay, 1976), the presence of bleeding is considered positive when presented within 20s after the probe insertion for measuring probing depth. These clinical parameters and each patient's plaque index will be recorded at baseline (pre-intervention period) as well as +30 and +90 days after the non-surgical periodontal therapy.