Clinical, Microbiological and Immunological Effects of Antimicrobial Photodynamic Therapy on Non-surgical Treatment of Aggressive Periodontitis: a Double-blind Split-mouth Randomized Controlled Clinical Trial.

Non-Surgical Periodontal Therapy

Seven days prior to the non-surgical periodontal therapy, periapical radiographs will be taken from the whole mouth of all patients. They will be set in an oral hygiene program (OHP) according to their specific needs. In this program, patients will be instructed about an effective self-performed plaque control, including information about the Bass Technique (Bass, 1954) and interproximal cleaning with dental floss and interdental brushes. They will be also motivated to brush the dorsal surface of the tongue once a day and will receive a dentifrice that shall be used throughout the experimental period (Colgate Total®, Anakol Ind. Com Ltda - Brazil's Kolynos - Colgate Palmolive Co., Sao Bernardo do Campo, SP, Brazil). After the OHP, subjects will undergo the assessment of clinical periodontal parameters previously described and the collection of subgingival plaque and GCF in selected sites (baseline) will be performed. Shortly, patients will receive supragingival scaling and coronal polishing with prophy cup on all the teeth present in the oral cavity. The non-surgical periodontal therapy will initiate 7 days after the OHP and initial supragingival scaling. Within 24 hours, a specialist in Periodontics will perform supra and subgingival scaling and root planing of all teeth with periodontal involvement, using hand (Gracey Curettes, Hu-Friedy, Chicago, IL, USA) and ultrasonic instruments. The instrumentation will be performed on each quadrant until achievement of an adequate cleaning and root planing, which will be verified with a dental explorer. Individuals will receive professional prophylaxis biweekly during three months after the end of the nonsurgical periodontal therapy. On biweekly follow-up visits, patient's cooperation will be monitored by verifying the status of oral hygiene.

Antimicrobial photodynamic Therapy

After a full-mouth scaling and root planning (SRP), the periodontal pockets of teeth selected to receive antimicrobial photodynamic therapy (aPDT) will be irrigated with distilled water. Shortly thereafter, the dye will be applied (phenothiazine hydrochloride- 10mg/mL) from the bottom of the pocket. After 1 minute, irrigation will be performed with distilled water to remove the excess of dye. The stained area will be irradiated with a diode laser (660 nm and a 60 mW/cm²). Six sites per tooth under treatment will be irradiated (10 seconds/ site). The applications of aPDT will be repeated in the same way until the second week (days: 2, 7,14). Before the application, the supragingival plaque will be removed.

Each patient will be impressed with alginate in order to obtain models of the dental arches and elaborate a guide plate made of acetate. This plate will present grooves that will be used as references to standardize the insertion and tilt of the automated periodontal probe (Florida Probe System, Florida Probe Corporation, Gainesville, FL, USA). The visible plaque index for each patient, rated dichotomously (O'Leary et al. 1972), will be determined by the percentage of tooth surfaces with deposits of plaque stained with disclosing solution.