Clinical and microbiological evaluation after treatment at the site of chronic periodontal disease, with gels containing antimicrobial agents

INTERVENTION: Doxycycline Drug Eighty male and female patients from Ribeirão Preto School of Dentistry ‐ USP will be selected and randomly divided (Office Excel® Worksheet) into 4 groups of 20 patients each (n = 20), in a randomized controlled double blind clinical trial design (patient and statistician). The sample size calculation is convenient and based on previous clinical studies of the research group (SATO et al., 2008; MIANI et al., 2012; BASTOS, 2015; CALEFI, 2017) namely: • Group 1 (Control) ‐ periodontal debridement with ultrasound (DPUS); • Group 2 ‐ DPUS + Subantimicrobial Doxycycline Gel (DOXI‐SDD); • Group 3 ‐ DPUS + metronidazole gel (MDZ) + (DOXI‐SDD); • Group 4 ‐ DPUS + Movie (MDZ) + (DOXI‐SDD). Metronidazole CONDITION: Chronic Periodontitis Periodontal disease Chronic periodontitis ; Chronic Periodontitis PRIMARY OUTCOME: In vivo evaluation of the effect of the formulations in improving the clinical parameters of periodontitis (probing depth, clinical level of insertion and bleeding on probing), using the Florida Probe â„¢ system, at times T0 (baseline) ‐ before periodontal therapy and application of formulations; T1 ‐ after one week; T2 ‐ after 1 month; T3 ‐ after 6 months, and T4 ‐ after 12 months of the treatment application.; ; Through validated primary surrogate clinical outcomes, it is expected to improve the clinical parameters of periodontitis over 12 months after the interventions.; ; SECONDARY OUTCOME: The absence and / or decrease of pathogens related to chronic periodontitis is expected after the proposed treatments, over 12 months after the interventions. Through secondary outcomes (evaluation of microbial diversity), the absence and / or decrease of pathogens related to chronic periodontitis is expected ; through the evaluation of the subgingival microbiota, using the genomic sequencing method, at the same times described in item 2 of the specific objectives. ; ; INCLUSION CRITERIA: Patients with chronic periodontitis, with clinical insertion level equal to or greater than 6mm in two or more teeth and probing depth equal to or greater than 5mm in one or more periodontal sites (MACHTEI et al., 1992); Age range from 30 to 75 years old; Not having used antibiotics for at least 3 months; No history of allergy to the components present in the formulations to be tested (MDZ and Tetracyclines).