This is a superiority placebo-controlled randomized clinical trial. The population that will be evaluated in the study will be selected at Institute of Science and Technology (ICT), São José dos Campos, College of Dentistry.~Sixty patients presenting Stage III/IV and Grade B/C periodontitis will be divided into 2 groups:~FMUD+Placebo (n=30): full-mouth ultrasonic periodontal debridement associated with administration of placebo formulation, twice a day for 30 days;~FMUD+Probiotic (n=30): full-mouth ultrasonic periodontal debridement associated with administration of probiotic formulation twice a day for 30 days.~The study will consist of two stages of treatment:~Initial therapy: Before starting treatment, a complete examination of the oral cavity and evaluation of periodontal parameters will be performed. All patients will undergo a prior adjustment of the oral environment and oral hygiene. Thirty days after completion of initial therapy, a new periodontal evaluation will be performed and only patients who present a visible plaque index less than or equal to 25% will undergo subgingival periodontal debridement.~Non-surgical periodontal therapy: After initial therapy, all patients will receive full-mouth ultrasonic periodontal debridement. Debridement will be performed by a single operator, trained, blind to the allocation of patients and different from the evaluator. If there is any complication that prevents the completion of full-mouth debridement, the procedure will be finished within a maximum period of 24 hours. The randomization envelope will be opened and the probiotic/placebo formulation will be delivered to patients. They will be instructed to consume the samples twice a day during the 30 days following periodontal treatment.~All clinical measurements will be performed by a single researcher, previously calibrated for the measurements. After periodontal therapy, treatment results will be evaluated three and six months after periodontal debridement associated with the use of placebo/probiotic formulation. Indications of adverse oral effects will be verified by visual assessment at 7, 30 and 90 days after the start of consumption of formulations.~To assess patient-centered parameters, the OHIP-14 questionnaire will be applied before and after 6 months of periodontal treatment for each patient. A 30-days diary will be used to assess the adherence to use and occurrence adverse effects.~Microbiological and immunological analyzes will be carried out through subgingival biofilm and gingival crevicular fluid samples collected from sites with moderate pockets and sites with deep pockets at baseline, 3 and 6 months after therapy.
The aim of this study is to evaluate the effects of probiotic administration of L. paracasei 28.4 as an adjunct to the non-surgical periodontal treatment in patients with periodontitis.