A randomized clinical trial will be performed single-blind to evaluate the effectiveness of sublingual metronidazole hydrogel 25 % in periodontitis in stage II and III.~At least 40 volunteers between the age of 18 and 80, will be enlisted, with the need to perform the SRP. In half of the mouth will be used the metronidazole hydrogel 25%, while in the other half no drugs will be used of delivered.~The study will be carried out in accordance with the Helsinki Declaration and the Protocol will be submitted to the Internal Review Board of the University to obtain authorization. Afterwards, the protocol will be recorded on the databa-se clinicaltrials.gov for clinical trials.~The protocol respects the SPIRIT parameters for the compilation of protocols on clinical trials and the study will respect the parameters of CONSORT sta-tement on randomized clinical trials.
A randomized clinical trial will be performed single-blind to evaluate the effectiveness of sublingual metronidazole hydrogel 25 % in periodontitis.