Evaluate and compare the effectiveness in a clinical and microbial perspective one stage full-mouth disinfection technique in relation to scaling and root planing per quadrant associated with chlorhexidine or azithromycin.

Seventy -seven systemically healthy subjects with chronic periodontitis were randomly included in 6 different predefined groups. The following periodontal parameters were evaluated: probing depth , clinical attachment level , plaque index, gingival index and percentage of areas affected by periodontal disease. Microbiologically were evaluated the bacterial load and specific load of five bacterias: The quantification of the bacteria was performed by real-time Polymerase Chain Reaction . The clinical and microbial baseline evaluations were performed ( periodontal pre- therapy) , 90 and 180 days after treatment.

Inclusion Criteria:

• Diagnosis of slight-moderate chronic periodontitis

Exclusion Criteria:

• Those who were making regular use of antibiotics or anti-inflammatory drugs or had done up to three months before the beginning of the study;
• those who were making regular use (twice a day) of oral rinses with chlorhexidine or essential oils or have made regular use within three months prior to study entry;
• individuals with a history of sensitivity to chlorhexidine or azithromycin;
• subjects undergoing periodontal therapy include dental scaling procedures in the 12 months preceding the start of the study;
• subjects with impaired bifurcation or trifurcation class III;
• who required antibiotic prophylaxis for conducting clinical periodontal examination
• subjects with removable partial dentures and removable or fixed orthodontic appliance.