RESUMO
OBJECTIVE: To compare the clinical and microbiological effects of three protocols for nonsurgical periodontal therapy, including full-mouth scaling and root planing plus systemic antibiotics, on the treatment of chronic periodontitis patients. METHODS: Twenty-nine patients diagnosed with moderate to severe chronic periodontitis, selected according to specific criteria, were randomly assigned to one of three treatment groups: quadrant scaling, full-mouth scaling, and full-mouth scaling supplemented by systemic antibiotics. Antibiotic selection was based on the results of individual susceptibility testing. Oral hygiene instructions and reinforcement were given during the study. All patients received a clinical periodontal and microbiological examination at baseline and at reexamination, 4-6 weeks after therapy. Means and standard deviations were calculated and differences between groups were analyzed via the Kruskal-Wallis test, p < 0.05. RESULTS: The mean age of the study sample was 49.1 + 11.6 years old, and there were 17 men and 12 women. Patients treated with antibiotics showed antimicrobial susceptibility for amoxicillin and doxycycline. All study groups showed a similar significant improvement in periodontal parameters. Plaque scores were reduced in a range of 29.0% to 42.6%. Bleeding on probing was reduced by 34.8% to 55.0%; the reduction for the full-mouth scaling group was larger. Mean reduction in pocket depth was 1.2 to 1.3 mm in all groups. Mean bacterial counts were reduced in the groups receiving full-mouth treatment, but not in the quadrant treatment group. CONCLUSION: The three protocols for non-surgical periodontal treatment demonstrated a similar positive effect on clinical parameters; however, only full-mouth treatment groups showed a reduction in anaerobic microbial counts at re-examination.