Introduction and objective:
Periodontal treatment is based on patient motivation and education as well as quadrantwise subgingival instrumentation. The literature suggests that periodontal scaling should be performed in 2 sessions spaced within 24 hours, combined with the use of chlorhexidine to decontaminate all sites in the mouth. The aim of this study is to evaluate and compare the effectiveness of quadrantwise periodontal treatment with the full-mouth disinfection protocol.

Material and methods:
The sample consisted of 58 patients aged between 40 and 60 years with stage III periodontitis. They were randomly divided into test and control groups. The control group was treated with scaling and root planing in several sessions while the test group underwent full-mouth disinfection within 24 hours. These individuals were evaluated at three different times over 60 days.

Results:
There were no significant differences in gender or age between the test and control groups. The findings revealed a substantial and progressive decline in the mean probing depth and clinical attachment level at 60 and 120 days for both treatments. A statistically significant difference was observed between the treatments at 60 days (probing depth and clinical attachment level) and 120 days (probing depth), with the test group demonstrating superior outcomes.

Conclusions:
It was evident that both treatment options were effective and that the full-mouth disinfection was more effective than the conventional quadrantwise treatment, resulting in a greater improvement in probing depth and clinical attachment level.