RESUMEN
BACKGROUND: The aim of the randomized controlled clinical trial study was to evaluate the effectiveness in reducing pathologically increased pocket probing depths (PPD > 3 mm) using the Guided Biofilm Therapy (GBT) protocol (adapted to the clinical conditions in non-surgical periodontal therapy (NSPT): staining, air-polishing, ultrasonic scaler, air-polishing) compared to conventional instrumentation (staining, hand curettes/sonic scaler, polishing with rotary instruments) both by less experienced practitioners (dental students). METHODS: All patients were treated according to a split-mouth design under supervision as diseased teeth of quadrants I/III and II/IV randomly assigned to GBT or conventional treatment. In addition to the treatment time, periodontal parameters such as PPD and bleeding on probing (BOP) before NSPT (T0) and after NSPT (T1: 5 ± 2 months after T0) were documented by two calibrated and blinded examiners (Ethics vote/ Trial-register: Kiel-D509-18/ DRKS00026041). RESULTS: Data of 60 patients were analyzed (stage III/IV: n = 36/ n = 24; grade A/ B/ C: n = 1/ n = 31/ n = 28). At T1, a PPD reduction of all diseased tooth surfaces was observed in 57.0% of the GBT group and 58.7% of the control group (p = 0.067). The target endpoint (PPD ≤ 4 mm without BOP) was achieved in 11.5% for GBT (conventional treatment: 11.2%; p = 0.714). With the exception for number of sites with BOP, which was at T1 15.9% in the GBT group and 14.3% in the control group (p < 0.05) no significant differences between the outcomes of the study were found. At 30.3(28.3) min, the treatment time was significantly shorter in GBT than in the control group at 34.6(24.5) min (p < 0.001). CONCLUSIONS: With both protocols (GBT/ conventional instrumentation) comparably good clinical treatment results can be achieve in NSPT in stage III-IV periodontitis patients. TRIAL REGISTRATION: The study was registered before the start of the study and can be found under the number DRKS00026041 in the German Clinical Trials Register. The registration date was 19/08/2021.