Clinical Outcomes with a Modified Surgical Technique Using Guided Biofilm Therapy (GBT®) Protocol in Step 3 of Periodontal Therapy: a Randomized Controlled Pilot Study
Stage III-IV periodontitis with residual periodontal pockets persisting after non-surgical (Step 2) periodontal therapy
Two-arm parallel RCT. Both arms receive Modified Widman Flap surgery under local anaesthesia (articaine 4% with epinephrine 1:100,000) with pre-surgical supragingival air-polishing, surgical loupes or microscope, and 4-0 interrupted sutures. Participants are allocated 1:1 to the two groups using a computer-generated random sequence with block randomisation to keep the groups balanced. The allocation is concealed in sequentially numbered, opaque, sealed envelopes prepared by a person not involved in recruitment or treatment, and each envelope is opened only after the participant has been enrolled and baseline measurements completed. Because the two procedures are visibly different, the operating surgeon cannot be blinded; however, the single calibrated examiner who performs all clinical measurements and the statistician (groups coded A and B) are both blinded to allocation. TEST ARM: Root surface decontamination using Guided Biofilm Therapy (GBT) protocol — erythritol powder air-polishing (AIRFLOW Prophylaxis Master, EMS; AIR-FLOW PLUS erythritol powder 14 um) as primary debridement under direct vision, with biofilm disclosure, and conservative use of PIEZON PS tip and Gracey curettes only for residual visible calculus. CONTROL ARM: Conventional root surface debridement using ultrasonic instrumentation (PIEZON handpiece with P tip) combined with Gracey curettes until all visible calculus is removed. No adjunctive air-polishing. Post-operative regimen identical in both arms: chlorhexidine 0.2% mouthrinse twice daily for 10 days, analgesics on demand, suture removal at 10 days. Follow-up at 3 and 6 months.
1. Age 18 years or older 2. Diagnosis of periodontitis stage III-IV according to the 2018 EFP/AAP classification 3. Completion of Step 2 periodontal therapy at least 6 weeks prior to inclusion 4. Between 4 and 6 teeth per quadrant with residual probing depth >=6 mm, presenting predominantly horizontal bone loss (<=2 mm intrabony component), confirmed radiographically and verified intra-surgically 5. Minimum 2 mm of keratinized tissue on all teeth in the operated quadrant 6. Full-mouth plaque score (FMPS) <=25% 7. Ability and willingness to provide written informed consent and to attend all study visits
1. Systemic conditions known to affect periodontium (e.g. uncontrolled diabetes mellitus, immunosuppressive therapy, metabolic bone disease) 2. Known allergy or hypersensitivity to erythritol or any component of the air-polishing powder 3. Currently smoking more than 10 cigarettes per day 4. Pregnancy or breastfeeding 5. Periodontal surgery at the experimental sites within the previous 12 months 6. Furcation involvement requiring regenerative procedures, or any grade III furcation involvement 7. Tooth mobility greater than Miller class II 8. Clinical or radiographic signs of vertical or horizontal tooth fracture or active occlusal trauma 9. Inability to comply with the study protocol or to provide informed consent