Effectiveness of nonsurgical re-instrumentation of residual pockets as step 3 of periodontal therapy: A field study.

Background: The study aims to analyze the effectiveness of nonsurgical re-instrumentation of residual pockets as step 3 of periodontal therapy and the stability of treatment outcomes at 18 months.

Methods: The study sample consisted of 489 patients diagnosed and treated nonsurgically for periodontitis. After a 6-month evaluation, residual pockets (≥5 mm) were re-instrumented. A final examination was performed at 18 months. Participants were categorized by treatment outcome at 6 months: (A) No residual pockets ≥5 mm, (B) Residual pockets 5-6 mm, or (C) Residual pockets ≥7 mm. The primary outcome was pocket closure (≤4 mm). Logistic regression models were built to evaluate the effectiveness of re-instrumentation and stability of initial outcomes at 18 months.

Results: Re-instrumentation of pockets 5 to 6 mm resulted in pocket closure of around 39% in groups B and C. The corresponding result at sites with deeper residual pocketing (probing pocket depth [PPD] ≥7 mm) was 28%. Combining hand and ultrasonic instrumentation was more effective than each alone. Healed sites (6 months) were more likely to remain closed in group A (80%) than in groups B (50%) and C (40%). The logistic regression revealed that the stability of outcomes of step 1 and step 2 therapy was influenced by PPD at baseline, tobacco smoking, age, and type of tooth.

Conclusions: At step 3, nonsurgical re-instrumentation can effectively improve periodontal health conditions. Treatment decisions after nonsurgical therapy should be based on residual probing depth, overall healing response, and patient behavior. The stability of clinical results was influenced by disease severity and the effectiveness of step 2 therapy.

Plain Language Summary: This study examined the effectiveness of nonsurgical re-treatment of residual pockets (periodontal pockets not healed) after initial therapy and the stability of treatment outcomes to 18 months. The study involved 489 patients with periodontitis (loss of tooth-supporting structures) treated in general dental practice. Residual pockets were re-treated after examination at 6 months. A final examination was performed at 18 months. Treatment of residual gingival pockets was more successful in moderately diseased pockets compared with the most severely diseased pockets. Clinical results achieved in patients with a mild form of periodontitis were better in terms of stability compared with patients suffering from moderate and severe periodontitis. The success of nonsurgical periodontal treatment was influenced by the severity of periodontitis at the study start, the type of tooth affected, the age of the patient, and whether the patient was a smoker or not.