Timing of Re-Evaluation After Periodontal Therapy: A Randomized Clinical Trial

To evaluate clinical and patient reported outcomes after subgingival instrumentation at two different re-evaluation timings in stage III/IV periodontitis and the influence of clinical and radiographic variables on final outcomes.

Forty participants were assigned to 3-month (control) or 6-month (test) re-evaluation after steps 1-2 of therapy. The primary outcome was the number of teeth reaching the Endpoints of Treatment (EoT). EoT was defined as a site with PPD < 6 mm or PPD = 4/5 mm without BoP. Secondary outcomes included changes in clinical parameters and in oral health-related quality of life (OHIP-14) scores. ANOVA, ANCOVA, mixed-effects models and multilevel models were applied.

Thirty-six patients completed the study. Patients allocated to the 3-month group had 15.8 ± 4.0 teeth reaching the EoT, accounting for 65.8% ± 14.3 of the teeth, while patients assigned to the 6-month group had 15.5 ± 5.9 (64.9% ± 21.5), without statistically significant differences. Percentages of sites achieving EoT were 68.5% ± 11.6 in the 3-month group and 71.9% ± 14.4 in the 6-month group, without statistically significant differences. Final OHIP-14 scores were 6.5 ± 8.9 in the 3-month group and 7.3 ± 7.5 in the 6-month group, without statistically significant differences. Risk for residual pockets at re-evaluation was influenced by higher baseline PPD (p < 0.0001), plaque (PI) at site level (p = 0.011), molar tooth (p = 0.012), furcation involvement (p < 0.0001), shallow intrabony defect (p = 0.018), deep intrabony defect (p = 0.002).

No difference in clinical and patient-centered outcomes was observed between groups. NSPT frequently failed to achieve EoT at pockets with intrabony defects, while EoT were frequently achieved at sites with mainly horizontal bony defects.

ClinicalTrials.gov identifier: NCT06086821 (https://clinicaltrials.gov/study/NCT06086821?cond=re-evaluation%20periodontal&rank=1).