To identify (i) the prevalence of meeting the endpoints of \'stable periodontitis\' (probing pocket depth [PPD] ≤ 4 mm, bleeding on probing [BoP] < 10%, no BoP at 4 mm sites), \'endpoints of therapy\' (no PPD > 4 mm with BoP, no PPD ≥ 6 mm), \'controlled periodontitis\' (≤4 sites with PPD ≥ 5 mm), \'PPD < 5 mm\' and \'PPD < 6 mm\' at the start of supportive periodontal care [SPC]) and (ii) the incidence of tooth loss in relation to not meeting these endpoints within a minimum of 5 years of SPC.
Systematic electronic and manual searches were conducted to identify studies where subjects, upon completion of active periodontal therapy, entered into SPC. Duplicate screening was performed to find relevant articles. Corresponding authors were contacted to confirm inclusion and retrieve required clinical data for further analyses to assess the prevalence of reaching endpoints and incidence of subsequent tooth loss, if available, within at least 5 years of SPC. Meta-analyses were carried out to evaluate risk ratios for tooth loss in relation to not reaching the various endpoints.
Fifteen studies including 12,884 patients and 323,111 teeth were retrieved. Achievement of endpoints at baseline SPC was rare (1.35%, 11.00% and 34.62%, respectively, for \'stable periodontitis\', \'endpoints of therapy\' and \'controlled periodontitis\'). Less than a third of the 1190 subjects with 5 years of SPC data lost teeth-a total of 3.14% of all teeth were lost. Statistically significant associations with tooth loss, at the subject-level, were found for not achieving \'controlled periodontitis\' (relative risk [RR] = 2.57), PPD < 5 mm (RR = 1.59) and PPD < 6 mm (RR = 1.98).
An overwhelming majority of subjects and teeth do not achieve the proposed endpoints for periodontal stability, yet most periodontal patients preserve most of their teeth during an average of 10-13 years in SPC.

While it is well-established that patients that develop signs of relapsing periodontitis in supportive periodontal care (SPC) will need to repeat subgingival instrumentation of the residual pockets, less certainty is available in terms of which protocol should be followed and whether the use of adjunctive therapies or physical agents might provide additional benefits to repeated instrumentation alone. The aim of this systematic review was therefore to assess whether repeating subgingival instrumentation in combination with adjunctive therapies (other than antimicrobials) might provide a significant benefit in terms of pocket closure, probing pocket depth (PPD) reduction or clinical attachment level (CAL) gain in patients during SPC with residual/relapsing pockets. Four databases were searched to identify randomized controlled trials (RCTs) and controlled clinical trials (CCTs) with a minimum follow-up of 3 months that investigated the use of adjunctive therapies (other than antimicrobials) in case of residual/relapsing pockets in patients in SPC since at least 3 months. Data extraction and risk of bias assessment were performed in the studies meeting the inclusion criteria and meta-analysis was performed when ≥3 studies assessing the same adjunctive therapy were identified. 12 studies (2 CCTs and 10 RCTs) were included for qualitative analysis. Meta-analysis was performed only for 3 studies on the adjunctive use of photodynamic therapy (PDT) and it indicated a nonsignificant benefit compared to the placebo in terms of PPD reduction and CAL gain at 3 months (weighted mean difference 0.07 and -0.03, respectively) and at 6 months of follow-up (weighted mean difference -0.09 and -0.18, respectively). While antiseptics did not provide significant benefits, one study on probiotics and one on the use of vitamin D and calcium supplementation showed significant improvements in periodontal parameters. There is currently insufficient/poor evidence to determine the efficacy of adjunctive strategies (other than antimicrobials) to improve the outcomes of SPC in case of residual/relapsing pockets.

OBJECTIVE: To systematically review the literature to evaluate the recurrence of disease of people in long-term supportive periodontal care (SPC), previously treated for periodontitis, and determine the effect of different methods of managing recurrence. The review focused on stage IV periodontitis.
METHODS: An electronic search was conducted (until May 2020) for prospective clinical trials. Tooth loss was the primary outcome.
RESULTS: Twenty-four publications were retrieved to address recurrence of disease in long-term SPC. Eight studies were included in the meta-analyses for tooth loss, and three studies for disease progression/recurrence (clinical attachment level [CAL] loss ≥2 mm). For patients in SPC of 5-20 years, prevalence of losing more than one tooth was 9.6% (95% confidence interval [CI] 5%-14%), while experiencing more than one site of CAL loss ≥2 mm was 24.8% (95% CI 11%-38%). Six studies informed on the effect of different methods of managing recurrence, with no clear evidence of superiority between methods. No data was found specifically for stage IV periodontitis.
CONCLUSIONS: A small proportion of patients with stage III/IV periodontitis will experience tooth loss in long-term SPC (tendency for greater prevalence with time). Regular SPC appears to be important for reduction of tooth loss. No superior method to manage disease recurrence was found.