title: Variables affecting tooth survival and changes in probing depth: a long-term follow-up of periodontitis patients.
abstract: OBJECTIVE
  To retrospectively assess tooth-survival rate and its association with patient and oral variables in periodontal office patients, followed up to 18 years.
  
  
  METHODS
  Patients in a private periodontal office whose files included initial examination (T0 ), reevaluation (TRe ) and ≥ 10 years after T0 (TF ) chartings, and received periodontal therapy and supportive periodontal therapy (SPT) after TRe were included. General health, plaque scores (PI), probing depth (PPD), bleeding on probing (BOP) at six points/tooth, tooth extractions, and SPT visits were extracted from patient files at T0 , TRe , and TF . Descriptive statistics and Cox regression analysis were performed.
  
  
  RESULTS
  Fifty patients (mean 26 ± 4 teeth/patient, 1301 teeth) fulfilled inclusion criteria. About 20 and 129 teeth respectively were extracted before/after TRe , 96 of them for periodontal causes. PPD>7 mm at TRe (HR = 17.7, 95%CI 8.6, 36.6), age above 60 years (HR = 3.3, 95%CI 1.5, 7.2), multi-rooted teeth (HR = 1.9, 95%CI 1.2, 3.1) and SPT<3 times/year (HR = 1.8, 95%CI 1.1, 2.9), were the best prognostic factors for tooth loss during follow-up. (p < 0.05, Cox regression analysis). A continuous, statistically significant reduction was observed in mean PPD among teeth that survived follow-up [4.3 ± 1.8 mm, 3.5 ± 1.4 mm, 3.2 ± 1.3 mm, at T0 , TRe , TF , respectively. (p < 0.001, Repeated-measures test)].
  
  
  CONCLUSIONS
  Regular SPT was associated with low tooth-loss rates and continuous reductions in probing depth. PPD after initial therapy, age above 60, multi-rooted teeth and infrequent SPT were strong negative prognostic factors for long-term tooth survival among periodontal patients.
authors.affiliation: Department of Periodontology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Saminsky
authors.affiliation: Department of Periodontology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Michal
authors.identifier: http://orcid.org/0000-0001-9242-0616
authors.initials: M
authors.lastname: Halperin-Sternfeld
authors.affiliation: Department of Periodontology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Eli E
authors.initials: EE
authors.lastname: Machtei
authors.affiliation: Department of Periodontology, Rambam Health Care Campus, Haifa, Israel.|Private Periodontal Practice, Tel-Aviv, Israel.
authors.forename: Jacob
authors.initials: J
authors.lastname: Horwitz
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003774:Dental Plaque Index; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008963:Molar / Q000473:pathology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000150:complications* / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate; D014081:Tooth Extraction; D016388:Tooth Loss / Q000209:etiology*; D016896:Treatment Outcome
keywords: long-term follow-up; periodontal private practice and statistical prediction model; periodontal risk factors; probing pocket depth; supportive periodontal treatment; tooth loss