title: Patient compliance and periodontal outcomes.
abstract: METHODS
  PubMed, Embase and Cochrane Central Register of Controlled Trials (CENTRAL) were searched until 2014. Reference lists from the articles were examinedStudy selectionTwo authors independently searched for randomised and non-randomised controlled trials and prospective and retrospective cohorts with a mean follow up period of at least five years.
  
  
  METHODS
  Quality of the studies was assessed using the Newcastle-Ottawa scale (NOS) and the data were extracted on a specially designed form. The primary outcome was calculated as risk ratio of tooth loss (RRTL). Risk difference of tooth loss (RDTL) and weighted mean difference of tooth loss rate (WDTLR) were also calculated.
  
  
  RESULTS
  One prospective and seven retrospective cohort studies including 1409 participants were included. The pooled RRTL was calculated as 0.56 (CI: 0.38,0.82) P<0.01, while the pooled RDTL was calculated as -0.05 (CI: -0.08, -0.01) p<0.01. Based on the risk difference, the NNT was calculated as 20.
  
  
  CONCLUSIONS
  Tooth loss rate was significantly lower in the regular compliance group over the five years. To prevent one extraction, 20 teeth have to be maintained with regular compliance for more than five years.
authors.affiliation: School of Dentistry, Faculty of Medicine and Dentistry, School of Dentistry, University of Alberta, Canada.
authors.forename: Camila
authors.initials: C
authors.lastname: Pachêco-Pereira
authors.affiliation: New York University College of Dentistry, New York, USA.
authors.forename: Silvia
authors.initials: S
authors.lastname: Spivakovsky
mesh_terms: D006801:Humans; D010349:Patient Compliance; D010510:Periodontal Diseases / Q000517:prevention & control*; D016388:Tooth Loss / Q000209:etiology*