title: A survey of cusp fractures in a population of general dental practices.
abstract: OBJECTIVE
  This study was conducted to expand the knowledge on the incidence of complete cusp fractures of posterior teeth in Dutch general practices.
  
  
  METHODS
  During a 3-month period, data were obtained from 28 general practitioners, representing 46,394 patients. For each new case of complete cusp fracture, clinicians recorded information using a standard form with questions relating to location of the fracture, cause of fracture, and restorative status of the tooth prior to the cusp fracture.
  
  
  RESULTS
  There were 238 cases of complete cusp fracture recorded. The results of this study indicate an incidence rate of cusp fractures of 20.5 per 1,000 person-years at risk. Molars were more frequently registered with cusp fractures than premolars (79% vs 21%). Maxillary molars presented more fractures of buccal cusps (66% vs 34%), while mandibular molars presented more fractures of lingual cusps (75% vs 25%). Almost 77% of the cases had been restored on three or more surfaces. Statistical analysis revealed a positive correlation between history of endodontic treatment and subgingival fracture location. Mastication was most frequently reported as the cause for fracture (54%), although one can argue whether the occlusal force was the cause or the immediate reason.
  
  
  CONCLUSIONS
  This study revealed that complete cusp fracture is a common phenomenon in dental practice and has shown differences in cusp fracture with respect to tooth type and restorative status of the tooth. Teeth with a history of endodontic treatment are susceptible to unfavorable subgingival fracture locations.
authors.affiliation: Department of Oral Function and Prosthetic Dentistry, College of Dental Sciences, University of Nijmegen, The Netherlands. w.fennis@dent.umcn.nl
authors.forename: Willem M M
authors.initials: WM
authors.lastname: Fennis
authors.forename: Ruud H
authors.initials: RH
authors.lastname: Kuijs
authors.forename: Cees M
authors.initials: CM
authors.lastname: Kreulen
authors.forename: F Joost M
authors.initials: FJ
authors.lastname: Roeters
authors.forename: Nico H J
authors.initials: NH
authors.lastname: Creugers
authors.forename: Rob C W
authors.initials: RC
authors.lastname: Burgersdijk
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001641:Bicuspid / Q000293:injuries; D001732:Bite Force; D016009:Chi-Square Distribution; D016001:Confidence Intervals; D003743:Dental Enamel / Q000293:injuries*; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D004198:Disease Susceptibility; D005260:Female; D005792:General Practice, Dental / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008334:Mandible; D008409:Mastication; D008437:Maxilla; D008875:Middle Aged; D008963:Molar / Q000293:injuries; D009426:Netherlands / Q000453:epidemiology; D012390:Root Canal Therapy / Q000706:statistics & numerical data; D012737:Sex Factors; D013223:Statistics as Topic; D019228:Tooth Crown / Q000293:injuries*; D014082:Tooth Fractures / Q000145:classification / Q000453:epidemiology*