title: Effect of different crown contours on periodontal health in dogs. Clinical results.
abstract: OBJECTIVE
  The aim of this study is to evaluate clinically the effect of different crown contours on the periodontium in beagle dogs.
  
  
  METHODS
  One month after commencing oral hygiene procedures the second and third premolars in three quadrants of four adult beagle dogs were prepared for receiving crowns. The unprepared second and third premolars in one quadrant served as controls. Crowns with three different emergence profiles (normal (=tooth) contour, 30 degrees and 50 degrees over-contour) were cemented where one quadrant received the same treatment. Clinical parameters were recorded on all four sites (mesial, buccal, distal and lingual) of test and control teeth at baseline, after 3 and 5 months. During the entire study period, professional oral hygiene was performed seven times a week.
  
  
  RESULTS
  The Plaque Index increased for the 30 degrees and 50 degrees over-contour groups, although no statistically significant differences could be observed. For the normal contour and control group minor changes occurred. Similar results could be depicted for the Gingival Index. The changes regarding the variables Plaque and Gingival Index were correlated to the Gingival Crevicular Fluid Flow. Here, significant differences for the Gingival Crevicular Flow were observed between the treatment groups and over the treatment period for the 30 and 50 degrees over-contour groups. Only slight differences for this parameter were observed in and between the control and normal contour groups. In the control group, the Pocket Probing depth remained stable during the entire study but increased in the crowned treatment groups over time. At 3 and 5 months the probing depth was significant greater in the 30 degrees and 50 degrees over-contour groups compared to the control group. There was a higher loss of clinical attachment levels for the test groups than for the control group. There were statistically significant differences at each timepoint between groups and also within groups except for the control group.
  
  
  CONCLUSIONS
  Within the limits of this study it can be concluded that over-contoured subgingival crowns seem to affect clinical periodontal health only slightly in dogs over 5 months when an intensive oral hygiene regimen is executed.
authors.affiliation: Department of Prosthodontics, Albert-Ludwigs University, Freiburg, Germany. kohal@zmk2.uni-freiburg.de
authors.forename: R J
authors.initials: RJ
authors.lastname: Kohal
authors.forename: T
authors.initials: T
authors.lastname: Gerds
authors.forename: J R
authors.initials: JR
authors.lastname: Strub
mesh_terms: D000818:Animals; D003442:Crowns / Q000009:adverse effects*; D003773:Dental Plaque / Q000209:etiology; D003774:Dental Plaque Index; D017267:Dental Prosthesis Design; D004285:Dogs; D005883:Gingival Crevicular Fluid; D017622:Periodontal Attachment Loss / Q000209:etiology; D010512:Periodontal Index; D018709:Statistics, Nonparametric