title: Clinical evaluation of replacement of class V resin based composite restorations.
abstract: OBJECTIVE
  The purpose of this clinical study was to evaluate any increase in size of Class V resin based composite restorations that required replacement. Emphasis was placed on measurements of the loss of tooth structure in areas distant from the site of failure.
  
  
  METHODS
  14 Class V restorations scheduled for replacement were recorded with pre-operative impressions and intra-oral photographs. Restorations were then removed and cavity preparations were completed. A second impression and photograph were taken and stone casts were prepared for each impression. The perimeter and area of each restoration and cavity preparation were measured with a video-based imaging system (Dage 725 CCD camera) equipped with a macro lens, at a fixed magnification of x 10-15. The initial measurements of the restoration image were compared to the measurements of the new cavity preparation, in both instances excluding the site of failure. Intra-class correlation coefficient (ICR) and paired t-test were used for statistical analysis.
  
  
  RESULTS
  A significant difference between the pre and post-operative measurements for both area (P=0.0125) and perimeter (P=0.003) was found.
  
  
  CONCLUSIONS
  The study showed that replacement of Class V resin based composite restorations resulted in increased size of the cavity preparation in areas distant from the site of failure.
authors.affiliation: College of Dentistry, Department of Operative Dentistry, Health Science Center, University of Florida, PO Box 100415, Gainesville, FL 32610-0415, USA. vgordan@dental.ufl.com
authors.forename: V V
authors.initials: VV
authors.lastname: Gordan
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D003731:Dental Caries / Q000628:therapy; D003737:Dental Cavity Preparation / Q000145:classification; D003743:Dental Enamel / Q000473:pathology*; D003761:Dental Impression Technique; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000145:classification*; D005899:Glass Ionomer Cements; D006801:Humans; D007091:Image Processing, Computer-Assisted; D003765:Models, Dental; D023861:Photography, Dental; D012008:Recurrence; D015203:Reproducibility of Results; D019233:Retreatment; D016037:Single-Blind Method; D013223:Statistics as Topic; D013499:Surface Properties; D014743:Videotape Recording
chemical_list: D003188:Composite Resins; D005899:Glass Ionomer Cements; C074741:Silux Plus; C084541:Fuji glass-ionomer lining cement