title: Restoring cervical lesions with flexible composites.
abstract: OBJECTIVE
  Flexure at the tooth cervix has been suggested to dislodge cervical restorations more rapidly. The objective of this randomized controlled clinical trial was to test the hypothesis that a higher composite flexibility better withstands tooth flexure stress.
  
  
  METHODS
  One hundred and forty-two non-carious cervical lesions were restored with composites with contrasting stiffness. Seventy-one patients randomly received two cervical restorations placed following two out of the three experimental groups: (1) the three-step etch-and-rinse adhesive Permaquick applied with the stiff micro-hybrid composite Amelogen Hybrid (PMQ/A-Hy, Ultradent), (2) Permaquick applied with the more flexible micro-filled composite Amelogen Microfill (PMQ/A-Mi, Ultradent), or (3) the 'golden standard' three-step etch-and-rinse adhesive Optibond FL applied with the micro-hybrid composite Prodigy (O-FL/Pro, Kerr).
  
  
  RESULTS
  The recall rate at 7 years was 80%. No statistically significant difference was found for any of the parameters evaluated neither between both adhesives, nor between both composites (McNemar, p>0.05). Eleven percent of the O-FL/Pro restorations were clinically unacceptable due to loss of retention (5.5%) and severe marginal discoloration (5.5%). In the PMQ-group, 22% of the PMQ/A-Mi restorations (8% loss of retention, 5% severe enamel margin defects, 3% severe dentin margin defects, 6% severe marginal discoloration, 3% extreme sensitivity) and 19% of the PMQ/A-Hy restorations (13% loss of retention, 3% severe enamel margin defects, 3% severe marginal discoloration) needed repair or replacement.
  
  
  CONCLUSIONS
  The clinical performance of the three adhesive/composite combinations was good and reliable during the 7-year clinical trial. It was concluded that the composite stiffness does not affect the clinical longevity of cervical composite restorations.
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium. marleen.peumans@med.kuleuven.ac.be
authors.forename: M
authors.initials: M
authors.lastname: Peumans
authors.forename: J
authors.initials: J
authors.lastname: De Munck
authors.forename: K L
authors.initials: KL
authors.lastname: Van Landuyt
authors.forename: P
authors.initials: P
authors.lastname: Kanumilli
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshida
authors.forename: S
authors.initials: S
authors.lastname: Inoue
authors.forename: P
authors.initials: P
authors.lastname: Lambrechts
authors.forename: B
authors.initials: B
authors.lastname: Van Meerbeek
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D003763:Dental Leakage; D018772:Dental Marginal Adaptation; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D003807:Dentin Sensitivity; D004548:Elasticity; D006801:Humans; D010316:Particle Size; D018583:Pliability; D011446:Prospective Studies; D019279:Resin Cements; D016037:Single-Blind Method; D018709:Statistics, Nonparametric; D019237:Tooth Cervix
chemical_list: D003188:Composite Resins; D019279:Resin Cements; C106662:amelogen