title: Fracture Resistance and Cusp Deflection of Lined or Non-lined Composite and Glass Hybrid Restorations Over Residual Demineralized Dentin.
abstract: OBJECTIVE
  To assess the fracture resistance (FR) and cusp deflection (CD) of lined or non-lined composite (CO) and glass hybrid (GH) restorations over residual demineralized dentin.
  
  
  METHODS
  In 48 extracted human premolars, artificial residual demineralized dentin was induced on pulpo-axial walls of standardized cavities. Various restorations were placed over this demineralized dentin: an experimental GH, a composite restoration (OptiBond FL+Tetric EvoCeram) without lining, or composite restorations with non-setting (Hypocal) or setting (Dycal) calcium hydroxide lining. After thermomechanical cycling, groups (n = 12) were compared regarding their CD and FR.
  
  
  RESULTS
  CD did not differ significantly between groups. FR was significantly lower in teeth restored with GH (median: 238 N; 25th/75th percentiles: 191/287 N) than in those restored with lined or non-lined composites (median range: 517-569 N; p < 0.05/Mann-Whitney), which did not differ significantly from each other (p > 0.05).
  
  
  CONCLUSIONS
  Within the conditions of this in vitro study, CH lining of pulpo-axial walls had only limited impact on CD and FR. GH showed the lowest FR and might not be optimal for restoring deep or extended cavitated lesions.
authors.forename: Michael
authors.initials: M
authors.lastname: Sawalt
authors.forename: Sebastian
authors.initials: S
authors.lastname: Paris
authors.forename: Uwe
authors.initials: U
authors.lastname: Blunck
authors.forename: Falk
authors.initials: F
authors.lastname: Schwendicke
mesh_terms: D001466:Barium Sulfate; D002126:Calcium Hydroxide; D003188:Composite Resins; D003736:Dental Cavity Lining; D003804:Dentin; D004338:Drug Combinations; D005898:Glass; D006801:Humans; D008422:Materials Testing; D008903:Minerals; D019279:Resin Cements; D017001:Tooth Demineralization
chemical_list: D003188:Composite Resins; D004338:Drug Combinations; D008903:Minerals; C469607:OptiBond FL; D019279:Resin Cements; C501891:Tetric EvoCeram; D001466:Barium Sulfate; C025702:Dycal; C088866:barium sulfate, calcium hydroxide drug combination; D002126:Calcium Hydroxide