title: Fracture resistance of weakened teeth restored with condensable resin with and without cusp coverage.
abstract: OBJECTIVE
  This in vitro study evaluated the fracture resistance of weakened human premolars (MOD cavity preparation and pulp chamber roof removal) restored with condensable resin composite with and without cusp coverage.
  
  
  METHODS
  Thirty human maxillary premolars were divided into three groups: Group A (control), sound teeth; Group B, wide MOD cavities prepared and the pulp chamber roof removed and restored with resin composite without cusp coverage; Group C, same as Group B with 2.0 mm of buccal and palatal cusps reduced and restored with the same resin. The teeth were included in metal rings with self-curing acrylic resin, stored in water for 24 h and thereafter subjected to a compressive axial load in a universal testing machine at 0.5 mm/min.
  
  
  RESULTS
  The mean fracture resistance values +/- standard deviation (kgf) were: group A: 151.40 +/- 55.32, group B: 60.54 +/- 12.61, group C: 141.90 +/- 30.82. Statistically significant differences were found only between Group B and the other groups (p<0.05). The condensable resin restoration of weakened human premolars with cusp coverage significantly increased the fracture resistance of the teeth as compared to teeth restored without cusp coverage.
  
  
  CONCLUSIONS
  The results showed that cusp coverage with condensable resin might be a safe option for restoring weakened endodontically treated teeth.
authors.affiliation: Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil. rafamond@fob.usp.br
authors.forename: Rafael Francisco Lia
authors.initials: RF
authors.lastname: Mondelli
authors.forename: Sérgio Kiyoshi
authors.initials: SK
authors.lastname: Ishikiriama
authors.forename: Otávio
authors.initials: O
authors.lastname: de Oliveira Filho
authors.forename: José
authors.initials: J
authors.lastname: Mondelli
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D019245:Compressive Strength; D003737:Dental Cavity Preparation; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D008434:Matrix Bands; D019228:Tooth Crown / Q000293:injuries; D014082:Tooth Fractures / Q000517:prevention & control*; D019553:Tooth, Nonvital
chemical_list: D003188:Composite Resins