title: Short communication: pre- and co-curing effect of adhesives on shear bond strengths of composite resins to primary enamel and dentine: an in vitro study.
abstract: OBJECTIVE
  To evaluate and compare shear bond strengths of composite resins to primary enamel and dentine when the adhesives are pre-cured (light cured before the application of the resin) or co-cured (adhesive and the resin light cured together).
  
  
  METHODS
  Buccal surfaces of 80 caries-free primary molars were wet ground to create bonding surfaces on enamel and dentine and specimens mounted on acrylic blocks. Two bonding agents (Prime and Bond NT® and Xeno III®) were applied to either enamel or dentine as per manufacturer's instructions. In 40 specimens, the bonding agent was light cured immediately after the application (pre-cured). The other 40 specimens were not light cured until the composite resin application (co-cured). Resin composite cylinders were made incrementally using acrylic moulds over the adhesives and light cured. Specimens were stored in deionised water for 24 hours at room temperature. Shear bond strength was measured using an Instron universal testing machine (in MPa) and was analysed with Student's unpaired t test.
  
  
  RESULTS
  Light curing the adhesive separately produced significantly higher bond strengths to primary dentine than co-curing (p<0.001). At the same time light curing the adhesive separately did not produce significantly different bond strengths to primary enamel (p>0.05).
  
  
  CONCLUSIONS
  Curing sequence had no significant effect on shear bond strength of adhesives on the primary enamel. Pre-curing adhesives before curing composite resins produced greater shear bond strength to primary dentine.
authors: Department of Paedodontics and Preventive Dentistry, College of Dental Sciences, Davangere, Karnataka, India. govisrev@rediffmail.com
authors: R
authors: R
authors: Viswanathan
authors: K K
authors: KK
authors: Shashibhushan
authors: V V
authors: VV
authors: Subba Reddy
mesh_terms: D003188:Composite Resins / Q000528:radiation effects; D001840:Dental Bonding; D003743:Dental Enamel; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents / Q000528:radiation effects; D006801:Humans; D055115:Light-Curing of Dental Adhesives / Q000379:methods*; D008963:Molar; D011109:Polymethacrylic Acids / Q000528:radiation effects; D019279:Resin Cements / Q000528:radiation effects; D033081:Shear Strength; D013997:Time Factors; D014094:Tooth, Deciduous
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D019279:Resin Cements; C487957:Xeno III