title: Influence of long-term water storage and thermocycling on shear bond strength of glass-ionomer cement to Er:YAG laser-prepared dentin.
abstract: OBJECTIVE
  To evaluate the influence of long-term water storage and thermocycling on the shear bond strength of a glass-ionomer cement to Er:YAG-irradiated and bur-prepared dentin.
  
  
  METHODS
  Fifteen bovine incisors were selected and the roots removed. Crowns were sectioned into four pieces, resulting in 60 samples that were individually embedded in polyester resin (n = 15) and ground to plane the enamel and expose the dentin. The bonding site was delimited and samples were randomly assigned according to the method of cavity preparation: Er:YAG laser (250 mJ/4 Hz) or high-speed handpiece (diamond bur #2096). Samples were fixed to a metallic device, where glass-ionomer cement (GIC) cylinders were prepared. Subsequently, they were subdivided according to the duration of water storage (WS) and number of thermocycles (TCs) - 24 h WS/no TCs and 6 months WS/12,000 TCs - and subjected to a shear bond strength test (500 N at 0.5 mm/min).
  
  
  RESULTS
  The duration of water storage and number of thermocycles tested had no statistically significant effect on the shear bond strength to laser-irradiated dentin (p > 0.05). For bur-prepared substrate, the long-term degradation process promoted a decrease in shear bond strength values (p < 0.05).
  
  
  CONCLUSIONS
  Long-term water storage and thermocycling did not affect shear bond strength of glass-ionomer cement bonded to Er:YAG laser-prepared dentin.
authors.forename: Vivian
authors.initials: V
authors.lastname: Colucci
authors.forename: Ana Bárbara
authors.initials: AB
authors.lastname: de Araújo Loiola
authors.forename: Daniela Segura
authors.initials: DS
authors.lastname: da Motta
authors.forename: Flávia Lucisano
authors.initials: FL
authors.lastname: do Amaral
authors.forename: Jesus Djalma
authors.initials: JD
authors.lastname: Pécora
authors.forename: Silmara Aparecida
authors.initials: SA
authors.lastname: Corona
mesh_terms: D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003754:Dental High-Speed Equipment; D003804:Dentin / Q000528:radiation effects* / Q000648:ultrastructure; D018130:Diamond / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D028022:Low-Level Light Therapy / Q000295:instrumentation; D008422:Materials Testing; D011897:Random Allocation; D033081:Shear Strength; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D005899:Glass Ionomer Cements; D014867:Water; D018130:Diamond