title: The role of dentin moisture in the degradation of resin-dentin interfaces under clinical and laboratory conditions.
abstract: BACKGROUND
  The authors conducted a study to evaluate the influence of dentin moisture on the degradation of the resin-dentin interface in primary teeth under clinical and laboratory conditions.
  
  
  METHODS
  The authors prepared 40 Class I restorations (five teeth per group) by using a cylindrical diamond bur, leaving a flat dentin surface on the pulpal floor. They vigorously rubbed two coats of a simplified etch-and-rinse adhesive on either dry or wet demineralized dentin under clinical or laboratory conditions. After performing restorative procedures, the authors extracted teeth prepared under clinical conditions after 20 minutes (immediately) or the teeth exfoliated after six months. The authors also tested the teeth prepared under laboratory conditions immediately or after six months of being stored in water. They sectioned the teeth to obtain resin-dentin bonded specimens for microtensile testing and for silver nitrate uptake (SNU) under scanning electron microscopy. They performed a three-way analysis of variance and Tukey test (α = .05) on the SNU bond strength data.
  
  
  RESULTS
  Statistically higher bond strength values (megapascals [standard deviation]) were observed when bonding was performed under laboratory conditions (clinical = 25.2 [3.6] MPa versus laboratory = 28.5 [4.4] MPa; P < .05). Degradation occurred only in the wet dentin groups under both experimental conditions (immediately = 31.3 [4.5] MPa versus after six months = 21.3 [2.1] MPa; P < .05). SNU occurred in all groups and was statistically higher after six months of clinical function or water storage (immediately = 13.9 [4.9 SD] percent versus after six months = 34.1 [4.5 SD] percent; P < .05).
  
  
  CONCLUSIONS
  The bonding of adhesives to dry demineralized dentin produces adhesive interfaces that are more resistant to degradation regardless of the bonding condition.
  
  
  CONCLUSIONS
  Resin-dentin bond strengths produced under laboratory conditions in primary teeth may be higher than those obtained under clinical circumstances, although both conditions (clinical and laboratory) seemed to yield similar results. Bonding to dry demineralized primary tooth dentin produced resin-dentin interfaces that were more resistant to degradation.
authors: Department of Restorative Dentistry, School of Dentistry, Rua Carlos Cavalcanti, 4748, Universidade Estadual de Ponta Grossa, Ponta Grossa, Paraná, Brazil, 84030-900. reis_ale@hotmail.com
authors: Alesssandra
authors: A
authors: Reis
authors: Ana C
authors: AC
authors: Chibinski
authors: Rodrigo
authors: R
authors: Stanislawczuk
authors: Denise S
authors: DS
authors: Wambier
authors: Rosa Helena M
authors: RH
authors: Grande
authors: Alessandro D
authors: AD
authors: Loguercio
mesh_terms: D000704:Analysis of Variance; D002648:Child; D001840:Dental Bonding; D003763:Dental Leakage / Q000175:diagnosis; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis; D003804:Dentin; D006801:Humans; D008963:Molar; D012835:Silver Nitrate; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D013997:Time Factors; D014094:Tooth, Deciduous; D017155:Wettability
chemical_list: D012835:Silver Nitrate