title: An in vitro evaluation of microtensile bond strengths of two adhesive bonding agents to residual dentine after caries removal using three excavation techniques.
abstract: OBJECTIVE
  To assess amounts of residual dentine retained after using three excavation techniques; the microtensile bond strengths (microTBS) to residual dentine, comparing etch-rinse vs. self-etching adhesives.
  
  
  METHODS
  42 carious molars were subdivided (N=21) dependent upon adhesive/composite system (Adper Scotchbond 1XT and Filtek Supreme vs. Filtek Silorane adhesive and composite). Dividing into three (N=7), dependent upon caries excavation technique employed (hand vs. chemo-mechanical: Carisolv gel vs. experimental enzymatic gel (SFC-V)), caries removal was assessed using visual/tactile criteria and in situ autofluorescence (AF) confocal fibre-optic micro-endoscopy (CFOME). Post-restoration/four-week hydrated storage, four 0.9 mm(2) beams per tooth underwent microTBS testing/microscopic analysis of fractured surfaces. Three cavities from each excavation group were analysed using SEM.
  
  
  RESULTS
  SEM revealed surface roughness with smear layer occluding tubule orifices in hand-excavated samples and a reduced, variable smear layer for both chemo-mechanical systems. CFOME AF assessment indicated hand excavation left sound dentine, Carisolv left affected dentine and SFC-V slightly under-prepared clinically. Mean microTBS values from etch-rinse samples (27 MPa (SD 3.9), hand; 22 MPa (SD 5.1), Carisolv; 26 MPa (SD 4.4), SFC-V) showed statistical differences between hand and Carisolv groups. Mean microTBS data for self-etch samples (22 MPa (SD 3.3), hand; 27 MPa (SD 6.1), Carisolv; 25 MPa (SD 4.7), SFC-V) showed significant differences between hand and Carisolv, and hand vs. SFC-V. Failure loci distribution in etch-rinse samples was between dentine-adhesive, within adhesive and within composite whereas self-etch samples exhibited failure predominantly between adhesive and composite.
  
  
  CONCLUSIONS
  Data indicated that all null hypotheses were disproved.
authors.affiliation: King's College London Dental Institute, KCL, United Kingdom. avijit.banerjee@kcl.ac.uk
authors.forename: A
authors.initials: A
authors.lastname: Banerjee
authors.forename: S
authors.initials: S
authors.lastname: Kellow
authors.forename: F
authors.initials: F
authors.lastname: Mannocci
authors.forename: R J
authors.initials: RJ
authors.lastname: Cook
authors.forename: T F
authors.initials: TF
authors.lastname: Watson
mesh_terms: D000134:Acid Etching, Dental; D000268:Adhesiveness; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology / Q000628:therapy*; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005453:Fluorescence; D018698:Glutamic Acid / Q000627:therapeutic use; D006801:Humans; D007930:Leucine / Q000627:therapeutic use; D008239:Lysine / Q000627:therapeutic use; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000473:pathology; D055100:Optical Fibers; D010434:Pepsin A / Q000627:therapeutic use; D019279:Resin Cements / Q000737:chemistry; D016369:Smear Layer; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D014867:Water / Q000737:chemistry
chemical_list: C119934:Carisolv; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C543062:Filtek LS Low Shrink resin; C474035:Filtek Supreme; D019279:Resin Cements; D014867:Water; D018698:Glutamic Acid; C041330:Scotchbond; D010434:Pepsin A; D007930:Leucine; D008239:Lysine