Microtensile bond strength of total-etch and self-etching adhesives to caries-affected dentine.
OBJECTIVE
To evaluate the microtensile bond strength of total-etch or self-etch adhesives to caries-affected versus normal dentine, and to correlate these bond strengths with DIAGNOdent laser fluorescence and Knoop microhardness (KH) measurements of the substrates.


METHODS
Extracted carious human molars were ground to expose flat surfaces where the caries lesion was surrounded by normal dentine. Surfaces were bonded with either Prime & Bond NT, Scotchbond 1, Clearfil SE Bond or Prompt L-Pop, according to manufacturers' recommendations. A crown was built up using resin composite (Tetric Ceram). After storage in water (37 degrees C, 24 h), teeth were vertically serially sectioned into 0.7 mm thick slabs and trimmed to yield 1 mm(2) test area that contained either caries-affected or normal dentine. Samples were tested in tension in an Instron machine at 1 mm/min. The quality of the dentine just beneath each fractured specimen was measured by laser fluorescence and KH.


RESULTS
Total-etch adhesives yielded higher bond strengths than self-etching systems. Significantly lower results were obtained with Prompt L-Pop. All the adhesives attained higher strengths in normal than in caries-affected dentine, but the differences were only significant for Prime & Bond NT and Clearfil SE Bond. Higher laser fluorescence values and lower KH (p<0.001) were recorded in caries-affected dentine compared to normal dentine.


CONCLUSIONS
The total-etch adhesives evaluated produced higher bond strengths to normal and caries-affected dentine than self-etching systems. Laser fluorescence measurements discriminated caries-affected dentine from normal dentine, and were strongly correlated with KH. However, laser fluorescence and KH did not permit high correlations with resin-dentine bond strengths in caries-affected dentine.
Ceballos
Laura
L
Department of Dental Mater, School of Dentistry, University of Granada, Granada, Spain.
Camejo
Defrén G
DG
Victoria Fuentes
M
M
Osorio
Raquel
R
Toledano
Manuel
M
Carvalho
Ricardo M
RM
Pashley
David H
DH
D000134:Acid Etching, Dental / Q000379:methods*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology*; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005453:Fluorescence; D006244:Hardness; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013696:Temperature; D013718:Tensile Strength; D014867:Water / Q000737:chemistry
C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; C408584:Prompt L-Pop; D019279:Resin Cements; C121818:Tetric ceram; D014867:Water; C041330:Scotchbond