Detection of acid diffusion through bovine dentine after adhesive application.
OBJECTIVE
Acidic diffusion through bovine dentine was investigated by measuring pH changes on dentine surfaces after applying three adhesive systems.


METHODS
Coronal incisor bovine dentine discs, 0.5 mm thick, were prepared from dentine close to the pulp chamber. A single-bottle adhesive system-Single Bond, a self-etching primer system-Clearfil SE Bond and an 'all-in-one' adhesive system-AQ Bond were used. The labial dentine surfaces were conditioned as follows: Single Bond groups: (SB-1) 35% phosphoric acid etchant was applied and left in place; (SB-2) the etchant was applied for 15 s and rinsed off for 10 s; (SB-3) application of adhesive agent and light curing following step SB-2; Clearfil SE Bond groups: (SE-1) SE primer was applied for 20 s and dried; (SE-2) application of adhesive agent and light curing following step SE-1; AQ Bond groups: (AQ-1) AQ Bond adhesive was applied for 20 s and dried, applied for additional 5 s and dried again; (AQ-2) light curing following step AQ-1. The pH change on the pulpal dentine surface was measured using a pH-imaging microscope.


RESULTS
All the Single Bond groups revealed a lower pH on the pulpal surface (pH 6.25, 6.59 and 6.64 for SB-1, SB-2 and SB-3, respectively) compared with intact dentine. Clearfil SE Bond and AQ Bond groups showed no significant deference in pH value from intact dentine.


CONCLUSIONS
Acid diffusion from phosphoric acid etching was observed when placed on 0.5 mm-thick dentine discs; however, there was only limited evidence of acid diffusion from SE primer and AQ Bond.
Hiraishi
N
N
Cariology and Operative Dentistry, Department of Restorative Sciences, Tokyo Medical and Dental University, Tokyo, Japan. noricoh@aol.com
Kitasako
Y
Y
Nikaido
T
T
Foxton
R M
RM
Tagami
J
J
Nomura
S
S
D000134:Acid Etching, Dental / Q000379:methods*; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000493:pharmacokinetics; D002417:Cattle; D003782:Dental Pulp / Q000737:chemistry; D003804:Dentin / Q000378:metabolism; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000493:pharmacokinetics*; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D010756:Phosphoric Acids / Q000493:pharmacokinetics; D019279:Resin Cements / Q000493:pharmacokinetics*
C453842:AQ bond; C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; C030242:phosphoric acid