The effects of common errors on sealing ability of total-etch adhesives.
OBJECTIVE
This study evaluated the effect of errors commonly made in using total-etch adhesives, on the resulting bond strength, fluid movement and nanoleakage of resin dentin bonds.


METHODS
Two total-etch adhesives were used for bonding to dentin according to the manufacturers' recommendations, with meticulous solvent evaporation (control), or with the introduction of common bonding errors-wet bonding without solvent evaporation (no evaporation), and dry bonding.


RESULTS
The 24-hour bond strength of the control was significantly higher than the other groups (p <0.05). For all groups, the higher initial permeability declined significantly after 24 h. The fluid movement across bonded dentin was similar in the control and dry bonding for both adhesives, whereas significantly higher permeability (p<0.05) was recorded for the no evaporation groups even after 24 h. Extensive silver impregnation within hybrid layers was seen by TEM in the no evaporation and dry bonding specimens after 24 h. Dry bonding caused collapse of the collagen matrix and interfered with resin infiltration. In contrast, inadequate solvent evaporation and/or residual water during dentin bonding results in dilution or incomplete polymerization of the resin, leading to severe nanoleakage formation.


CONCLUSIONS
Increased permeability associated with incomplete solvent evaporation in total-etch adhesives may lead to poor bond strength.
Hashimoto
Masanori
M
Division of Pediatric Dentistry, Hokkaido University, Graduate School of Dental Medicine, Kita 13, Nishi 7, Sapporo 060-8586, Hokkaido, Japan. masanori-h@mue.biglobe.ne.jp
Tay
Franklin R
FR
Svizero
Nadia R
NR
de Gee
Anton J
AJ
Feilzer
Albert J
AJ
Sano
Hidehiko
H
Kaga
Masayuki
M
Pashley
David H
DH
D000134:Acid Etching, Dental; D000269:Adhesives / Q000737:chemistry; D003094:Collagen / Q000648:ultrastructure; D001840:Dental Bonding; D003763:Dental Leakage / Q000145:classification; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D003890:Desiccation; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D010539:Permeability; D019279:Resin Cements / Q000737:chemistry; D012212:Rheology; D012997:Solvents / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000269:Adhesives; D017220:Dentin-Bonding Agents; C420130:Excite cement; D008689:Methacrylates; C451600:OptiBond Solo Plus; D019279:Resin Cements; D012997:Solvents; D014867:Water; D003094:Collagen