Effect of evaporation of primer components on ultimate tensile strengths of primer-adhesive mixture.
OBJECTIVE
The purpose of the present study was to evaluate the effect of evaporation of primer components on the ultimate tensile strength (UTS) of primer-adhesive mixtures.


METHODS
The UTSs of 1:3 by weight primer-adhesive mixtures and of the pure adhesives (controls) were measured after 0-, 2-, 5-min and 24-h storage in a 37 degrees C oven for the three-step etch&rinse adhesive OptiBond FL (Kerr) and the two-step self-etch adhesive Clearfil SE (Kuraray).


RESULTS
Evaporation of primer components increased with time for both adhesives investigated. OptiBond FL showed a higher evaporation of primer components than Clearfil SE at the 2-, 5-min and 24-h storage time. As compared to the pure adhesive, the UTS of the primer-adhesive mixture was lower after 0- and 2-min storage for OptiBond FL and after 0-, 2- and 5-min storage for Clearfil SE. The UTS of OptiBond FL was higher than that of Clearfil SE at the 0- and 2-min storage time, though there was no difference at the 5-min and 24-h storage time.


CONCLUSIONS
The degree of evaporation of primer components depended largely on the primer solvents employed. The significant decrease in UTS of adhesive resin when mixed with primer must be attributed to incomplete evaporation of primer components. Complete evaporation of solvents is hard to achieve, even by thorough air drying.
Ikeda
Takatsumi
T
Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium.
De Munck
Jan
J
Shirai
Kenichi
K
Hikita
Kazuhiro
K
Inoue
Satoshi
S
Sano
Hidehiko
H
Lambrechts
Paul
P
Van Meerbeek
Bart
B
D000269:Adhesives / Q000737:chemistry*; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D003890:Desiccation; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D012997:Solvents; D013718:Tensile Strength; D013997:Time Factors; D014835:Volatilization
D000269:Adhesives; C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; C469607:OptiBond FL; D019279:Resin Cements; D012997:Solvents