The in vitro dentin bond strengths of two adhesive systems in class I cavities of human molars.
OBJECTIVE
The purpose of this study was to evaluate the in vitro dentin bond strengths of two dentin bonding systems in Class I cavities following fatigue load cycling (FLC) with thermal cycling (TC).


METHODS
Class I cavities were prepared in 12 human molars and restored with either Clearfil SE Bond (SE) and Clearfil AP-X resin composite (AP-X) or Single Bond (SB)/AP-X according to the manufacturers' instructions. After water storage for 1 week, untreated controls and test samples were subjected to 50,000 FLC with TC from 5 degrees C to 55 degrees C for 625 cycles and stored in water for 1 week. Microtensile bond strength (MTBS) tests were measured on the floor of the cavities at a crosshead speed of 1 mm/min. Data were statistically analyzed using one- and two-way ANOVA and Fisher's PLSD test at a 5% level of significance.


RESULTS
The MPa results were: SE 30.5+/-12.8 (control) and 23.2+/-10.8 (50,000 FLC); SB 5.1+/-9.2 (control) and 4.7+/-5.7 (50,000 FLC). Bond strengths were not statistically significantly affected by FLC (p > 0.05); however, they were influenced by the bonding system (p < 0.05). The MTBS of SE was significantly higher than that of SB (p < 0.05) under FLC and TC test conditions. Over half of the SB specimens debonded during sample preparation, showing blister-like structures, suggesting that an over-wet phenomenon occurred on the cavity floor.


CONCLUSIONS
SE produced excellent dentin bonds that were much stronger than those produced by SB, which was shown to be a technique-sensitive bonding system.
Nikaido
Toru
T
Cariology and Operative Dentistry, Department of Restorative Sciences, Tokyo Medical and Dental University, Japan. nikaido.ope@tmd.ac.jp
Kunzelmann
Karl-Heinz
KH
Ogata
Miwako
M
Harada
Naoko
N
Yamaguchi
Saori
S
Cox
Charles F
CF
Hickel
Reinhard
R
Tagami
Junji
J
D000134:Acid Etching, Dental; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000145:classification*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008963:Molar; D019279:Resin Cements / Q000737:chemistry; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013816:Thermodynamics; D014867:Water / Q000737:chemistry; D016474:Weight-Bearing
C112828:Clearfil AP-X; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate