Influence of collagen removal on shear bond strength of one-bottle adhesive systems in dentin.
OBJECTIVE
The aim of this study was to evaluate the influence of collagen removal on shear bond strength (SBS) of three hydrophilic one-bottle adhesive systems in dentin.


METHODS
Test specimens were taken from one-hundred twenty bovine incisors. The specimens were debrided, polished with 320- to 600-grit Al2O3 paper, and randomly divided into 6 groups (n = 20): G1: acid/10% NaOCl + Bond 1 (B1H); G2: acid + Bond 1 applied according to manufacturer's instructions (B1); G3: acid/10% NaOCl + Optibond Solo (OSH); G4: acid + Optibond Solo used according to manufacturer's instructions (OS); G5: acid/10% NaOCl + Single Bond (SBH); G6: acid + Single Bond used according to manufacturer's instructions. In all groups, dentin was etched for 15 s, rinsed, and dried. In groups 1, 3, and 5, the 10% NaOCl was applied with a dwell time of 60 s, rinsed, and dried. In all groups, the adhesive systems were applied and light cured, and then a restorative composite resin (Z-100) was inserted in a teflon matrix and cured. The specimens were stored in humid conditions for 7 days at 37 degrees C. The SBS tests were performed in an EMIC universal testing machine with a crosshead speed of 0.5 mm/min. The mean bond strengths in MPa (+/- SD) were analyzed with two-way ANOVA and Tukey's test (alpha = 0.05).


RESULTS
The application of NaOCl significantly increased the SBS values of all systems except Optibond Solo. The means (SD) for adhesive systems with 10% NaOCl treatment were: SBH = 14.28 (4.21)a; B1H = 14.39 (3.61)a; OSH = 10.35 (5.74)a; and values without 10% NaOCl were: SB = 10.35 (2.95)a; B1 = 9.38 (3.10)a; OS = 9.79 (3.48)b. Different superscripts indicate significant difference.


CONCLUSIONS
The removal of collagen increased the strength of dentin bonding, depending on the adhesive system used.
de Castro
A K
AK
Department of Restorative Dentistry, School of Dentistry of Piracicaba, University of Campinas, Piracicaba, Brazil.
Hara
A T
AT
Pimenta
L A
LA
D000134:Acid Etching, Dental; D000704:Analysis of Variance; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D003094:Collagen / Q000737:chemistry / Q000648:ultrastructure*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D007180:Incisor; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D016877:Oxidants / Q000737:chemistry; D010756:Phosphoric Acids / Q000008:administration & dosage; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide; D012973:Sodium Hypochlorite / Q000737:chemistry; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D015040:Zirconium
C115611:BOND-1 adhesive; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; C092987:Optibond; D016877:Oxidants; D010756:Phosphoric Acids; D019279:Resin Cements; C083568:Z100 composite resin; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D003094:Collagen; D015040:Zirconium; D012973:Sodium Hypochlorite