In vitro bonding performance of all-in-one adhesives. Part I--microtensile bond strengths.
OBJECTIVE
The objective of this project was to compare the microtensile bond strengths (microTBS) of five "all-in-one" adhesives using two 2-step adhesives as controls.


METHODS
Eighty-four extracted human molars were randomly assigned to one of three substrates: dentin, unground enamel, or ground enamel. For each substrate, specimens were randomly assigned to one of five all-in-one adhesives: (1) Adper Prompt L-Pop (AP, 3M ESPE); (2) Clearfil S3 Bond (S3, Kuraray); (3) G-Bond (GB, GC America) (4) iBond (iB, Heraeus Kulzer); (5) Xeno IV (XE, Dentsply Caulk). Adper Single Bond Plus (SB, 3M ESPE) was used as a two-step etch-and-rinse control, while Clearfil SE Bond (SE, Kuraray) was used as a two-step self-etching control. Crowns were built with Filtek Z250 (3M ESPE) and sectioned in x and y directions. The resulting sticks were fractured in tension at a crosshead speed of 1 mm/min. Statistical analysis was computed for each substrate with one-way ANOVA and Duncan's post-hoc test at p < 0.05.


RESULTS
Means+/-SD are given in MPa; pretesting failures are shown in brackets. Dentin--SE: 79.1+/-20.5, [0/85]; SB: 76.3+/-19.3, [0/82]; AP: 51.6+/-21.9, [0/90]; XE: 40.5+/-22.9, [7/81]; S3: 27.8+/-13.2, [7/91]; iB: 17.4+/-15.6, [25/91]; GB: 11.7+/-7.4, [5/92]. Unground enamel--SB: 33.1+/-10.5, [0/69]; AP: 27.6+/-7.5, [0/66]; S3: 24.6 +/-12.0, [0/70]; SE: 16.8+/-11.7, [3/60]; XE 15.4+/-14.1, [16/63]; iB: 11.2+/-11.5, [18/64]; GB: 9.5+/-12.4, [31/63]. Ground enamel--SB: 33.7+/-9.1, [0/69]; AP: 33.2+/-7.9, [0/77]; SE: 26.4+/-9.5, [0/67]; S3: 25.5+/-8.9; [0/56]; XE: 21.0 +/-8.9, [3/68]; GB: 18.2+/-10.3, [4/68]; iB: 12.3+/-8.9, [11/52]. For dentin, the Duncan's test ranked the means in 6 statistical subsets: GB <iB <S3 <XE < AP < SB = SE. For unground enamel, means were ranked in 4 statistical subsets: GB = iB < XE = SE < S3 = AP < SB. For ground enamel, the means were also ranked in 4 statistical subsets: iB < GB = XE < S3 = SE< AP = SB.


CONCLUSIONS
The bonding ability of the newest all-in-one adhesives depends on their specific composition. In light of the low in vitro bond strengths and high rate of spontaneous failures of some all-in-one adhesives compared to those of the two-step adhesives, the newest adhesives should be screened more strictly before they are recommended for clinical use.
Perdigão
Jorge
J
Division of Operative Dentistry, Department of Restorative Sciences, University of Minnesota, Minneapolis, MN 55455, USA. perdi001@umn.edu
Gomes
George
G
Gondo
Renata
R
Fundingsland
Jon W
JW
D000269:Adhesives / Q000737:chemistry*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
D000269:Adhesives; C505694:Clearfil S3 Bond; C438313:Clearfil SE Bond; D020770:Compomers; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; C498353:G-Bond; D008689:Methacrylates; C408584:Prompt L-Pop; D019279:Resin Cements; C511238:Single Bond Plus; C417842:Xeno compomer; C477386:iBond; D017438:Bisphenol A-Glycidyl Methacrylate