TY - JOUR
T1 - Six-month evaluation of adhesives interface created by a hydrophobic adhesive to acid-etched ethanol-wet bonded dentine with simplified dehydration protocols
AU - Sadek, Fernanda T.
AU - Mazzoni, Annalisa
AU - Breschi, Lorenzo
AU - Tay, Franklin R.
AU - Braga, Roberto R.
N1 - Funding Information:
This study was partially supported by a post-doctoral grant from FAPESP (process number 07/55117-9 ). The authors wish to thank Prof. Antonio Muench (University of São Paulo, Dept. of Dental Materials) for statistical support.
PY - 2010/4
Y1 - 2010/4
N2 - Objectives: To evaluate the efficacy of simplified dehydration protocols, in the absence of tubular occlusion, on bond strength and interfacial nanoleakage of a hydrophobic experimental adhesive blend to acid-etched, ethanol-dehydrated dentine immediately and after 6 months. Methods: Molars were randomly assigned to 6 treatment groups (n = 5). Under pulpal pressure simulation, dentine crowns were acid-etched with 35% H3PO4 and rinsed with water. Adper Scotchbond Multi-Purpose was used for the control group. The remaining groups had their dentine surface dehydrated with ethanol solutions: group 1 = 50%, 70%, 80%, 95% and 3 × 100%, 30 s for each application; group 2 the same ethanol sequence with 15 s for each solution; groups 3, 4 and 5 used 100% ethanol only, applied in seven, three or one 30 s step, respectively. After dehydration, a primer (50% BisGMA + TEGDMA, 50% ethanol) was used, followed by the neat comonomer adhesive application. Resin composite build-ups were then prepared using an incremental technique. Specimens were stored for 24 h, sectioned into beams and stressed to failure after 24 h or after 6 months of artificial ageing. Interfacial silver leakage evaluation was performed for both storage periods (n = 5 per subgroup). Results: Group 1 showed higher bond strengths at 24 h or after 6 months of ageing (45.6 ± 5.9a/43.1 ± 3.2a MPa) and lower silver impregnation. Bond strength results were statistically similar to control group (41.2 ± 3.3ab/38.3 ± 4.0ab MPa), group 2 (40.0 ± 3.1ab/38.6 ± 3.2ab MPa), and group 3 at 24 h (35.5 ± 4.3ab MPa). Groups 4 (34.6 ± 5.7bc/25.9 ± 4.1c MPa) and 5 (24.7 ± 4.9c/18.2 ± 4.2c MPa) resulted in lower bond strengths, extensive interfacial nanoleakage and more prominent reductions (up to 25%) in bond strengths after 6 months of ageing. Conclusions: Simplified dehydration protocols using one or three 100% ethanol applications should be avoided for the ethanol-wet bonding technique in the absence of tubular occlusion, as they showed decreased bond strength, more severe nanoleakage and reduced bond stability over time.
AB - Objectives: To evaluate the efficacy of simplified dehydration protocols, in the absence of tubular occlusion, on bond strength and interfacial nanoleakage of a hydrophobic experimental adhesive blend to acid-etched, ethanol-dehydrated dentine immediately and after 6 months. Methods: Molars were randomly assigned to 6 treatment groups (n = 5). Under pulpal pressure simulation, dentine crowns were acid-etched with 35% H3PO4 and rinsed with water. Adper Scotchbond Multi-Purpose was used for the control group. The remaining groups had their dentine surface dehydrated with ethanol solutions: group 1 = 50%, 70%, 80%, 95% and 3 × 100%, 30 s for each application; group 2 the same ethanol sequence with 15 s for each solution; groups 3, 4 and 5 used 100% ethanol only, applied in seven, three or one 30 s step, respectively. After dehydration, a primer (50% BisGMA + TEGDMA, 50% ethanol) was used, followed by the neat comonomer adhesive application. Resin composite build-ups were then prepared using an incremental technique. Specimens were stored for 24 h, sectioned into beams and stressed to failure after 24 h or after 6 months of artificial ageing. Interfacial silver leakage evaluation was performed for both storage periods (n = 5 per subgroup). Results: Group 1 showed higher bond strengths at 24 h or after 6 months of ageing (45.6 ± 5.9a/43.1 ± 3.2a MPa) and lower silver impregnation. Bond strength results were statistically similar to control group (41.2 ± 3.3ab/38.3 ± 4.0ab MPa), group 2 (40.0 ± 3.1ab/38.6 ± 3.2ab MPa), and group 3 at 24 h (35.5 ± 4.3ab MPa). Groups 4 (34.6 ± 5.7bc/25.9 ± 4.1c MPa) and 5 (24.7 ± 4.9c/18.2 ± 4.2c MPa) resulted in lower bond strengths, extensive interfacial nanoleakage and more prominent reductions (up to 25%) in bond strengths after 6 months of ageing. Conclusions: Simplified dehydration protocols using one or three 100% ethanol applications should be avoided for the ethanol-wet bonding technique in the absence of tubular occlusion, as they showed decreased bond strength, more severe nanoleakage and reduced bond stability over time.
KW - Bond strength
KW - Dentine
KW - Ethanol-wet bonding
KW - Interfacial nanoleakage
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U2 - 10.1016/j.jdent.2009.11.007
DO - 10.1016/j.jdent.2009.11.007
M3 - Article
C2 - 19995589
AN - SCOPUS:77649339779
SN - 0300-5712
VL - 38
SP - 276
EP - 283
JO - Journal of Dentistry
JF - Journal of Dentistry
IS - 4
ER -