Self-etch vs etch-and-rinse adhesives: effect of thermo-mechanical fatigue loading on marginal quality of bonded resin composite restorations.

Abstract

OBJECTIVE:

This study evaluated the marginal integrity of dentine adhesives bonded to enamel and dentine, before and after thermo-mechanical loading (TML).

METHODS:

MO cavities with proximal boxes beneath the CEJ were prepared in extracted human third molars. Direct resin composite restorations (Tetric Ceram) were bonded with 3-step etch-and-rinse (Syntac Classic, Solobond Plus, OptiBond FL), 2-step etch-and-rinse (Admira Bond, Single Bond), 2-step self-etch (AdheSE, Clearfil SE Bond), and 1-step self-etch (all-in-one) adhesives (Adper Prompt, Xeno III, iBond). Marginal gaps were analyzed using SEM of epoxy resin replicas. Bonded interfaces before TML were examined with TEM to identify pre-existing attributes for subsequent marginal disintegration.

RESULTS:

In enamel, high percentages of gap-free margins were initially identified for all adhesives. After TML, etch-and-rinse adhesives exhibited significantly higher percentages of gap-free margins (approximately 90%) compared with two-step self-etch (approximately 75%) and all-in-one (approximately 55%) adhesives (p<0.05). iBond did not completely etch through the enamel smear layer. In dentine, 89-100% gap-free margins were initially observed. After TML, there were no statistical differences among etch-and-rinse (62-70%) and two-step self-etch (62-63%) adhesives (p>0.05). The all-in-one adhesives exhibited significantly less gap-free margins (<40%) in dentine (p<0.05), with iBond showing the worst marginal integrity (15%). The presence of pre-existing water channels within the adhesives probably expedited water sorption when restorations were under functional stresses.

CONCLUSION:

Enamel bonding was more effective with phosphoric acid-etching. Etch-and-rinse and 2-step self-etch adhesives showed promising marginal adaptation to dentine and may have a better clinical prognosis than the all-in-one bonding approach.

• Authors: Roland Frankenberger, Franklin R Tay
• Journal: Dental materials : official publication of the Academy of Dental Materials (Dent Mater) Vol. 21 Issue 5 Pg. 397-412 (May 2005) ISSN: 0109-5641 [Print] England
• PMID: 15826696 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Acrylic Resins
• AdheSE cement
• Adper Prompt Self-Etch
• Clearfil SE Bond
• Composite Resins
• Dentin-Bonding Agents
• Methacrylates
• OptiBond FL
• Organophosphates
• Resin Cements
• Solobond Plus adhesive
• Syntac dentine adhesive
• Tetric ceram
• Xeno III
• admira bond
• iBond
• single bond
• Bisphenol A-Glycidyl Methacrylate

Topics

• Acid Etching, Dental (methods)
• Acrylic Resins
• Bisphenol A-Glycidyl Methacrylate
• Composite Resins
• Dental Bonding
• Dental Marginal Adaptation
• Dental Restoration, Permanent
• Dental Stress Analysis
• Dentin-Bonding Agents
• Hot Temperature
• Humans
• Methacrylates
• Organophosphates
• Random Allocation
• Resin Cements
• Statistics, Nonparametric