Resin-dentin bond strength as related to different surface preparation methods

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials Engineering

Background:

• Dental adhesives are crucial for bonding restorative materials to tooth structure.
• Dentin surface preparation methods can influence the smear layer and topography, potentially affecting adhesion.
• Understanding these effects is vital for optimizing clinical bonding procedures.

Purpose of the Study:

• To evaluate the microtensile bond strength of OptiBond FL and Clearfil SE Bond to dentin prepared with various methods.
• To analyze the micromorphological structures of bonded dentin surfaces using scanning electron microscopy.

Main Methods:

• Human molars were prepared using six different surface treatments (SiC papers, diamond burs, carbide bur).
• Two dental adhesives (OptiBond FL, ClearSeal SE Bond) were applied to bond composite resin.
• Microtensile bond strength testing and scanning electron microscopy were performed.

Main Results:

• Statistical analysis revealed that surface preparation method affects dentin adhesion when within-tooth correlations are considered.
• Carbide bur preparation resulted in the lowest bond strength for both adhesives.
• Diamond bur preparation led to a more compact smear layer compared to SiC papers, influencing bond strength.

Conclusions:

• Dentin surface preparation critically influences smear layer characteristics and topography, thereby affecting resin-dentin bond strength.
• Smear layer denseness, rather than thickness, appears to be a more significant factor in compromising adhesive bonding efficacy, particularly for self-etch systems.