Surface treatment of indirect resin composite surfaces before cementation

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• The use of hydrofluoric acid (HFA) for preparing indirect composite precementation surfaces remains a topic of debate.
• Effective surface treatment is crucial for optimal bonding of indirect restorations.

Purpose of the Study:

• To compare the effects of combining hydrofluoric acid (HFA) or orthophosphoric acid (OPA) with microetching as precementation surface treatments for indirect composites.
• To evaluate the impact of different surface preparation methods on the bond strength of indirect composite restorations.

Main Methods:

• Three types of composite materials were used to create simulated indirect restorations.
• Specimen surfaces were treated with HFA, OPA, or microetching.
• Bond strength was assessed using specific dental cements and bonding protocols.
• Scanning electron microscopy (SEM) and microscopic analysis were employed for surface and fracture evaluation.

Main Results:

• No significant differences in bond strengths were observed across all tested surface treatments.
• Hybrid composites exhibited higher bond strength with etching compared to microfill composites.
• Mechanical roughening yielded the highest bond strengths for microfill composites.
• Microetching with orthophosphoric acid (OPA) resulted in higher bond strengths on hybrid composites compared to microetching with hydrofluoric acid (HFA).

Conclusions:

• Acid etching alone is insufficient for achieving effective bond strengths in indirect composite restorations.
• Hydrofluoric acid (HFA) treatments appear to be detrimental to the integrity and bonding of resin composites.