Marginal adaptation of a new compomer under different conditioning methods

Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Biomaterials

Background:

• Compomer restorations are widely used in pediatric and adult dentistry.
• Achieving optimal marginal adaptation is crucial for restoration longevity and preventing secondary caries.
• The role of cavity conditioning protocols on compomer marginal seal requires further investigation.

Purpose of the Study:

• To evaluate the marginal adaptation of compomer restorations under three different cavity conditioning protocols.
• To compare the effects of 36% phosphoric acid etching, a non-rinse conditioner (NRC), and no conditioning on enamel and dentine interfaces.

Main Methods:

• This in vitro study utilized 30 extracted human molars with standardized cavity preparations.
• Cavities were restored with Dyract AP and Prime&Bond NT adhesive after applying one of three conditioning protocols: 36% phosphoric acid, NRC, or no conditioning.
• SEM analysis of epoxy resin replicas assessed the marginal adaptation at both enamel-restorative and dentine-restorative interfaces.

Main Results:

• No significant difference in marginal gap or cohesive failures was observed at the enamel-restorative interface across all groups.
• Uniform hybrid layers and long resin tags were noted in groups conditioned with 36% phosphoric acid and NRC.
• A significantly lower proportion of marginal gap (2%) was found at the dentine-restorative interface when using 36% phosphoric acid compared to no conditioning (30%).

Conclusions:

• Pre-treating cavities with 36% phosphoric acid significantly enhances compomer and adhesive adaptation to dentine.
• The conditioning method does not influence the marginal quality at the enamel-compomer interface.
• Optimizing dentine conditioning is key for improving compomer restoration marginal integrity.