Effect of operator-specific handling on tooth-composite interface and microleakage formation

Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Adhesive Dentistry

Background:

• Class II cavities require precise restoration to prevent microleakage.
• Total-etch adhesive systems are widely used but can be technique-sensitive.
• Understanding interface morphology is crucial for predicting restoration longevity.

Purpose of the Study:

• To compare tooth-composite interface morphology and microleakage in Class II cavities restored with a three-step, total-etch adhesive.
• To evaluate the influence of operator technique on adhesive performance.
• To gather data for future comparisons with other adhesive systems.

Main Methods:

• In vitro study on 40 extracted molars with Class II cavities.
• Restorations performed using a multi-component, three-step, total-etch adhesive by three operators.
• Microleakage testing and scanning electron microscopy (SEM) for interface assessment.
• Part B involved a double application of the final adhesive component.

Main Results:

• Operator differences were observed in adhesive layer formation, penetration, and failure modes.
• Enhanced intertubular and peritubular adhesive penetration correlated with lower dentin microleakage.
• Double adhesive application showed partial improvements in sealing and reduced dentin failures but no significant microleakage reduction.

Conclusions:

• The etch-and-rinse adhesive system demonstrates technique sensitivity regarding interface morphology and microleakage.
• Operator skill significantly influences the quality of the adhesive bond and sealing.
• Findings provide a baseline for comparing the performance of other bonding systems.