Comparative Study of Universal Adhesives Applied in Self-Etch and Total-Etch Modes

Abstract

Background: Universal adhesives have been introduced to simplify bonding procedures by allowing clinicians to select either a self-etch or a total-etch mode with the same material.

Objective: To evaluate and compare the microtensile bond strength and microleakage of a universal adhesive in self-etch and total-etch modes to human dentin.

Materials and Methods: The present in vitro comparative experimental study was conducted in the Department of Operative Dentistry, Islamic International Dental Hospital Islamabad, Pakistan from November 2025 to April 2026 for a period of 6 months. Eighty caries-free human premolars were freshly extracted and randomly allocated into two groups (n=40 in each group). SPSS version 25 was used to analyze the data, and a p-value <0.05 was taken as significant.

Results: The mean microtensile bond strength for the total-etch group was significantly higher than that for the self-etch group (34.7 ± 6.1 MPa vs 28.4 ± 5.6 MPa, p<0.001). The total-etch group also had significantly lower microleakage scores than the self-etch group (p=0.004). The most frequent mode of bond failure in both groups was adhesive-type bond failure, with higher occurrence in the self-etch group.

Conclusion: Total-etch mode application of the universal adhesive produced significantly higher microtensile bond strength and lower microleakage than self-etch mode.