Comparative Evaluation of Effect of Salivary Contamination on Microleakage Using 8th Generation Bonding Agent with and Without Laser Application: An In Vitro Study.

Abstract

Introduction: This study highlights that microleakage significantly affects the longevity of bonded restorations, especially in Class V cavities where moisture control is difficult. Salivary contamination reduces bond strength, leading to clinical failures. While advanced 8th-generation nano-adhesives improve adhesion, limited research exists on laser activation after contamination—making this study crucial in evaluating its effect on microleakage and bonding performance

Objectives:

The aim of this study is to evaluate the Microleakage after Salivary Contamination Using 8th Generation Bonding Agent with and without Laser Application.

METHOD AND MATERIALS:

Thirty freshly extracted human premolars were collected for the study. These teeth were randomly divided into three groups (n=10): Group 1 (control), Group 2 (salivary contamination without laser activation), and Group 3 (salivary contamination with laser activation).

A Class V cavity was prepared on the buccal surface of each tooth. The bonding agent was applied and light cured without contamination in Group 1. For Group 2, the teeth were contaminated with saliva before curing the bonding agent, while for Group 3, the teeth were contaminated with saliva, and laser activation was performed before curing the bonding agent. All groups were then restored with composite restoration.

All samples underwent thermocycling and were prepared for dye immersion. The samples were immersed in 2% Methylene Blue dye for 24 hours and then sectioned buccolingually. Each half of the buccolingually sectioned samples was observed under a stereomicroscope at 40x magnification to evaluate microleakage.

STATISTICAL ANALYSIS:

Statistical analysis was conducted using the anova and post hoc Test to compare microleakage between the control and saliva-contaminated groups, as well as the effect of laser treatment on bonding agent.

RESULTS :

Results showed that samples treated with laser activation after salivary contamination exhibited significantly lower microleakage indicating a stronger seal compared to non-laser-treated samples.

Conclusion:

Laser activation enhances bonding effectiveness in contaminated conditions, reducing microleakage and supporting its use in challenging clinical settings.