# Comparative Evaluation of Microleakage in Class II Composite Restorations Using Two Light-Cure Pulp Capping Agents as Cavity Liners: An In Vitro Study

## TL;DR

This study compared two light-cure pulp capping agents as cavity liners in dental restorations and found that Bio-LCB reduced microleakage more effectively than the other materials.

## Contribution

The study introduces a novel comparison of two light-cure pulp capping agents as cavity liners for reducing microleakage in class II composite restorations.

## Key findings

- Bio-LCB showed the lowest mean microleakage of 1.15 ± 0.93.
- Group 1 (self-etch bonding agent) had the highest microleakage at 3.35 ± 0.59.
- Groups 2 and 3 performed significantly better than group 1 (p < 0.05).

## Abstract

Introduction: Reducing microleakage is crucial for maintaining the long-term efficacy of composite restorations. The selection of the cavity liner may affect both the marginal seal and the structural integrity of the restoration. This study aimed to assess and compare microleakage in class II composite restorations using two distinct light-cured pulp capping agents as cavity liners, analyzed under a stereomicroscope.

Materials and methods: Class II cavities with standardized dimensions were prepared for 60 noncarious human mandibular premolars. All the specimens were randomly allocated to three distinct groups, each containing 20 samples. In group 1 (n = 20), a self-etch bonding agent (Scotchbond Universal, 3M, Minnesota, USA) was uniformly applied to the entire cavity using an applicator tip and subsequently light-cured for 20 seconds. The cavities were then restored using composite resin (Filtek Z350 XT, 3M, Minnesota, USA) and light-cured for 30 seconds. In group 2 (n = 20), an approximately 0.8-mm-thick layer of TheraCal LC (Bisco Inc., Illinois, USA) was applied to the axial wall as a cavity liner. Group 3 (n = 20) involved the application of an approximately 0.8-mm-thick layer of Bio-LCB (Essential Dental Systems, New Jersey, USA) on the axial wall as a cavity liner. All tooth surfaces, except the 2-mm-wide area surrounding the edges of each restoration, were sealed with two nail polish coats. This was followed by a 48-hour immersion in 2% methylene blue dye. The teeth were then rinsed and sectioned longitudinally in the mesiodistal direction, coincident with the center of the restoration, using a slow-speed water-cooled diamond disc. To assess microleakage, the two tooth parts exhibiting dye penetration were examined under a stereomicroscope at 20x magnification (RSMr-6 series; Radical Scientific Equipment Pvt. Ltd., Haryana, India). Intergroup comparisons were performed using one-way analysis of variance (ANOVA), followed by post-hoc analysis using Tukey’s test.

Results: Statistically significant differences were observed between the groups (p < 0.05). Group 1 exhibited the highest mean microleakage values (3.35 ± 0.59), group 2 showed a moderate reduction in microleakage with a mean value of 2.30 ± 1.17, and group 3 had the lowest mean microleakage of 1.15 ± 0.93. Post-hoc analysis revealed significant differences between the groups. Groups 2 and 3 showed better results than group 1 (p < 0.05).

Conclusion: It can be concluded that Bio-LCB, as a light-cure pulp capping agent, showed minimal microleakage when used as a cavity liner in class II composite restorations.