Micro-CT assessment of internal adaptation in Class V restorations using different liner/base strategies: a pilot study

Abstract

The internal adaptation of pulp liner/base materials may influence interfacial gap formation and internal voids in restorations. This pilot in vitro study used high-resolution micro-computed tomography (Micro-CT) to evaluate interfacial gap volumes and internal void characteristics in Class V restorations using three liner/base strategies. In this in vitro pilot study, three liner/base strategies were evaluated: TheraCal LC, Ultra-Blend Plus, and a multilayer system consisting of Dycal combined with resin-modified glass ionomer cement (RMGI). Following standardized Class V cavity preparation, liner/base placement, composite resin restoration, and thermocycling, specimens were scanned using Micro-CT. The measured outcomes included interfacial gap volume at the tooth–liner and composite-liner interfaces, as well as internal void volume and porosity within the evaluated restorative systems. Data were analyzed using the Kruskal–Wallis test with exact permutation procedures at a significance level of α = 0.05. No statistically significant differences were observed among the three strategies at the composite-liner interface. At the tooth-liner interface, the median interfacial gap volume was significantly higher for TheraCal LC than for the Dycal + RMGI multilayer system. Although Ultra-Blend Plus showed an intermediate median value, its differences from the other groups were not statistically significant. The Dycal + RMGI system exhibited the highest internal void volume within the pulp-capping material. The three liner/base strategies showed different patterns of interfacial adaptation and internal void formation in this pilot study. The statistically significant difference in tooth-liner gap volume was limited to the comparison between TheraCal LC and Dycal + RMGI; no significant differences involving Ultra-Blend Plus were detected. Given the small sample size, these findings are preliminary and require confirmation in larger studies before their clinical relevance can be established.

The authors' abstract, as published at the source. BMC Oral Health, 2026 · DOI ↗