# Clinical performance of short fiber-reinforced and indirect resin composites in class I and class II restorations: A three-year randomized clinical trial

## TL;DR

A three-year study found that short fiber-reinforced and indirect lab composites performed similarly to traditional resin composites in dental restorations.

## Contribution

This study provides long-term clinical evidence comparing new composite materials to traditional ones in posterior teeth.

## Key findings

- SFRC and indirect lab composites showed clinical success rates of 100% compared to 96.43% for microhybrid resin composites.
- No significant differences were found among the materials in terms of clinical performance over three years.
- Indirect lab composites had higher treatment time and cost, making direct methods more favorable.

## Abstract

This prospective randomized clinical trial was designed to evaluate and compare the three-year clinical performance of short fiber-reinforced composite (SFRC) and indirect laboratory (lab) composite with that of a microhybrid resin composite placed in Class I and Class II cavities, with marginal adaptation defined as the primary outcome.

Thirty-three participants, each exhibiting 3 posterior carious teeth (Class I or II, ICDAS 4 or 5) under stable occlusion, were enrolled in this study. A total of 99 restorations (33 for each material) were placed as follows: SFRC (everX Posterior), indirect lab composite (SR Nexco), and microhybrid resin composite (G-aenial Posterior). Clinical assessments were conducted at baseline (1 week), 6 months, 1, 2, and 3 years by two blinded examiners utilizing FDI criteria, with marginal adaptation designated as the primary outcome, whereas other FDI criteria were assessed as secondary outcomes. Intragroup differences across follow-ups were assessed using Friedman and Wilcoxon post-hoc tests, while intergroup comparisons were analyzed using Kruskal-Wallis and Mann-Whitney U tests. The significance level was set at α = 0.05.

Twenty-eight patients with a total of 84 restorations were evaluated at the end of the 3-years with 84.45% recall rates. The outcomes revealed no statistically significant differences among SFRC, indirect lab composite, and microhybrid resin composite restorations for the assessed criteria (p > 0.05). The clinical success rates for SFRC (everX Posterior), indirect lab composite (SR Nexco), and microhybrid resin composite (G-aenial Posterior) were 100%, 100%, and 96.43%, respectively.

After a three-year follow-up period, both SFRC and indirect lab composite demonstrated acceptable clinical performance, comparable to that of microhybrid resin composite, as evaluated by the FDI criteria.

Although the tested resin composite materials revealed similar clinical behavior in posterior teeth, the prolonged treatment time and higher cost of indirect lab composite favor the direct approach.

The online version contains supplementary material available at 10.1007/s00784-025-06593-x.