The purpose of this study was to evaluate several bilayer biomimetic composite resin techniques in class I cavities over the course of 18 months in a randomized, double-blind clinical trial.

To make resin composite restorations more resistant to cracking in cavities that are under a lot of stress, some have proposed using fiber reinforcement. This proposal is supported by numerous prior investigations that have demonstrated the efficacy of these repairs. By adjusting their orientation, fibers can control the pressures brought on by polymerization shrinkage. Therefore, marginal microleakage has been reduced in comparison to conventional resin composites. One way the material's fibers improve its structural characteristics is by preventing cracks from propagating. Composites are ideal for direct restorations of large cavities in healthy teeth and teeth that have had endodontic treatment because the fiber structure improves their mechanical properties. Moreover, in 2021, a comprehensive analysis of research found that resin composite restorations reinforced with fibers had better adaptability and higher fracture resistance than the standard ones.

Inclusion Criteria:

• Proper oral hygiene
• Availability for follow-up periods

Exclusion Criteria:

• Endodontically treated or non-vital teeth
• Parafunctional habits such as tooth clenching or grinding