Performance of GIOMER Based Resin Composite Restorations Versus Conventional Nanohybrid Resin Composite Restorations in Complex Proximal Carious Cavities in Posterior Teeth. (A 24-month Randomized Clinical Trial)

Scientific background:

One of the advancements in resin composite technology to support its use as a bioactive material, is the evolution of GIOMER based resin composite material which has an added benefit of sustained fluoride and other ions release and rechargeability. A distinguishing feature of the "giomer" class of restorative materials is the stable surface prereacted glass core (sPRG) that is lined with an ionomer in a resin matrix. This configuration enables the glass core to be protected from moisture, giving it long term aesthetics and the durability of conventional resin composites with ion release and recharge1. When evaluating the clinical performance of low shrinkage giomer based resin composite (Beautifil II LS; Shofu Inc.) compared with a conventional nanohybrid resin composite in class I and class II cavities, It was found that in both groups, according to FDI criteria, the restorations were mostly rated with best scores (Score 1 or 2) regarding the biological, functional, and optical parameters 2. Also, after five years of clinical performance, both the nano-hybrid giomer restorative materials flowable giomer (Beautifil Flow Plus F00; Shofu Inc.) and the conventional nano-hybrid giomer restorative material (Beautifil II; Shofu Inc.) were comparably acceptable and not significantly different for any of the parameters evaluated in occlusal cavities 3. Meanwhile in a recent systematic review, it was concluded that GIOMER based resin composites showed similar clinical performance concerning marginal adaptation and better surface roughness when compared to Resin-modified glass ionomer cement 4.

Statement of the problem:

The survival rate for resin-based composite restorations declined to roughly 85-90% after ten years. Bulk fractures and wear, which accounted for about 70% of replacements, were the main causes of restorative replacement. About 20% of the resin-based restorations were replaced because of caries at the margins of the restorations, and 10% were due to retention loss, poor color matching, poor marginal integrity, endodontic therapy, or cusp fracture 5. These failures are correlated mainly with patient risk profile i.e., caries risk , presence of parafunctional habits and those with high number of restored surfaces (complex cavities) 6.

Rationale: