“A failure mode analysis of a 5th generation adhesive using 2% graphene oxide and 5% hydroxyapatite nanoparticles both in isolation and in combination in class 1 cavity: Protocol for an InVitro Study” (Preprint)

BACKGROUND The durability of dentin-resin adhesion plays crucial role in long-term success of composite restorations. However, bond degradation over time leads to restoration failure and secondary caries. Incorporation of nanoparticles such as graphene oxide (GO) and hydroxyapatite (HA) into dental adhesives has shown potential to improve mechanical properties, bioactivity, and bond strength. GO offers high surface area and antimicrobial properties, while HA exhibits remineralization potential. Despite individual successes, their combined effect on adhesive failure modes remains underexplored. OBJECTIVE This study will aim to evaluate and compare the failure mode analysis of a 5th generation dental adhesive modified with 2% GO, 5% HA, and a combination of both, in Class I cavity restorations using a stereomicroscope METHODS Class I cavities will be prepared on extracted human molars and restored using four groups of adhesives: Group I: Unmodified 5th generation adhesive (control) Group II: 5th generation adhesive + 2% GO Group III: 5th generation adhesive + 5% HA Group IV: 5th generation adhesive + 2% GO + 5% HA Following bonding and composite restoration, samples will undergo thermocycling and mechanical loading. Shear bond strength tests will be performed, and failure modes will be assessed using a stereomicroscope. The data will be analyzed statistically to determine significant differences among the groups. RESULTS It is anticipated that the modified adhesive groups will exhibit improved resistance to adhesive failure. The combination group (GO + HA) is expected to show the highest incidence of cohesive or mixed failures, indicating a stronger and more durable bond compared to the control and individual nanoparticle groups CONCLUSIONS The study will provide valuable insights into the development of next-generation, nanoparticle-enhanced adhesive systems aimed at improving clinical outcomes in restorative dentistry. CLINICALTRIAL Since this investigation will be conducted entirely as an in vitro study, registration with the Clinical Trials Registry - India (CTRI) was not applicable and therefore not required.