Novel primer for bonding and debonding of high-strength dental ceramics

University Of Mississippi Med Ctr, Jackson MS

Investigators

Abstract

SUMMARY We aim to combine the laser energy with a novel primer for bonding reversibly to high-strength ceramic crowns. This proposal seeks to investigate the novel primer’s bonding and debonding capabilities to address the destructive and traumatic removal of high-strength all-ceramic crowns using high-speed rotary instrumentation which in addition compromises the underneath tissue, and fatigues the patient and clinician. This common clinical problem, affecting many dentists and their patients, is highlighted by the National Dental Practice-Based Research Network, with an estimated 2.5M all-ceramic restorations removed yearly. We introduce a novel, drill-free, efficient, and non-yet-available debonding approach for high-strength ceramic restorations. This method uses a unique binding promoter system comprising carbon nanosphere chains (CNSCs) and 10-methacryloxydecyl dihydrogen phosphate (MDP), facilitating strong bonding to ceramics but also enabling debonding after laser irradiation. This method offers innovative bond-debond applications for primers in dentistry for high-strength adhesively bonded ceramics such as lithium disilicate glass-ceramic and partially stabilized zirconia (PSZ) ceramics. We will utilize an erbium-based laser, widely adopted in dental practice, especially in North America, with a dominant 35% market share in 2021. The proposal’s specific aims are 1) Characterize the bonding and debonding capabilities of lithium disilicate and PSZ ceramics treated with the novel CNSC-MDP-based primer against benchmark products, and 2) Evaluate spiral and s- shaped laser irradiation modes to promote efficient debonding. In addition, we will verify thermal changes across different ceramic thicknesses, color changes, contact angle, viscosity, and the biocompatibility of the novel primer. Our initial findings indicate a paradigm shift regarding PSZ ceramics’s low thermal conductivity, as laser irradiation using 7.5 W at 20 PPS effectively transmits heat through PSZ ceramics, softening the resin cement without affecting its integrity. Another novel aspect is the rigorous thermal mapping of the laser irradiation and testing of standard geometry and clinically relevant specimens. We will test up to five CNSC concentrations (0.06, 0.12, 0.18, 0.24, and 0.30 wt%). The findings of this proposal will elicit the dual functionality of the novel primer for convenient, efficient, and predictable debonding of resin-bonded all- ceramic crowns. Anticipated outcomes include improved removal ease, reduced patient trauma, and restoration preservation, yielding significant time and cost savings. This revised application mantains the original focus and incorporates reviewer's feedback, including bonding to tooth structure, verifying ceramics’ optical properties, and measuring CNSCs concentrations’ viscosity. This R03 will serve as a stepping stone for future studies into primer activation using various external photonic triggers, such as varied laser energies and potential UV irradiation. Future research will expand to other ceramic restorations, multi-unit, and 3D-printed prostheses to streamline the novel primer across various applications and transition it from lab to clinic.