Effect of Chlorhexidine Digluconate and Immediate Dentin Sealing on the Shear Strength of Lithium Disilicate Fixed Partial Denture

Abstract

Introduction: Immediate dentin sealing (IDS) with a two-bottle system dentin bonding agent (DBA) and additional resin coating serves as an innovative approach to enhance the adhesion and durability of indirect restorations. Chlorhexidine digluconate (CHX) has the ability to inhibit the activity of collagen matrix metalloproteinases (MMPs) that degrade the hybrid layer on dentin, leading to restoration failure. This study aims to investigate the influence of CHX application and IDS on the adhesion of lithium disilicate fixed partial denture based on shear bond strength, hybrid layer thickness and failure modes. Methods: Twenty-four recently extracted premolar teeth, divided into four groups: IDS and resin coating (IDSRC), IDS and resin coating with CHX application, delayed dentin sealing (DDS) with CHX application, and DDS as control group. All specimens underwent preparations and treatments in accordance with the requirements for each treatment group. Provisional restorations were cemented onto the specimens. Temporary cement removal was carried out using air abrasion. Following a 24-hour immersion in distilled water, lithium disilicate cementation took place. Shear bond strength (SBS) testing used a universal testing machine. A stereomicroscope allowed for the measurement of the hybrid layer's (HL) thickness and failure mode. Results: Significantly higher SBS and HL were found in the IDSRC CHX group (p<0.05). Conclusion: Application of CHX 2% along with IDS and resin coating improves the hybrid layer, thus increasing shear strength when using two-bottle system with universal DBA.