The efficacy of a novel zinc-containing desensitizer CAREDYNE Shield on dentin hypersensitivity: study protocol for a pilot randomized controlled trial

Abstract

Background: Dentin hypersensitivity (DH) is a condition characterized by short and sharp pain which will arise in response to tactile, chemical, thermal, evaporative or osmotic stimuli. The painful symptoms cause discomfort to the patients and decrease their quality of life. Recently, a novel zinc-containing desensitizer CAREDYNE Shield is developed. It is a new type of desensitizer which acts as a desensitizer by inducing chemical occlusion of dentinal tubules, and releases zinc ion for root caries prevention. However, the clinical effectiveness of CAREDYNE Shield on DH is still unclear. Therefore, the aim of this study is to evaluate the effectiveness of CAREDYNE Shield on DH by comparing with that of another desensitizer Nanoseal commonly used in Japan.Methods/Design: This study protocol is a two-arm parallel pilot randomized controlled trial. Forty DH patients will be randomly allocated into 2 groups. Participants in the intervention group will be treated with CAREDYNE Shield; participants in the control group will be treated with Nanoseal. Primary outcome is the reduction of pain intensity in response to air stimuli measured with 5-points verbal response scale from baseline to 4 weeks after the intervention and Fisher's exact test will be used for analysis.Discussion: CAREDYNE Shield can be casually applied to subgingival areas and proximal surfaces because it reacts with only tooth substance. Moreover, zinc is reported to reduce the demineralization of enamel and dentin and inhibit biofilm formation, plaque growth and dentin collagen degradation. Therefore, CAREDYNE Shield may be expected to become a novel useful desensitizer which act not only as a desensitizer but also as a root caries inhibitor.

Effects of Various Desensitizing Agents on the Microtensile Bond Strength of a Hypersensitive Dentin Model Produced <i>in vitro</i> Using a One-step Self-etch System

“…Although the SS group exhibited nearly the same failure mode as that in the Cont(#4000), it is not currently known why the bond strength was lower. In the CS group, it is thought that deposited calcium fluoride or calcium phosphate or released zinc ions [24][25][26][27] may have suppressed the etching effect of the acidic monomer of the bonding resin 26) , thereby decreasing the bonding strength, demonstrating the failure at the interface between the dentin and the bonding resin. However, the NS group exhibited nearly the same bond strength and failure mode (cohesive failure inside the bonding resin, cohesive failure inside the resin and cohesive failure inside the dentin) as in the Cont(#4000) group, and the interfacial failure was found in some specimens.…”