Development of a mesoporous biomaterial for treatment of dentin hypersensitivity

Dentin hypersensitivity is a common chief complaint in dental clinics. The clinical experience and several investigations exhibited the inefficiency of most of commercialized dentin sealants in the persistent time. Objectives: 1) to investigate the efficacy of Seal & Protect, DP-bioglass and nano@CaO mesoporous silica for occlusion of dentinal tubules 2) to investigate the influence of pulp pressure on the efficacy of desensitizing agents to seal dentinal tubules. Methods: In this research, we produced nano@CaO mesoporous silica by calcination and impregnation methods. Then, we used two methods to examine the efficacy of three desensitizing agents, Seal & Protect, DP-bioglass and nano@CaO mesoporous silica, for occlusion of dentinal tubules. The first method was to test dentin permeability with a fluid flow model. We measured the fluid flow rate to compare the effects of different materials. The other method was SEM investigation. To observe the depth and the sealing quality of the plugs or precipitants penetrating into dentinal tubules. Results: The results expressed that nano@CaO mesoporous silica performed best. It made the dentin permeability down to the lowest level(19.1%) among the tested materials, and the SEM showed excellent sealing ability and deep penetration(> 100 nm) of the crystal precipitants. The efficacy of three desensitizing agents with or without pressure supply to push them out of dentinal tubules. All of the tested desensitizing agents did not exhibit significant difference. Conclusions: 1) The nano@CaO mesoporous silica could react quickly with 30% phosphoric acid and occlude the dentinal tubules well. This porous material had the potential in treatment of dentin hypersensitivity clinically. 2) Pulp pressure did not affect the dentinal tubules sealing ability of these test materials.