Effects of microsurface structure of bioactive nanoparticles on dentinal tubules as a dentin desensitizer

Abstract

In this in vitro study, spherical mesoporous bioactive glass nanoparticle (MBGN) and nonporous bioactive glass nanoparticle (BGN) were fabricated. The impact of mesopores on dentinal tubule occlusion and bioactivity was compared to examine the potential of these materials in alleviating dentine hypersensitivity (DH). MBGN, dense BGN were synthesized by sol-gel methods and characterized. Bioactivity and ion dissolution ability were analyzed. Twenty-four simulated sensitive dentin discs were prepared and randomly divided into three groups (n = 8 each); Group 1, no treatment; Group 2, Dense BGN; Group 3, MBGN. Then, four discs per group were treated with 6wt.% citric acid challenge to determine the acidic resistance. The effects on dentinal tubule occlusion were observed by FESEM. The microtensile bond strength (MTBS) was also measured. Cytotoxicity was examined using the MTT assay. According to the results, dense BGN without mesopore and MBGN with mesopore were successfully fabricated. Dense BGN and MBGN occluded the dentinal tubule before and after acid challenge. However, only MBGN formed a membrane-like layer and showed hydroxyapatite formation after soaking SBF solution. There were no significant differences in MTBS among dense BGN, MBGN (P>0.05). The cell viability was above 72% of both materials. The higher bioactivity of MBGN compared with that of dense BGN arises from the structural difference and it is anticipated to facilitate dentin remineralization by inducing hydroxyapatite deposition within the dentinal tubule.

Bonding Performance of Universal Adhesives Applied to Nano-Hydroxyapatite Desensitized Dentin Using Etch-and-Rinse or Self-Etch Mode

“…Based on the EDX analysis, pure nHAp may provide more potential calcium sites for chemical reactions with 10-MDP to compromise the adverse effects on the bond strength. Therefore, pure nHAp could explain higher bond strength than nHAp-based toothpastes, which was in agreement with previous reports [ 9 , 13 , 44 ].…”

Effect of bioactive glasses containing strontium and potassium on dentin permeability

“…A scanning electron microscope (Mira 3, TESCAN, Czech Republic) coupled to an energy-dispersive X-ray (EDX) spectrometer was used, which allowed qualitative chemical analysis. 6,8 About 3 mg of each sample were added in isopropanol, and then the system was submitted to a vortex shaker (Biomixer QL-901, Taboão da Serra, SP, Brazil) for dispersion of the particles. After this procedure, 5 μl of the solution was removed and placed on a metallic sample holder and taken to the oven at 50 C for 12 h before the analysis.…”

“…The equipment operated in absorption mode using the potassium bromide (KBr) pellet technique, with a spectral resolution of 4 cm À1 from 2000 to 400 cm À1 . 6,8,17,25 We collected the mean spectra of 32 scans.…”

“…Hence, the development of dental materials which are bioactive and interact with tissues without producing adverse effects, such as bioactive ceramics, have been the subject of several studies, either through creating new materials or by improving the characteristics of those that already exist. [5][6][7][8] Bioactive ceramics have been intensively studied since Bioglass ® was first used as a material for bone regeneration in the early 1970s. 9 These materials can quickly (in a few hours or days) bond with hard tissues and some soft tissues, stimulating bone growth away from the bone-implant interface.…”

“…[14][15][16] It is relevant to note that this property of bioactive glasses and other bioactive ceramics depends primarily on their chemical composition, surface area, and crystalline phases (in case of glass-ceramics and ceramics). [5][6][7][8][9][10][11][12] Thus, different modifications can be tested, aiming to improve their efficiency according to the desired application.…”