Study on Occluding Dentinal Tubules with a Nanosilver-Loaded Silica System In Vitro

Abstract

The effects of most clinical treatments for dentin hypersensitivity are not long-lasting. To overcome the defects, the mesoporous silica nanoparticles and silver nanoparticles entered the field of oral materials. This study aimed to synthesize a novel, lowcytotoxic dentin desensitizer and investigate its occlusion effects on dentinal tubules. The biphasic stratification approach, a chemical reduction method, and the Stober method were used to synthesize silver nanoparticle-loaded and nonporous silica-encapsulated mesoporous silica (Ag-MSNs@nSiO 2 ), which was a noncrystalline structure with an average size of approximately 128 nm and a silver content of 3.506%. Atomic absorption spectrometry and the 3-(4,5dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide cell viability assay showed that Ag-MSNs@nSiO 2 slowly released silver ions and had nearly no cytotoxicity. An electron microscope was used to observe the blocking effects on the dentinal tubules of sensitive tooth disc models, which were randomly divided into the following four groups: a deionized water group, a 5.9 M silver nitrate solution group, an Ag-MSNs@nSiO 2 group, and a Gluma desensitizer group. There were no significant differences in the relative area of open dentinal tubules between the Ag-MSNs@nSiO 2 group and the Gluma desensitizer group (P > 0.05). Detection of protein structures showed that multilevel structures of bovine serum albumin in dentin tubules were significantly changed by silver ions from Ag-MSNs@nSiO 2 . These results suggest that nearly noncytotoxic Ag-MSNs@nSiO 2 was successfully synthesized by a series of methods. Ag-MSNs@nSiO 2 occluded dentin tubules immediately and effectively. Moreover, the blockage effects may be enhanced and maintained by continuous condensation of proteins in dentinal tubules.

Synthesis of novel silver-loaded clay AgF@Hec for the prevention of dental caries in vitro

“…External stimuli can cause fluid flow in exposed dentin tubules, stimulate sensory nerve endings, and lead to dentin hypersensitivity. Blocking dentinal tubules is the only effective way to treat tooth hypersensitivity [25]. To investigate the ability of different samples (figure 4(D-a) Water, figure 4(Db) NaF, figure 4(D-c) Hec, figure 4(D-d) SDF and figure 4(D-e) AgF@Hec) to block dentin tubules, a pH cycling test was performed.…”

Prospects of silver diamine fluoride (SDF) in reducing dentin hypersensitivity: An updated review

“…There is an assumption that the chemical interactions between fluoride ions and free calcium ions result in calcium fluoride that can block the dentinal tubules and decrease the dentinal permeability, 15 and is partially insoluble in saliva, 13,36 and silver ions cause protein denaturation and aggregation in the dentinal tubules. 37 SEM studies have demonstrated granular precipitates in the peritubular dentin after topical application of fluorides. The traditional understanding is that, a layer of silver and dentin organic matrix protein conjugates forms when SDF is applied on sensitive dentin surfaces, which partially closes the exposed dentinal tubules.…”