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

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

Dental caries, a chronic infectious disease characterized by tooth mineral loss caused by plaque, is one of the major global public health problems. Silver diamine fluoride (SDF) has been proven to be a highly effective anti-caries drug due to its high bacterial inhibition and remineralization ability. However, the SDF solution is unstable, which immensely limits its clinical application. Therefore, new silver-load clay named AgF@Hec was designed by replacing the NH3with hectorite in this study. Fourier transform infrared spectroscopy and x-ray diffraction spectroscopy were employed to confirm the structure of AgF@Hec. Dynamic light scattering analysis was used to reveal the effect of different hectorite concentrations on the stability of AgF@Hec. Moreover, AgF@Hec exhibits significant remineralization and hardness recovery of the initial carious lesions. Bacteriostatic experiments also proved that it has a significant inhibitory effect onA. Viscosus, S. mutans, S. sanguinis, S. salivarius, Lactobacillus sp.and both gram-positive and gram-negative bacteria. We therefore believed that AgF@Hec should be a promising biomaterial that can be applied in the prevention of dental caries.

Treating hypersensitivity in older adults with silver diamine fluoride: A randomised clinical trial

OBJECTIVE

This study aimed to evaluate the desensitizing effect of topically applied 38% silver diamine fluoride (SDF) solution on the exposed root surface of hypersensitive teeth in older adults.

METHOD

This double-blind randomised clinical trial recruited healthy older adults with dentine hypersensitivity. A trained examiner tested the most hypersensitive tooth root surface with a blast of compressed cold air from a three-in-one syringe. The participants gave a sensitivity score (SS) in visual analogue scale from 0 (no pain) to 10 (agonizing) at the baseline visit. Then, they received 38% SDF or 5% potassium nitrate solution (control) as intervention on the root surface. After the intervention, they received a compressed cold air test and reported the SS again. The compressed cold air test followed by intervention was repeated at 4- and 8-week follow ups. The primary outcome was the reduction in SS at 8-week follow-up with reference to the SS at baseline before intervention. Shapiro-Wilk and Mann-Whitney U tests were performed for data analysis following a normality test of SS.

RESULTS

This trial recruited 148 participants, and 139 (94%) participants completed the trial. The median percentage reductions in SS in the SDF and potassium nitrate groups were 60% and 50%, respectively (p < 0.001).

CONCLUSION

According to the results, 38% SDF solution reduced hypersensitivity on the exposed root surface of older adults. In addition, 38% SDF was more effective than 5% potassium nitrate solution to reduce hypersensitivity on the exposed root surface of older adults.

CLINICAL SIGNIFICANCE

Dentin hypersensitivity is common amongst older adults and negatively affects their quality of life. To date, there is no gold standard professionally applied desensitizing therapy in treating hypersensitivity. Evidence from this clinical trial could aid clinical practice and improve oral health in older adults.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov (NCT05392868).