Effect of Silver-Diamine-Fluoride and Potassium-Iodide on Shear-Bond-Strength of Glass-Ionomer

Objectives: To investigate the effect of silver diamine fluoride (SDF) and potassium iodide (KI) treatment on the shear bond strength (SBS) and tooth discolouration of glass ionomer cements (GICs) to artificial caries-affected dentine.
Methods: Sixty human dentine slices were demineralised to mimic caries-affected dentine. They were randomly allocated for treatment (n=20 per treatment) with SDF+KI, SDF (positive control) or water (negative control). All slices were immersed in the artificial saliva for 24 hours after treatments. The colour of the treated surfaces was assessed using the CIELAB system. Lightness values were measured. Total colour change (△E) was calculated using water as the reference group and was visible to naked eyes if △E>3.7. All dentine slices were bonded with GICs. The SBS was measured using a universal testing machine. Colour parameters and the SBS were analysed using a one-way ANOVA test.
Results: The slices treated with SDF+KI had a higher lightness value than the reference group water, whereas those treated with SDF presented a lower lightness value compared to those treated with water. The treatment with SDF+KI did not introduce any adverse colour effect to demineralised dentine (△E=14.4), whereas the application of SDF alone caused significant staining (△E=24.6). The SBS (mean±SD) after treatment with SDF+KI, SDF and water were 3.0±1.4 MPa, 2.3±0.9 MPa and 2.6±1.1 MPa, respectively (p=0.217).
Conclusions: The immediate application of KI solution after SDF treatment does not adversely affect the adhesion of GICs to artificial caries-affected dentine. Furthermore, SDF+KI treatment can reduce discolouration of demineralised dentine caused by SDF.