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Background: This study investigated the remineralisation effect of bioactive glass on artificial dentine caries. Methods: Dentine disks with artificial caries were treated with bioactive glass (group BAG), casein phosphopeptideamorphous calcium phosphate (CPP-ACP) (group CPP-ACP), sodium fluoride glycerol (group F) or deionized water (group W). All disks were subjected to pH cycling for 28 days subsequently. The topography, microhardness and remineralisation depth of the dentine carious lesion were assessed by atomic force microscopy (AFM), microhardness testing and confocal laser scanning microscope (CLSM), respectively. Results: AFM images indicated mineral depositions on the surface of the carious lesion in group BAG. The changes of Vickers hardness number (ΔVHN, mean ± SD) after pH cycling were 9.67 ± 3.60, 6.06 ± 3.83, 5.00 ± 2.19 and − 1.90 ± 2.09 (p < 0.001) in group BAG, group CPP-ACP, group F and group W, respectively. The remineralisation depth (mean ± SD) of the carious lesion in group BAG, group CPP-ACP, group F and group W were 165 ± 11 μm, 111 ± 11 μm, 75 ± 6 μm and 0 μm (p < 0.001), respectively. Conclusion: Bioactive glass possessed a promising remineralisation effect on artificial dentine caries and could be a therapeutic choice for caries management.

Objectives: To compare the long-term in vitro effectiveness of a newer desensitizing agent containing bioactive glass and two other commercial products employed for dentin hypersensitivity.Methods: Fifty occlusal dentin disks from extracted sound human third molars were treated with 0.5M ethylenediaminetetraacetic acid for 2 min then randomly divided into five groups (n=10). Specimens were brushed for 2 min twice daily with Actimins Paste (Group1), Lesening Super Desensitizing Toothpaste (Group2), Colgate Sensitive Pro-Relief Desensitising Polishing Paste (Group3) and distilled water (Group4) at 9:00 am and at 5:00 pm. Specimens in Group5 had no brushings. All specimens were immersed sequentially for 5 min into coffee (pH=5.4) at 10:00 am and undiluted cola (pH=2.5) at 6:00 pm. Dentin permeability was measured weekly over one month using electrochemical impedance spectroscopy (EIS). Data were analyzed using two-way repeated measures ANOVA and post hoc LSD tests. Dentin microstructures were observed at one month by atomic force microscopy and scanning electron microscopy. Results:The three desensitizing agents significantly reduced dentin permeability over one month. Post hoc LSD tests of the EIS values indicated that brushing with Actimins showed no significant difference from Colgate Sensitive (P=0.32), and that both agents had significantly less permeability than Lesening (P<0.05). Conclusions:The three desensitizing agents were effective in occluding dentinal tubules and reducing permeability to varying extents over one month, with Actimins and Colgate Sensitive being the most effective. Actimins might be initially, a faster-working desensitizing agent.Clinical significance: Actimins, a newer desensitizing agent containing bioactive glass, has the potential to relieve dentin hypersensitivity in the presence of long-term daily acidic beverage ingestion.