IADR Abstract Archives
Synergistic Effects of SDF and Hypochlorite on Primary Dentine Lesions
Objectives: The aim was to investigate the effects of sodium hypochlorite pre-treatment on primary molar dentine artificial carious lesions undergoing silver diamine fluoride (SDF) treatment using X-ray microtomography (XMT) and Backscattered scanning electron microscopy (BSE).
Methods: Five extracted primary molar teeth were sectioned to create five control and five test blocks. The occlusal enamel was removed and the blocks varnished to reveal a 2x2mm window of occlusal dentine. The blocks were demineralised for 24 in acetic acid (0.1M, pH 4) to create standardised artificial carious lesions. The test blocks underwent 120s sodium hypochlorite (5%) pre-treatment followed by SDF treatment (Riva Star). The control blocks received SDF treatment. All blocks were then remineralised (CaCl2, KH2PO4, NaCl) for 5 days. XMT (60kV, 20 hours) was used to obtain 3D images of the blocks at baseline, before and after remineralisation to compare mineral deposition and backscattered electron microscopy (BSE) was used to confirm the silver distribution.
Results: XMT showed that the test group showed higher mineral density values (LAC 3.22) at the artificial lesion surface than the control group (LAC 1.51). Higher silver concentrations were seen in the body of the demineralised lesion in the control group (LAC 1.25) than the test group (LAC 1.0). A 'sub lesion zone' of silver deposition was more distinct in the test group 100-200μm below the lesion base.
BSE imaging revealed surface silver was seen in the test group that projected from within the dentine tubules beyond the occlusal border of dentine (10-20μm). The dentine tubules within the sub lesion zone below the lesion base were more saturated with silver particles in the test group.
Conclusions: Sodium hypochlorite pre-treatment of artificial dentine carious lesions may operate synergistically with SDF to enhance its protective and caries arrest properties.
Methods: Five extracted primary molar teeth were sectioned to create five control and five test blocks. The occlusal enamel was removed and the blocks varnished to reveal a 2x2mm window of occlusal dentine. The blocks were demineralised for 24 in acetic acid (0.1M, pH 4) to create standardised artificial carious lesions. The test blocks underwent 120s sodium hypochlorite (5%) pre-treatment followed by SDF treatment (Riva Star). The control blocks received SDF treatment. All blocks were then remineralised (CaCl2, KH2PO4, NaCl) for 5 days. XMT (60kV, 20 hours) was used to obtain 3D images of the blocks at baseline, before and after remineralisation to compare mineral deposition and backscattered electron microscopy (BSE) was used to confirm the silver distribution.
Results: XMT showed that the test group showed higher mineral density values (LAC 3.22) at the artificial lesion surface than the control group (LAC 1.51). Higher silver concentrations were seen in the body of the demineralised lesion in the control group (LAC 1.25) than the test group (LAC 1.0). A 'sub lesion zone' of silver deposition was more distinct in the test group 100-200μm below the lesion base.
BSE imaging revealed surface silver was seen in the test group that projected from within the dentine tubules beyond the occlusal border of dentine (10-20μm). The dentine tubules within the sub lesion zone below the lesion base were more saturated with silver particles in the test group.
Conclusions: Sodium hypochlorite pre-treatment of artificial dentine carious lesions may operate synergistically with SDF to enhance its protective and caries arrest properties.