IADR Abstract Archives
Synergistic Effects of Sodium Hypochlorite on SDF Treated Primary Dentine
Objectives: To investigate the effects of a sodium hypochlorite pre-treatment on silver diamine fluoride treated primary dentine artificial lesions using Micro-CT analysis
Methods: An extracted primary tooth was mounted and cut to create an enamel and dentine block using a diamond blade. Occlusal enamel was removed to create a 2mm thick dentine disc and to expose the occlusal dentine tubules. The disc was cut again to make two smaller dentine blocks. These were covered in protective varnish exposing only a 2x2mm window of occlusal dentine. Each block was demineralised in 100 ml acetic acid (0.1M pH 4) for 24 hours at 37 degrees celsius. The control block was topically treated using SDF (Riva Star, Australia) and then remineralised for 5 days in 100ml of remineralisation solution (CaCl2, KH2PO4, NaCl, pH 7) at 37 degrees celsius. The test block was pre-treated using sodium hypochlorite (5%) for 1 minute followed by identical topical SDF application and remineralisation for 5 days. Micro-CT analysis was undertaken at baseline, after demineralisation, and after remineralisation for both blocks.
Results: Micro-CT analysis revealed significant differences in the characteristics of silver compound between the test pre-treated hypochlorite and control blocks. For the control block, a distinct deposition of silver was present at the base of the artificial lesion with significant penetration of silver throughout the whole thickness of the block. Whereas, for the test block, a considerably thicker surface layer of silver compounds. Furthermore, silver deposition up to 200 microns below the artificial lesion base was seen, but there was no further penetration of silver deeper into the block.
Conclusions: There has been concern that SDF can penetrate through the entire thickness of dentine into the pulp of primary teeth. This study shows that a sodium hypochlorite pre-treatment could add safety factor to reduce the penetration of silver deeper towards the pulp. Furthermore, a thicker surface silver layer and an increased deposition of silver compounds in the sub-lesion zone may provide improved clinical cariostatic properties with less safety concerns.
Methods: An extracted primary tooth was mounted and cut to create an enamel and dentine block using a diamond blade. Occlusal enamel was removed to create a 2mm thick dentine disc and to expose the occlusal dentine tubules. The disc was cut again to make two smaller dentine blocks. These were covered in protective varnish exposing only a 2x2mm window of occlusal dentine. Each block was demineralised in 100 ml acetic acid (0.1M pH 4) for 24 hours at 37 degrees celsius. The control block was topically treated using SDF (Riva Star, Australia) and then remineralised for 5 days in 100ml of remineralisation solution (CaCl2, KH2PO4, NaCl, pH 7) at 37 degrees celsius. The test block was pre-treated using sodium hypochlorite (5%) for 1 minute followed by identical topical SDF application and remineralisation for 5 days. Micro-CT analysis was undertaken at baseline, after demineralisation, and after remineralisation for both blocks.
Results: Micro-CT analysis revealed significant differences in the characteristics of silver compound between the test pre-treated hypochlorite and control blocks. For the control block, a distinct deposition of silver was present at the base of the artificial lesion with significant penetration of silver throughout the whole thickness of the block. Whereas, for the test block, a considerably thicker surface layer of silver compounds. Furthermore, silver deposition up to 200 microns below the artificial lesion base was seen, but there was no further penetration of silver deeper into the block.
Conclusions: There has been concern that SDF can penetrate through the entire thickness of dentine into the pulp of primary teeth. This study shows that a sodium hypochlorite pre-treatment could add safety factor to reduce the penetration of silver deeper towards the pulp. Furthermore, a thicker surface silver layer and an increased deposition of silver compounds in the sub-lesion zone may provide improved clinical cariostatic properties with less safety concerns.