PURPOSE: To investigate the effects of desensitizing agents on dentin tubule occlusion, acid and tooth brushing challenge, and microhardness change of human dentin. METHODS: Partially demineralized dentin slabs were divided into four groups (n = 30): (1) Control, (2) Non-desensitizing toothpaste, (3) Pro-Argin toothpaste, (4) CPP-ACP paste. The specimens were treated with these dentifrices for 2 minutes/day and soaked in artificial saliva (AS) for 24-hour remineralization. Then the dentin discs were divided into three subgroups for removal resistance tests: acid challenge, mechanical brushing challenge and blank control. Changes in dentin morphology were observed using scanning electron microscopy (SEM). Vickers microhardness measurements were performed at baseline and after 24-hour remineralization for all groups. RESULTS: A surface layer and intra-tubular crystals were observed in SEM imaging of Pro-Argin toothpaste and CPP-ACP paste groups, which occluded most of the dentin tubules for those specimens. But the dentin tubules were opened after the acid challenge again. Moreover, the dentin microhardness showed a slight increase after 24-hour AS immersion. The percentage microhardness gain (PMG) values of these two groups were 5.4% and 5.1% respectively, which were significantly higher than the other groups (P < 0.05).
PURPOSE: To investigate the effects of desensitizing agents on dentin tubule occlusion, acid and tooth brushing challenge, and microhardness change of human dentin. METHODS: Partially demineralized dentin slabs were divided into four groups (n = 30): (1) Control, (2) Non-desensitizing toothpaste, (3) Pro-Argin toothpaste, (4) CPP-ACP paste. The specimens were treated with these dentifrices for 2 minutes/day and soaked in artificial saliva (AS) for 24-hour remineralization. Then the dentin discs were divided into three subgroups for removal resistance tests: acid challenge, mechanical brushing challenge and blank control. Changes in dentin morphology were observed using scanning electron microscopy (SEM). Vickers microhardness measurements were performed at baseline and after 24-hour remineralization for all groups. RESULTS: A surface layer and intra-tubular crystals were observed in SEM imaging of Pro-Argin toothpaste and CPP-ACP paste groups, which occluded most of the dentin tubules for those specimens. But the dentin tubules were opened after the acid challenge again. Moreover, the dentin microhardness showed a slight increase after 24-hour AS immersion. The percentage microhardness gain (PMG) values of these two groups were 5.4% and 5.1% respectively, which were significantly higher than the other groups (P < 0.05).
Authors: James R Fernando; Peiyan Shen; Christina P C Sim; Yu-Yen Chen; Glenn D Walker; Yi Yuan; Coralie Reynolds; David P Stanton; Colin M MacRae; Eric C Reynolds Journal: Sci Rep Date: 2019-02-04 Impact factor: 4.379