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Effects of different enamel pretreatment methods and timing of application on shear bond strength of orthodontic brackets and enamel microhardness after demineralization: an in vitro study |
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| รหัสดีโอไอ | |
| Title | Effects of different enamel pretreatment methods and timing of application on shear bond strength of orthodontic brackets and enamel microhardness after demineralization: an in vitro study |
| Creator | Usanee Pattamalai |
| Contributor | Sutiwa Benjakul, Advisor |
| Publisher | Thammasat University |
| Publication Year | 2566 |
| Keyword | Caries prevention, Enamel pretreatment methods, Orthodontics, Shear bond strength, Vickers hardness, White-spot lesions |
| Abstract | Objective: This in vitro study aimed to evaluate which enamel pretreatment methods and their timing of application with fluoride varnish, resin infiltration, flat resin sealant and S-PRG (Surface pre-reacted glass ionomer) coating material could prevent enameldemineralization on enamel surface without affecting the shear bond strength (SBS) of brackets in orthodontic patient who has high caries risk.Materials and methods: Part I: Enamel microhardness test: The teeth were randomized into 6 groups (n = 10).Group 1: no enamel pretreatment, Group 2: demineralization, Group 3-6 were treated with different enamel pretreatment methods; fluoride varnish (DuraphatTM), resin infiltration (ICONTM), flat resin sealant (Pro SealTM) and S-PRG (PRG Barrier CoatTM). After enamel pretreatment procedure, group 3-6 were immersed in demineralizing solution for 96 hours. Vickers hardness (VH) was tested. Differences between Vickershardness number (HV) were analyzed by Kruskal-Wallis followed by post-hoc multiple comparison. Statistically significant was set at P < 0.05. Part II: SBS and ARI test: The teeth were randomized into 10 groups (n = 14). Group 1: no enamel pretreatment, Group 2: demineralization , Group 3-10 were treated with different enamel pretreatment methods; fluoride varnish (DuraphatTM), resin infiltration(ICONTM), flat resin sealant (Pro SealTM) and S-PRG (PRG Barrier CoatTM) followed with immediate or delayed brackets bonding for 30 days, respectively. After bracket bonding, group 2-10 were demineralized. SBS and ARI were evaluated. Differences between SBS values were analyzed by two-way ANOVA followed by Tamhane. TheARI scores were analyzed using Fisher’s Exact test. Statistically significant was set at P < 0.05.Results: Part I: There was significant difference in HV among all groups compared to control except DuraphatTM group. The highest and the lowest HV among enamel pretreatment groups was found in DuraphatTM and PRG Barrier CoatTM groups, respectively. However, there was no significant difference in HV of DuraphatTM, ICONTM and ProSealTM groups. In addition, HV of DuraphatTM group was significantly higher thandemineralization group. Part II: The mean bracket SBS of all enamel pretreatment methods was in the clinically accepted values. There was no significant difference in SBS among all groups compared to control. The highest SBS was found in Pro SealTM with delayed bonding, which was significantly higher than demineralization and the immediate bonding ofDuraphatTM, Pro SealTM and PRG Barrier CoatTM. The timing of application had no effect on SBS, excepted in Pro SealTM, which was increased in delayed group. The ARI scores were statistically significant difference between groups.Conclusions: In order to achieve acidic enamel resistance in orthodontic patient who has high caries risk with adequate SBS of orthodontic brackets, enamel pretreatment with DuraphatTM with delayed bracket bonding is recommended to be performed. |
