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INTRODUCTION: White spot lesions (WSLs) represent a prominent pathology encountered during orthodontic treatment, originating from enamel demineralization induced by the accumulation of bacterial biofilms. The previously developed bioinspired enamel coating form of self-assembling antimicrobial peptide D-GL13K exhibited antimicrobial activity and enhanced acid impermeability, offering a potential solution to prevent demineralization. The primary aim of this investigation is to assess the in vivo anti-demineralization properties and biocompatibility of the D-GL13K coating. METHODS: A rat model was developed to assess the antimicrobial enamel coating during fixed orthodontic treatment. The anti-demineralization efficacy attributed to the D-GL13K coating was evaluated by employing optical coherence tomography, Vickers microhardness testing, and scanning electron microscopy. The biocompatibility of the D-GL13K coating was investigated through histologic observations of vital organs and tissues using hematoxylin and eosin. RESULTS: The D-GL13K coating demonstrated significant anti-demineralization effects, evidenced by reduced demineralization depth analyzed through optical coherence tomography and enhanced Vickers hardness than in the noncoated control group, showcasing the coating's potential to protect teeth from WSLs. Scanning electron microscopy analysis further elucidated the diminished enamel damage observed in the group treated with D-GL13K. Importantly, histologic examination of vital organs and tissues using hematoxylin and eosin staining revealed no overt disparities between the D-GL13K coated group and the noncoated control group. CONCLUSIONS: The D-GL13K enamel coating demonstrated promising anti-demineralization and biocompatibility properties in a rat model, thereby suggesting its potential for averting WSLs after orthodontic interventions. Further research in human clinical settings is needed to evaluate the coating's long-term efficacy.
RESUMO
Objective @#To analyze and discuss the effect of 4 different surface treatment methods on the bonding effect between polymerization porcelain and metal bracket s.@*Methods@# 45 polymer-ceramics specimens were made and 40 of them were selected and randomly divided into 5 groups according to different surface treatment methods. A group:surface without special treatment. B group: 9.6% hydrofluoric acid gel combine with bonding agent, C group: 9.6% hydrofluoric acid gel combine with silane, D group: 35％ phosphoric acid gel combine with bonding agent, E group: 35％ phosphoric acid gel combine with silane. All specimens were stored in water for 24 hours at 37 ℃ after bonding 10 min utes and then cycled 500 cycles (5 ℃ to 55 ℃). To measure the shear bonding strength and record the damage cases and the adhesive remnant index.@*Results @#The shear strength values were: 3.24 in the control group, 7.24 MPa in the hydrofluoric acid etching treatment group. 10.78 MPa in the hydrofluoric acid gel combined with silane group. 4.17 MPa in the phosphoric acid-only group, 6.84 MPa in the phosphoric acid gel combined with silane group. The results of each group were statistically different from those of the other four groups (P < 0.001). The rate of breakage after the removal of brackets of the hydrofluoric acid gel combined with silane group is higher than the others. @*Conclusion @#As to the high shear bonding strength and low rate of breakage after the removal of brackets, we recommend 35% phosphoric acid etching combining with silane coupling agent in clinical.
