Biomimetic Effect of Nano-Hydroxyapatite in Demineralized Enamel before Orthodontic Bonding of Brackets and Attachments: Visual, Adhesion Strength, and Hardness in In Vitro Tests

Abstract

Dietary habits with high consumption of acidic food can induce in orthodontic patients an increased risk of demineralization lesions around orthodontic brackets and bands. The purpose of the present laboratory study is to assess the in vitro visual efficacy of a biomimetic nano-hydroxyapatite remineralizing solution in a hypomineralized enamel surface and its effect on adhesion of fixed orthodontic appliances and on enamel microhardness. Intact teeth were demineralized, and subsequently the areas of demineralization were visually recorded using a 0–100 scale. Subsequently, a remineralizing solution (Biorepair® Repair Shock Treatment) was applied for ten minutes once a day/for one week per month for a total remineralizing treatment of 3 months. Visual effects were recorded. Moreover, bond strength was recorded and adhesive remnant index scores were measured for both orthodontic brackets and composite attachments both before demineralization and after demineralization and application of remineralizing solution. Also, Vickers microhardness was measured. All data were submitted to statistical analysis. The application of remineralizing solution induced a significant in vitro reduction of demineralized areas after the first week of application. No significant differences between untreated enamel surfaces and remineralized surfaces were detected after 2 months of remineralizing treatment. Bond strength values were significantly reduced for both brackets and attachments after remineralizing treatment. However, attachments showed higher adhesion values than brackets in both conditions tested. Remineralized enamel showed significantly higher microhardness values than demineralized enamel and lower values than intact enamel.

Fear of the Relapse: Effect of Composite Type on Adhesion Efficacy of Upper and Lower Orthodontic Fixed Retainers: In Vitro Investigation and Randomized Clinical Trial

“…The Unit Internal Review Board approved this study. Forty freshly extracted bovine incisors were selected after meeting the inclusion criteria: integrity of the buccal surface, absence of enamel wear or caries, absence of anomalies of volume, shape and structure, and absence of traumatic lesions [24]. After being extracted, teeth were kept inside a solution of 0.1% (w/v) thymol free of alcohol, in complete darkness [25].…”

“…The preparation of the samples described above and the subsequent SBS test were performed according to previous studies [11,24]. Each sample was secured in the lower jaw of a universal testing machine (Model 3343, Instron, Canton, MA, USA) keeping the long axis of the splints parallel to the edge of the blade.…”

Impact of self-assembling peptides in remineralisation of artificial early enamel lesions adjacent to orthodontic brackets

“…Moreover, microcrystalline hydroxyapatite (HAP) particles were suggested as suitable candidates for the prevention of demineralisation and the stimulation of remineralisation process on www.nature.com/scientificreports/ tooth tissue 20,36 . It was reported that after nanohydroxyapathite treatment the enamel was more mineralised 37 and harder than demineralised enamel 38 .…”

The Effect of Biodentine Maturation Time on Resin Bond Strength When Aged in Artificial Saliva

“…Biodentine is a bioactive dentine substitute material [ 2 ] that has been recommended for coronal, radicular restorations and in vital pulp therapy [ 8 ]. Biomimetic materials have been introduced in order to obtain a remineralizing effect on both dentine and enamel, showing promising results in terms of bond strength and tissue microhardness [ 21 ]. Strength of the bond between a final filling material and the underlined Biodentine is one of the most critical influences affecting the quality and success of the final restoration.…”