Development of a novel bioactive glass for air-abrasion to selectively remove orthodontic adhesives

Ayam A Taha,Padhraig S Fleming,Robert G Hill,Mangala P Patel

doi:10.1007/s00784-017-2279-8

Ayam A Taha, Padhraig S Fleming + Show 2 more

Open Access

https://doi.org/10.1007/s00784-017-2279-8

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Abstract

ObjectivesTo develop a novel, bioactive glass for removing residual orthodontic adhesive via air-abrasion, following bracket debonding, and to evaluate its effectiveness against a proprietary bioactive glass 45S5(Sylc™)-air-abrasion, and a slow-speed tungsten carbide (TC) bur.Materials and methodsThree glasses were prepared and their bioactivity was proved. One novel glass (QMAT3) was selected due to its appropriate hardness, lower than that of enamel/45S5(Sylc™). Sixty extracted human premolars were randomly assigned to adhesive removal using: (a) QMAT3-air-abrasion, (b) 45S5(Sylc™)-air-abrasion, and (c) TC bur, which were further subdivided (n = 10) based on the adhesive used (Transbond XT™ or Fuji Ortho LC™). Enamel roughness was assessed using scanning electron microscopy (SEM) and non-contact profilometry before bracket bonding, after removing residual adhesive following bracket debonding and after polishing.ResultsQMAT3 formed apatite faster (6 h) than 45S5(Sylc™) (24 h) in Tris solution. QMAT3-air-abrasion gave the lowest enamel roughness (Ra) after removing the adhesives. SEM images showed a pitted, roughened enamel surface in the TC bur group and to a lesser extent with 45S5(Sylc™), while a virtually smooth surface without any damage was observed in the QMAT3-air-abrasion group. The time taken for adhesive removal with QMAT3 was comparable to 45S5(Sylc™) but was twice as long with the TC bur.ConclusionsQMAT3-air-abrasion is a promising technique for selective removal of adhesives without inducing tangible enamel damage.Clinical relevanceA novel bioactive glass has been developed as an alternative to the use of TC burs for orthodontic adhesive removal.

Highlights

Several factors may predispose to or directly induce enamel damage during, or after, fixed orthodontic treatment
No technique has proven capable of complete and efficient removal of residual adhesives, without inducing even a minor amount of enamel damage [4]. These surface changes reduce the resistance of enamel to bacterial/organic acid attacks increasing its susceptibility to demineralization and dental caries
The experimentally determined Vickers hardness number (VHN) were converted to GPa units using the equation: GPa = VHN × 0.009807

Summary

Introduction

Several factors may predispose to or directly induce enamel damage during, or after, fixed orthodontic treatment. Various methods have been proposed for clean-up of residual orthodontic adhesives from the enamel surface, such as: hand instruments, stones (Arkansas stone, green stone), wheels and discs, scalers, dental burs (typically tungsten carbide burs), lasers and pumice or zirconium paste [3]. No technique has proven capable of complete and efficient removal of residual adhesives, without inducing even a minor amount of enamel damage [4]. These surface changes reduce the resistance of enamel to bacterial/organic acid attacks increasing its susceptibility to demineralization and dental caries.

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