The effect of aluminum oxide sandblasting and discs on shear bond strength of metal brackets rebonded in eroded enamel

Luciana De Vasconcelos Leão,Sigmar De Mello Rode,Adriana Oliveira,Jefferson Chaves Moreira,Luiz Renato Paranhos,Flavia Pardo Salata Nahsan

doi:10.33448/rsd-v10i13.20132

Abstract

This research aimed to assess the effect of aluminum oxide sandblasting and discs on the bond strength of metal brackets rebonded on artificially eroded enamel. Fifty-four bovine incisors were divided into groups: Control (Artificial Saliva), AlOx (Aluminum oxide sandblasting), and SL (Aluminum oxide discs). They had their enamel surface flattened with Al2O3 discs and a metallographic polisher, then Knoop microhardness was assessed. AlOx and SL specimens were eroded with Coca-Cola™ for 1 minute, 3 times a day for 7 days. Metal brackets were bonded to the tooth. Shear strength was measured by an EMIC universal testing machine (0.5 mm/min). The Adhesive Remnant Index (ARI) was performed after shearing through magnifying glass (10X). Kolmogorov-Smirnov, Levene, homoscedasticity and ANOVA tests were applied to assess microhardness and shear strength (p=0.163). All groups presented shear bond strength with no significant differences. The ARI showed statistically significant difference between the groups. The prevalence for the control group was ARI 3. However for AlOx and SL, ARI 1 and 2 prevailed. The aluminum oxide sandblasting and aluminum oxide discs did not positively increase the bond strength of brackets when bonded to artificially eroded enamel. The ARI indicated that eroded teeth present higher resin adhesion to enamel.

Highlights

Tooth wear has presented a significant prevalence increase over the last years because of the high consumption of acidic beverages such as sports drinks, fruit juices, and industrialized teas, which have the potential to cause enamel demineralization (Deery, Wagner, Longbottom, Simon & Nugent, 2000; Federlin, Thonemann, Schmaiz & Urlinger, 1998; Meira et al, 2021)
The control group (C) presented higher microhardness mean when compared to the Aluminum oxide sandblasting (AlOx) and Sof-Lex Pop On disc (SL) groups, which were subjected to the erosive challenge with acidic beverage (Table 1 and Graph 1)
A higher mean was observed for AlOx, where brackets were treated with aluminum oxide sandblasting

Summary

Introduction

Tooth wear has presented a significant prevalence increase over the last years because of the high consumption of acidic beverages such as sports drinks, fruit juices, and industrialized teas, which have the potential to cause enamel demineralization (Deery, Wagner, Longbottom, Simon & Nugent, 2000; Federlin, Thonemann, Schmaiz & Urlinger, 1998; Meira et al, 2021). For being highly consumed, are considered one of the main extrinsic etiological factors (Ganss, Klimek & Giese, 2001). Erosion is the loss of superficial dental structure because of a chemical action, with no involvement of microorganisms, characterizing a demineralization process that weakens enamel surface with subsequent wear, which may affect dentin (Meurman & Ten Cate, 1996; Lussi, Jaeggi & Zero, 2004). The use of orthodontic brackets directly on sound enamel is a constant clinical practice, but the presence of a sound enamel in ideal conditions for adhesion is not always established (Mine et al, 2010), considering that ionic exchanges, chemical and mechanical challenges, and changes related to the individual and the dynamic environment that is the oral cavity constantly occur (Tavares et al, 2003)

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