Comparative study of dental enamel loss after debonding braces by analytical scanning electron microscopy (SEM)

Abstract

Clinical procedures when shear forces are applied to brackets suggest adhesion forces between 2.8 and 10.0 MPa as appropriate. In this study dental enamel was evaluated by scanning electron microscopy (SEM) before and after removing the brackets. Thirty bicuspids (previous prophylaxis) with metallic brackets (Roth Inovation 0.022 GAC), Transbond Plus SEP 3M Unitek adhesive and Transbond XT 3M resin were used. The samples were preserved to 37°C during 24 hr and submited to tangential forces with the Instron Universal machine 1.0 mm/min speed load strength resistance debonding. Also the Adhesive Remanent Index (ARI) test was made, evaluating the bracket base and the bicuspid surface. All the bracket SEM images were processed with AutoCAD to determine the enamel detached area. The average value was 6.86 MPa (SD ± 3.2 MPa). ARI value 1= 63.3%, value 2= 20%, value 3= 13.3% and 33% presented value 0. All those samples with dental enamel loss, presented different situations as fractures, ledges, horizontal, and vertical loss in some cases, and some scratch lines. There is no association between the debonding resistance and enamel presence. Less than half of the remanent adhesive on the dental enamel was present in most of the samples when the ARI test was applied. When the resin area increases, the debonding resistance also increases, and when the enamel loss increases, the resin free metallic area of the bracket base decreases in the debonding.

Evaluation of enamel loss by scanning electron microscopy after debonding brackets place with four different adhesives

“…SBS values higher than 11.3 MPa can cause fissures in the enamel surface and values lower than 7.3 MPa are less likely to cause enamel fissures (Bishara et al, 1995). Even though another study concurs with the adequate clinically values, it was observed enamel loss and therefore there is no relationship between the SBS and enamel loss (Rodríguez‐Chávez, Arenas‐Alatorre, & Belio‐Reyes, 2017). The reported values for a conventional adhesives range from 10.4 to 11.8 MPa (Bishara, VonWald, Laffoon, & Warren, 2001).…”

Debonding and Clean-Up in Orthodontics: Evaluation of Different Techniques and Micro-Morphological Aspects of the Enamel Surface

“…The literature reports several methods for investigating the surfaces of enamel [19,[23][24][25][26][27][28]. As a result of the quantitative data provided, atomic force microscopy, environmental SEM, a profilometer, energy dispersive X-ray spectroscopy, and in vivo confocal microscopy analysis were used for these studies [29][30][31]. In particular, atomic force microscopy allows the morphological and mechanical properties of dental tissue surfaces with no peculiar treatment to be investigated [32].…”

Evaluation of Enamel Topography after Debonding Orthodontic Ceramic Brackets by Different Er,Cr:YSGG and Er:YAG Lasers Settings

“…Endo et al (2009) found that values of SBS between 2.80 and 10.00 MPa did not cause damage or enamel loss [22]. Rodriguez-Chavez et al (2017) found that even with SBS values as low as 6.8 MPa, it is possible to observe damage and enamel loss [23]. Enamel tearing could be observed when SBS values were higher than 13.8 MPa [24].…”