Shear bond strength of orthodontic brackets bonded with glass ionomer cement

Abstract

Introduction. A great number of techniques have been used for bonding orthodontic brackets to the tooth surfaces. Glass ionomer cements are frequently used material for this purpose. The aim of this study was to measure the shear bond strength of orthodontic brackets bonded with glass ionomer cement Ortho Fuji LC and remained adhesive on the enamel surface after brackets debonding. Material and methods. A total of 40 extracted premolars for orthodontic reasons in different gender patients, 10-16 years old, were randomly divided into four groups. Using glass ionomer cement Ortho Fuji LC (Tokyo, Japan) stainless steel brackets were bonded to the teeth with the average surface area of the bracket base of 14.7 mm2. The shear bond strengths were measured at a crosshead speed of 1 mm per minute, and the load applied at the time of fracture was recorded using electronic dynamometer. Remained adhesive on the enamel after bracket debonding was evaluated using the adhesive remnant index (ARI). Results. Shear bond strength had the highest value for the group where enamel was etched right before bonding bracket (9.14 MPa), than in the group 2 (7.43 MPa), while in the groups 1 (6.72 MPa) and 3 (6.22 MPa), where etching was not performed, bond strength was lower. Conclusion. Shear bond strength of orthodontic brackets bonded with glass ionomer cement Ortho Fuji LC had higher values when the enamel was etched than without etching

Con Tec Lc Light-Curing Adhesive in Orthodontics

“…When analyzing and discussing such high values arrived at by certain authors in in vitro studies, in terms of the debonding force, which indirectly reflects the adhesive power of adhesive, the following facts have to be taken into account: firstly, these values most probably would not be so high had the study been undertaken with the same adhesives but in in vivo conditions, because based on in vitro research protocol, we do not have all these negative factors adversely affecting the strength of bracket-tooth bond in the oral cavity (impossibility to ensure an absolutely dry operating area, impossibility of the patient to be absolutely calm, etc.). Secondly, if these results (during an in vivo study), were still higher than 14MPs, even with the decreasing of the stated values, that would take us to the other extreme: by decreasing the risk of unwanted bracket failure, the degree of risk for enamel damage during debonding would be increased, a fact that many authors point at as warning [11,[23][24][25][26][27][28]. Namely, the purpose of these studies was also to determine the average bond strength achieved between the bracket and the tooth with various types of teeth, because arch activation most frequently has the same effect on all brackets "threatening" to separate the bracket from the tooth.…”

“…The protocol determined by the requirements, that is to say, manufacturer's instructions was used during bonding brackets. The study was done in vitro like this was done by many other researchers before [10][11][12][13][14][15][16][17][18][19]. An in vitro study of adhesives has advantages over an in vivo study, as the factor of speed of work connected to the dexterity of researcher is eliminated, thus excluding the possibility of contaminating the working area by saliva (which reduces the adhering power of adhesive), taking into account that most adhesives are sensitive to humidity as "one of the most common causes for bracket failure".…”

A Comparasion of Bracket Debonding Forces Between the Two Adhesives: Con Tec Lc and Con Tec Duo

“…The study was done in vitro as this was done by many other investigators before [15][16][17][18][19][20] who tested certain characteristics of adhesive types in order to understand their specific properties, advantages and shortcomings compared to each other. An in vitro study of adhesives is more favorable compared to in vivo study, because it eliminates the factor of speed of work depending on researcher's dexterity, thus reducing the possibility of contamination of the working area with saliva, (which in turn reduces the adhesive strength of the bonding agent), having in mind that most adhesives are sensitive to moist as "one of the most common causes for bracket failure".…”