Valiollah Arash; Abdolmajid Alizadeh
Abstract
Aim: There are currently many patients who need orthodontic treatment. Given the high expense of orthodontic therapy and the fact that orthodontic brackets are recyclable elements, this study was carried out to compare the shear Bond strength of new and recycled brackets in vitro.materials and Method: ...
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Aim: There are currently many patients who need orthodontic treatment. Given the high expense of orthodontic therapy and the fact that orthodontic brackets are recyclable elements, this study was carried out to compare the shear Bond strength of new and recycled brackets in vitro.materials and Method: Thirty healthy extracted first premolars without cracks or decay were selected. the teeth were randomly assigned to two groups and etched by 37% phosphoric acid for 30 seconds. An icy surface was obtained and brackets (018 standard Dentaurum)were assigned equally to two groups of 15 new and recycled brackets each. After 500 round thermo-cycling in temperatures between 5°C and 55°C, shear bond strength was obtained by dividing the force by bracket cross-sector. The Adhesive Remnant Index (ARI) and the Enamel detachment index (EDI) were evaluated.
Results: Average shear Bond strengths for the new and recycled brackets were 17.5717±7.3929 Mpa and 16.6811±5.3899 Mpa, respectively. There were no significant and differences in Bond strength between two brackets. Furthermore, no significant difference was observed in EDI and ARI ratios.Conclusion: With respect to shear Bond strength, recycled brackets may be a viable option for fixed orthodontic treatment in clinical practice.
Valiollah Arash; Shaghayegh Bozorgzadeh
Abstract
Aim: Light cure composites are routinely used to attach orthodontic brackets, so bond strength and cure time must be considered. Ilowever, the disadvantages of the conventional halogen apparatus include heat and lengthy composite curing. Therefore, the purpose of this study was to compare shear bond ...
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Aim: Light cure composites are routinely used to attach orthodontic brackets, so bond strength and cure time must be considered. Ilowever, the disadvantages of the conventional halogen apparatus include heat and lengthy composite curing. Therefore, the purpose of this study was to compare shear bond strength of orthodontic brackets composite cured by plasma arc (PAC), conventional halogen (QTII), light- emitting diode (LED) and self-cure.Materials and Methods: In this in vitro study, sixty premolar teeth extracted for orthodontic purposes from patients tinder 18 years of age were collected and divided into four equal groups. In the first group, the brackets were bonded by self-cure composite. In the second, third, and fourth groups, they were bonded by halogen, LED and plasma arc, respectively. The samples were thcrmocycicd and finally the force required for brackt failure was measured. Shear bond strength was obtained by dividing the exerted force by the bracket base surface. AR1 (Adhesive Remnant Index) and EDI(Enamel Detachment index) were also evaluated. Data were analyzed by ANOVA followed by TUKEY test.
Results: Average shear bond strengths were 14.7±5.4 MPa in the self—cure group, 14.6±5.3 MPa in the halogen group, 14.7±4.5 MPa in the LED group, and 14.2±5 MPa in the plasma group. There were no significant differences among the groups. EDI and AR1 did not differ between the light-cure and self-cure groups.
Conclusion: No significant difference was observed in shear bond strength among different methods of composite curing. Therefore, despite the high cost of plasma arc, it is recommended in order to reduce operation time.
