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Shear bond strength of metallic brackets bonded with a new orthodontic composite
Romano, Fábio Lourenço; Correr, Américo Bortolazzo; Sobrinho, Lourenço Correr; Magnani, Maria Beatriz Borges de Araújo & de Siqueira, Vânia Célia Vieira
Abstract
Aim:
The aim of this study was to assess the shear bond strength of orthodontic brackets in different enamel surfaces
using the Transbond Plus Color Change composite (TPCC-3M Unitek), and to analyze the Adhesive Remnant
Index (ARI).
Methods:
Seventy-two human premolars were divided into six groups (n = 12), as follows: Group
1(control) - Transbond XT conventional; in Groups 2 to 6, TPCC was used under the following enamel treatment
conditions: phosphoric acid and XT-primer; Transbond Plus Self-Etching Primer (TPSEP); phosphoric acid only;
phosphoric acid, XT-primer and saliva; and TPSEP and saliva, respectively. Twenty-four hours after bonding, the
brackets were debonded with an Instron machine at a crosshead speed of 0.5 mm/min, and ARI was evaluated by
using a stereoscopic magnifying glass.
Results:
The mean shear strength values (MPa) for Groups 1 to 6 were 24.6,
18.7, 17.5, 19.7, 17.5 and 14.8, respectively. Data were submitted to ANOVA and Tukey’s test (α = 0.05). Group 1 had
significantly higher shear bond strength values than Groups 3, 5, and 6 (p < 0.05), but did not differ significantly
from Groups 2 and 4 (p > 0.05). No statistically significant differences (p > 0.05) were found between Groups 2, 3,
4, 5 and 6.
Conclusions:
Bracket bonding using TPCC showed adequate adhesion for clinical use, and the type of
enamel preparation had no influence.
Keywords
composite resins, shear strength, orthodontic brackets, orthodontics.
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