Luiz Antônio Alves Bernardes

Shear bond strength of brackets bonded to enamel with a self-etching primer. Effects of increasing storage time after activation.

OBJECTIVE To evaluate bonding efficacy of activated Transbond Plus Self-Etching Primer (TPSEP) used at different time points with Transbond XT to bond metallic orthodontic brackets to bovine incisors. MATERIALS AND METHODS The inferior incisors of 210 bovines were randomly divided into seven groups (n = 30). TPSEPs were mixed, activated, and kept activated for 30 (group 30), 21 (group 21), 15 (group 15), 7 (group 7), 3 (group 3), or 1 (group 1) days before bonding, and in one group (group 0) TPSEP was used immediately after mixed. At day zero, incisors in each group were bonded in exactly the same way. After applying TPSEP, brackets were bonded with Transbond XT, according to the manufacturers instructions. After 24 hours, shear bond strength (SBS) tests were performed for all samples at a crosshead speed of 0.5 mm/min, and the Adhesive Remnant Index was scored. RESULTS There were no significant differences between the SBS of groups 0, 1, 3, 7, and 15 (P > .05) However, those groups had higher SBS (P < .05) compared with groups 21 and 30. No significant difference (P > .05) was observed between groups 21 and 30. Despite the decrease in SBS for groups 21 and 30, bond strength values were still satisfactory. CONCLUSION After activation, the TPSEP mix can be stored for a period of 15 days without losing its adhesive properties.

Treatment of ankylosis of the mandibular first molar with orthodontic traction immediately after surgical luxation

The aim of this article was to report a clinical case of orthodontic treatment in a patient with Class II malocclusion and ankylosis of a maxillary first molar. Surgical luxation was performed, followed immediately by traction with an orthodontic arch with straps. The results obtained were satisfactory, and occlusal equilibrium was improved.

Avaliação cefalométrica das alterações verticais e ântero-posteriores em pacientes Classe II esquelética, tratados com aparelho extrabucal de tração cervical ou combinada

AIM: To evaluate the antero-posterior and vertical changes in patients with skeletal Class II malocclusions (ANB > 5o) by means of the cephalometry. The patients had been treated with either cervical traction device (Group 1) or combined traction device (Group 2) both in association with a Edgewise-type device. METHODS: The sample consisted of 60 lateral cephalometric radiographs of 30 Caucasian individuals, 13 males and 17 females, obtained during both pre-treatment and post-treatment phases. The 15 patients of Group 1 had mean ages of 10 years and 7 months in the pre-treatment and 13 years and 9 months in the post-treatment. The other 15 patients of Group 2 had mean ages of 11 years and 5 months in the pre-treatment and 14 years and 9 months in the post-treatment. The cephalometric measures obtained in the beginning as well as in the end of the treatment were analysed and compared by using the Students t test. RESULTS AND CONCLUSIONS: No significant changes regarding the facial growth pattern during the treatment in both groups. In Group 2, whose patients had a tendency of vertical growth (GoGn-SN> 36°), the extraoral combined traction device was not capable of reducing the mandibular plane angle despite of causing no extrusive effect on the upper molars. The anterior movement of the maxilla was restricted, whereas the vertical movement was stable in both groups studied. Although growth and anterior movement of the mandible were observed, the mandibular inclination was unchanged. The maxillary-mandibular relationship was shown to be significantly improved in both groups, with a perceptible reduction of the ANB measure.