The purpose of this study was to evaluate the bond strength of metallic orthodontic brackets to feldspathic ceramic with different etching times, bonding materials and with or without silane application. Cylinders of feldspathic ceramic were etched with 10% hydrofluoric acid for 20 or 60 s. For each etching time, half of the cylinders received two layers of silane. Metallic brackets were bonded to the cylinders using Transbond XT (3M Unitek) or Fuji Ortho LC (GC). Light-activation was carried out with total exposure time of 40 s using UltraLume 5. Shear bond strength testing was performed after 24 h storage. Data were submitted to three-way ANOVA and Tukey's test (α=0.05). The adhesive remnant index (ARI) was used to evaluate the amount of adhesive remaining on the ceramic surface at ×8 magnification. Specimens etched for 60 s had significantly higher bond strength compared with 20 s. The application of silane was efficient in increasing the shear bond strength between ceramic and both fixed materials. Transbond XT showed significantly higher (p<0.05) bond strength than Fuji Orth LC. There was a predominance of ARI score 0 (clean ceramic failure surface) for all groups, with an increase in scores 1, 2 and 3 (adhesive material increasingly present on ceramic failure aspect) for the 60-s etching time. In conclusion, 60-s etching time, silane and Transbond XT improved significantly the shear bond strength of brackets to ceramic.

Summary Introduction The objective of this study is to assess the oral and maxillofacial characteristics of microcephalic children associated with congenital Zika syndrome (CZS). Methods A cross-sectional, observational study was carried out with 61 patients with microcephaly/CZS born between June 2015 and September 2017 (29 boys and 32 girls, average age of 22.8 months) and a control group with 58 non-CZS children born in the same period (25 boys and 33 girls, average age of 23.8 months). The functional clinical analysis considered the labial and lingual frena, tongue anterior projection, oral escape, palate form, and first tooth eruption. For the craniofacial analysis, facial anthropometric points and the cephalic perimeter at the time were measured. Demographic data were collected from medical records, and a clinical exam was performed in order to register the intrabuccal characteristics and craniofacial measures. The chi-square test and Student’s t-test were used with a significance level of 0.05. Results The narrow palate form, tongue anterior projection, oral escape, and late first tooth eruption were significantly more present in the group with microcephaly/CZS. As for the craniofacial analysis, face width (Bi-Zi), mandible width (Go-Go), height of face upper third (Tr-G), and monthly growth of cephalic perimeter were significantly smaller, whereas height of face lower third (Sn-Gn) was significantly bigger in the group with microcephaly/CZS (P &lt; 0.05). Conclusion Children with microcephaly resulting from a congenital Zika infection showed functional, oral, and maxillofacial changes and smaller facial development in comparison with non-CZS children in the same age group.

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This technique is used in many areas of medicine, but poorly explored in dentistry and orthodontics. This treatment is cheap and non-invasive and can be applied by own orthodontist, and it can improve the treatment with a faster and safe tooth movement, without pain.

The aim of this study was to evaluate the effect of different number of thermal cycles on the shear bond strength (SBS) of metallic orthodontic brackets bonded to feldspathic ceramic by a composite resin. Twenty-five ceramic cylinders were etched with 10% hydrofluoric acid for 60 s and received two layers of silane. Brackets were bonded to the cylinders using Transbond XT and assigned to 5 groups (n=5): Group 1 -Control group (without thermal cycling); Group 2 -500 thermal cycles; Group 3 -5,000 thermal cycles; Group 4 -7,000 thermal cycles and Group 5 -10,000 thermal cycles. Light-activation was carried out by Radii Plus LED. SBS testing was carried out after 24 h of storage in deionized water and thermal cycling (5/55 o C and 30 s dwell time). Five brackets were bonded to each cylinder, totalizing 25 brackets for each group. Data were submitted to one-way ANOVA and Tukey's test (α=0.05). The Adhesive Remnant Index (ARI) was evaluated at 8× magnification. The SBS (MPa) of control group (9.3±0.8), 500 (9.0±0.7) and 5,000 (8.4±0.9) thermal cycles were significantly higher than those after 7,000 (6.8±0.6) and 10,000 (4.9±1.0) thermal cycles (p<0.05). The ARI showed a predominance of Scores 0 (adhesive failure) prevailed in all groups, as shown by the ARI, with increased scores 1 and 2 (mixed failures) for control group and 500 thermal cycles. In conclusion, thermal fatigue may compromise the bonding integration between metallic brackets and ceramic restorations. For in vitro testing, use of at least 7,000 cycles is advised to result in significant fatigue on the bonding interface. I n f l u e n c e o f T h e r m a l C y c l e s N u m b e r o n B o n d S t r e n g t h o f M e t a l l i c B r a c ke t s t o C e r a m i c

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