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In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey’s test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

Ciência Odontológica Brasileira ReSumoObjetivos: A aplicação tópica de flúor é a principal estratégia para remineralizar lesões de mancha branca (MB). Foi proposto que o aumento na retenção deste íon na superfície pode favorecer a remineralização. Portanto, o tratamento prévio da superfície do esmalte foi proposto para otimizar sua eficácia. Material e Métodos: Este estudo objetivou avaliar a capacidade de remineralização do fluoreto com e sem pré-tratamento do esmalte com ácido fosfórico e nitrato de alumínio e a resistência do esmalte após novo desafio ácido. Vinte e quatro blocos de esmalte bovino foram obtidos e selecionados pela média inicial de microdureza de superfície (MS). Em seguida, MB foram artificialmente induzidas através de ciclagem DES-RE e os espécimes aleatorizados em dois grupos de acordo com o pré-tratamento do esmalte a ser avaliado (n=12): F (flúor gel acidulado 1,23% -APF -4 min) e P-Al-F (ácido fosfórico 37% -30s + nitrato de alumínio 0,05M 1min + APF por 4 min). Após o tratamento, um novo desafio ácido semelhante ao inicial foi realizado. Novas avaliações de MS foram obtidas em cada etapa. Os valores foram processados e a porcentagem de perda mineral da superfície (%PDS) foi obtida. Os dados foram analisados estatisticamente por ANOVA dois critérios e teste de Tukey (p<0,05). Resultados: Não houveram diferenças entre os protocolos avaliados. Para ambos grupos, uma diferença significante entre as fases do estudo foi detectada: observouse uma queda no %PDS após o tratamento e aumento do %PDS após novo desafio ácido. Conclusão: O pré-tratamento do esmalte com ácido fosfórico associado com nitrato de alumínio promoveu efeito similar à aplicação isolada do APF na remineralização das MB artificiais, recuperando parcialmente a dureza de superfície. Após o novo desafio ácido, os dois grupos ofereceram resistência parcial. PAlAvRAS-ChAveCáries dental; Esmalte dentário; Fluoreto; Remineralização dentária. ABSTRACTObjective: The topical fluoride application is the main strategy to remineralize white spots lesions (WSL). It is assumed that increasing its retention in the surface can favor remineralization. Therefore, previous treatments of the enamel surface are purposed to optimize its efficacy. This study aimed to evaluate the remineralization capacity of the fluoride without and with the pre-treatment of the enamel with phosphoric acid and aluminum nitrate and then, the enamel acid-resistance after new acid challenge. Material and Methods: Twenty-four enamel bovine blocks were obtained and selected by means of initial surface microhardness (SMH) measurements. In sequence, WSL were artificially inducted by DE-RE cycling and randomized in two groups according to the enamel pretreatment to be tested (n=12): F (1.23% fluoride gel -APF-4min) and P-Al-F (37% phosphoric acid-30s + 0.05M aluminum nitrate 1min + APF-4min). After then, a new acid challenge was equally performed. Additional SMH assessments were performed in each step. The values were processed and the percentage of SH loss (%SHL) was obtain...

The objective of this case report was to present the orthodontic treatment of an 8‐year‐old female patient with Fanconi's anemia and Class III skeletal pattern and agenesis of maxillary lateral incisors. Patient presented in the late mixed dentition with a Class III malocclusion with anterior and posterior crossbites. Rapid maxillary expansion and facemask therapy was performed for 12 months. Phase II was simplified with a 6 × 2 fixed appliance only in the mandibular arch for solving the anterior crowding. Maxillary canines were reshaped as lateral incisors and the central incisors were augmented for closing spaces. Although the systemic disease, orthodontic intervention is possible if individual limitations are considered and treatment is simplified.

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