99 research outputs found
Clínicas de Inovação: Um Programa de Fomento ao Empreendedorismo Universitário
Este artigo apresenta o cotejamento entre constructos teóricos obtidos a partir de literatura científica qualificada e ilustração de dois casos do programa de fomento ao empreendedorismo universitário, Clínicas de Inovação da Universidade Federal de Santa Catarina. As atividades de desenvolvimento de modelos de negócios utilizadas pelo programa são baseadas na abordagem design thinking, que atua alinhando as necessidades dos usuários à proposição de negócio. Então, essa pesquisa abordará o método de trabalho da Clínica, resultados dos casos e lições aprendidas. Como resultado, identificou-se a influência do ambiente universitário na intenção empreendedora dos graduandos e que seus valores e preferências afetam diretamente o desenvolvimento de seus negócios
Evaluation of the shear bond strength of the Orthobond composite under different conditions
Objective: Evaluate the shear bond strength of metal brackets bonded with Orthobond composite (Dental Morelli Ltda, Sorocaba, Brazil) under different enamel surface conditions. Methods: Ninety bovine mandibular permanent incisors were divided into six groups (n = 15). In Group 1 (control) and Group 2 the bonding procedures were performed by using Transbond XT (3M Unitek, Monrovia, USA) and Orthobond (Dental Morelli Ltda, Sorocaba, Brazil) composites,respectively, according to the manufacturer’s recommendations. In the other groups brackets were bonded with Orthobond composite (Dental Morelli Ltda, Sorocaba, Brazil) as follows: Group 3 – dental surface conditioned with Transbond Plus Self-Etching Primer (3M Unitek, Monrovia, USA); Group 4 – bonding procedure without application of Orthoprimer (Dental Morelli Ltda, Sorocaba, Brazil); Group 5 - Eagle Bond applied on saliva/blood-contaminated dental surface; and Group 6 – use of homogenized Orthobond (Dental Morelli Ltda, Sorocaba, Brazil). After bonding the brackets, all the samples were submitted to shear bond strength tests by means of an Emic Universal Testing Machine at a crosshead speed of 0.5 mm/min. The results obtained in mega Pascal (MPa) were submitted to the analysis of variance (ANOVA) and then to the Tukey test. Results: The results in mega Pascal showed statistically significant differences between Groups 1 and 2 (p= 0.041), 1 and 5 (p=0.000) and between 4 and 5 (p=0.016). The ARI (Adhesive Remnant Index) scores showed evidence of a higher number of fractures at the bracket/composite interface. Conclusion: In all tested situations the Orthobond (Dental Morelli Ltda, Sorocaba, Brazil) was shown to be apt for bracket bonding
Biocompatibility of orthodontic adhesives in rat subcutaneous tissue
ABSTRACT OBJECTIVE: The objective of the present study was to verify the hypothesis that no difference in biocompatibility exists between different orthodontic adhesives. MATERIAL AND METHODS: Thirty male Wistar rats were used in this study and divided into five groups (n=6): Group 1 (control, distilled water), Group 2 (Concise), Group 3 (Xeno III), Group 4 (Transbond XT), and Group 5 (Transbond plus Self-Etching Primer). Two cavities were performed in the subcutaneous dorsum of each animal to place a polyvinyl sponge soaked with 2 drops of the respective adhesive in each surgical loci. Two animals of each group were sacrificed after 7, 15, and 30 days, and their tissues were analyzed by using an optical microscope. RESULTS: At day 7, Groups 3 (Transbond XT) and 4 (Xeno III) showed intense mono- and polymorphonuclear inflammatory infiltrate with no differences between them, whereas Groups 1 (control) and 2 (Concise) showed moderate mononuclear inflammatory infiltrate. At day 15, severe inflammation was observed in Group 3 (Transbond XT) compared to other groups. At day 30, the same group showed a more expressive mononuclear inflammatory infiltrate compared to other groups. CONCLUSION: Among the orthodontic adhesive analyzed, it may be concluded that Transbond XT exhibited the worst biocompatibility. However, one cannot interpret the specificity of the data generated in vivo animal models as a human response
Cytotoxicity of intermaxillary orthodontic elastics of different colors: an in vitro study
OBJECTIVES: Natural latex does not fall into the category of materials known to be entirely inoffensive. The purpose of this in vitro study was to test the hypothesis that there is no difference in the cytotoxicity between elastics of different colors and those from different manufacturers. MATERIAL AND METHODS: Different latex intraoral elastics of different colors (5/16 = 7.9 mm, mean load) were compared. The sample was divided into 7 groups of 24 elastics each: Group T (TP Orthodontics, natural latex elastics, control); Groups U1, U2, U3, U4, U5 and U6 (Uniden, natural latex elastics and colored elastics, namely, green, pink, yellow, red and purple, respectively). Cytotoxicity assays were performed by using cell culture medium containing epithelioid-type cells (Hep-2 line) derived from human laryngeal carcinoma. The cytotoxicity was evaluated by using the "dye-uptake" test, which was employed at two different moments (0 and 24 h). Data were compared by analysis of variance (ANOVA) and Tukey's test (
Effect of orthodontic treatment on tooth autotransplantation : systematic review of controlled clinical trials
This systematic review was focused on evaluating tooth autotransplantation, considering its impacts on the teeth, bone, soft tissues, and aesthetics in orthodontic patients. A bibliographic search was conducted without limitations on year of publication or language in the databases of PubMed, Web of Science, Scopus, Medline Complete, Cochrane, Clinical Trials, and Trials Central. For triage of articles, indications, surgical planning, orthodontic movement, risk factors for treatment, and long-term follow-ups were considered. For outcomes, the results with reference to teeth, alveolar bone, periodontal tissues, and esthetic satisfaction were considered. Risk of bias was evaluated using the methodological index for nonrandomized studies-MINORS. The results showed 10 controlled clinical trials, and no randomized clinical trials were found. The selected studies included 715 patients and 934 autotransplanted teeth among which there were premolars, molars, and anterior teeth evaluated in the long term, indicating that orthodontics associated with autotransplantation indicated a result that was generally clinically acceptable. The quality of the set of evidence was considered medium due to the presence of different methodological problems, risk of bias, and significant heterogeneity in the evaluated studies. There was a sufficient body of evidence that justified autotransplantation in patients who needed orthodontic movement. In teeth, there was an increase in root resorption influenced by orthodontics, but without impacting on the general clinical result in the long term. Bone and periodontal tissue do not appear to be affected by orthodontics. The patient’s aesthetic satisfaction was not considered in the studies
TiF4 varnish protects the retention of brackets to enamel after in vitro mild erosive challenge
The effect of fluoride agents on the retention of orthodontic brackets to enamel under erosive challenge is little investigated. Objective: The aim of this study was to evaluate the effect of titanium tetrafluoride (TiF4) and sodium fluoride (NaF) agents on the shear bond strength of brackets to enamel and on the enamel microhardness around brackets under erosive challenge. Methods: Brackets were bonded to bovine incisors. Five groups were formed according to fluoride application (n=10): TiF4 varnish, TiF4 solution, NaF varnish, NaF solution and control (without application). The specimens were submitted to erosive challenge (90 s cola drink/2h artificial saliva, 4x per day for 7 days). Solutions were applied before each erosive cycle and varnishes were applied once. Vickers Microhardness (VHN) was obtained before and after all cycles of erosion and the percentage of microhardness loss was calculated. Shear bond strength, adhesive remnant index and polarized light microscopy were conducted after erosion. The data were analyzed by ANOVA, Tukey, Kruskal-Wallis and Mann-Whitney U tests (α=0.05). Results: The %VHN had no statistically significant differences among the experimental groups. However, considering the comparisons of all groups with the control group, TiF4 varnish showed the highest protection from enamel demineralization (effect size of 2.94, while the effect size for the other groups was >2.4). The TiF4 varnish group had significantly higher shear bond strength compared to other groups. There was no difference among groups for adhesive remnant index. Polarized light microscopy showed higher demineralization depth for the control group. Conclusions: Application of NaF and TiF4 agents during mild erosive challenge minimized the enamel mineral loss around brackets, however only the experimental TiF4 varnish was able to prevent the reduction of shear bond strength of brackets to enamel.
TiF 4 varnish protects the retention of brackets to enamel after in vitro mild erosive challenge
The effect of fluoride agents on the retention of orthodontic brackets to enamel under erosive challenge is little investigated. Objective: The aim of this study was to evaluate the effect of titanium tetrafluoride (TiF<i>4</i>) and sodium fluoride (NaF) agents on the shear bond strength of brackets to enamel and on the enamel microhardness around brackets under erosive challenge. Methods: Brackets were bonded to bovine incisors. Five groups were formed according to fluoride application (n=10): TiF<i>4</i> varnish, TiF<i>4</i> solution, NaF varnish, NaF solution and control (without application). The specimens were submitted to erosive challenge (90 s cola drink/2h artificial saliva, 4x per day for 7 days). Solutions were applied before each erosive cycle and varnishes were applied once. Vickers Microhardness (VHN) was obtained before and after all cycles of erosion and the percentage of microhardness loss was calculated. Shear bond strength, adhesive remnant index and polarized light microscopy were conducted after erosion. The data were analyzed by ANOVA, Tukey, Kruskal-Wallis and Mann-Whitney U tests (α=0.05). Results: The %VHN had no statistically significant differences among the experimental groups. However, considering the comparisons of all groups with the control group, TiF<i>4</i> varnish showed the highest protection from enamel demineralization (effect size of 2.94, while the effect size for the other groups was >2.4). The TiF<i>4</i> varnish group had significantly higher shear bond strength compared to other groups. There was no difference among groups for adhesive remnant index. Polarized light microscopy showed higher demineralization depth for the control group. Conclusions: Application of NaF and TiF<i>4</i> agents during mild erosive challenge minimized the enamel mineral loss around brackets, however only the experimental TiF<i>4</i> varnish was able to prevent the reduction of shear bond strength of brackets to enamel
Synthesis of a chitosan nanoparticle suspension and its protective effects against enamel demineralization after an in vitro cariogenic challenge
Objective: Our study aims to synthesize, characterize, and determine the effects of a ChNPs suspension on human enamel after cariogenic challenge via pH-cycling. Methodology: ChNPs were synthesized by ion gelation and characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering. Forty enamel blocks were divided into four groups (n=10/group): (i) ChNPs suspension; (ii) chitosan solution; (iii) 0.05% sodium fluoride (NaF) solution; and (iv) distilled water. Specimens were exposed to cariogenic challenge by cycling in demineralization solution (3 h) and then remineralized (21h) for 7 days. Before each demineralization cycle, the corresponding solutions were passively applied for 90 s. After 7 days, specimens were examined for surface roughness (Ra) and Knoop hardness (KHN) before and after the cariogenic challenge; % KHN change (variation between initial and final hardness), and surface topography by an optical profilometer. The data were analyzed by repeated-measures ANOVA, One-way ANOVA, and Tukey tests (α=0.05). Results: TEM images showed small spherical particles with diameter and zeta potential values of 79.3 nm and +47.9 mV, respectively. After the challenge, all groups showed an increase in Ra and a decrease in KHN values. Optical profilometry indicated that ChNPs- and NaF-treated specimens showed uneven roughness interspersed with smooth areas and the lowest %KHN values. Conclusion: The ChNPs suspension was successfully synthesized and minimized human enamel demineralization after a cariogenic challenge, showing an interesting potential for use as an oral formulation for caries prevention
A higiene bucal de bebês edêntulos e sua influência na microbiota bucal: os profissionais de saúde devem preconizá-la? – revisão crítica
Introduction: The indication of oral hygiene in edentulous babies is still controversial among health professionals, being necessary the search of this recommendation and the standardization of information. Objective: To investigate critically the evidence related to the indication of oral hygiene for edentulous babies. Methods: The search for articles was performed in the PUBMED, LILACS and GOOGLE SCHOLAR databases, in order to assess the following question: "Can oral cavity hygiene of edentulous babies influence oral microbiota? A search in 8 books of Pediatric Dentistry was also performed. Results: 317 articles were found (167-PUBMED, 146-GOOGLE SCHOLAR and 4-LILACS). There were no primary studies that evaluated the effect of oral hygiene of edentulous infants on microbiota, which impair the conduction of a systematic review. Thus, it was included for this review six studies that investigated microorganisms in the oral cavity of edentulous infants and the role of salivary immunoglobulins. Among the textbooks evaluated, only 4 indicated the oral hygiene in edentulous infants. Conclusion: According to the data, there are no primary studies that assessed the effect of oral hygiene in the oral microbiota of edentulous babies. It is relevant to conduct clinical studies in order to obtain scientific evidence about the indication or no of the oral hygiene in edentulous babies.Introdução: A indicação de higiene bucal em bebês edêntulos entre os profissionais de saúde ainda é controversa, sendo necessária a busca científica sobre esta indicação e a padronização da informação. Objetivo: Investigar criticamente as evidências relacionadas a indicação da higiene bucal para bebês edêntulos. Métodos: A busca de artigos foi realizada nas bases de dados PUBMED, LILACS e GOOGLE SCHOLAR, de modo a avaliar a seguinte pergunta: “A higienização da cavidade bucal de bebês edêntulos pode influenciar a microbiota bucal?”. Uma busca em 8 livros de Odontopediatria também foi realizada. Resultados: Foram encontrados 317 artigos (167-PUBMED, 146-GOOGLE SCHOLAR e 4-LILACS). Não foram encontrados estudos primários que avaliaram o efeito da higiene bucal em bebês edêntulos na microbiota, impossibilitando a condução de revisão sistemática. Assim, para a revisão foram incluídos 6 estudos que investigaram micro-organismos na cavidade bucal de bebês edêntulos e o papel das imunoglobulinas salivares. Dentre os livros avaliados, somente 4 indicaram a higiene bucal em bebês edêntulos. Conclusão: Diante dos dados analisados, não existem estudos primários que avaliaram o efeito da higienização na microbiota bucal de bebês edêntulos. Torna-se relevante a condução de estudos clínicos para obtenção de evidências científicas sobre a indicação ou não da higienização da cavidade bucal de bebês edêntulos
- …