Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2018-05-22T17:33:36Z No. of bitstreams: 2 Tese - Andreia Assis Carvalho - 2018.pdf: 4561805 bytes, checksum: 5562226572f75d161d963c396d0c974f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-05-23T11:38:00Z (GMT) No. of bitstreams: 2 Tese - Andreia Assis Carvalho - 2018.pdf: 4561805 bytes, checksum: 5562226572f75d161d963c396d0c974f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-23T11:38:00Z (GMT). No. of bitstreams: 2 Tese - Andreia Assis Carvalho - 2018.pdf: 4561805 bytes, checksum: 5562226572f75d161d963c396d0c974f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-04-20 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The objective of this study was to evaluate the clinical behavior of direct composite resin restorations (Class I and II), varying the universal dental adhesive application protocol, using the FDI and USPHS evaluation criteria. It was a randomized, double-blind, mouth5 divided, and sample-based randomized controlled trial. The selected participants should have a Class I and/or II restorative need for at least three dental elements or multiples of three resulting from the presence of carious lesions and/or unsatisfactory restorations. Three protocols for the application of the Single Bond Universal adhesive (3M ESPE) were tested (n=150): CAT (control) = etch-and-rinse + adhesive (n=50); CASE = selective etching in enamel + adhesive (n=50) and Ac = self-etch (n=50). The three groups were similarly restored using Filtek Z350 XT composite resin (3M ESPE) by means of the oblique incremental technique. Clinical evaluations were performed by two evaluators at the baseline (T1) and after 15.8 (±2.7 months) (T2), using the FDI and USPHS criteria. Friedman (between groups at different times), Wilcoxon (between times for each group) and McNemar (between FDI and USPHS criteria) were performed, α=0.05. The Kappa test showed excellent inter-examiner agreement (κ>0.80). For the "superficial staining" property, a statistically significant difference was observed in T2 between the CAT and CASE groups (p=0.01) with higher values for CAT and, when T1 and T2 were compared for each group, there were differences in the CAT group (p=0.001) and in the Ac group (p=0.007) for T2. For the other comparisons between groups and times there were no statistically significant differences, even when the FDI and USPHS criteria were compared (p≥0.05). It can be concluded that the different protocols of universal adhesive application (CAT, CASE and Ac) did not influence the clinical behavior of the restorations evaluated in 15.8 months of evaluation. The FDI and USPHS criteria provided comparable results. / Esse trabalho objetivou avaliar o comportamento clínico de restaurações diretas de resina composta (Classe I e II), variando o protocolo de aplicação do adesivo dentário universal, por meio dos critérios de avaliação FDI e USPHS. Trata-se de um ensaio clínico contrlado randomizado, duplo-cego, boca-dividida e de amostra por conveniência. Os participantes selecionados deveriam ter necessidade restauradora de Classe I e/ou II no mínimo em três elementos dentários ou múltiplos de três, resultantes da presença de lesões cariosas e/ou restaurações insatisfatórias. Três protocolos de aplicação do adesivo Single Bond Universal (3M ESPE) foram testados (n=150): CAT (controle) = Condicionamento ácido total + adesivo (n=50); CASE = Condicionamento ácido seletivo em esmalte + adesivo (n=50) e Ac = autocondicionante (n=50). Os três grupos foram restaurados de forma similar utilizando resina composta Filtek Z350 XT (3M ESPE) por meio da técnica incremental oblíqua. As avaliações clínicas foram realizadas por dois avaliadores no baseline (T1) e após 15,8 (±2,7 meses) (T2), por meio dos critérios FDI e USPHS. Foram realizados os testes Friedman (entre os grupos nos diferentes tempos), Wilcoxon (entre os tempos para cada grupo) e McNemar (entre os critérios FDI e USPHS), α=0,05. O teste Kappa apresentou excelente concordância interexaminadores (κ>0,80). Para a propriedade “manchamento superficial”, observou-se diferença estatisticamente significante no T2 entre os grupos CAT e CASE (p=0,01) com maiores valores para CAT e, quando comparados T1 e T2 para cada grupo, houve diferença no grupo CAT (p=0,001) e no grupo Ac (p=0,007) para T2. Para as demais comparações entre os grupos e tempos não houve diferenças estatisticamente significantes, inclusive quando os critérios FDI e USPHS foram comparados (p≥0,05). Pode-se concluir que os diferentes protocolos de aplicação do adesivo universal (CAT, CASE e Ac) não influenciaram o comportamento clínico das restaurações avaliadas em 15,8 meses de avaliação. Os critérios FDI e USPHS proporcionaram resultados comparáveis entre si.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-18T14:18:46Z No. of bitstreams: 1 sergioluizmotajunior.pdf: 65970440 bytes, checksum: b08afa740679beb93b85550945b417d2 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-01T18:47:10Z (GMT) No. of bitstreams: 1 sergioluizmotajunior.pdf: 65970440 bytes, checksum: b08afa740679beb93b85550945b417d2 (MD5) / Made available in DSpace on 2016-07-01T18:47:10Z (GMT). No. of bitstreams: 1 sergioluizmotajunior.pdf: 65970440 bytes, checksum: b08afa740679beb93b85550945b417d2 (MD5) Previous issue date: 2012-02-14 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo do presente estudo foi o desenvolvimento de uma nova ponteira para ser acoplada aos aparelhos fotopolimerizadores utilizados para colagem de bráquetes e acessórios ortodônticos, e teste da efetividade da mesma em ensaio mecânico in vitro. A ponteira é espelhada na superfície interna e baseia-se em conceitos físicos de refração e reflexão de luz. Apresenta como principal vantagem, a redução do tempo clínico necessário para o procedimento de colagem, reduzindo, dessa forma, a possibilidade de contaminação durante o processo. Através do ensaio de resistência mecânica ao cisalhamento e da determinação do Indice Remanescênte de Adesivo (IRA), testou-se a ponteira em uma amostra composta por 120 corpos de prova, sendo a mesma dividida em 2 grupos. No grupo 1 foi utilizado aparelho fotopolimerizador de fonte de luz halógena e no grupo 2 foi utilizado fonte de LED. Cada grupo foi subdividido. Nos subgrupos H1 e L1 utilizou-se a ponteira convencional dos respectivos instrumentos. Nos subgrupos H2 e L2 a colagem foi feita utilizando-se a ponteira desenvolvida. Os valores dos testes de cisalhamento e IRA para os subgrupos foram comparados entre si. Os resultados mostraram que não houve diferença estatisticamente significante, tanto para os ensaios de resistência ao cisalhamento (p>0,05), quanto para o IRA (p>0,05) entre os subgrupos. Conclui-se que 1 - os testes de ensaios mecânicos, assim como a análise do IRA mostraram que a nova ponteira desenvolvida, cumpriu os requisitos necessários à colagem dos acessórios ortodônticos; 2 – o tempo de colagem foi reduzido pela metade, sendo necessária uma só incidência. / The porpose of the present study was the development of a new device to be coupled to light-curing units for bonding orthodontic brackets and accessories and test of its efficacy in “in vitro” mechanical trial. The inner surface of the device is mirrored and is based on physical concepts of light refraction and reflection. The main advantage of such device is the reduced clinical time needed for bonding and the lesser possibility of contamination during the process. 120 bodies of proof were used for testing the shear bond strength of brackets bonded with the device. The Adhesive Remnant Index (ARI) was also determined. The sample was divided into 2 groups. In group 1 a halogen light-curing unit was used and in group 2 a led lightcuring unit was used. Each group was then subdivided. In subgroups H1 and L1, a conventional light guide rod was used. In subgroups H2 and L2 bonding was performed with the mirrored device coupled to the tip of the guide light rod. The values obtained for the shear bond strength and the ARI in the subgroups were compared. Results showed that there was no statistically significant difference for the shear strength (p>0,05) and the ARI (p>0,05) between the subgroups. Conclusions are that 1 - The tests of mechanical trials and the ARI analysis showed that the new device fulfilled the requisites for bonding orthodontic accessories; 2 - time for bonding was reduced to half, being necessary only one light exposure.

Background: The light-cured resin-based pit and fissure sealants success and longevity are enhanced by sufficient curing. Multiple emission peak Light Emitting Diode Light Curing Units offer a wider range of wavelengths and different levels of irradiances to ensure sufficient curing.The irradiance is considered a main curing factor that can affect the material properties. Purpose: The aim of this study was to assess the effect of different settings of a multiwave LED LCU on the degree of conversion and microhardness of a pit and fissure sealant comparing the irradiance of 1000 mW/cm2 to 1400 mW/cm2 and 3200 mW/cm2 irradiances of the LCU using manufacturer’s guidelines for curing times at 2, 4 and, 6 mm distances. Methods: A multiwave LED light curing unit was evaluated on three different irradiance levels 1000 mW/cm2 (S), 1400 mW/cm2 (H), and 3200 mW/cm2 (X). A total of 90 samples made from the fissure sealant were fabricated and divided into eighteen groups (n=5/group). Samples were cured following manufacturer’s guidelines of curing times for each curing mode at 2, 4, or 6 mm distance between the light tip and top of samples. The DC was measured using (ATR-FTIR) spectroscopy. The KHN test was performed on five different locations of each specimen using a hardness tester (Leco LM247AT, MI, USA, software; Confident V 2.5.2). Results: The top DC for H-8 was significantly higher than S-10 at 2 and 4mm, H-20 DC was significantly lower than S-30 at only 2mm. The bottom DC for H-8 was significantly higher than S-10 at 2mm only, H-20 DC was significantly lower than S-30 at 4 and 6mm only. H-8 KHN at top surface was significantly lower than S-10 at 2mm only, H-20 was significantly lower than S-30 at 2 and 6mm only. H-8 KHN at bottom surface was significantly lower than S-10 at 4 and 6mm but significantly higher at 2mm. H-20 was significantly lower than S-30 at 2mm but significantly higher at 4 and 6mm. The top DC for X-3 was significantly lower than S-10 at all curing distances with no significant difference at all curing distances between X-9 and S-30. The bottom DC for X-3 was significantly higher than S-10 at all curing distances with no significant difference between X-9 and S-30. X-3 KHN at top surface was significantly lower than S-10s at all curing distances. X-9 was significantly lower than S-30 at 6mm only. X-3 KHN at bottom surface was significantly lower than S-10 at 2 and 4mm only with no significant difference at all curing distances between X-9 and S-30. Conclusions: Using a multiwave LED LCU to polymerize Delton Opaque resin-based fissure sealants will result in an optimal DC and KHN values for any irradiance level if the curing distance is kept at 4 mm or less and with at least two cycles of the shortest curing time recommended by the manufacturer. Using a multiwave LED LCU with 1000, 1400 or 3200 mW/cm2 irradiance levels with shortest curing times recommended resulted in unsatisfactory DC and KHN levels. LED LCU with high and extra high irradiance levels (1400 and 3200 mW/cm2) can result in high DC and KHN levels when used adequately. Xtra Power mode (3200 mW/cm2) used on shortest curing time (3 seconds) resulted in significantly lower mechanical properties and for that reason it is not recommended to be used.

Indiana University-Purdue University Indianapolis (IUPUI) / Reduction of the polymerization shrinkage stress inherent of dimethacrylate-based resin composites has been a work in progress since the phenomenon was first described by Dr. Rafael L. Bowen in 1967. Contemporary efforts to modify the composites or the curing protocols for polymerization have proven a challenging task with controversial results. Influenced by existing mathematical models relating exposure, curing time and depth of cure of resin composites, a novel method for the reduction of polymerization shrinkage stress is proposed. By polymerizing through a single aperture mask, a dental light curing unit is transformed from a planar light source to a point light source, and a fully cured, three-dimensional “bullet” shaped curing front is predicted for the cured resin below. So long as the edges of the bullet do not touch the cavity walls or floor, the shrinkage stress of the bullet is not transferred. Follow-up with an unmasked curing unit then fully polymerizes the restoration. By reducing the volume of uncured composite in contact with the cavity walls and floor, shrinkage stress of the restoration is also reduced. The objective of the present study was to demonstrate this curing phenomenon with a model resin composite using masks with aperture diameters of 0.5, 0.4, and 0.25 mm and curing times of 10, 20, 30, and 40 seconds. The resulting curing front was evaluated quantitatively and qualitatively. From this, mathematical models of the curing front were derived. Selected combinations of aperture mask and curing time were then investigated to evaluate the influence of this phenomenon on the degree of conversion, Knoop hardness, and polymerization shrinkage stress of the same model resin composite. Group differences were analyzed using a one-way ANOVA at 5% significance.