Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-05T00:11:28Z No. of bitstreams: 1 ItaniellyDantasSilveiraCruz_DISSERT.pdf: 2442849 bytes, checksum: 02e55bdcb8191be6836bcbfa7df46f9c (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-16T23:01:44Z (GMT) No. of bitstreams: 1 ItaniellyDantasSilveiraCruz_DISSERT.pdf: 2442849 bytes, checksum: 02e55bdcb8191be6836bcbfa7df46f9c (MD5) / Made available in DSpace on 2017-10-16T23:01:44Z (GMT). No. of bitstreams: 1 ItaniellyDantasSilveiraCruz_DISSERT.pdf: 2442849 bytes, checksum: 02e55bdcb8191be6836bcbfa7df46f9c (MD5) Previous issue date: 2017-07-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Objetivo: Analisar o efeito de diferentes protocolos de fotoativa??o na resist?ncia de uni?o ao cisalhamento (RUC) de br?quetes met?licos colados em esmalte e no grau de convers?o (GC) de uma resina ortod?ntica utilizando tr?s aparelhos fotoativadores. Metodologia: 230 coroas de incisivos bovinos foram distribu?das aleatoriamente em 23 grupos (n=10). Ap?s ser realizado o tratamento de superf?cie com ?cido fosf?rico (15 segundos) e Primer Transbond XT (3M Unitek), br?quetes met?licos foram colados ao esmalte com resina Transbond XT (3M Unitek) utilizando 23 protocolos de fotoativa??o de acordo com os fatores ?aparelho fotoativador? (FlashMax P4 ? RMO, Valo Cordless ? Ultradent ou Radii-Cal ? SDI), ?faces fotoativadas? (centro/vestibular; mesial, distal, cervical e incisal; mesial e distal ou cervical e incisal) e ?tempo de fotoativa??o? (2, 3, 4, 6, 20 ou 40 segundos). O ensaio de cisalhamento (100KgF, 1mm/min) foi realizado ap?s o armazenamento das amostras por 4 meses (?gua destilada, 37?C). Utilizando os mesmos protocolos de fotoativa??o, 230 discos de resina (0,1 mm de espessura e 5 mm de di?metro, em m?dia) foram confeccionados para an?lise do GC. Os dados da RUC (MPa) e do GC (%) foram avaliados descritivamente e atrav?s do teste T de Student, da ANOVA one way e do teste de Tukey. As falhas de uni?o foram classificadas de acordo com o ?ndice Remanescente Adesivo (IRA), analisadas descritivamente e atrav?s do teste de Kruskal-Wallis. Resultados: De todos os 23 protocolos, apenas 5 apresentaram valores de RUC clinicamente aceitos de acordo com a literatura. No que diz respeito aos fatores ?faces fotoativadas? e ?tempo de fotoativa??o?, os protocolos do Valo Cordless foram os ?nicos que apresentaram resultados quanto ? RUC estatisticamente semelhantes (p=0,230 e p=0,093, respectivamente). Das compara??es que apresentaram diferen?a estatisticamente significativa (p?0,05) quanto ao fator ?tempo de fotoativa??o? de acordo com a RUC, 66,6% correspondem aos protocolos onde apenas a face central do br?quete foi fotoativada. Ao comparar os grupos onde apenas duas faces foram fotoativadas, aqueles em que o par de faces correspondeu ? mesial e ? distal foram os que resultaram maiores valores de RUC. Quanto ao GC, tendo em vista o fator ?faces fotoativadas?, apenas os resultados dos grupos do FlashMax P4 foram estatisticamente diferentes (p?0,05). O Valo Cordless foi o ?nico aparelho no qual o fator ?tempo de fotoativa??o? n?o afetou de forma estatisticamente significa os valores do GC (p=0,968). E a maioria (66,6%) dos valores mais elevados do GC quando apenas duas faces foram fotoativadas correspondeu ?queles protocolos nos quais tais faces foram a mesial e a distal. Em rela??o ao IRA, houve diferen?a estatisticamente significativa entre os escores (p=0,000), sendo que o escore 2 foi o mais observado (52,6%). Conclus?o: A RUC dos br?quetes met?licos colados ao esmalte e o GC da Transbond XT podem apresentar diferen?as estatisticamente significativas a depender do aparelho fotoativador selecionado e do protocolo de colagem utilizado pelo ortodontista. E sup?e-se que a for?a adesiva entre a resina e o esmalte dent?rio ? maior do que aquela entre o br?quete e a Transbond XT. / Objective: To analyze the effect of different photoactivation protocols on shear bond strength (SBS) of metallic brackets bonded to enamel and the degree of conversion (DC) of an orthodontic resin using three photoactivating devices. Methodology: 230 crowns of bovine incisors were randomly distributed in 23 groups (n = 10). After the surface treatment with phosphoric acid (15 seconds) and Primer Transbond XT (3M Unitek), metal brackets were bonded to the enamel with Transbond XT resin (3M Unitek) using 23 photoactivation protocols according to the factors "photoactivator" (FlashMax P4 ? RMO, Valo Cordless ? Ultradent or Radii-Cal ? SDI), "photoactivated faces" (center/vestibular; mesial, distal, cervical and incisal; mesial and distal or cervical and incisal) and "photoactivation time" (2, 3, 4, 6, 20 or 40 seconds). The shear test (100KgF, 1mm/min) was performed after storage of the samples for 4 months (distilled water, 37?C). Using the same photoactivation protocols, 230 resin discs (0,1 mm thick and 5 mm diameter, on average) were made for DC analysis. The SBS (MPa) and DC (%) data were evaluated descriptively and through Student's T-test, one-way ANOVA and the Tukey test. The union failures were classified according to the Adhesive Remnant Index (ARI), analyzed descriptively and through the Kruskal-Wallis test. Results: Of all 23 protocols, only 5 presented clinically accepted SBS values according to the literature. Regarding the factors "photoactivated faces" and "photoactivation time", the Valo Cordless protocols were the only ones that presented statistically similar SBS results (p=0,230 and p=0,093, respectively). Of the comparisons that presented a statistically significant difference (p?0,05) regarding the factor "time of photoactivation" according to SBS, 66,6% corresponded to the protocols where only the central face of the bracket was photoactivated. When comparing the groups where only two faces were photoactivated, those in which the pair of faces corresponded to the mesial and the distal were the ones that resulted in higher SBS values. Regarding the CG, considering the "photoactivated faces" factor, only the results of the FlashMax P4 groups were statistically different (p?0,05). The Valo Cordless was the only device in which the factor "time of photoactivation" didn?t affect statistically means the values of the DC (p=0,968). And the majority (66,6%) of the highest DC values when only two faces were photoactivated corresponded to those protocols in which such faces were mesial and distal. Regarding ARI, there was a statistically significant difference between the scores (p=0,000), and the score 2 was the most observed (52,6%). Conclusion: The SBS of the metal brackets bonded to the enamel and the DC of the Transbond XT resin may present statistically significant differences depending on the selected photoactivating device and the bonding protocol used by the orthodontist. And it?s assumed that the adhesive force between the resin and the dental enamel is greater than that between the bracket and the Transbond XT.