Made available in DSpace on 2015-04-14T13:30:29Z (GMT). No. of bitstreams: 1 452168.pdf: 1481490 bytes, checksum: ac569335421ad138a02a15752e11a756 (MD5) Previous issue date: 2013-09-23 / Introduction : There are many tools on the market dental rotary for use in polishing of a restoration adhesive. As there are many choices, and the same manufacturer have more than one type of rotary apparatus of restoration, does not establish a single conduit to determine which tool to use composites containing nanoparticles. Objective : To evaluate, in vitro, the effect of two different polishing systems, based on a multi steps and on the quality and surface roughness of two composites nanoparticles. Materials and methods : The samples were prepared with nanofilled material resin Filtek Z 350 XT (3M ESPE) and nanoh?brid Tetric N Ceran (Ivoclar Vivadent). The samples were made in cylindrical molds measuring 3 mm X 6 mm. A single operator executed all procedures. Each group consisted of 20 samples: 1) ZXT-control (without polishing); TNC-2) control (without polishing); 3) ZXT Sof-Lex (Orange fine and Superfine); 4) ZXT Optrapol; 5) TNC Optrapol; 6) TNC Sof-Lex (Orange fine and Superfine). The surface roughness was assessed with porfilometry (Ra), SEM and AFM. Statistical analyses : For analysis of mean roughness Ra (um), the data were tested for normality of ANOVA, at a significance level of 5%. Once verified the normal distribution of the results, they were subjected to analysis of variance followed by Tukey's test with a significance level of 5%. Results : The qualitative and quantitative analyzes showed that resins polished with Optrapol showed higher surface roughness and polishing with Sof-Lex showed no statistical difference between the resins tested. The lowest roughness was obtained with the control group, with no statistical difference between the resins. Conclusion : Optrapol promotes greater roughness in the resins tested, and ZXT showed higher roughness. Polishing with Soft-Lex showed no statistically significant differences between the tested resins. The surface roughness of the resins with TNC was lower when compared with Optrapol. The lowest surface roughness was obtained by the control group. / Introdu??o : Existe no mercado odontol?gico muitos instrumentos rotat?rios para serem utilizados no polimento final de uma restaura??o adesiva. Como s?o muitas as op??es, e um mesmo fabricante tem mais de um tipo de instrumento rotat?rio para realizar a finaliza??o da restaura??o, n?o se estabelece uma conduta ?nica que determine qual o instrumento utilizar para resinas compostas que contenham nanopart?culas. Objetivo : Avaliar, in vitro, o efeito de dois diferentes sistemas de polimento, baseados em um e multi etapas, sobre a qualidade e rugosidade da superf?cie de duas resinas com nanopart?culas. Materiais e m?todos : As amostras foram confeccionadas com resina nanoparticulada Filtek Z 350 XT (3M ESPE) e nanoh?brida Tetric N Ceran (Ivoclar Vivadent ). As amostras foram confeccionadas em moldes cil?ndricos medindo 3 mm X 6 mm. Um ?nico operador executou todos os procedimentos. Cada grupo foi composto por 20 amostras: 1) ZXT-Controle (sem polimento); 2)TNC-Controle (sem polimento); 3) ZXT+ Sof-Lex (seq??ncia Laranja fina e superfina); 4) ZXT+ Optrapol; 5) TNC+ Optrapol ; 6) TNC+ Sof- Lex (seq??ncia Laranja fina e superfina ). A rugosidade de superf?cie foi avaliada com rugos?metro (Ra), MEV e AFM. Estat?stica : Para an?lise das m?dias de rugosidade Ra (μm), os dados foram submetidos aos testes de normalidade de ANOVA, ao n?vel de signific?ncia de 5%. Uma vez verificada a distribui??o normal dos resultados, estes foram submetidos ? an?lise de vari?ncia, seguida pelo teste de Tukey com n?vel de signific?ncia de 5%. Resultados : As an?lises qualitativas e quantitativas mostraram que as resinas polidas com Optrapol apresentaram maior rugosidade superficial e o polimento com Sof-Lex n?o mostrou diferen?a estat?stica entre as resinas testadas. A menor rugosidade foi obtida com os grupos controle, sem diferen?a estat?stica entre as resinas. Conclus?o : Optrapol promove maior rugosidade nas resinas testadas, e ZXT apresentou maior rugosidade. O polimento com Soft-Lex n?o mostrou diferen?as estatisticamente significantes entre as resinas testadas. A rugosidade superficial das resinas foi menor com TNC, quando comparado com Optrapol. A menor rugosidade de superf?cie obtida foi pelo grupo controle.

Made available in DSpace on 2015-04-14T13:30:29Z (GMT). No. of bitstreams: 1 452974.pdf: 3097525 bytes, checksum: fb30a932f49f0911b5cf750d9aaf97e9 (MD5) Previous issue date: 2013-11-01 / The aims of this study were: (a) establish, through a review of the literature, the state of the art regarding the use of photodynamic therapy for the disinfection of the root canal system as well as future prospects, (b) evaluate the periapical tissues response on rats teeth with apical periodontitis, to photodynamic therapy as an adjunct to endodontic treatment through histological, microbiological and radiological analysis. Therefore, 32 left lower rats molars were exposed to the oral environment for 21 days to induce apical periodontitis. The animals were randomly divided into four groups according to proposed treatment: endodontic treatment in one session (G1); endodontic treatment in two sessions with with calcium hydroxide [Ca(OH)2] dressing for 14 days (G2) ; endodontic treatment in one session associated with photodynamic therapy (PDT) (G3) and endodontic treatment in two sessions with Ca(OH)2 for 14 days, associated with PDT (G4). After 28 days, the animals were killed and the jaws prepared for evaluation. For microbiological analysis samples were collected before and after each treatment step. Quantification of CFU/mL were analyzed using linear mixed models, showing significant microbial reduction after all proposed treatments, compared to the initial collection, although no significant difference between groups were found. The radiographic results were submitted to ANOVA, showing no statistically significant difference between groups. For histological data, Kruskal-Wallis test were used, followed by Mann-Whitney U test for those cases where differences were detected. These differences were found in neutrophils and eosinophils populations in groups where PDT was used and macrophages and giant cells when Ca(OH)2 was used, with or without PDT. These data seem to point to a better repair quality when PDT is applied, caused by laser biomodulator effect in periapical tissues. The association of PDT with an interappointment dressing with Ca(OH)2 produces better conditions to stimulate repair, being more research needed to determine this relationship. / Os objetivos deste estudo foram: (a) estabelecer, atrav?s de revis?o da literatura, o estado da arte na aplicabilidade da terapia fotodin?mica para a desinfec??o do sistema de canais radiculares bem como as perspectivas futuras; (b) avaliar a resposta dos tecidos periapicais de dentes de ratos, portadores de periodontite apical, ? terapia fotodin?mica como coadjuvante ao tratamento endod?ntico, atrav?s de an?lise histol?gica, microbiol?gica e radiogr?fica. Para tanto, 32 molares inferiores esquerdos de ratos foram expostos ao meio bucal por 21 dias, para indu??o da periodontite apical. Ap?s, foram divididos aleatoriamente em quatro grupos conforme o tratamento proposto: tratamento endod?ntico em sess?o ?nica (G1); tratamento endod?ntico em duas sess?es com medica??o intracanal ? base de hidr?xido de c?lcio [Ca(OH)2] por 14 dias (G2); tratamento endod?ntico em sess?o ?nica, associado ? terapia fotodin?mica (PDT) (G3) e tratamento endod?ntico em duas sess?es com Ca(OH)2 por 14 dias, associado ? PDT (G4). Ap?s 28 dias, os animais foram mortos e as mand?bulas preparadas para avalia??o. Para avalia??o microbiol?gica foram realizadas coletas antes e ap?s cada etapa de tratamento. As quantifica??es de UFC/mL foram analisadas atrav?s de modelos mistos lineares, mostrando significativa redu??o microbiana ap?s todos os tratamentos propostos, quando comparados ? coleta inicial, n?o havendo por?m diferen?a significativa entre os grupos. Os resultados radiogr?ficos foram submetidos a ANOVA, n?o havendo diferen?a estatisticamente significativas entre os grupos. Para os dados histol?gicos, foi utilizado o teste de Kruskall-Wallis seguido por Mann-Whitney U para aqueles casos onde diferen?as foram detectadas. Estas diferen?as foram encontradas nas popula??es de neutr?filos e eosin?filos nos grupos onde a PDT foi utilizada e para macr?fagos e c?lulas gigantes quando o Ca(OH)2 foi utilizado, independentemente da PDT. Os dados parecem apontar para uma melhor condi??o de reparo quando da utiliza??o da PDT, pelo efeito biomodulador do laser nos tecidos periapicais. A associa??o da PDT com MIC com Ca(OH)2 parece propiciar os melhores resultados, sendo necess?rios mais estudos para determinar esta rela??o.

Made available in DSpace on 2015-04-14T13:30:30Z (GMT). No. of bitstreams: 1 453105.pdf: 815759 bytes, checksum: 659cc00433933dc2531b046154e2f3ee (MD5) Previous issue date: 2013-08-13 / Genioplasty is the surgical correction of the deformities of the chin. It is performed mainly to enhance facial harmony, however improvement in inferior lip posture and elimination of labial incompetence are noteworthy. Even though it is considered to be very stable, several factors can affect its stability, such as osteosynthesis performed. Several fixation methods have been described, such as wire osteosynthesis, positioning screws, plates and screws, Kirschner wires, resorbable plates and screws, which suggests a lack of a gold-standard. This retrospective study compared two of the most used fixation methods nowadays, two positioning screws and one pre-shaped plate, with regard to skeletal stability after advancement genioplasties. Cephalometric records from 26 fully grown, not consecutive patients (8 who had the osteotomy fixed with two positioning screws and 18 with one pre-shaped plate) were selected from the files of Hospital S?o Lucas da PUCRS. Immediate and 6-month postoperative cephalometric radiographs were inserted into Dolphing Imaging 11.7 for digital cephalometric analysis. Stability of the osteotomy was assessed through tracings superimposition and observation of differences in the vertical position of Menton and horizontal position of Pogonion. The two groups did not differ statistically, neither in Pg horizontal position (p=0.470), nor in Me vertical position (p=0.040). The fact that few patients had a complete documentation may have influenced the result. Further research with bigger samples is required. / A mentoplastia ? a corre??o cir?rgica das deformidades do mento. ? realizada principalmente com o intuito detornar a face mais harm?nica, por?m deve-se ressaltar a melhora na postura do l?bio inferior e elimina??o da incompet?ncia labial que acompanha algumas deformidades dentofaciais. Mesmo sendo considerada bastante est?vel, v?rios fatores podem influenciar sua estabilidade. Um deles ? o m?todo de osteoss?ntese usado para fixar a osteotomia. Diversos m?todos j? foram descritos, desde fios de a?o, parafusos posicionais, placas e parafusos, fios de Kirschner, at? placas e parafusos reabsorv?veis, o que sugere n?o haver um padr?o-ouro para a fixa??o desta osteotomia. Esse estudo retrospectivo comparou dois dos m?todos mais utilizados atualmente para a fixa??o da mentoplastia, dois parafusos posicionais e uma placa pr?-conformada, quanto ? estabilidade esquel?tica ap?s mentoplastias de avan?o. A documenta??o cefalom?trica de 26 pacientes adultos, n?o-consecutivos (oito cuja fixa??o foi feita com dois parafusos posicionais e dezoito com uma placa pr?-conformada) foi selecionada dos registros do Hospital S?o Lucas da PUCRS. Radiografias p?s-operat?rias imediatas e de seis meses foram inseridas no programa Dolphin Imaging 11.7 para an?lise cefalom?trica digital. A estabilidade da osteotomia foi verificada atrav?s da sobreposi??o dos tra?ados e observa??o de diferen?as na posi??o horizontal do Pog?nio e na posi??o vertical do Menton. Os dois grupos n?o diferiram estatisticamente, seja na posi??o horizontal do Pog?nio (p=0.470), seja na posi??o vertical do Menton (p=0.040). O fato de poucos pacientes apresentarem uma documenta??o completa pode ter influenciado os resultados. Mais pesquisas com maiores amostras se fazem necess?rias.

Made available in DSpace on 2015-04-14T13:30:30Z (GMT). No. of bitstreams: 1 453301.pdf: 1209405 bytes, checksum: fe63725c45a175b928e5abd3af600b87 (MD5) Previous issue date: 2013-10-31 / The reduction that occurs in the alveolar dimensions after tooth extraction can compromise the patients aesthetics and function. Due to the events of alveolar healing with loss of a wall were not described. The present study was designed to evaluate the characteristics of bone healing in socket with loss of a wall and test the influence of immediate treatment with alloplastic graft material. The two incisors of the sample of sixteen male rabbits, weighing between 2.5 and 3 kg, with 120 days were extracted. One of the walls was mechanically removed from its buccal aspect of the alveolar ridge 5 mm (WL) and the other was preserved (PR). Half of the sample received alloplastic graft (beta tricalcium phosphate) in both regions tested and, the remaining eight animals received no graft. Occlusive sutures were performed on all sites. The animals were grouped according to the graft presence and evaluation period as follows: Group A - no graft evaluated in two weeks, Group B - no graft and evaluated in sixteen weeks groups C and D received graft and were evaluated in two and sixteen weeks, respectively. Evaluation was performed using microtomography and histomorphology. Group A showed little material radiodense within the socket. Histological analysis showed bone tissue formation process. Group B showed more spongy bone volume with differences between WL and PR (p < 0.05). Group C exhibited distinct behavior of group A in bone formation, increasing radiodense material inside the socket and no volume difference between WL and PR. Group D showed increased bone, statistically significant when compared to group B, for both regions, with no difference between the sides. Areas had bone tissue composition, fibrous tissue, and non- resorbed particles. The wall loss negatively affect the alveolar volume. The immediate placement of alloplastic graft allowed to reduce the contraction ridge with socket wall preserved and lost, and can be an option for treatment of bone loss during the extraction. The periosteum has limitations in the containment of the particles within the graft when the absence of alveolar bone wall. / Ap?s a exodontia ocorre redu??o das dimens?es ?sseas que pode vir a comprometer a est?tica e fun??o. Devido aos eventos de reparo alveolar com perda de uma parede n?o terem sido descritos o presente estudo prop?s-se avaliar as caracter?sticas do reparo de alv?olos com perda da parede vestibular e testar a influ?ncia do tratamento imediato com enxerto de material alopl?stico. Foram extra?dos os dois incisivos inferiores da amostra de dezesseis coelhos machos, com 120 dias, pesando entre 2,5 e 3kg. Um dos alv?olos teve sua parede vestibular mecanicamente removida a 5 mm da crista alveolar (WL) e a outra foi preservada (PR). Metade da amostra recebeu enxerto (beta fosfato tric?lcio) em ambas as regi?es testadas e os oito animais restantes n?o receberam enxerto. Suturas oclusivas foram realizadas em todos os alv?olos. Os animais foram agrupados de acordo com a presen?a de enxerto e per?odo de avalia??o, sendo o Grupo A - sem enxerto, avaliado em duas semanas, grupo B - sem enxerto e avaliado em dezesseis semanas, grupo C e D receberam enxerto e foram avaliados em duas e dezesseis semanas respectivamente. Avalia??o foi realizada atrav?s de microtomografia e histomorfologia. O grupo A apresentou pouco material radiodenso dentro do alv?olo. A an?lise histol?gica mostrou tecido ?sseo em processo de forma??o. Grupo B apresentou osso esponjoso com maior volume ?sseo havendo diferen?as entre WL e PR (p <0,05). Grupo C exibiu distinto comportamento do grupo A na forma??o ?ssea, com aumento de material radiodenso no interior do alv?olo e nenhuma diferen?a de volume entre WL e PR. O Grupo D demonstrou aumento de osso, estatisticamente significativo, quando comparado ao grupo B, para ambas regi?es, sem diferen?a entre os lados. As ?reas apresentavam composi??o de tecido ?sseo, tecido fibroso, e part?culas n?o-reabsorvidas. A perda de parede interferiu negativamente no volume alveolar final. A coloca??o imediata do enxerto alopl?stico foi capaz de reduzir a contra??o alveolar para locais com paredes alveolares preservadas e perdidas, podendo ser uma op??o para tratamento de perdas ?sseas durante o processo de exodontia. O peri?steo apresentou limita??o na conten??o das part?culas de enxerto no interior do alv?olo quando da aus?ncia de parede ?ssea.

Made available in DSpace on 2015-04-14T13:30:32Z (GMT). No. of bitstreams: 1 458210.pdf: 1144060 bytes, checksum: 47ded64d10f4581406f15e3b1488e6d1 (MD5) Previous issue date: 2014-02-27 / Introduction: The aim of the present study was to evaluate the apical enlargement areas of three-rooted human upper premolars by means of micro-computed tomography-(&#956;CT). M?todos: After the cavity access, canal exploration and odontometry, eighteen samples were divided into three groups according to the preparation technique: manual group (Hand) (n=6) teeth were instrumented by crown-down technique and stainless steel files; ProTaper group (GPt) (n=6) teeth were instrumented by using the Rotary movement and ProTaper system; and WaveOne group (GWO) (n=6) teeth were instrumented by WaveOne instrument operated in reciprocating movement. The final canal enlargement at mesiobuccal (MB), distobucal (DB) and palatal (P) roots match 0,25 mm, 0,25 mm and 0,40 mm, respectively. Micro-computed tomography-(&#956;CT) was performed before and after preparation. The pre and post images corresponding to 0, 2, 4 and 6 mm from the apical stop were overlaid and the difference between the areas of surgical and anatomical canals were measured with the aid of PhotoShop program. The groups were statistically compared using two-way Analysis of Variance (ANOVA) and Tukey post-hoc test at 5% significance level. Results: There was no difference between the preparation techniques. Regardless of the technique, we found further enlargement toward the cervical portion of the canal. Some canals had excessive enlargement, but no perforation. Moreover, untouched areas were observed in some roots. Conclusion: There were no differences in all roots when comparing hand, rotary and reciprocating techniques. All of them are safe for the instrumentation of the apical third of three-rooted premolars. / Introdu??o: Este estudo avaliou, in vitro, atrav?s da microtomografia computadorizada (&#956;TC), as ?reas de desgaste em canais radiculares de pr?-molares superiores com tr?s ra?zes, causadas por tr?s diferentes sistemas de preparo. M?todos: Ap?s a abertura coron?ria, esvaziamento dos canais e estabelecimento da odontometria a 1,5 mm do v?rtice radiogr?fico, dezoito esp?cimes foram divididos em tr?s grupos, de acordo com a t?cnica de preparo empregada para o preparo do canal radicular: Grupo manual (Hand) (n=6) - os dentes foram preparados manualmente pela t?cnica coroa-?pice, com limas de a?o-inoxid?vel flex?veis; Grupo ProTaper (GPt) (n=6) dentes preparados pelo sistema rotat?rio ProTaper e Grupo WaveOne (GWO) (n=6) - dentes preparados pelo sistema reciprocante WaveOne. Os alargamentos apicais finais nos canais m?sio-vestibular (MV), disto-vestibular (DV) e palatino (P) corresponderam a 0,25 mm, 0,25 mm e 0,40 mm, respectivamente. Os dentes foram microtomografados antes e ap?s o preparo dos canais. As imagens pr? e p?s-operat?rias, correspondentes a 0, 2, 4, 6 mm do batente apical, foram sobrepostas e a diferen?a entre as ?reas dos canais cir?rgico e anat?mico foram mensuradas, com o aux?lio do programa PhotoShop. Os grupos foram comparados estatisticamente, empregando-se Anova de Dois Crit?rios e Post-hoc de Tukey (P<0,05). Resultados: N?o houve diferen?a entre as t?cnicas de preparo (P<0,05). Independente da t?cnica empregada, percebeu-se um maior alargamento em dire??o a por??o mais cervical do canal. Alguns canais apresentaram alargamento excessivo por?m, n?o houve perfura??o. Por outro lado, em algumas ra?zes observou-se ?reas n?o tocadas. Conclus?o: N?o houve diferen?a entre as t?cnicas manual, rotat?ria e reciprocante, empregadas para o preparo apical de pr?-molares com tr?s ra?zes. Todas s?o seguras para o preparo do ter?o apical desses dentes.

Made available in DSpace on 2015-04-14T13:30:32Z (GMT). No. of bitstreams: 1 458211.pdf: 2390147 bytes, checksum: 88c6a01bcd87265c68297af0c6ea8e78 (MD5) Previous issue date: 2014-03-27 / Bioresorbable polymers have been used as scaffolds in tissue engineering, thus representing an important alternative for reconstruction of lesions and tissue losses. This study aimed to evaluate the in vivo performance of three-dimensional scaffolds made of polycaprolactone (PCL), by means of through a PCL implant on the subcutaneous tissues of rats back and calvaria, as well as the reaction of their kidneys, lungs and liver. The histological analysis of the bone repair process in calvaria showed the presence of newly formed bone growing towards the center of the defects. The formation of a thin fibrous capsule was observed in the tissues adjacent to the scaffold implanted on the back of all animals, with collagenous fibers involving the implant. As for events occurring in animals' kidneys, lungs and liver, there were no harmful tissue alterations in these organs nor the presence of inflammatory process, hyperplasia, metaplasia, dysplasia or hemorrhage. A quantitative analysis of the bone repair process was performed using histomorphometry and cone beam computed tomography (CBCT). Results showed that the newly formed bone grew towards the center of the defects. Statistical analysis revealed that the total area of new bone formation was greater in experimental defects at 21, 60 and 120 days, showing a statistically significant difference. In tomographic analysis found that new bone formation is more likely to occur in experimental defects, but with no statistically significant difference. Considering tomographic analysis as a new method for the assessment of new bone formation, the data obtained from this assessment could not be correlated with those obtained from histomorphometric analysis. Therefore, it can be concluded that PCL scaffolds produced on an additive manufacturing machine are biocompatible, non-cytotoxic and bioresorbable products that promote osteoconduction. PCL showed great potential for clinical use in the treatment of bone defects by increasing bone ?rea and seems to be an appropriate biomaterial to be used in other studies aiming to elucidate issues related to this topic. Additionally, CBCT does not seem to be a useful tool in the evaluation of new bone formation of rat calvaria, which means that histomorphometric analysis is still the most appropriate method. / Pol?meros biorreabsorv?veis v?m sendo utilizados como scaffolds na engenharia tecidual, destacando-se como alternativa para reconstru??o de les?es e perdas teciduais. Neste estudo, avaliou-se o desempenho in vivo de scaffolds tridimensionais de pol?mero policaprolactona (PCL), atrav?s do implante do PCL nos tecidos subcut?neos do dorso e na calv?ria, bem como da rea??o dos ?rg?os rins, pulm?es e f?gado de ratos. A an?lise histol?gica qualitativa do processo de reparo ?sseo nas calv?rias mostrou neoforma??o ?ssea e que o osso neoformado cresceu em dire??o ao centro de defeitos. Nos tecidos adjacentes ao scaffold implantado no dorso, percebeu-se que em todos os animais houve forma??o de c?psula fibrosa fina, com fibras col?genas organizadas envolvendo o implante. Com rela??o aos eventos ocorridos nos rins, f?gado e pulm?es dos animais, n?o houve altera??es teciduais danosas aos ?rg?os, tampouco a presen?a de processo inflamat?rio, hiperplasia, metaplasia, displasia ou hemorragia. A an?lise quantitativa do processo de reparo ?sseo foi realizada atrav?s de histomorfometria e tomografia computadorizada de feixe c?nico (TCFC). Ap?s an?lise estat?stica, a ?rea total de neoforma??o ?ssea em mm2 foi maior nos defeitos experimentais aos 21, 60 e 120 dias, com diferen?a estatisticamente significativa. Na an?lise tomogr?fica, percebeu-se uma tend?ncia de maior neoforma??o ?ssea nos defeitos experimentais, mas sem diferen?a estatisticamente significativa. Considerando-se a an?lise tomogr?fica como uma nova metodologia para avalia??o de neoforma??o ?ssea, os dados obtidos atrav?s dessa avalia??o n?o puderam ser correlacionados com aqueles obtidos na an?lise histomorfom?trica. Portanto, conclui-se que os scaffolds de PCL produzidos na plataforma experimental de manufatura aditiva s?o biocompat?veis, n?o citot?xicos, biorreabsorv?veis e promovem osteocondu??o. O PCL apresentou grande potencial de aplica??o cl?nica nos defeitos onde se espera aumentar a ?rea ?ssea e parece adequado como um biomaterial de escolha para outros estudos que elucidem as quest?es pertinentes. A TCFC n?o parece ser uma ferramenta ?til na avalia??o da neoforma??o ?ssea em calv?ria de ratos, de modo que a an?lise histomorfom?trica permanece como m?todo mais adequado.

Made available in DSpace on 2015-04-14T13:30:33Z (GMT). No. of bitstreams: 1 458702.pdf: 893873 bytes, checksum: aa6c924f918b3560d3db63066e71a2f2 (MD5) Previous issue date: 2014-03-12 / The present study aimed to evaluate the influence of the following irrigating solutions on dentin microhardness and structure of the root canal: 2% and 5% NaOCl, 400 ppm Sterilox? and 17% EDTA. Therefore, 80 roots from bovine incisors were randomly divided into 8 groups (n=10): 2% NaOCl, 5% NaOCl, 400 ppm Sterilox?, associated (2NaOCl+E, 5NaOCl+E, Sx+E) or not (2NaOCl, 5NaOCl, Sx) with 17% EDTA (final irrigation for 5 min), 17% EDTA (E), and distilled water (H2O) - negative control. Chemomechanical preparation of the root canals (30 min), using one of the irrigating solutions tested, was performed by the classical technique. All samples were then sectioned perpendicularly to the long axis at the coronal portion in order to obtain a coronal (5 mm) and an apical root segment (15 mm). The thesis was divided into two chapters. First, coronal segments were submitted to Vickers Microhardness Test at two points, one at about 500-1000 &#956;m from the root canal lumen (distance 1) and the other at about 500-1000 &#956;m from the external root surface (distance 2). Wilcoxon test was applied to compare distances 1 and 2 in each group, and Kruskal-Wallis test, followed by Dunn test, compared the groups to each other. The significance level was set at 5%. Results showed microhardness values significantly smaller at distance 1 than distance 2, except for 5NaOCl and 5NaOCl+E (P>0.05). EDTA presented the lowest microhardness values, significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness values near the root canal lumen compared to those found near the external root surface, and at this point, EDTA promoted a greater microhardness reduction in comparison to Sterilox?. In the second chapter, apical segments were longitudinally cut into two hemi-roots, one prepared for the study of the collagen structure by light microscopy (LM), and the other for the analysis of the topography of the inorganic component of dentin, by scanning electron microscopy (SEM). Picrosirius stained slides were analyzed and classified into 4 scores classified into four scores according to the orientation pattern of the collagen fibers and the regularity of the root canal contour. SEM images of coronal dentinal tubules near the root canal lumen were analyzed descriptively in relation to their parallelism, obliteration and the presence of dentinal erosion. Data from histological analyzes were submitted to Kruskal-Wallis test followed by multiple comparisons test at 5% significance level. Results showed that the higher the concentration of the NaOCl, the greater its effect, in depth, on organic layer of dentin (collagen). It is possible to conclude that 5% NaOCl, associated or not with 17% EDTA, and 2% NaOCl + EDTA caused the greatest change in the organic matrix of collagen. 2% NaOCl was similar to Sterilox?, associated or not with EDTA, promoting a more superficial disorganization of collagen and in a smaller area. Regarding changes of the inorganic component of dentin, demineralized areas were observed in all groups in which EDTA was employed. However, areas of erosion and open tubules were detected only when it was combined with NaOCl. It was concluded that 5% NaOCl, whether associated or not with 17% EDTA, caused significant damage to dentin collagen. SEM images obtained by SEM revealed demineralization in all groups in which EDTA was used, however areas of erosion and open tubules were observed only when it was combined with NaOCl. / O presente estudo objetivou avaliar a influ?ncia das solu??es irrigadoras NaOCl 2% e 5%, Sterilox? 400 ppm e EDTA a 17% na microdureza e na estrutura dentin?ria do canal radicular. Para tanto, 80 ra?zes de incisivos bovinos foram divididas aleatoriamente em 8 grupos (n=10): NaOCl 2%; NaOCl 5%; Sterilox? 400 ppm, associados (NaOCl2+E, NaOCl5+E, Sx+E) ou n?o (NaOCl2, NaOCl5, Sx) ao EDTA 17% (5 min de irriga??o final); EDTA 17% (E); e ?gua destilada (H2O) controle negativo. O preparo qu?mico mec?nico dos canais radiculares (30 min), utilizando uma das solu??es irrigadoras testadas, foi realizado pela t?cnica cl?ssica. A seguir as amostras foram seccionadas perpendicularmente ao longo eixo na por??o mais coronal, a fim de serem obtidos um segmento radicular cervical (5 mm) e um apical (15 mm). A tese foi ent?o dividida em dois cap?tulos. No primeiro, os segmentos cervicais foram submetidos ao Teste de Microdureza Vickers, em dois pontos, um em aproximadamente 500-1000 &#956;m a partir da luz do canal (dist?ncia 1), e o outro, em aproximadamente 500-1000 &#956;m a partir da superf?cie externa do dente (dist?ncia 2). O teste de Wilcoxon comparou as dist?ncias 1 e 2 em cada grupo, e o Kruskal-Wallis, seguido do teste de Dunn, compararam os grupos entre si. O n?vel de signific?ncia considerado foi de 5%. Os resultados mostraram valores de microdureza na dist?ncia 1 significativamente menores do que os valores da dist?ncia 2, exceto para os grupos NaOCl5 e NaOCl5+E (P>0.05). O EDTA demonstrou os menores valores de microdureza, sendo significativamente diferente apenas em rela??o ao Sx na dist?ncia 2. Conclui-se que todas as solu??es testadas mostraram menores valores de microdureza pr?ximos ? luz do canal em compara??o com os encontrados pr?ximos ? superf?cie externa radicular, sendo que o EDTA promoveu uma maior redu??o desta em compara??o com o Sterilox? pr?ximo ? superf?cie externa da raiz. No segundo cap?tulo, os segmentos apicais foram seccionados longitudinalmente em duas hemirra?zes, sendo uma preparada para o estudo da estrutura do col?geno, em microscopia ?ptica (MO), e a outra para a an?lise da topografia do componente inorg?nico da dentina, em microscopia eletr?nica de varredura (MEV). As l?minas coradas com Picross?rius foram analisadas e classificadas em 4 escores de acordo com o padr?o de orienta??o das fibras col?genas pr?ximas ? luz do canal e com a regularidade do contorno perimetral do canal. As imagens em MEV dos t?bulos dentin?rios cervicais pr?ximos ? luz do canal radicular foram analisadas descritivamente com rela??o ao paralelismo entre os t?bulos dentin?rios, a exist?ncia de oblitera??o na sua entrada e presen?a de ?reas de eros?o. Os dados da an?lise histol?gica foram submetidos ao teste de Kruskal-Wallis seguido pelo Teste de Compara??es M?ltiplas ao n?vel de signific?ncia de 5%. Os resultados mostraram que quanto maior a concentra??o do NaOCl testado, maior foi seu efeito em profundidade na camada org?nica da dentina (col?geno). Foi poss?vel concluir que o NaOCl 5%, associado ou n?o ao EDTA 17% e o NaOCl 2% + EDTA causaram a maior altera??o na matriz org?nica de col?geno. O NaOCl 2% teve comportamento semelhante ? solu??o de Sterilox?, associada ou n?o ao EDTA, promovendo desorganiza??o mais superficial do col?geno e em uma ?rea menor. Em rela??o ? altera??o do componente inorg?nico da dentina, em todos os grupos em que o EDTA foi empregado observaram-se ?reas de desmineraliza??o. No entanto, ?reas de eros?o e t?bulos abertos somente foram observados quando este foi associado ao NaOCl. ? poss?vel concluir que NaOCl 5%, quando associado ou n?o ao EDTA 17%, provocou expressivo dano ao col?geno da dentina. As imagens obtidas em MEV revelaram desmineraliza??o em todos os grupos em que o EDTA foi utilizado, no entanto ?reas de eros?o e t?bulos abertos foram verificados somente quando este foi associado ao NaOCl.

Made available in DSpace on 2015-04-14T13:30:35Z (GMT). No. of bitstreams: 1 459062.pdf: 3282874 bytes, checksum: e29fb295dfeeacf089328b5b93cff4a0 (MD5) Previous issue date: 2014-02-26 / The persistence of infection within the root canal system is one of the main factors responsible for endodontic failures. The complexity of the internal anatomy of root canals prevents its complete removal by current instrumentation techniques. Thus, alternative disinfection protocols, including irrigating solutions and photo-activated therapy (PAD), have been acessed. In this study, 10 dogs were randomly divided into two groups (n= 5): with and without PAD. The canals of upper and lower premolars of each dog were distributed in the experimental subgroups: SX (400ppm Sterilox), H2 (2% sodium hypochloride (NaOCl)), H5 (5% NaOCl) and C+ (positive control: saline solution) in a total sample of 134 root canals. Teeth of the experimental and C+ groups were opened and the canals were left exposed to the oral environment for 15 days and then sealed for apical periodontitis (AP) induction. After 60 days, the root canals were treated in accordance with each disinfection protocol proposed and filled in the same session. After 120 days, the dogs were euthanized and the following procedures were carried out: periapical radiography (PR), to measure the AP area; cone beam computed tomography (CBCT), to measure the AP area and volume; light microscopy, to evaluate inflammatory periapical events. Based on the colected data, the study was divided into two papers. The first carried out an evaluation of the efficacy of 400ppm Sterilox, 2%NaOCl and 5%NaOCl, with and without PAD, in a single visit root canal treatment of dog s teeth with AP. In the histological evaluation, scores were given according to the intensity of inflammatory infiltrate. Data was colected and analized statistically with Kruskall-Wallis and Mann-Whitney tests (&#945;= .05). The PAD did not produce significant differences in the scores for apical inflammation when used after chemo-mechanical preparation. The irrigating solutions SX, H2 and H5 without PAD were statistically different from SS (P<0,05) that presented the greatest scores for apical inflammation. In conclusion, PAD did not show any clinical relevance for the treatment of root canal with pulpal necrosis and AP. The use of 400 ppm Sterilox in the chemo-mechanical preparation provided efficient cleaning and may be considered an alternative to NaOCl in root canal treatment. The second paper investigated the correlation and agreement between PR (area) and CBCT (area and volume) data, correlating with the correspondig histopathological data. The correlation between methods was evaluated by Pearson's coefficient and Bland-Altman's (BA) method was used to assess the agreement between PR and CBCT data. The results showed that, despite a strong correlation between PR and CBCT areas, the limits of agreement were very broad (95%: 0.19 to 1.08). PR only measured on average 63% of CBCT values. Although the strong correlation between PR area and CBCT volume, BA suggests that the larger the CBCT volume the more underestimated the PR value. When APs had volumes smaller than 6 mm3, the PR estimates of CBCT data were unpredictable. The correlation between PR area, CBCT area, CBCT volume and histology data was significant. In conclusion, the diagnosis of AP based on PR data is clinically limited and it should not be used for scientific investigations. / A persist?ncia de infec??o no interior do sistema de canais radiculares constitui um dos principais fatores respons?veis pelos insucessos endod?nticos. A complexidade da anatomia interna dos canais dificulta sua elimina??o completa pelas t?cnicas de instrumenta??o atuais. Diante desta realidade, protocolos alternativos de desinfec??o, abrangendo meios qu?micos e terapia fotodin?mica (PAD), t?m sido pesquisados. Nessa pesquisa, 10 c?es foram divididos aleatoriamente em dois grandes grupos (n=5): submetidos ou n?o ? PAD. Os canais dos dentes pr?-molares superiores e inferiores de cada c?o foram distribu?dos nos subgrupos experimentais: SX (Sterilox 400ppm), H2 (hipoclorito de s?dio (NaOCl) 2%), H5 (NaOCl 5%) e controle: C+ (controle positivo: soro fisiol?gico) totalizando uma amostra de 134 canais radiculares. Os dentes dos grupos experimentais e do grupo C+ foram abertos e os canais foram deixados expostos ao ambiente oral por 15 dias. Ap?s o selamento das cavidades, aguardaram-se 60 dias, objetivando-se a indu??o de periodontite apical (PA). Os canais foram preparados de acordo com cada protocolo de desinfec??o proposto e obturados na mesma sess?o. Decorridos 120 dias, os c?es foram mortos, sendo realizados os seguintes procedimentos: radiografias periapicais (PR), para mensura??o das ?reas das PAs; tomografias cone beam (CBCT), para mensura??o das ?reas e dos volumes das PAs; microscopia ?ptica, para avalia??o dos eventos inflamat?rios periapicais. Com base na coleta desses dados, o experimento foi dividido em 2 artigos. O primeiro realizou uma avalia??o da efic?cia das solu??es irrigadoras Sterilox 400ppm e NaOCl nas concentra??es de 2% e 5%, associados ou n?o ? PAD, na endodontia em sess?o ?nica de dentes de c?es com PAs. Na avalia??o histol?gica, o processo inflamat?rio 6 apical foi categorizado em escores, de acordo com a intensidade. Os dados foram coletados e analisados estatisticamente com os testes Kruskall-Wallis e Mann-Whitney (&#945;= .05). A PAD n?o apresentou efeito significativo sobre o processo inflamat?rio apical quando utilizada ap?s o preparo qu?mico-mec?nico (PQM). As solu??es irrigadoras H5, H2 e SX do grupo sem PAD apresentaram diferen?as estat?sticas do grupo C+ (P=.02). Este estudo sugere que o emprego da PAD n?o apresentou relev?ncia cl?nica nos resultados da endodontia de dentes com necrose pulpar associados a PA. O emprego do Sterilox 400ppm no PQM promoveu limpeza eficiente e pode ser considerado como um irrigante alternativo ao NaOCl no tratamento endod?ntico. O segundo artigo avaliou a correla??o e a concord?ncia existentes entre as medidas da PA, fornecidas pela PR (?rea) e pela CBCT (?rea e volume), correlacionando com seu correspondente histol?gico. A correla??o entre os m?todos foi avaliada por meio do coeficiente de Person e a concord?ncia pelo m?todo de Bland-Altman (BA). Os resultados demonstraram que, apesar de uma forte correla??o entre as medidas das ?reas obtidas na PR e na CBCT, os limites de concord?ncia se apresentaram muito amplos (95%: 0.19 a 1.08). A PR mensurou em m?dia apenas 63% do valor da ?rea da CBCT. De acordo com o m?todo de BA, apesar da forte correla??o entre a ?rea da PR e o volume da CBCT, quanto maior o volume da PA na CBCT, mais subestimado ? o seu tamanho pela PR. Quando as PAs apresentaram volumes menores de 6 mm3, a estimativa dos valores da CBCT pela PR foram imprevis?veis. A correla??o da ?rea da PR, ?rea da CBCT e volume da CBCT com os dados histol?gicos foi significativa. Em conclus?o, o diagn?stico da PA baseado em dados radiogr?ficos ? clinicamente limitado e n?o deveria ser usado para investiga??es cient?ficas.

Made available in DSpace on 2015-04-14T13:30:38Z (GMT). No. of bitstreams: 1 464308.pdf: 1229366 bytes, checksum: 15f5108f3d26340d17db98cc5a6c5697 (MD5) Previous issue date: 2014-11-03 / The presence of bacterial endotoxin (LPS) in the root canal system is related to the maintenance and evolution of the pulp and periapical diseases. So far, there is none technical or material that is completely effective in eliminating the LPS. Therefore, in order to enhance the disinfection process, and thereby, to increase the success rate of endodontic treatment, it has been sought alternatives to clinical protocols held nowa-days. The use of auxiliary equipments with principles of action based on electrofulguration and in the potential application of ozone gas appears as an alterna-tives. Thus, the first article of this thesis initially sought to verify the feasibility for the use of bovine teeth instead of human teeth, in in vitro experiments with contamination by LPS, because there are no studies in the literature using this methodology. For this, twenty bovine (B) central incisors and twenty single-rooted human (H) premolars had removed their dental crowns and standardized their root length to 16 mm. The root ca-nals were prepared until size 60 K-type instrument and subjected to sterilization by gamma irradiation with 60 cobalt. According to the two types of dental species, the teeth were randomly divided into two subgroups, positive (P) and negative (N). The root canals of the positive groups (HP and BP) were inoculated with Escherichia coli LPS (O55:B5). The root canals of negative groups (HN and BN) were exposed only to a py-rogenic water. After the teeth incubation in a 37?C atmospheric humidity during 24 hours, the samples of the solutions from the main root canals were collected with a py-rogenic absorbent paper points. The quantification of the levels of LPS was made by Limulus Amebosytes Lysate (LAL) and data were subjected to oneway ANOVA, fol-lowed by Tukey post hoc, with a 5% significance level. The results showed significant differences (P<0,001) between the two experimental models. The use of bovine teeth showed not to be the best option for LPS contamination studies. Following this result, a second article of the Thesis was performed in order to verify the effect of ozone gas (OZY? system) and high frequency electric pulses (Endox? System) in human root canals previously contaminated by LPS. Fifty single-rooted premolars received the same protocol for root canals preparation, as reported in the first article. Once ready, the specimens were divided into five groups (n=10), according to the disinfection protocol established: OZY? System, one 120-second-pulse (OZY 1p); OZY? System, four 24-second-pulses (OZY 4p); Endox? System (ENDOX). Contaminated and non-contaminated canals, exposed only to apyrogenic water, were used as positive (C+) and negative (C-) controls, respectively. The Escherichia coli LPS (O55:B5) was inoculated into the root canals, except in the C- group teeth. After performing the disinfection pro-tocols, fluid samples were collected from the canals using apyrogenic paper tips. The method for quantification of LPS levels and statistical analysis were the same as de-scribed in the first article. The results showed that the disinfection protocols were una-ble to reduce significantly the LPS levels. The use of ozone gas and high frequency electric pulses were not effective in the elimination of LPS in root canals. / A presen?a da endotoxina (LPS) bacteriana no sistema de canais radiculares est? relacionada com a manuten??o e evolu??o das doen?as pulpares e periapicais. At? o momento, n?o h? nenhuma t?cnica ou material que seja completamente eficaz na elimina??o do LPS. Logo, com objetivo de aprimorar o processo de desinfec??o e, consequentemente, aumentar as taxas de sucesso no tratamento endod?ntico, tem-se buscado alternativas aos protocolos cl?nicos realizados atualmente. A utiliza??o de equipamentos auxiliares com princ?pios de a??o baseados na eletrofulgura??o e no potencial de aplica??o do g?s oz?nio surge como alternativas. Sendo assim, o primeiro artigo desta tese buscou, inicialmente, verificar a viabilidade para utiliza??o de dentes bovinos ao inv?s de humanos, em experimentos in vitro com contamina??o por LPS, tendo em vista n?o haver estudos na literatura com essa metodologia. Para isso, vinte incisivos centrais bovinos (B) e vinte pr?-molares monorradiculares humanos (H) tive-ram suas coroas dent?rias removidas e comprimento radicular padronizado em 16 mm. Os canais radiculares foram preparados at? o instrumento tipo K n?. 60 e submetidos ? esteriliza??o por radia??o gama com cobalto 60. De acordo com os dois tipos de esp?-cies dent?rias, os dentes foram divididos aleatoriamente em dois subgrupos, positivo (P) e negativo (N). Os canais dos grupos positivos (HP e BP) foram inoculados com LPS de Escherichia coli (O55:B5). J? os canais dos grupos negativos (HN e BN) foram apenas expostos ? ?gua apirog?nica. Ap?s a incuba??o dos dentes, a 37?C, com umidade atmosf?rica durante 24 horas, amostras das solu??es do canal principal foram coletadas com pontas de papel absorvente apirog?nicas. A quantifica??o dos n?veis de LPS foi feita por Limulus Amebosytes Lisado (LAL) e os dados obtidos foram submetidos ? ANOVA de uma via, seguido de Post Hoc Tukey, com n?vel de signific?ncia de 5%. Os resultados demonstraram que houve diferen?a significativa (P<0,001) entre os dois modelos experimentais. A utiliza??o de dentes bovinos n?o apresentou ser a melhor op??o dent?ria para pesquisas laboratoriais com contamina??o por LPS. Foi realizado, ent?o, o segundo artigo da Tese a fim de verificar o efeito do g?s oz?nio (sistema OZY?) e de pulsos el?tricos de alta frequ?ncia (sistema Endox?) em canais radiculares humanos previamente contaminados com LPS. Cinquenta pr?-molares unirradiculares receberam o mesmo protocolo para preparo da amostra relatado no primeiro artigo. Depois de prontos, os esp?cimes foram divididos em cinco grupos (n=10), de acordo com o protocolo de desinfec??o institu?do: Sistema OZY?, um pulso de 120 segundos (OZY 1p); Sistema OZY?, quatro pulsos de 24 segundos (OZY 4p); Sistema Endox? (EN-DOX). Canais contaminados e n?o contaminados, apenas expostos ? ?gua apirog?nica, foram utilizados como controle positivo (C+) e negativo (C-), respectivamente. O LPS de Escherichia coli (O55:B5) foi inoculado nos canais radiculares, exceto nos dentes do grupo C-. Ap?s os protocolos de desinfec??o, amostras do flu?do foram coletadas dos canais com pontas de papel apirog?nicas. O m?todo para quantifica??o dos n?veis de LPS e a an?lise estat?stica empregada tamb?m foram os mesmos descritos no primeiro artigo. Os resultados mostraram que os protocolos de desinfec??o n?o foram capazes de reduzir significativamente os n?veis de LPS. O uso do g?s oz?nio e de pulsos el?tricos de alta frequ?ncia n?o foram eficazes na elimina??o do LPS em canais radiculares.

Made available in DSpace on 2015-04-14T13:30:40Z (GMT). No. of bitstreams: 1 386674.pdf: 1956239 bytes, checksum: da367d39b339a7c9d25bd4969faa71c0 (MD5) Previous issue date: 2006-12-15 / A crioterapia com nitrog?nio l?quido tem sido terapeuticamente utilizada em diferentes tipos de tecidos. Entretanto, ainda n?o h? registros na literatura referentes ? sua utiliza??o em canais radiculares. Assim, o objetivo deste trabalho foi elaborar um modelo experimental in vitro para conhecer o comportamento dos tecidos dent?rios na condu??o de temperatura com aplica??o de nitrog?nio l?quido intracanal e estabelecer um protocolo para a sua aplica??o. Termopares fixos ? superf?cie externa radicular nas regi?es apical, m?dia, cervical e no interior do canal foram utilizados como sensores para medidas das varia??es de temperaturas em um dente mantido em banho de calibra??o t?rmica. O agente crioter?pico utilizado foi nitrog?nio l?quido em sistema aberto na forma de spray intracanal na regi?o apical. Os sinais foram digitalizados e analisados em um software. Foram realizados 13 testes com 15 segundos de aplica??o divididos em 3 grupos conforme temperatura ambiente: 20?C, 25 ?C e 27 ?C. As m?dias de temperatura obtidas foram: intracanal, regi?o apical -45,23?C, superf?cie externa radicula r, regi?o apical -19,77?C, regi?o m?dia -17,46?C e regi?o cervical 4,15?C. Concluiu-se que o modelo experimental permite conhecer a condutividade das estruturas dent?rias quando aplicado um agente crioter?pico no interior do canal radicular. Tamb?m se verificou que a aplica??o de nitrog?nio l?quido por 15 segundos no modelo proposto atinge temperaturas capazes de causar morte celular em estruturas de sustenta??o dent?ria localizadas pr?ximas ao ?pice radicular