Orientador: Marcia Carneiro Valera / Banca: Flaviana Bombarda de Andrade / Banca: Carlos Henrique Ribeiro Camargo / Resumo: O presente estudo teve como objetivo detectar espécies bacterianas, quantificar microrganismos e endotoxinas em canais radiculares com insucesso endodôntico e presença de lesão periapical, correlacionando-os com os sinais e sintomas clínicos e, avaliar a ação do hipoclorito de sódio 1% e extrato glicólico de gengibre 20% sobre estes microrganismos e endotoxinas. Foram selecionados para o estudo dez dentes tratados endodonticamente com lesões periapicais persistentes que foram divididos em 2 grupos (n=5), de acordo com a substância química auxiliar utilizada durante o preparo biomecânico (PBM): hipoclorito de sódio 1% e extrato glicólico de gengibre 20% intercalado com solução salina fisiológica. Foram realizadas coletas do conteúdo do canal radicular imediatamente após a desobturação do dente, imediatamente após a instrumentação e, imediatamente após 14 dias da ação da medicação intracanal (MIC) de hidróxido de cálcio. Para todas as coletas foram realizados os seguintes testes: a) avaliação da atividade antimicrobiana por cultura microbiológica e através do método molecular - PCR; b) quantificação de endotoxinas verificada pelo lisado de amebócitos de Limulus. Os resultados foram submetidos a análise estatística de Wilcoxon e Mann-Whitney e mostraram que tanto o PBM quanto à MIC foram capazes de reduzir a quantidade de microrganismos e de endotoxinas, independente da solução utilizada. No entanto, endotoxinas não foram completamente neutralizadas. Espécies de E. faecalis, T. denticola, T. forsythia, P. endodontalis, P. gingivalis, P. nigrescens, P. intermedia, P. micra foram detectadas nos canais radiculares. Observou-se correlação positiva entre a quantidade de endotoxinas e o diâmetro das lesões. Concluiuse que as substâncias testadas foram eficazes na redução de microrganismos e de endotoxinas / Abstract: The aim of the present study was to detect bacterial species, quantify microorganisms and endotoxins within failed root canals presenting periapical lesion, to correlate them with clinical signs and symptoms, and to evaluate the effect of 1% sodium hypochlorite and 20% glycolic ginger extract on microorganisms and endotoxins. Ten endodontically treated teeth presenting persistent periapical lesion were selected for this study and divided into 2 groups (n=5), according to the auxiliary chemical substance employed during the biomechanical preparation (BMP): 1% sodium hypochlorite and 20% glycolic ginger extract interposed with saline solution. Root canal contents were collected right after root canal filling removal, right after instrumentation, and 14 days of calcium hydroxide intracanal medication (ICM) activity. The following tests were performed for every collection: a) antimicrobial activity evaluation by means of microbiologic culture and molecular biology - PCR; b) endotoxins quantification assessed by Limulus amebocyte lysate. The results were submitted to statistical analysis by Wilcoxon and Mann-Whitney tests. Both BMP and ICM were able to reduce microorganisms and endotoxins quantity, regardless the employed solution. However, endotoxins were not completely neutralized. E. faecalis, T. denticola, T. forsythia, P. endodontalis, P. gingivalis, P. nigrescens, P. intermedia, P. micra species were detected within root canals. A positive correlation was detected for the endotoxin quantity and the diameter of lesion. It can be concluded the tested substances were efficient for endotoxin and microorganisms reduction / Mestre

No description available.

No description available.

Periodontitis is inflammatory and infectious disease on attachment tissue of teeth and it is one of principal reason for tooth loss. Periodontal treatment consists on scaling and root planning associate with high standard oral hygiene with aim of reduce periodontal inflammation levels. Stability of attachment levels is a major aim to be achieved after periodontal treatment conclusion. Although periodontal treatment effectivity and need in cooperate with supportive periodontal treatment (SPT) be well established in literature, a little is known about periodontal status and follow-up of individuals who use philanthropic service. The aim of this study was to evaluate periodontal status of individuals treated/retreated on a philanthropic service. At first, 77 individuals who did periodontal treatment after a mean of 3.5 years were evaluated. Demographic and socioeconomic data were collected by structured interview. Periodontal variables evaluated were: Plaque Index (PlI), Gingival Index (GI), Probing Depth (PD), Clinical Attachment Level (CAL) and Bleeding on Probing (BoP). Individuals who showed high percentage of BoP (≥25%) were lead to retreatment. The final exam was done, in mean, 2.4 years after retreatment and individuals were categorized on three groups: did not receive any dental retreatment (NDentT); received some dental treatment, except periodontal (DentT); and those who received periodontal retreatment (PerioRT). The group which received periodontal retreatment had lower GI mean when compared with group that did not receive any dental treatment (P<0.05), however, they stayed with high BoP percentages. Mean of PlI, PD, BoP and CAL were not different among groups (P≥0.05). It was not observed difference on disease progression among the groups (P≥0.05). Although individuals have possibility of a free dental treatment, those who were retreated at this place showed no significant changes on BoP percentage and PD≥5mm with BoP percentage. These results may be related to the fact patients did not return to do regular and individualized STP. / Periodontite é uma doença infecto-inflamatória que acomete os tecidos de suporte dos dentes e uma das principais responsáveis por perdas dentárias. Seu tratamento consiste na raspagem e alisamento radicular associado à medidas de higiene bucal adequadas, com objetivo de reduzir os níveis de inflamação periodontal. Estabilidade dos níveis de inserção é um dos maiores objetivos a serem alcançados após a conclusão do tratamento periodontal. Embora a efetividade do tratamento periodontal e da cooperação com a manutenção periódica preventiva (MPP) estejam bem estabelecidas na literatura, pouco se sabe sobre as condições periodontais e o acompanhamento de indivíduos atendidos no serviço filantrópico. O objetivo do presente estudo foi avaliar longitudinalmente a condição periodontal de indivíduos tratados/retratados em uma unidade de serviço filantrópico. Inicialmente, 77 indivíduos foram avaliados, em média, 3,5 anos após o tratamento periodontal. Dados demográficos e socioeconômicos foram coletados por meio de uma entrevista estruturada. Os parâmetros periodontais avaliados foram Índice de Placa (IPl), Índice Gengival (IG), Profundidade de Sondagem (PS), Nível de Inserção Clínica (NIC) e Sangramento à Sondagem (SS). Indivíduos que apresentaram altas porcentagens de sangramento à sondagem (≥25%) foram encaminhados para retratamento. O exame final foi realizado, em média, 2,4 anos após o retratamento e os indivíduos foram categorizados em três grupos: não receberam tratamento odontológico (NTOd); receberam tratamento odontológico, exceto periodontal (TOd); receberam retratamento periodontal (RPeriod). O grupo RPeriod apresentou menor média de IG quando comparado ao grupo NTOd (P<0,05), porém, manteve altas porcentagens de SS. As médias de IPl, PS, SS e NIC, assim como a progressão da doença, não diferiram entre os três grupos (P≥0,05). A despeito da possibilidade de acesso a um serviço filantrópico sem custo, os indivíduos que foram retratados nesse serviço não apresentaram alterações significantes na porcentagem de sítios com SS e com PS≥5mm +SS. Esses resultados podem estar relacionados ao fato de que esses indivíduos não retornaram para realizar MPP de maneira regular e de forma personalizada.

Made available in DSpace on 2014-06-11T19:24:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-17Bitstream added on 2014-06-13T20:12:42Z : No. of bitstreams: 1 cardoso_fgr_me_sjc.pdf: 1483322 bytes, checksum: f86eb5ab19c152a059b91d3c96772605 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente estudo teve como objetivo detectar espécies bacterianas, quantificar microrganismos e endotoxinas em canais radiculares com insucesso endodôntico e presença de lesão periapical, correlacionando-os com os sinais e sintomas clínicos e, avaliar a ação do hipoclorito de sódio 1% e extrato glicólico de gengibre 20% sobre estes microrganismos e endotoxinas. Foram selecionados para o estudo dez dentes tratados endodonticamente com lesões periapicais persistentes que foram divididos em 2 grupos (n=5), de acordo com a substância química auxiliar utilizada durante o preparo biomecânico (PBM): hipoclorito de sódio 1% e extrato glicólico de gengibre 20% intercalado com solução salina fisiológica. Foram realizadas coletas do conteúdo do canal radicular imediatamente após a desobturação do dente, imediatamente após a instrumentação e, imediatamente após 14 dias da ação da medicação intracanal (MIC) de hidróxido de cálcio. Para todas as coletas foram realizados os seguintes testes: a) avaliação da atividade antimicrobiana por cultura microbiológica e através do método molecular - PCR; b) quantificação de endotoxinas verificada pelo lisado de amebócitos de Limulus. Os resultados foram submetidos a análise estatística de Wilcoxon e Mann-Whitney e mostraram que tanto o PBM quanto à MIC foram capazes de reduzir a quantidade de microrganismos e de endotoxinas, independente da solução utilizada. No entanto, endotoxinas não foram completamente neutralizadas. Espécies de E. faecalis, T. denticola, T. forsythia, P. endodontalis, P. gingivalis, P. nigrescens, P. intermedia, P. micra foram detectadas nos canais radiculares. Observou-se correlação positiva entre a quantidade de endotoxinas e o diâmetro das lesões. Concluiuse que as substâncias testadas foram eficazes na redução de microrganismos e de endotoxinas / The aim of the present study was to detect bacterial species, quantify microorganisms and endotoxins within failed root canals presenting periapical lesion, to correlate them with clinical signs and symptoms, and to evaluate the effect of 1% sodium hypochlorite and 20% glycolic ginger extract on microorganisms and endotoxins. Ten endodontically treated teeth presenting persistent periapical lesion were selected for this study and divided into 2 groups (n=5), according to the auxiliary chemical substance employed during the biomechanical preparation (BMP): 1% sodium hypochlorite and 20% glycolic ginger extract interposed with saline solution. Root canal contents were collected right after root canal filling removal, right after instrumentation, and 14 days of calcium hydroxide intracanal medication (ICM) activity. The following tests were performed for every collection: a) antimicrobial activity evaluation by means of microbiologic culture and molecular biology – PCR; b) endotoxins quantification assessed by Limulus amebocyte lysate. The results were submitted to statistical analysis by Wilcoxon and Mann-Whitney tests. Both BMP and ICM were able to reduce microorganisms and endotoxins quantity, regardless the employed solution. However, endotoxins were not completely neutralized. E. faecalis, T. denticola, T. forsythia, P. endodontalis, P. gingivalis, P. nigrescens, P. intermedia, P. micra species were detected within root canals. A positive correlation was detected for the endotoxin quantity and the diameter of lesion. It can be concluded the tested substances were efficient for endotoxin and microorganisms reduction

RESUMO Objetivo: Investigar fatores associados à recidiva, retratamento por abandono e óbito entre retratados por abandono para pacientes com TB pulmonar, de ambos os sexos, maiores que treze anos, residentes em área periférica do município de São Paulo. Material e Métodos: Estudos de caso-controle não pareado aninhado a uma coorte prospectiva de pacientes com TB pulmonar confirmada por cultura, selecionados entre 2001 e 2002 e acompanhados até 2006. Os casos foram pacientes que apresentaram recidivas, retratamento por abandono e óbito entre retratados por abandono; os controles foram pacientes com cura sem retratamento. Os dados foram obtidos mediante aplicação de questionários estruturados aplicados à época do ingresso no estudo e por entrevista domiciliar em 2004 e 2006, complementados por informação da Vigilância de TB. Na investigação dos fatores associados à recidiva, ao retratamento por abandono e óbito entre retratados por abandono, esses três desfechos foram tomados como variáveis dependentes e como variáveis independentes, as exposições de interesse. As odds ratio (OR) brutas e ajustadas foram estimadas com os respectivos intervalos de 95% de confiança pela regressão logística multivariada não condicional. A importância das variáveis para o modelo final foi avaliada através do teste da razão de verossimilhança, utilizando-se p<0,05. Resultados: As variáveis associadas à recidiva e ajustadas para sexo e idade independentemente das demais foram: co-infecção com HIV (OR=9,3; IC95%= 1,6 - 54,1), contato domiciliar prévio (OR= 2,2; IC95% = 0,8 - 6,2), caso de TB no domicílio após o paciente (OR= 3,8; IC95%= 1,2 - 12,8); diabetes (OR=1,6; IC95%= 0,3 - 7,7), MDR (OR=15,5; IC95%= 1,2 - 200,5). As variáveis associadas ao retratamento por abandono ajustadas para sexo e idade independentes das demais variáveis foram: TBMDR (OR=38,7; IC95%= 2,9 - 515,3), co-infecção com HIV (OR=24,8; IC95%= 3,8 - 163,0), história de alcoolismo (OR= 4,2; IC95%=1,1 - 17,5) e internação por complicações de TB (OR= 7,2; IC95% =2,5 - 21,0). As variáveis associadas ao óbito entre retratados por abandono ajustadas para sexo e idade independente das demais e foram: TBMDR (OR=152,4; IC95%= 9,8 - 237,4), co-infecção com HIV (OR=29,0; IC95%=7,1 -1 19,1), alcoolismo (OR=11,8; IC95%=1,3-102,8) e regime prisional (OR=5,0; IC95%= 1,0-25,8). Conclusões: Os resultados apresentados apontam grupos de maior risco para retratamento por TB por recidiva, abandono de tratamento e óbito que devem ser considerados no aperfeiçoamento do DOTS em nosso país. / ABSTRACT Objective: Investigate factors associated to relapse, re-treatment by default and death among patients retreated by default for patients with pulmonary tuberculosis, of both sexes, more than thirteen years old, living in the periphery of the city of São Paulo. Material and Methods: A nested case-control study not paired to a prospective cohort of pulmonary tuberculosis patients confirmed by culture, selected between 2001 e 2002 and followed up until 2006. Cases were patients who had relapses, re-treatment by default and death among patients retreated by default; controls were patients with cure without re-treatment. The data were obtained through application of structured questionnaires applied at the time of entry in the study and interview at home in 2004 and 2006, supplemented by information from the surveillance of TB and Information System Mortality of the Foundation SEADE. Relapse, re-treatment by default and death among patients retreated by default were taken as dependent variables and the variables of interest as independent. Crude and adjusted odds ratio (OR) and its 95% confidence interval were calculated by multiple logistic regression not conditional. Statistical significance was assessed by the likelihood ratio test with p < 0.05. Results: The variables associated independently with relapse and adjusted for sex and age were: case of MDR-TB (OR=15.5; 95% CI: 1.2-200.5), co-infection with HIV (OR=9.3 ,95%CI: 1.6-54.1), diabetes (OR=1.6, 95% CI: 0.3-7.7), previous household contact with TB (OR=2.2, 95% CI: 0.8-6.2) and TB at home after patient studied (OR=3,8, 95% CI: 1,2-12,8). The variables associated independently with the retreatment of default and adjusted for sex and age were: case of MDR-TB (OR = 38.7, 95 % CI: 2.9-515.3), co-infection with HIV (OR=24.8, 95% CI: 3.8-163.0), alcohol abuse (OR=4.2, 95% CI: 1.1-17.5) and hospitalization to TB complications (OR=7.2, 95% CI: 2.5-21.0). The variables associated independently with death among patients retreated by default and adjusted for sex and age were: case of MDR-TB (OR=152.4, 95% CI: 9.8-237.4), co-infection with HIV (OR=29.0, 95%CI: 7.1-119.1), alcohol (OR=11.8, 95% CI: 1.3-102.8) and prison system (OR=5.0, 95%CI: 1.0-25.8). Conclusions: The results presented here show groups of higher risk among TB patients for re-treatment by relapse, treatment default and death among re-treated by default to be considered in the improvement of DOTS in our country.

O presente estudo teve por objetivo avaliar ex vivo a eficiência de sistemas para retratamento (ProTaper Universal Retratamento, Mtwo Retratamento e D-Race), na desobturação de canais mésio vestibulares curvos de molares superiores, por meio de tomografia computadorizada por feixe cônico. Foram utilizados canais mésio vestibulares com curvatura entre 20° e 40°, de 36 molares superiores, preparados com Protaper Universal (até instrumento F2), obturados com cone ProTaper F2 e cimento AH Plus, pela técnica de condensação lateral. Para a desobturação, os dentes foram divididos em grupos (I: ProTaper Universal Retratamento, II: Mtwo Retratamento e III: D-Race). A captura das imagens foi realizada após a obturação e após a desobturação dos canais radiculares, por meio de tomografia computadorizada por feixe cônico de pequeno volume (Prexion 3D XTrillion Inc). As imagens foram segmentadas utilizando o programa InVesalius, para verificar o material obturador remanescente. O tempo para desobturação também foi analisado. De posse dos valores, iniciais e finais, de volume de material obturador e de estrutura dentinária, a proporção dos volumes foi calculada. Para a análise estatística, os resultados foram avaliados pelos testes de ANOVA e de Múltiplas Comparações de Bonferroni. Os grupos ProTaper Universal Retratamento (13,97%) e D-Race (9,87%), apresentaram os menores volumes percentuais médios de material obturador remanescente, não havendo diferença estatística significante entre eles; porém, apresentaram diferença estatística significante (p 0,05) do grupo Mtwo Retratamento (33,88%). Os três sistemas provocaram desgaste semelhante de dentina após a desobturação. O grupo D-Race apresentou menor tempo para desobturação, estatisticamente diferente em relação aos demais sistemas. As características dos sistemas de retratamento podem interferir na eficiência de desobturação quanto ao tempo e volume de material remanescente. / The present study aimed to evaluate, ex vivo, the efficiency of systems for retreatment (ProTaper Universal Retreatment, Mtwo Retreatment and D-Race), in removal filling material of curved mesiobuccal canals of maxillary molars, using cone beam computed tomography. Were used mesiobuccal canals with curvature between 20 ° and 40 °, of 36 molars prepared with ProTaper Universal (until instrument F2), filled with cone F2 ProTaper and AH Plus sealer by lateral condensation. For the removal procedure of filling material, the teeth were divided into groups (I: Protaper Universal Retreatment, II: Mtwo Retreatment and III: D-Race). The capture of images was performed after filling and after the removal procedure of root canal through cone beam computed tomography of small volume (Prexion 3D - XTrillion Inc). The images were segmented using the software InVesalius to check the remaining filling material. The time for removal procedure was also analyzed. Possession of values, initial and final, of volume filling material and dentin structure, the ratio of the volumes was calculated. For statistical analysis, the results were evaluated by ANOVA and Bonferroni\'s Multiple Comparisons. ProTaper Universal Retreatment (13.97 %) and D-Race (9.87 %) groups had the lowest average percent volume remaining filling material, with no statistically significant difference between them, but showed a statistically significant difference (p 0.05) group Mtwo Retreatment (33.88 %). The three systems caused similar wear dentin after removal procedure. The group D-Race had less time for removal procedure, statistically different compared to the other systems. The characteristics of retreatment systems may interfere with the efficiency of removal procedure on the time and volume remaining material.

Magister Chirurgiae Dentium - MChD / When faced with a failing or failed root treatment, the dentist must decide whether the tooth can be retreated and saved or extracted. The dentist's decision to retreat is often based on the x-ray presenting a failing root treatment. The dentist must be aware that there might be a number of factors that have contributed to the failure and which may preclude, following retreatment, a successful long term clinical function. The current study has been made to determine those factors that may influence the prognosis in order to assist the clinician in advising the patient of the best course of treatment. A literature review was made to determine and identify these factors and explain their relevance and influence on the healing process. The current study included identifying the factors described in the literature review and noting their influence on the prognosis following non-surgical retreatment. Retreatment of failed root treated teeth requires special knowledge and skill from the clinician in order to correct and manage the case. The current study was made in a clinical setting and compared results of retreatment with two types of rotary files on the market: progressive or variable taper (Pro Taper) with constant non-ISO 06 taper (K3). Clinical signs and symptoms were noted at the patient's presentation and following recalls at 1, 4 months and 1 year. The results were recorded and statistically analysed and the results were discussed. The results showed that out of 81 patients 10cases of retreatment were considered to have failed and 68 cases were considered to have been successful. Three patients did not return for their assessments and were therefore not considered in further results. There was a statistically significant (p<0.1 0) recording of deep periodontal pockets associated with teeth with failing root treatments (40%) and (13%) in the "Success" group. The two estimated proportions of "Sinus" present (60%) in the "Failure" group and 10% in the 'Success' group were significantly different (p<0.01). "Sinus present" in the "Success group" means in the initial clinical assessment before retreatment was initiated. The presence of a sinus at the One Year follow up signified a failure of the root retreatment (p<0.001). The two estimated proportions of "Occlusion" present (80% and 99%) in the "Failure" and "Success" group were significantly different (p<0.05). Therefore, teeth in "occlusion" were more within the "Success" group. 70% of those teeth that failed had pretreatment apical rarefactions of greater than 6mm diameter; whereas 76.5% of successful retreatments had areas less than 6mm diameter. The differences were significant according to Fisher's Exact Test (p<0.01). 44% of failed cases had areas of rarefaction described as "diffuse"; and 56% of failed cases had areas that were described as "well-defined". 95% of cases that were successful had areas described as "diffuse" and the rest were "welldefined". The differences between the success and failure categories were statistically significant (p<0.0 1). The two estimated proportions of "Post present" (0% and 31%) in the "Failure" and "Success" groups were significantly different (p<0.1 0). Therefore, the "Post was present" in many more cases within the "Success" group than in the "Failure" group. There was no difference between the Median "Crown/Root" ratios of the "Failure" (Median = 0.595) or "Success" groups (Median = 0.662) (Wilcoxon Test, p>O.10). Teeth with longer roots tend to lead to failure, however there was a considerable overlap between the distributions. Therefore the finding is that the Median length of the roots of the "Failures" is longer than that of the "Successes". (Wilcoxon Rank Sum Test, p-value = 0.0628). The results also indicated that previous short root filling preparation contributes to the final success of retreatment (Fisher Exact Test, p<0.05). There was a significant difference between the distribution of the "Failure" and "Success" (88.2%) groups (Fisher Exact Test, p<O.OI) in those cases with initial short obturated fillings. When comparing the outcome following the use of the two types of rotary files it was found that the "Successes" with K3 File (35 out of 41) was 85%; and with Protaper File (32 out of 36) 89%. The "Success" rate certainly was not different between the two file types. The conclusions drawn from the current study was not significantly different from those in the literature review and the overall results were of a similar nature with some minor changes. However it is clear that non-surgical root retreatment offers a good prognosis and should be included as an option for failed or failing root treatment.

<p>U slučajevima neuspe&scaron;ne endodontske terapije, neophodno je ponovno lečenje kanala korena. Ortogradni endodontski retretman podrazumeva uklanjanje postojećeg materijala za punjenje iz kanala uz dodatno či&scaron;ćenje, dezinfekciju i ponovnu finalnu opturaciju kanala. Važan korak u toku retretmana je &scaron;to potpunije uklanjanje postojećeg kanalnog punjenja kako bi se pristupilo svim delovima kanalnog sistema. Cilj doktorske teze bio je da se ispita kvalitet čis&scaron;ćenja zidova kanala korena nakon endodontskog retretmana pomoću skening elektronske mikroskopije (SEM). Posmatran je uticaj vrste materijala za opturaciju, uticaj upotrebe rastvarača i uticaj ručnih i ma&scaron;inskih instrumenata na količinu zaostalog materijala na zidovima kanala. Takođe, ispitan je uticaj ovih faktora na apikalnu transportaciju materijala i na vreme potrebno za retretman, a utvrđena je i učestalost o&scaron;tećenja kori&scaron;ćenih instrumenata. Materijal i metode: Ukupan uzorak činilo je 125 ekstrahovanih, humanih jednokorenih zuba. Nakon preparacije kanala korena, 120 zuba je podeljeno u dve grupe i napunjeno pomoću dva različita materijala za opturaciju (gutaperkom i resilonom). U zavisnosti od tehnike uklanjanja ovih materijala, grupe su dalje podeljene u odnosu na kori&scaron;ćene instrumente (Hedstrom, ProTaper i Twisted File) i u odnosu na upotrebu rastvarača (sa i bez hloroforma). Preostalih 5 zuba, bez kanalnog punjenja, kori&scaron;ćeni su kao kontrolna grupa. Nakon zavr&scaron;enog retretmana, korenovi su uzdužnim cepanjem razdvojeni, a odabrane polovine posmatrane na SEM-u. Mikrofotografije svake trećine kanala načinjene su pri uveličanju od 500x. Količina preostalog materijala za punjenje ocenjivana je pomoću skale. Otvoreni dentinski kanalići prebrojavani su na mikrofotografijama načinjenim pri uveličanju od 1000x, u odnosu na uvek konstantnu povr&scaron;inu. Rezultati: Analiza rezultata ukazala je na postojanje statistički značajne razlike u kvalitetu či&scaron;ćenja zidova kanala u zavisnosti od uklanjanog materijala za opturaciju. Kvalitet či&scaron;ćenja zidova kanala bio je veći nakon uklanjanja gutaperke nego nakon uklanjanja resilona. Rotirajućim, ma&scaron;inskim instrumentima je efikasnije uklanjana gutaperka, a ručnim Hedstrom turpijama je bolje uklanjan resilon. Posmatrajući ceo uzorak, ProTaper instrumenti ostavljali su velike količine materijala na zidovima kanala nakon endodontskog retretmana. Međutim, uklanjanje materijala pomoću ovih instrumenata bilo je najbrže. Primena rastvarača značajno je doprinela bržem uklanjanju materijala, dok uticaj na kvalitet či&scaron;ćenja zidova kanala nije bio značajan. Posmatrajući kanal korena po trećinama, najveća količina materijala nalazila se u apikalnoj trećini, bez obzira na vrstu uklanjanog materijala i kori&scaron;ćenih instrumenata, i bez obzira na upotrebu rastvarača tokom retretmana. Učestalost o&scaron;tećenja instrumenata bila je značajno veća prilikom upotrebe Twisted File instrumenata. Apikalna transportacija materijala je bila veća tokom uklanjanja resilon materijala i kada su kori&scaron;ćene ručne Hedstrom turpije. Zaključak: Kvalitet či&scaron;ćenja zidova kanala nakon uklanjanja gutaperke je veći nego nakon uklanjanja resilona. Dizajn i vrsta instrumenata utiče na kvalitet či&scaron;ćenja zidova kanala korena. Upotreba rastvarača tokom retretmana ne utiče značajno na smanjenje količine materijala zaostalog na zidovima kanala. Ma&scaron;inski pokretani instrumenti i upotreba rastvarača značajno skraćuju vreme potrebno za endodontski retretman.</p> / <p>In cases when endodontic treatment fails, it is necessary to retreat the root canal. Orthograde endodontic retreatment requires the removal of the existing root filling material with additional cleaning, disinfection and refilling of the canal. An important step during retreatment is complete removal of existing filling materials, to regain access to all parts of the canal system. The aim of the doctoral thesis was to investigate the cleanliness of root canal walls after removal of two different obturation material. The retreatment efficacy was observed depending on the usage of solvent and different hand or rotary instruments. The amount of residual material on the canal walls was assessed using scanning electron microscopy (SEM). Also, apical transportation of the obturation material, working time and frequency of instrument damage during retreatment was recorded. Materials and Methods: The total sample consisted of 125 extracted, single-rooted human teeth. After root canal preparation, 120 teeth were divided in two groups and filled using two different obturation materials (gutta-percha and resilon). Depending on the technique of removing these materials, the groups were further divided, in relation to the used instruments (Hedstrom, ProTaper and Twisted File), as well as in relation to the use of solvent (with or without chloroform). The remaining 5 tooth without canal filling were used as a control group. After root canal desopturation, the longitudinaly splitted root halves were observed on SEM. Microphotography of each third were made at magnification of 500x. The amount of remaining filling material was evaluated by using a scale. Open dentinal tubules were counted on microphotographies made at a magnificiation of 1000x, on a surface that was always constant. Results: Analysis of the results indicated a significant difference in the cleanliness of the canal walls depending on the used obturation material. Cleanliness of the canal walls was higher after gutta-percha removal than after the removal of resilon.&nbsp; Rotary instruments were more effective in removing gutta-percha and Hedstrom hand files better removed resilon. ProTaper instruments left more residual material on canal walls, however endodontic retreatment with these instruments was the fastest. The application of solvent significantly contributed to faster material removal, while the impact on the increase of canal cleanliness was not significant. The largest amount of material remained in the apical third, regardless of the type of material removed and instruments used, and also regardless whether solvent was used for retreatment. The frequency of instrument deformation and fracture was significantly higher when Twisted File instruments were used. Apical transportation of material had a significantly higher occurrence during resilon removal and when manual Hedstrom files were used. Conclusion: Cleanliness of the canal walls was higher after the removal of gutta-percha than after the removal of resilon. The use of solvent is not significant on the increase of canal wall cleanliness, but significantly shortens the time needed for retreatment. There is a difference in the cleanliness of root canal walls depending on the used instruments. Engine-driven rotary instruments and the use of a solvent significantly shortens the time needed for endodontic retreatment.</p>

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