Resumo Este estudo laboratorial avaliou por meio de micro-CT a eficiência do uso de um único instrumento de três sistemas rotatórios em retratamentos endodônticos, comparados a um instrumento único reciprocante. Sessenta caninos extraídos foram preparados usando o sistema ProTaper Universal (F2) e obturados. Após 30 dias de armazenamento a 37 ºC e 100% de umidade, os dentes foram divididos aleatoriamente em quatro grupos (n = 15), de acordo com o instrumento utilizado para remover as obturações endodônticas: ProTaper NEXT (PTN), ProTaper Gold (PTG), TRUShape 3D (TS) e WaveOne (WO). Os canais foram retratados usando apenas o instrumento tamanho 40 de cada sistema, seguindo as recomendações do fabricante para torque e velocidade. O tempo necessário para remover a obturação foi registrado em segundos. A quantidade de material remanescente e o volume de dentina removida foram avaliadas por meio de micro-CT. Análise estatística foi realizada (ANOVA e Kruskal-Wallis), com nível de significância de 5%. O tempo de trabalho no grupo TS foi significativamente maior (p<0.05) (média, 384,80 ± 144,92) comparado a WO (229,67 ± 68,16) e PTG (248,67 ± 64,22), e similar a PTN (327,67 ± 133,3). Não houve diferenças entre os grupos na quantidade de dentina removida e nas porcentagens de material obturador residual. O uso de apenas um instrumento rotatório dos sistemas PTG, TS e PTN foi tão eficaz quanto o do sistema WO reciprocante na remoção do material obturador. No entanto, nenhum dos instrumentos conseguiu remover completamente os materiais obturadores.

Abstract This study evaluated the efficiency of using a single instrument from three different rotary multi-file systems and compared them with that of a reciprocating single-file for endodontic retreatment by means of micro-CT. Sixty extracted canines were prepared using a size F2 ProTaper Universal file and obturated. After 30 days of storage at 37ºC and 100% humidity, the teeth were randomly divided into four groups (n=15) based on the type of instrument used to retreatment: ProTaper Next (PTN), ProTaper Gold (PTG), TRUShape 3D (TS), and WaveOne (WO). The canals were retreated using only the size 40 instrument from each system according to the manufacturer’s recommendations for torque and speed. The time required to remove the filling material was recorded in seconds. The amount of initial and residual filling material and the quantity of dentin removed were assessed by means of micro-CT. Data were statistically analyzed (ANOVA and Kruskal-Wallis) at a 5% significance level. TS instruments required the highest (p<0.05) amount of time (mean, 384.80 ±144.92) compared with the WO (229.67±68.16) and PTG (248.67±64.22) and not so different from PTN instruments (327.67±133.3). No differences in the amount of dentin removed, initial and residual filling volume, and percentages of filling material were observed among the groups. The use of a single rotary instrument from the PTG, TS, and PTN systems was as effective as that of the single-file reciprocating WO system. However, none of the instruments was able to remove the filling materials completely.

Resumo Introdução O MTA é um importante material de uso na odontologia, com boas propriedades biológicas. As respostas experimentais aos cimentos endodônticos que utilizam este composto no selamento e preenchimento do sistema de canais radiculares, aliados a uma boa instrumentação e limpeza, podem ser importantes no processo de reparo periapical. Objetivo Avaliar in vitro a profundidade de penetração de dois diferentes cimentos endodônticos nos túbulos dentinários e a infiltração bacteriana em obturações com os cimentos AH Plus e MTA Fillapex. Material e método 34 pré-molares monorradiculados humanos foram selecionados, suas coroas removidas e suas raízes padronizadas em 16 mm, a seguir foram, então, divididos aleatoriamente em dois grupos de 15 espécimes e instrumentados com o sistema rotatório Pro Taper. Um grupo foi obturado com o cimento AH Plus (Grupo AH) e outro com MTA Fillapex (Grupo FI). Nestes grupos, avaliaram-se a infiltração coronária de bactérias para Enterococcus Faecalis e a profundidade de penetração nos túbulos dentinários. Para a aferição da infiltração bacteriana, usou-se o teste exato de Fisher; para a penetração intratubular, usou-se o teste-t. Resultado Para a infiltração bacteriana, considerando o número de amostras infiltradas para AH e MTA Fillapex, houve diferença estatística significativa (p=0,0341). Na avaliação da penetração intratubular, a diferença entre os dois grupos de cimentos foi considerada estatisticamente significativa (p=0,0006). Conclusão Ambos os cimentos apresentaram infiltração bacteriana, sendo que o MTA Fillapex teve pior desempenho. A capacidade de penetração nos túbulos dentinários do AH Plus foi significativamente maior que a do MTA Fillapex.

Abstract Introduction The MTA is an important use in dentistry material with good biological properties. The experimental responses to sealers using this compound in the sealing and filling of the root canal system, combined with a good instrumentation and cleaning, may be important in the periapical healing process. Objective To evaluate in vitro penetration depth of two different sealers in dentinal tubules and bacterial infiltration in fillings with AH Plus and MTA Fillapex cements. Material and method 34 premolars human monorradiculados were selected, their removed and their standardized root crowns in 16mm, after then randomly divided into two groups of 15 specimens, and instrumented with rotary system Pro Taper. One group was obturated with cement AH Plus (group HA) and another MTA Fillapex (FI Group). These groups are evaluated for coronary infiltration of bacteria Enterococcus faecalis and the depth of penetration in the dentinal tubules. For the measurement of bacterial infiltration used Fisher's exact test for Intratubular penetration we used the t-test. Result For bacterial infiltration, considering the number of infiltrated samples AH and MTA Fillapex, there was a statistically significant difference (p = 0.0341). In the evaluation of intratubular penetration, the difference between the two groups of cement was statistically significant (p = 0.0006). Conclusion Both cements showed bacterial infiltration and the MTA Fillapex had worse performance, capabilities to enter the dentinal tubules AH Plus was significantly higher than the MTA Fillapex.

Objective: To analyze possible correlations among tubular dentine cement penetration, adhesiveness and apical leakage in fillings performed with gutta percha and an endodontic cement based on epoxy amine resin. Material and Methods: Sixty similar, extracted human mandibular central incisors were irrigated, instrumented and filled following the same protocol. First, apical leakage was quantified by fluid filtration tests. Then, these same specimens were sectioned for analysis of tubular dentine cement penetration and the middle thirds were submitted to push-out tests to analyze the adhesiveness of the fillings. Results: In brief, the means and standard deviations with a confidence interval of 95% were as follows: tubular dentine cement penetration (8.875±4.540), adhesiveness (4.441±2.683) and apical leakage (0.318±0.215). The data were confronted using the Pearson's test (P>0.05), and it was possible to prove that there was no correlation between (1) tubular dentine cement penetration and apical leakage (r2: 0.08276), (2) tubular dentine cement penetration and adhesiveness (r2: -0.2412) and (3) adhesiveness and apical leakage (r2: 0.1340). Conclusion: After analysis of these data, it could be observed that there exists no correlation among the variables analyzed in this study.

O propósito deste estudo foi avaliar a eficiência dos instrumentos rotatórios ProFile, GT, ProTaper, Race e K3 comparados com limas K para a remoção do material obturador durante o retratamento. Sessenta pré-molares inferiores foram instrumentados com o sistema rotatório GT e obturados usando a técnica de compactação termomecânica de guta-percha com cimento AH Plus. Os dentes foram divididos aleatoriamente em seis grupos de dez espécimes cada. As raízes foram seccionadas longitudinalmente, imagens digitais foram criadas através de um scanner, e as áreas de remanescentes de material foram medidas usando o programa Image Tool 1.21. Os resultados indicaram que o GT deixou significantemente menos material remanescente (1,18 ± 1,47) do que os instrumentos manuais (3,70 ± 3,16) e os instrumentos Hero (2,99 ± 2,58) (p<0,05). Não houve diferença estatisticamente significante entre as outras técnicas ProFile (1,99 ± 2,66), ProTaper (2,00 ± 1,99) e K3 (2,71 ± 2,87) quando comparadas com o GT. Como conclusão, GT, ProFile, ProTaper e K3 foram revelados como mais efetivos em remover a guta-percha do que os instrumentos manuais e os instrumentos Hero.

The purpose of this study was to evaluate the efficiency of ProFile, GT, ProTaper, Race and K3 rotary instruments compared with hand K-files for removal of gutta-percha during retreatment. Sixty mandibular premolars were instrumented with GT rotary files and filled by thermomechanical compaction of gutta-percha and AH Plus sealer. The teeth are randomly divided into 6 groups of 10 specimens each. The roots were split longitudinally, digital images were created using a flatbed scanner, and the areas with remaining filling material were demarcated using Image Tool 1.21 software. The results indicate that GT left significantly less (p<0.05) remaining filling material (1.18 ± 1.47) than hand (3.70 ± 3.16) and Hero instruments (2.99 ± 2.58). There was no statistically significant difference (p<0.05) among the others techniques: ProFile (1.99 ± 2.66), ProTaper (2.00 ± 1.99) and K3 (2.71 ± 2.87) when compared with GT. In conclusion, GT, ProFile, ProTaper and K3 were more effective in removing gutta-percha than manual and Hero instruments.

OBJECTIVES: The aim of this study was to evaluate cases of dental trauma treated at the specialized center of Pontifical Catholic University of Paraná, Curitiba, Brazil, during a period of 2 years. MATERIAL AND METHODS: A total of 647 patients were evaluated and treated between 2003 and 2005. Data obtained from each patient were tabulated and analyzed as to gender, age, etiology, time elapsed after the injury, diagnosis (type of trauma), and affected teeth. RESULTS: The results revealed that male individuals aged 7 to 13 years presented the highest prevalence of injury, and falling was the main causal factor. In most cases, the time elapsed between the accident and the first care ranged from 4 to 24 h. A total of 1,747 teeth were affected, with higher incidence of concussion/subluxation and coronal fracture, followed by lateral luxation and avulsion. The permanent maxillary central incisors were the most commonly affected teeth. CONCLUSION: The frequency and causes of dentoalveolar trauma should be investigated for identification of risk groups, treatment demands and costs in order to allow for the establishment of effective preventive measures that can reduce the treatment duration and costs for both patients and oral health services.

Este estudo in vitro avaliou, por um modelo de infiltração bacteriano, se a medicação intracanal com hidróxido de cálcio associado a diferentes veículos, tem efeito inibitório na penetração coronária de bactéria. Quarenta caninos humanos instrumentados foram medicados com Ca(OH)2 p.a. associados à G1= água destilada; G2= polietilenoglicol (PG); G3= polietilenoglicol e paramonoclorofenol canforado (PMCP); e G4= glicerina. Cinco dentes hígidos foram utilizados como grupo controle negativo e cinco dentes instrumentados sem medicação intracanal serviram como grupo controle positivo. Todos os dentes foram montados em um aparato de duas câmaras e expostos a saliva humana por 63 dias. A infiltração foi verificada através da observação do turvamento do meio de cultura na câmara inferior. Cinqüenta por cento das amostras do G1 e G2, 10% do G3 e 80% do G4 foram totalmente contaminadas após 9 semanas. Diferenças estatisticamente significantes foram observadas quando foram realizadas comparações pareadas entre G3 e G4 (p=0,0069), com G3 alcançando um melhor selamento contra infiltração bacteriana do que G4.

This in vitro study evaluated, using a bacterial leakage model, whether intracanal medication with calcium hydroxide [Ca(OH)2]-based pastes prepared with different vehicles, has inhibitory effect on corono-apical leakage of bacteria. Forty instrumented human canines were dressed with Ca(OH)2 p.a. associated with: G1= distilled water; G2= polyethylene glycol (PG); G3= PG + CMCP; and G4= glycerin. Five teeth with intact crowns served as negative controls and 5 instrumented teeth without temporary dressing served as positive controls. All teeth were mounted in a 2-chamber apparatus and then exposed to human saliva for 63 days. Leakage was recorded when turbidity was observed in the lower chamber. Fifty percent of the samples of G1 and G2, 10% of G3 and 80% of G4 were fully contaminated after 9 weeks. Statistically significant differences were observed with paired comparisons G3 and G4 (p=0.0069), with G3 achieving better seal against bacterial leakage than G4.

O presente estudo avaliou a capacidade de limpeza promovida pela técnica de instrumentação rotatória, com limas de níquel-titânio Profile .04, associado à soluções de hipoclorito de sódio (NaOCl), em diferentes concentrações, quando utilizados em canais com achatamento mésio-distal. Vinte dentes incisivos centrais inferiores humanos, unirradiculares, foram selecionados e divididos aleatoriamente em 4 grupos: Grupo I: NaOCl a 0,5%; Grupo II: NaOCl a 1%; Grupo III: NaOCl a 5%; Grupo IV: água destilada e deionizada. Após o preparo biomecânico, os dentes foram submetidos ao processamento histológico e análise morfométrica. A análise morfométrica mostrou que o NaOCl a 5% era estatisticamente mais eficiente na limpeza do canal radicular que o NaOCl a 0.5% e a água destilada, que apresentaram os mais baixos níveis de limpeza dos canais radiculares (p<0,01).

This study evaluated the cleaning capacity of Profile .04 instruments with different concentrations of NaOCl solutions on flattened root canals. Twenty central mandibular incisors were divided into 4 groups: Group I: 0.5% NaOCl; Group II: 1% NaOCl; Group III: 5% NaOCl; Group IV: distilled and deionized water. After chemomechanical preparation, the teeth were submitted to histological preparation and morphometric analysis. Morphometric analysis showed that the 5% NaOCl was significantly more efficient in cleaning the root canal than 0.5% NaOCl and distilled water, which had the lowest levels of cleaning of the root canals (p<0.01).