Outcome of Endodontic Treatment through Existing Full Coverage Restorations: An Endodontic Practice Case Series.

INTRODUCTION: This case series assessed the outcome of nonsurgical endodontic treatment completed through retained full coverage restorations (FCRs) in a board-certified endodontist private practice. The number of cases completed by the first author was 153. METHODS: All cases were performed following a standardized protocol for treatment and restoration depending on the type of FCR. Number of cases that showed up for 2- to 4-year follow-up was 127, with 83% recall rate. The age range of patients was 33-95 years, with mean age of 54.734 years. The mean recall time was 2.448 years. FCRs and their distribution were as follows: 4 anterior teeth, 14 premolars, and 109 molars. There were 103 nonsurgical root canal treatments and 24 retreatments. Patients who presented for recall had 74 porcelain fused to metal crowns, 17 zirconia crowns, 15 abutments of porcelain fused to metal bridges, 14 lithium disilicate crowns, 5 gold crowns, 1 full metal crown, and 1 gold onlay. RESULTS: There were no endodontically related failures. Six cases failed; 3 were due to vertical root fractures, 1 was due to horizontal root fracture, and 2 were due to extensive recurrent caries causing restorative failure. The percentage of healed cases following the American Association of Endodontists outcome criteria adopted in 2004 with intact retained FCR was 95.3%. CONCLUSIONS: The results suggest predictable favorable outcomes for nonsurgical endodontic treatment through FCR following the proposed protocol for diagnosis, treatment, and restoration.

Analysis of mandibular second molars with fused roots and shallow radicular grooves by using micro-computed tomography.

AIM: This study aimed to describe the morphological and morphometric aspects of fused mandibular second molars with radicular shallow grooves using micro-computed tomography (CT). MATERIALS AND METHODS: Eighty-eight mandibular second molars with fused roots were scanned in a micro-CT scanner at a voxel size of 19.6 µm. After reconstruction, only molars without C-shaped roots and presenting shallow radicular grooves were selected. 30 molars were chosen for further analysis. Canal cross-sections were classified according to Fan's modified classification (C1, C2, C3, and C4) and morphometric parameters at the apical region, examination of accessory foramina and tridimensional configuration were evaluated. RESULTS: Three-dimensional reconstructions indicated a higher prevalence of merging type (n = 22). According to Fan's modified classification, the C4 configuration was predominant in the 3 apical mm. Roundness median values revealed a more round-shaped canals at 3 mm (0.72) than at 2 (0.63) and 1 (0.61) mm from the apex. High values of major and minor diameters were observed in the canals of these evaluated sections. In addition, few accessory apical foramina were observed at 1 and 2 mm from the apex. The average distance between last accessory foramina and the anatomic apex was 1.17 mm. A less complex internal anatomy is found when a mandibular second molar presents fused roots with shallow radicular grooves. The merging type canal was frequently observed. Moreover, the C4 configuration was predominant at a point 3 mm from the apex and presented rounded canals, large apical diameters, and few accessory foramina. The cervical and middle thirds presented C3 and C1 canal configurations most frequently. CONCLUSION: A minor morphological complexity is found when fused mandibular second molars present shallow radicular grooves.

Influência do hidróxido de cálcio na adaptação e na penetração às paredes do canal de dentes obturados com um cimento resinoso à base de metacrilato / The influence of calcium hydroxide on adaptation and root canal penetration in teeth filled with methacrylate-based resin sealer

Introdução: o objetivo deste trabalho foi avaliar, por meio da microscopia confocal de varredura a laser (MCVL), o efeito da medicação intracanal com pasta de hidróxido de cálcio sobre a penetração e a porcentagem de adaptação — nos terços cervical, médio e apical — de canais obturados com o sistema obturador à base de metacrilato (Sistema Epiphany). Métodos: trinta incisivos inferiores humanos foram instrumentados até a lima 40.04 do sistema ProFile e a solução irrigadora usada foi o hipoclorito de sódio. Os dentes foram aleatoriamente divididos em três grupos (n = 10): Grupo I = sem hidróxido de cálcio (Ca(OH)2) (grupo controle); Grupo II = com Ca(OH)2 por 14 dias e remoção com solução salina + lima K #40; e Grupo III = similar ao Grupo II, mas utilizando o EDTA a 17% para remoção da medicação. O cimento Epiphany foi corado com rodamina B, e todos os canais foram obturados com o sistema Epiphany. Três secções de cada dente foram avaliadas sob magnificações de cinco e de quarenta vezes. Resultados: os testes estatísticos de ANOVA e Tukey indicaram significância estatística na redução dos valores de penetração do cimento no terço apical, comparado aos outros terços (p < 0,05). A maior profundidade de penetração foi observada nos terços coronal e médio do Grupo II. Os Grupos II (93%) e III (86%) tiveram as maiores porcentagens de adaptação, comparados ao Grupo I (78%) (p < 0,05). Conclusões: o Ca(OH)2 favoreceu a profundidade de penetração do cimento e a porcentagem de adaptação na interface dentina/cimento em dentes obturados com o cimento à base de metacrilato.

Microbiologic cross-contamination and infection control in intraoralconventional and digital radiology / Contaminação microbiológica e controle de infecção em radiologia intraoral convencional e digital

The microbiologic contamination can occur in all the steps of an intraoral conventional or digital radiographic examination, unless some measures to avoid the cross-infection are applied. Scientific articles have shown that during the radiograph taking procedure, there is contact with the patient?s oral fluids (saliva and blood) and, consequently, the contamination of the film or digital sensor, film-holding devices, operator?s hands and afterwards, the contamination of the surfaces, the X-Rays equipment, the processing environment and its solutions. Also, the literature shows that the existence of infection control protocols is mandatory for dental offices and colleges. The aim of this article is to review how the microbiologic contamination can occur in Dental Radiology practice and to describe more efficient methods to avoid it, in order to get a safe environment for patients, professionals and workers. It is extremely important that the professional be aware and use efficient protection barriers in all steps of an intraoral radiographic examination, whether conventional or digital.

A contaminação microbiológica pode ocorrer em todas as etapas de um exame radiográfico intra-oral convencional ou digital, caso não sejam tomadas medidas para evitar a infecção cruzada. Artigos científicos têm mostrado que durante a tomada radiográfica, existe o contato com fluidos orais do paciente (saliva e/ou sangue) e consequentemente, a contaminação de filmes radiográficos ou sensores digitais, posicionadores, mãos do operador e posteriormente, de superfícies do ambiente de trabalho, partes do aparelho de Raios-X, ambiente deprocessamento radiográfico e suas soluções. A literatura também mostra que a existência de protocolos de controle de infecção é obrigatóriapara consultórios e faculdades de Odontologia. Este trabalho se propõe a revisar como a contaminação microbiológica pode ocorrer na prática da Radiologia Odontológica e descrever os métodos mais efetivos para combatê-la, garantindo um ambiente seguro para pacientes, profissionais e funcionários que o freqüentam. É de fundamental importância que o profissional esteja consciente e utilize barreiras de proteção eficazes em todas as etapas do exame radiográfico intraoral, seja convencional ou digital.

In Vitro Alkaline pH Resistance of Enterococcus faecalis

Enterococcus faecalis is a bacterial species often found in root canals with failed endodontic treatment. Alkaline pastes are widely used in Endodontics because of their biocompatibility and antimicrobial activity, but this microorganism can resist alkalinity. The purpose of this study was to evaluate in vitro the alkaline pH resistance of E. faecalis for different periods up to 14 days. Samples were obtained from the oral cavity of 150 patients from the Endodontic clinic. The pH of the experimental tubes (n=84) was first adjusted with 6M NaOH to pH values of 9.5, 10.5, 11.5 and 12.5 (21 tubes per pH). Twenty clinical isolates and the ATCC 29212 strain were tested. The 5 positive controls and experimental tubes of each pH were inoculated with 10 µL of bacterial suspension and incubated at 36 °C for 24, 48 and 72 h, 7 and 14 days. For each period, the turbidity of the medium was visually compared with a 0.5 McFarland standard. The presence of the microorganism was confirmed by seeding on M-Enterococcus agar. Four tubes containing BHI broth adjusted to the tested pHs were incubated for 14 days to verify if pH changes occurred. The pH of inoculated BHI broth was also measured on day 14 to determine if the microorganism acidified the medium. The growth of all E. faecalis strains occurred at pH 9.5 to 11.5 in all periods. Although turbidity was not observed at pH 12.5, there was growth of 13 and 2 strains at 24 and 48 h, respectively, on M-Enterococcus agar. No tube showed growth at pH 12.5 after 72 h. It was concluded that E. faecalis can survive in highly alkaline pH, and some clinical isolates require 72 h at pH 12.5 to be killed.

Enterococcus faecalis é uma espécie bacteriana frequentemente encontrada em canais radiculares com insucesso do tratamento endodôntico. Pastes alcalinas são amplamente utilizada em Endodontia por causa de sua biocompatibilidade e atividade antimicrobiana, porém esse microrganismo pode ser resistente a alcalinidade. Este estudo avaliou in vitro a resistência do E. faecalis ao pH alcalino por diferentes períodos até 14 dias. Amostras foram obtidas da cavidade oral de 150 pacientes da Clínica de Endodontia. O pH dos tubes experimentais (n=84) foram inicialmente ajustados com NaOH 6M a valores de pH 9.5, 10.5, 11.5 e 12.5 (21 tubes per pH). Vinte isolados clínicos e a cepa ATCC 29212 foram testados. Os 5 controles positivos e os tubos experimentais de cada pH foram inoculados com 10 µL de suspensão bacteriana e incubados a 36 °C por 24, 48 e 72 h, 7 e 14 dias. Para cada período, turvação do meio foi compara visualmente com padrão 0.5 da escala de McFarland. A presença de microorganism foi confirmada por semeadura no meio ágar M-Enterococcus. Quatro tubos contendo caldo BHI ajustado aos pHs testados foram incubados por 14 dias para verificar a ocorrência de alterações de pH. O pH do caldo BHI inoculado também foi medido no 14° dia para determinar se o microrganismo acidificou o meio. O crescimento de todas as cepas de E. faecalis ocorreu com pH entre 9.5 e 11.5 em todos os períodos. Embora não tenha sido observada turvação do meio no pH 12.5, houve crescimento de 13 e 2 cepas às 24 e 48 h, respectivamente, no meio ágar M-Enterococcus. Nenhum tube apresentou crescimento bacteriano no pH 12.5 após 72 h. Concluiu-se que o E. faecalis pode sobreviver em pH altamente alcalino, que alguns isolados clínicos requerem 72 h em pH 12.5 para serem eliminados.

In vitro alkaline pH resistance of Enterococcus faecalis.

Enterococcus faecalis is a bacterial species often found in root canals with failed endodontic treatment. Alkaline pastes are widely used in Endodontics because of their biocompatibility and antimicrobial activity, but this microorganism can resist alkalinity. The purpose of this study was to evaluate in vitro the alkaline pH resistance of E. faecalis for different periods up to 14 days. Samples were obtained from the oral cavity of 150 patients from the Endodontic clinic. The pH of the experimental tubes (n=84) was first adjusted with 6M NaOH to pH values of 9.5, 10.5, 11.5 and 12.5 (21 tubes per pH). Twenty clinical isolates and the ATCC 29212 strain were tested. The 5 positive controls and experimental tubes of each pH were inoculated with 10 µL of bacterial suspension and incubated at 36 °C for 24, 48 and 72 h, 7 and 14 days. For each period, the turbidity of the medium was visually compared with a 0.5 McFarland standard. The presence of the microorganism was confirmed by seeding on M-Enterococcus agar. Four tubes containing BHI broth adjusted to the tested pHs were incubated for 14 days to verify if pH changes occurred. The pH of inoculated BHI broth was also measured on day 14 to determine if the microorganism acidified the medium. The growth of all E. faecalis strains occurred at pH 9.5 to 11.5 in all periods. Although turbidity was not observed at pH 12.5, there was growth of 13 and 2 strains at 24 and 48 h, respectively, on M-Enterococcus agar. No tube showed growth at pH 12.5 after 72 h. It was concluded that E. faecalis can survive in highly alkaline pH, and some clinical isolates require 72 h at pH 12.5 to be killed.

Efeito da irrigação e medicação endodôntica em dentina infectada por biofilmes orais / The effect of endodontic irrigation and medication on biofilm infected dentin

O objetivo desse estudo foi avaliar o efeito antimicrobiano da irrigação e da medicação endodôntica em dentina infectada por biofilmes orais. Na primeira parte do estudo, avaliaram-se as seguintes soluções irrigadoras: hipoclorito de sódio a 1%, clorexidina a 2%, ácido cítrico a 10% e EDTA a 17%. Na segunda parte, avaliaram-se soluções irrigadoras contendo associações (MTAD, Smear Clear, Qmix, ácido maleico a 7%, iodo-iodeto de potássio a 2% e ácido peracético a 4%), sendo essas soluções comparadas a 2 concentrações de hipoclorito de sódio. Na terceira parte, avaliou-se o efeito de dispositivos sônicos, ultrassônicos e de laser na capacidade de limpeza do hipoclorito de sódio a 6%, com uso de microscópio eletrônico de varredura. Na quarta parte, avaliaram-se os efeitos antimicrobianos de 3 pastas de hidróxido de cálcio contendo 3 radiopacificadores diferentes (óxido de zinco, sulfato de bário e iodofórmio). No último experimento, foram avaliadas as propriedades antimicrobianas da pasta triantibiótica, da clorexidina em gel e da pasta aquosa de hidróxido de cálcio. Os resultados mostraram que todas as soluções de hipoclorito de sódio testadas e o ácido peracético a 4% foram mais efetivas sobre o biofilme em comparação a todos os irrigantes testados. As soluções de hipoclorito de sódio propiciaram significativamente uma melhor limpeza da dentina. O ácido peracético foi também efetivo para dissolver células do biofilme. A ativação do hipoclorito de sódio com o ultrassom e com laser interferiu favoravelmente na limpeza da dentina infectada. A pasta triantibiótica e o hidróxido de cálcio associado ao iodofórmio foram os medicamentos mais efetivos na descontaminação da dentina infectada. Portanto, o protocolo ideal que deve ser adotado para garantir uma descontaminação efetiva da dentina contaminada por biofilmes orais inclui o uso de hipoclorito de sódio ativado por ultrassom ou laser e medicação intracanal de hidróxido de cálcio com iodofórmio...

The aim of this study was to evaluate the antimicrobial effect of endodontic irrigation and medication on biofilm infected dentin. In the first part, we evaluated the following irrigant solutions: 1% sodium hypochlorite, 2% chlorhexidine, 10% citric acid and 17% EDTA. In the second part, irrigant solutions containing combinations of antimicrobials such as "MTAD," "Smear Clear", "Qmix", 7% maleic acid and 2% iodine-potassium iodide and 4% peracetic acid were evaluated. These solutions were compared to 2 concentrations of sodium hypochlorite. In the third part, we evaluated the effect of sonic, ultrasonic and laser irrigation on the cleaning ability of biofilm infected dentin using 6% sodium hypochlorite under scanning electron microscope. In the fourth part, we evaluated the antimicrobial effects of 3 calcium hydroxide pastes containing 3 different radiopacifiers (zinc oxide, barium sulfate and iodoform). In the last experiment, we evaluated the antimicrobial properties of the triantibiotic paste, 2% chlorhexidine gel and calcium hydroxide paste. The results showed that the sodium hypochlorite and the peracetic acid solutions were more effective to decontaminate the biofilm infected dentin in comparison to all of the tested irrigants. The sodium hypochlorite solutions allowed significantly better cleaning of the dentine. The peracetic acid was also effective to dissolve the biofilm cells. Activation of 6% sodium hypochlorite with ultrasonic and laser increased the cleaning of biofilm infected dentin. The triantibiotic paste and calcium hydroxide associated to iodoform were the most effective intracanal dressings available for the decontamination of the infected dentin. Therefore, the ideal protocol to be adopted in order to ensure an effective decontamination of biofilm infected dentin includes the use of sodium hypochlorite, specially activated by ultrasound or laser; and the use of calcium hydroxide with iodoform intracanal dressing...

Effect of different radiopacifying agents on the physicochemical properties of white Portland cement and white mineral trioxide aggregate.

INTRODUCTION: The aim of this study was to evaluate the pH, calcium ion release, setting time, and solubility of white mineral trioxide aggregate (WMTA) and white Portland cement (WPC) combined with the following radiopacifying agents: bismuth oxide (BO), calcium tungstate (CT), and zirconium oxide (ZO). METHODS: Fifty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH and calcium release (atomic absorption spectrophotometry) at 3, 24, 72, and 168 hours. For evaluation of setting time, each material was analyzed according to the American Society for Testing and Materials guidelines 266/08. The solubility test was performed according to American National Standards Institute/American Dental Association specification no. 57/2000. Solubility, setting time, and pH values were compared by using analysis of variance and Tukey test, and the values of calcium release were compared by the Kruskal-Wallis and Miller tests. The significance level was set at 5%. RESULTS: The pH and calcium release were higher at 3 and 24 hours. WPC was the material with the higher values for both properties. WMTA had the greatest solubility among all materials (P < .05). All radiopacifiers increased the setting time of WPC, and WMTA had the shortest setting time among all materials (P < .05). CONCLUSIONS: All materials released calcium ions. Except for WPC/CT at 168 hours, all materials promoted an alkaline pH. On the basis of the obtained results, ZO and CT can be considered as potential radiopacifying agents to be used in combination with Portland cement.

Análise qualitativa da obturação do sistema de canais radiculares em função da interação entre cimentos e técnicas / Qualitative analisys of obturation of root canals system in relation of the interaction between technique and obturation material

Este trabalho teve como objetivo avaliar qualitativamente a obturação de canais radiculares, observando a interação entre a técnica híbrida de Tagger com a condensação lateral ativa quando do emprego dos cimentos Endomethasone® e Sealer 26®. Para isso foram utilizados quarenta caninos superiores humanos, que foram instrumentados pela técnica escalonada regressiva. Feito isso foram divididos em 4 grupos com 10 dentes cada, obedecendo a seguinte ordem: Grupo I: Condensação lateral ativa + Endomethasone ®; Grupo II: técnica híbrida de Tagger + Endomethasone®; Grupo III: Condensação lateral ativa + Sealer 26 ® e Grupo IV: Técnica híbrida de Tagger + Sealer 26®. Após a obturação os dentes foram radiografados tanto no sentido mésiodistal, quanto no vestíbulo-lingual e em seguida clivados no sentido longitudinal. As radiografias foram utilizadas para avaliar possíveis falhas na obturação, nas quais foram atribuídos escores de acordo com as mesmas. Já as hemisecções foram analisadas por meio de lupa esterioscópica. Os dados obtidos foram submetidos ao teste de Krusskal-Wallis para análise global e o teste de Miller para comparações individuais, ambos com o nível de significância 5%. De acordo com os resultados ficou evidenciado melhor qualidade da obturação quando da associação da técnica híbrida de Tagger com o cimento Endomethasone®. Assim conclui-se que a técnica híbrida de Tagger foi superior a condensação lateral ativa e que cimentos derivados do óxido de zinco e eugenol propiciam, principalmente na radiografia, obturações mais homogêneas que os cimentos resinosos, especialmente na técnica híbrida de Tagger

The aim of this study was to evaluate the quality of root canal fillings, observing the interaction between the Tagger’s hybrid technique and active lateral condensation when applying Endomethasone and Sealer 26 cements. The root canals of forty extracted maxillary canines were prepared by the classic technique. The teeth were divided into four groups of 10 teeth each, following this order: Group I: Active lateral condensation + Endomethasone, Group II: Tagger’s hybrid technique + Endomethasone, Group III: Active lateral condensation + Sealer 26 and Group IV: Tagger’s hybrid technique + Sealer 26. After root canal filling, each tooth was exposed to X-rays, in both direction as in the mesiodistal and buccolingual and then cleaved longitudinally. The resulting images were interpreted for presence of gaps and scores were assigned by endodontists. The half-sections were analyzed by stereoscopic magnifying glass. The data were tested using the Krusskal-Wallis test for global analysis of individual comparisons to Miller test, both with the significance level 5%. According to the results was apparent the quality of the filling when using the association of Tagger’s hybrid technique with Endomethasone cement. It was concluded that the Tagger’s hybrid technique was superior to active lateral condensation and cements derived from zinc oxide and eugenol provided, especially in X-rays, more homogeneous fillings than the resin cements, especially in the Tagger’s hybrid technique

Removal efficiency of propolis paste dressing from the root canal

OBJETIVES: The aim of this study was to investigate through scanning electron microscopy (SEM) the cleaning of root canal walls after the use of experimental propolis or calcium hydroxide root canal dressings. MATERIAL AND METHODS: Twenty single-rooted teeth were used. After conventional cleaning and shaping procedures and removal of the smear layer with 17 percent EDTA, the teeth were divided into four groups according to the medication used (N=5): Group I (control) - No drug, Group II - Calcium hydroxide dressing, Group III - Propolis paste A70D and Group IV - Propolis paste D70D. The medications were introduced into the root canals and maintained for 7 days, then removed with a K-file and 5 mL of 1 percent sodium hypochlorite irrigation. Finally, the canals were flushed with 2 mL of 17 percent EDTA for 3 min. For SEM analysis, the roots were cleaved and microphotographs from the middle third of the root canal were taken at 750x. The cleaning of the root canal walls was determined by the number of open dentinal tubules as verified with the software Image Tool 3.1. The statistical analysis was performed by ANOVA and Tukey's test (p<0.05). RESULTS: The results showed no statistically significant difference between the calcium hydroxide and propolis groups. CONCLUSIONS: The experimental propolis pastes presented acceptable physical characteristics to be used as intracanal medicaments.

Evaluation of the physical and chemical properties of two commercial and three experimental root-end filling materials.

OBJECTIVE: The aim of this study was to evaluate the pH, calcium release, setting time, and solubility of two commercially available mineral trioxide aggregate (MTA) cements (white MTA Angelus and MTA Bio), and of three experimental cements (light-cured MTA, Portland cement with 20% bismuth oxide and 5% calcium sulfate, and an epoxy resin-based cement). STUDY DESIGN: For evaluation of pH and calcium ion release, polyethylene tubes with 1.0 mm internal diameter and 10.0 mm length were filled with the cements and immediately immersed in flasks containing 10 mL deionized water. After 3, 24, 72, and 168 hours, the tubes were removed and the water from the previous container was measured for its pH and calcium content with a pH meter and an atomic absorption spectrophotometer. For analysis of the setting time, Gilmore needles weighing 100 g and 456.5 g were used, in accordance with the American Society for Testing and Materials specification no. C266-03. Solubility of each cement was also tested. RESULTS: All the cements were alkaline and released calcium ions, with a declining trend over time. After 3 hours, Portland cement + bismuth oxide and MTA Bio had the highest pH and light-cured MTA the lowest. After 1 week, MTA Bio had the highest pH and light-cured MTA and epoxy resin-based cement the lowest. Regarding calcium ion release, after 3 hours, Portland cement + bismuth oxide showed the highest release. After 1 week, MTA Bio had the highest. Epoxy resin-based cement and light-cured MTA had the lowest calcium release in all evaluation periods. Regarding setting times, white MTA Angelus and MTA Bio had the shortest, Portland cement + bismuth oxide had an intermediate setting time, and the epoxy resin-based cement had the longest. The materials that showed the lowest solubility values were the epoxy resin-based cement, Portland cement + bismuth oxide, and light-cured MTA. The highest solubility values were presented in white MTA Angelus and MTA Bio. CONCLUSIONS: The white MTA Angelus and MTA Bio had the shortest setting times, higher pH and calcium ion release, and the highest solubility. In contrast, the epoxy resin-based cement and light-cured MTA showed lower values of solubility, pH, and calcium ion release.

Removal efficiency of propolis paste dressing from the root canal.

OBJECTIVES: The aim of this study was to investigate through scanning electron microscopy (SEM) the cleaning of root canal walls after the use of experimental propolis or calcium hydroxide root canal dressings. MATERIAL AND METHODS: Twenty single-rooted teeth were used. After conventional cleaning and shaping procedures and removal of the smear layer with 17% EDTA, the teeth were divided into four groups according to the medication used (N=5): Group I (control) - No drug, Group II - Calcium hydroxide dressing, Group III - Propolis paste A70D and Group IV - Propolis paste D70D. The medications were introduced into the root canals and maintained for 7 days, then removed with a K-file and 5 mL of 1% sodium hypochlorite irrigation. Finally, the canals were flushed with 2 mL of 17% EDTA for 3 min. For SEM analysis, the roots were cleaved and microphotographs from the middle third of the root canal were taken at 750x. The cleaning of the root canal walls was determined by the number of open dentinal tubules as verified with the software Image Tool 3.1. The statistical analysis was performed by ANOVA and Tukey's test (p<0.05). RESULTS: The results showed no statistically significant difference between the calcium hydroxide and propolis groups. CONCLUSIONS: The experimental propolis pastes presented acceptable physical characteristics to be used as intracanal medicaments.

Influence of preflaring on the accuracy of length determination with four electronic apex locators.

INTRODUCTION: The aim of this study was to compare the influence of preflaring on the accuracy of 4 electronic apex locators (EALs): Root ZX, Elements Diagnostic Unit and Apex Locator, Mini Apex Locator, and Apex DSP. METHODS: Forty extracted teeth were preflared by using S1 and SX ProTaper instruments. The working length was established by reducing 1mm from the total length (TL). The ability of the EALs to detect precise (-1mm from TL) and acceptable (-1+/-0.5 mm from TL) measurements in unflared and preflared canals was determined. RESULTS: The precise and acceptable (P/A) readings in unflared canals for Root ZX, Elements Diagnostic Unit and Apex Locator, Mini Apex, and Apex DSP were 50%/97.5%, 47.5%/95%, 50%/97.5%, and 45%/ 67.5%, respectively. For preflared canals, the readings were 75%/97.5%, 55%/95%, 75%/97.5%, and 60%/87.5%, respectively. For precise criteria, the preflared procedure increased the percentage of accurate electronic readings for the Root ZX and the Mini Apex Locator (P < .05). For acceptable criteria, no differences were found among Root ZX, Elements Diagnostic Unit and Apex Locator, and Mini Apex Locator (P > .05). Fisher test indicated the lower accuracy for Apex DSP (P < .05). CONCLUSIONS: The Root ZX and the Mini Apex Locator devices increased significantly the precision to determine the real working length after the preflaring procedure. All the EALs showed an acceptable determination of the working length between the ranges of+/-0.5mm except for the Apex DSP device, which had the lowest accuracy.

Periodontite apical induzida em cães: efeito do tratamento endodôntico. Estudo microbiológico, tomográfico e de microscopia confocal / Induced apical periodontitis induced in dogs: effect of the endodontics treatment. Microbiological, tomographic and confocal microscopy study

Este trabalho teve o objetivo de avaliar a capacidade da bactéria Enterococcus faecalis em induzir periodontite apical no modelo experimental canino; verificar se o preparo químico-mecânico afeta a sobrevivência dessa bactéria no sistema de canais radiculares e avaliar o reparo desses dentes por meio de radiografia periapical e tomografia computadorizada cone beam. Dentes com e sem tratamento endodôntico foram avaliados por meio de microscopia confocal de varredura a laser. Para tal, foram utilizados 2 cães. A bactéria Enterococcus faecalis foi inoculada nos canais de 4 pré-molares superiores, 11 prémolares inferiores e 9 incisivos superiores. As câmaras pulpares foram seladas e, após 60 dias, os canais das raízes distais dos pré-molares e de 7 incisivos superiores foram submetidos a tratamento endodôntico em sessão única e os canais das raízes mesiais dos pré-molares e 2 incisivos superiores foram deixados sem tratamento (controle). Amostras microbiológicas foram feitas antes e após o preparo químico-mecânico. O reparo foi avaliado após 6 meses do tratamento mediante radiografias periapicais e por tomografia computadorizada cone beam. A comparação entre as imagens obtidas após o período experimental pelos 2 métodos foi feita por medições da área em mm2 de cada lesão encontrada, utilizando o software ImageTool Os resultados mostraram que a presença de periodontite apical crônica foi verificada em todos os dentes inoculados, independentemente da colonização pela bactéria Enterococcus faecalis ou pela flora mista. O preparo químico-mecânico reduziu significativamente o número de bactérias no interior dos canais radiculares (p<0.05). Os resultados radiográficos e tomográficos demonstraram lesões de menor diâmetro nos dentes tratados endodonticamente em...

The aims of this study were to evaluate the Enterococcus faecalis ability to induce apical periodontitis in dogs root canals, to verify the bacterias ability to survive to the cleaning and shaping procedures and to assess the healing of the induced apical periodontitis by periapical radiograph and cone beam computed tomography. Also, endodontically treated and non-treated teeth were evaluated by confocal laser scanning microscope. Two mongrel dogs were used in the experiment. Enterococcus faecalis strain was inoculated into the root canals of 4 maxillary premolars, 11 mandibular premolars and 9 maxillary incisors. After 60 days the root canals of the distal roots of the mandibular and maxillary pre-molars and 7 maxillary incisors were endodontically treated. The premolars mesial root canal and 2 maxillary incisors were used as control (no treatment). Microbiologic samples were done after and before the cleaning and shaping procedure. The healing was evaluated after 6 months by periapical radiographs and cone beam computed tomography. The comparison between obtained images after the experimental period by the two methods was done using measures of the lesion area in mm2 with ImageTool software. The results showed the presence of chronic apical periodontitis in every inoculated teeth, with Enterococcus faecalis or mixed infection. The cleaning and shaping procedures reduced the number of bacteria of the root canals (p<0.05). The radiographic and tomographic results showed the lower diameter lesion in endodontically treated teeth than in the control group (p<0.05). The comparison between the methods showed statistical difference and greater radiolucent areas were evident in cone beam computed tomography images (p<0.05). It is possible to conclude that the bacteria Enterococcus faecalis induced chronic apical periodontitis as well as the mixed microflora; the endodontic treatment reduced the number of cultivable bacteria in a significant way, ...

Confocal laser scanning microscopy is appropriate to detect viability of Enterococcus faecalis in infected dentin.

The purpose of this study was to explore the potential of confocal laser scanning microscopy (CLSM) for in situ identification of live and dead Enterococcus faecalis in infected dentin. Eight cylindrical dentin specimens were infected with Enterococcus faecalis in BHI for 21 days. After the experimental period, the specimens were stained with fluorescein diacetate (FDA) and propidium iodide (PI) or acridine orange (0.01%) and analyzed by CLSM. Two noninfected dentin specimens were used as negative controls. CLSM analysis shows that the discrimination between viable (green) and dead (red) bacteria in infected dentinal tubules could be observed after staining with FDA/PI. Acridine orange was able to show metabolic activity of the E. faecalis cells inside the dentinal tubules showed by its red fluorescence. The viability of bacteria in infected dentin can be determined in situ by CLSM. FDA/PI and acridine orange are useful for this technique.