This aim of this study was to evaluate and compare the efficacy of different chemical methods to disinfect gutta-percha cones (GP). Eighty-six size 80 GP cones were used. The cones were contaminated by immersion in saliva and Enterococcus faecalis. Four chemical agents were used: 1% sodium hypochlorite (G1), 2% chlorhexidine gluconate (G2), 10% povidone iodine (G3) and 0.9% saline solution (G4). GP cones were immersed in the solutions for periods of 1 and 10 min. After the disinfection procedure, the cones were incubated in blood heart infusion and the presence of bacterial growth was analysed by turbidity of the medium. In G4, bacterial growth was observed in all specimens; G3 showed growth after immersion for 1 min when contaminated with E. faecalis; G1 showed diverse results after the immersion for 1 min. Meanwhile, G1 and G3 after 10 min, and G2 at both times evaluated did not show bacterial growth. The immersion of GP cones in 2% chlorhexidine gluconate for 1 min was an effective method for GP disinfection, while 10% povidone iodine and 1% sodium hypochlorite needed 10 min of immersion to disinfect the GP.

The aim of this study was to determine the minimum inhibitory concentration (MIC) of iodoform, calcium hydroxide, IKI (iodine potassium iodine) and CFC (ciprofloxacin, Flagyl (metronidazole) and calcium hydroxide) required to kill S. aureus, Pseudomonas aeruginosa, Enterococcus faecalis and B. fragilis. In the experiment, medicaments were added to bacterial species into test tubes, in 10 different concentrations. The MIC was the lowest concentration of the drug at which bacterial growth could not be observed. In this investigation, CFC was the most effective medicament against all bacteria. All drugs were able to eliminate E. faecalis and B. fragilis, while IKI was not effective against S. aureus. IKI and calcium hydroxide were not able to eliminate P. aeruginosa as well.

ObjectiveThe aim of this study was to evaluate the in vitro action of ProTaper retreatment files and ProTaper Universal in the retreatment of mandibular premolars. Material and methodsThe amount of debris extruded apically was measured and the time to reach the working length and to complete the removal of gutta-percha was observed. Thirty teeth had their canals prepared using ProTaper Universal files and were obturated by the single cone technique. The teeth were then stored at 37ºC in a humid environment for 7 days. During the use of the rotary instruments for root canal filling removal, the apical portions of the teeth were attached to the open end of a resin tube to collect the apically extruded debris. ResultsProTaper Universal files were significantly faster (p=0.0011) than the ProTaper retreatment files to perform gutta-percha removal, but no significant difference was found between the files regarding the time to reach the working length or the amount of apical extrusion. ConclusionsProTaper Universal rotary had better results for endodontic retreatment, and both techniques promote similar apical extrusion of debris.

Purpose: This study evaluated the inflammatory reaction caused by the implantation of iodoform and calcium hydroxide in the back of rats. These drugs may be used as intracanal dressings to eliminate residual bacteria of the root canal system. Methods: Twenty albinic rats (Rattus norvegicus, var Wistar) were divided into four groups: control group 1 (CG1) had normal skin; control group 2 (CG2) had wounded tissue without drugs; in groups 3 and 4, iodoform (IG) and calcium hydroxide (CHG) were inserted into the wounds, respectively. After 3, 5 and 11 days, slices of the implanted areas were macroscopically and microscopically observed regarding to their qualitative and quantitative aspects.Results: In the macroscopical analysis, the CHG showed a large area of necrosis and swelling, which progressively decreased; in the IG the presence of iodoform surrounded by normal tissue was observed. The qualitative and quantitative histological analysis showed that IG promoted a shorter delay in the inflammatory response than the CHG.Conclusion: The inflammatory reaction for iodoform had a peak period five days after the drug insertion. By comparison, calcium hydroxide showed a very large area of necrosis that could only be partially eliminated after eleven days.Key words: Calcium hydroxide; Endodontics; inflammation; iodoform ResumoObjetivo: O objetivo deste estudo foi avaliar a resposta inflamatória causada pela implantação do iodofórmio ou hidróxido de cálcio em dorso de ratos. Estas drogas podem ser usadas como curativo intracanal para eliminar bactérias residuais do sistema de canal radicular.Metodologia: Foram utilizados 20 ratos albinos (Rattus norvegicus, var Wistar) e divididos em 4 grupos: grupo controle 1 (CG1) representado por tecido normal íntegro; grupo controle 2 (CG2) com ferida e sem medicação; nos grupos 3 e 4, Iodofórmio (IG) e hidróxido de cálcio (CHG) foram, respectivamente, inseridos nas feridas. Após três, cinco e onze dias, cortes microscópicos das áreas implantadas foram observados macroscópica e microscopicamente quanto a seus aspectos qualitativos e quantitativos.Resultados: Na análise macroscópica, o CHG mostrou uma grande área de necrose e edema, o que diminuiu progressivamente, no GI, a presença de iodofórmio rodeada por tecido normal foi observado. A análise qualitativa e quantitativa histológica mostrou que IG promoveu um prazo mais curto na resposta inflamatória do que o CHG.Conclusão: A reação inflamatória de iodofórmio teve um período de pico de cinco dias após a inserção de drogas. Em comparação, o hidróxido de cálcio mostrou uma grande área de necrose que só poderia ser parcialmente eliminada após onze dias.