ABSTRACT
Abstract The present study aims to verify the effect of ozone gas (OZY® System) and high frequency electric pulse (Endox® System) systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p); OZY® System, four 24-second-pulses (OZY 4p); and Endox® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.
Subject(s)
Humans , Oxidants, Photochemical , Ozone , Lipopolysaccharides/analysis , Dental Pulp Cavity/microbiology , Electrocoagulation/methods , Endotoxins/analysis , Escherichia coli , Time Factors , Random Allocation , Reproducibility of Results , Analysis of Variance , Root Canal Preparation , Limulus TestABSTRACT
The present study aimed to determine the feasibility of using bovine teeth as a suitable alternative for human teeth, in experiments involving in vitro endotoxin contamination. Twenty bovine central incisors and 20 human single-root premolars had their dental crowns removed and root lengths set at 16 mm. Root canals were prepared up to #60 K-file size and sterilized with cobalt-60 gamma irradiation (20 kGy, 6 h). The teeth were randomly divided into four groups: G1-bovine teeth (bovine negative control, n = 10), G2-human teeth (human negative control, n = 10), G3-bovine teeth, inoculated withEscherichia coli (055:B55) LPS, and G4-human teeth inoculated with E. coli LPS. The G1 and G2 groups were exposed to apyrogenic water. After the teeth had been incubated at 37 °C and atmospheric humidity for 24 h, the samples of solutions in the main canals were collected with apyrogenic absorbent paper tips. LPS levels were quantified using Limulus Amebocyte Lysate assay. The data obtained were statistically analyzed using one-way ANOVA, with a significance level of 5%. A high amount of endotoxin was detected in the inoculated human teeth (G4) when compared to the sterilized teeth (G2), as well as in the inoculated bovine teeth (G3) when compared to the inoculated human teeth (G4). However, there was no statistical difference between bovine teeth before and after the E. coli endotoxin inoculation. Therefore, under the mentioned experimental conditions, the use of bovine teeth should not be a choice for laboratory research on endotoxin contamination.
Subject(s)
Animals , Cattle , Humans , Dental Pulp Cavity/microbiology , Lipopolysaccharides/analysis , Analysis of Variance , Cobalt/chemistry , Escherichia coli , Feasibility Studies , In Vitro Techniques , Limulus Test , Nephelometry and Turbidimetry/methods , Random Allocation , Reproducibility of Results , Time FactorsABSTRACT
O tratamento endodontico de um dente com polpa necrosada e formação radicular incompleta apresenta dificuldades para a instrumentação e para o bom selamento apical. O objetivo deste trabalho é apresentar um caso clínico em que, por meio da técnica de apicificação, obteve-se sucesso no tratamento de um dente com rizigênese incompleta e necrose pulpar. Além disso, apresenta-se uma revisão de literatura sobre o assunto e discutem-se alguns pontos relevantes. Também é abordada a importância da reabilitação estética e o reforço da estrutura dentária, visto que um dente que tem sua formação radicular incompleta torna-se muito suscetível a fratura. O caso trata de um incisivo central superior com formação radicular incompleta em que um traumatismo gerou uma fratura coronorradicular e, consequentemente necrose pulpar. Por meio de trocas de pasta de hidróxido de cálcio durante sete meses foi possível induzir o término da formação radicular, permitindo a conclusão da endodontia. Em seguida, foi realizada a restauração definitiva com a utilização do fragmento do dente e a reconstrução do restante com resina composta fotopolimerizável. Conclui-se que a apicificação é uma técnica consagrada para o tratamento da rizogênese incompleta, sendo de fácil realização, bem aceita pelos pacientes e apresentando alto índice de sucesso