RESUMO
AIM: To compare the effects of three instrumentation systems, and a supplementary approach with a finishing instrument, on filling material removal during retreatment of mandibular molar canals. METHODS: Sixty mesial canals from mandibular molars (Vertucci's type IV anatomy) were instrumented, filled and subjected to retreatment. After initial removal of the root canal filling material using the D-RaCe system, the canals were randomly distributed into three groups (n = 20) according to the instrument system used for preparation: the Self-Adjusting File (SAF), TRUShape or XP-endo Shaper. The filling material volume in the apical 5 mm of the canals was assessed by means of micro-computed tomography (micro-CT) before and after retreatment. All specimens with residual filling material were subjected to a supplementary approach with the XP-endo Finisher R instrument and another micro-CT scan was taken. Data on the volumes of filling material and incidence of total removal were compared between groups by the general linear model for paired data and the Fisher's exact test. The effects of the refinement step were evaluated by the Wilcoxon Signed Ranks test. RESULTS: The amount of removed material was 92.4%, 96.9% and 96.9% for the SAF, TRUShape and XP-endo Shaper, respectively. There were no significant differences between them (P > 0.05). Canals were completely cleaned of filling material in 70% of the specimens for XP-endo Shaper, 55% for SAF and 30% for TRUShape; the difference between XP-endo Shaper and TRUShape was significant (P = 0.03). The supplementary step with the XP-endo Finisher R instrument was associated with additional filling material removal of 38% (P < 0.001). Six more canals were rendered free of filling material after using this finishing instrument. CONCLUSIONS: The tested systems were equally effective in removing the mass of filling material from the apical 5 mm of molar canals. The supplementary step with the XP-endo Finisher R instrument enhanced filling material removal.
Assuntos
Materiais Restauradores do Canal Radicular , Preparo de Canal Radicular , Cavidade Pulpar , Dente Molar , Retratamento , Microtomografia por Raio-XRESUMO
AIM: To evaluate in vivo the antibacterial effectiveness of the self-adjusting file (SAF) using molecular methods. METHODOLOGY: Root canals from single-rooted teeth with apical periodontitis were instrumented using the SAF system under continuous irrigation with 2.5% NaOCl. DNA extracts from samples taken before and after instrumentation were subjected to quantitative analysis of total bacteria counts and levels of streptococci by quantitative real-time polymerase chain reaction (qPCR). The reverse-capture checkerboard assay was also used to identify 28 bacterial taxa before (S1) and after (S2) SAF instrumentation. SAF was also compared with a conventional hand nickel-titanium instrumentation technique for total bacterial reduction. Data from qPCR were analysed statistically within groups using the Wilcoxon matched pairs test and between groups using the Mann-Whitney U-test and the Fisher's exact test, with significance level set at P < 0.05. RESULTS: Self-adjusting file significantly reduced the total bacterial counts from a mean number of 1.96 × 10(7) cells to 1.34 × 10(4) cells (P < 0.001). Quantitatively, the 99.9% reduction in total bacterial counts associated with the SAF system was significantly superior to the 95.1% reduction obtained by hand instrumentation (P < 0.001). Qualitatively, SAF resulted in significantly more cases with negative PCR results for bacteria (54.5%) than hand instrumentation (4.5%) (P < 0.001). The SAF system succeeded in significantly reducing the streptococcal levels, but four cases still harboured these bacteria in S2. Checkerboard analysis revealed that not only streptococci but also some anaerobic and even as-yet-uncultivated bacteria may resist the effects of chemomechanical procedures. CONCLUSION: The SAF instrumentation system was highly effective in reducing bacterial populations from infected root canals and performed significantly better than hand instrumentation. However, because half of the samples still had detectable bacteria after preparation with SAF, supplementary disinfection is still required to maximize bacterial elimination.
Assuntos
Cavidade Pulpar/microbiologia , Periodontite Periapical/microbiologia , Periodontite Periapical/cirurgia , Preparo de Canal Radicular/instrumentação , Carga Bacteriana , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Irrigantes do Canal Radicular/farmacologia , Hipoclorito de Sódio/farmacologiaRESUMO
AIM: Bacterial reduction in oval-shaped root canals by a single-instrument technique was compared ex vivo with a conventional nickel-titanium rotary technique. Data obtained from two quantification methods, quantitative real-time polymerase chain reaction (qPCR) and culture, were also compared. METHODOLOGY: Oval-shaped canals of extracted teeth contaminated with Enterococcus faecalis were instrumented using either a single Reciproc instrument or the BioRaCe instrument series. Bacteriological samples were taken before (S1) and after instrumentation (S2). Bacterial quantification was performed using qPCR and culture. RESULTS: Intragroup analysis showed that both protocols promoted a highly significant bacterial reduction (P < 0.001). Intergroup analysis (S2 samples) showed no significant differences between the two instrumentation systems (P > 0.05). As for the quantification methods, qPCR revealed significantly higher counts of E. faecalis in S1 than culture (P < 0.05), but no significant differences occurred for S2 (P > 0.05). CONCLUSION: The single-file technique was comparable with the conventional technique in oval-shaped canals provided the width of apical preparation, volume of irrigants and duration of irrigation are kept similar. No significant difference was observed for qPCR and culture in post-instrumentation samples, indicating that both methods can be reliably used for studies of antibacterial effectiveness.
Assuntos
Cavidade Pulpar/microbiologia , Enterococcus faecalis/isolamento & purificação , Preparo de Canal Radicular/instrumentação , Carga Bacteriana , Técnicas Bacteriológicas , Dente Pré-Molar/microbiologia , Biofilmes , Ligas Dentárias/química , Ácido Edético/uso terapêutico , Desenho de Equipamento , Humanos , Incisivo/microbiologia , Teste de Materiais , Microscopia Eletrônica de Varredura , Níquel/química , Reação em Cadeia da Polimerase em Tempo Real , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Rotação , Camada de Esfregaço , Hipoclorito de Sódio/uso terapêutico , Titânio/químicaRESUMO
The title compounds, C(17)H(13)FN(2)O(3) and C(18)H(16)N(2)O(4), are new potent aromatase inhibitors combining the common features of second- and third-generation nonsteroid anti-aromatase compounds. The molecules have a propeller shape, with dihedral angles between adjacent planes in the range 49-86°. A quantum mechanical ab initio Roothaan-Hartree-Fock calculation for the isolated molecules shows values for these angles close to the ideal value of 90°. Docking studies of the molecules in the aromatase substrate show that their strong inhibitor potency can be attributed to molecular flexibility, hydrophobic interactions, heme Fe coordination and hydrogen bonding.
Assuntos
Inibidores da Aromatase/química , Inibidores da Aromatase/farmacologia , Benzodioxóis/química , Imidazóis/química , Cristalografia por Raios X , Ligação de Hidrogênio , Estrutura Molecular , Teoria QuânticaRESUMO
The title compound, C(19)H(26)O(2), a B-norandrogen with a 6beta-methyl group, is a recently identified and experimentally tested potent new aromatase inhibitor. It shares structural and physicochemical similarities both with the natural substrate of the enzyme, androstenedione, and with exemestane, another potent aromatase inhibitor having a 6-methylidene group. X-ray diffraction results indicate that the B-nor molecule and exemestane have nearly the same oxygen-oxygen and methyl-methyl separations, though they have distinct configurations of the hydrophobic groups at the 6-position. These structural comparisons allow correlations to be inferred between the active site geometry of the molecules and the aromatase inhibition power of the studied compound.
Assuntos
Androstadienos/química , Androstenodiona/química , Inibidores da Aromatase/química , Noresteroides/química , Androstenodiona/farmacologia , Inibidores da Aromatase/farmacologia , Sítios de Ligação , Catálise , Cristalografia por Raios X , Estrutura Molecular , Ligação Proteica , Difração de Raios XRESUMO
The International Classification of Diseases (ICD) provides codes for all conditions and permits international comparisons of morbidity and mortality. Because it has to be used all over the world its codes are not always perfectly appropriate. There are revisions from time to time to bring up-to-date the classification. This has happened with AIDS, included in the chapter of infectious diseases in the last revision, ICD-10. The use of ICD-10 AIDS codes is here appraised. All surveillance report forms of one specialized hospital in infectious diseases, notified in 1994, have been codified, but it was found that many diagnoses could not be codified in accordance with a single ICD-10 AIDS code.