Assessing apical transportation in curved canals: comparison between cross-sections and micro-computed tomography

The aim of this study was to compare two methods of assessing apical transportation in curved canals after rotary instrumentation, namely, cross-sections and micro-computed tomography (mu CT). Thirty mandibular molars were divided into two groups and prepared according to the requirements of each method. In G1 (cross-sections), teeth were embedded in resin blocks and sectioned at 2.0, 3.5, and 5.0 mm from the anatomic apex. Pre- and postoperative sections were photographed and analyzed. In G2 (mu CT), teeth were embedded in a rubber-base impression material and scanned before and after instrumentation. Mesiobuccal canals were instrumented with the Twisted File (TF) system (SybronEndo, Orange, USA), and mesiolingual canals, with the Endo Sequence (ES) system (Brasseler, Savannah, USA). Images were reconstructed, and sections corresponding to distances 2.0, 3.5, and 5.0 mm from the anatomic apex were selected for comparison. Data were analyzed using Mann-Whitney's test at a 5% significance level. The TF and ES instruments produced little deviation from the root canal center, with no statistical difference between them (P > 0.05). The canal transportation results were significantly lower (0.056 mm) in G2 than in G1 (0.089 mm) (p = 0.0012). The mu CT method was superior to the cross-section method, especially in view of its ability to preserve specimens and provide results that are more closely related to clinical situations.

Morphologic micro–computed tomography analysis of mandibular premolars with three root canals

Introduction: This study aimed to describe the anatomy of mandibular premolars with type IX canal configuration by using micro–computed tomography. Methods: Mandibular premolars with radicular grooves (n = 105) were scanned, and 16 teeth with type IX configuration were selected. Number and location of canals, distances between anatomic landmarks, occurrence of apical delta, root canal fusion, and furcation canals, as well as 2-dimensional (area, perimeter, roundness, major and minor diameters) and 3-dimensional (volume, surface area, and structuremodel index) analysis were performed. Data were statistically compared by using analysis of variance and Kruskal-Wallis tests (a = 0.05). Results: Overall, specimens had 1 root with a main canal that divided into mesiobuccal, distobuccal, and lingual canals at the furcation level. Mean length of the teeth was 22.9 2.06 mm, and the configuration of the pulp chamber was mostly triangle-shaped. Mean distances from the furcation to the apex and cementoenamel junction were 9.14 2.07 and 5.59 2.19 mm, respectively. Apical delta, root canal fusion, and furcation canals were present in 4, 5, and 10 specimens, respectively. No statistical differences were found in the 2-dimensional and 3-dimensional analyses between root canals (P > .05). Conclusions: Type IX configuration of the root canal system was found in 16 of 105 mandibular premolars with radicular grooves. Most of the specimens had a triangle-shaped pulp chamber. Within this anatomic configuration, complexities of the root canal systems such as the presence of furcation canals, fusion of canals, oval-shaped canals in the apical third, small orifices at the pulp chamber level, and apical delta were also observed

A preliminary study of the antibacterial potential of cetylpyridinium chloride in root canals infected by E. faecalis

The aim of this preliminary study was to verify the antibacterial potential of cetylpyridinium chloride (CPC) in root canals infected by Enterococcus faecalis. Forty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. The teeth were randomly assigned to the following groups: 1: Root canal preparation (RCP) + 0.1% CPC with positive-pressure irrigation (PPI, Conventional, NaviTip®); 2: RCP + 0.2% CPC PPI; 3: RCP + 2.5% NaOCl PPI; 4: RCP + 2.5% NaOCl with negative-pressure irrigation system (NPI, EndoVac®); 5: Positive control; and 6: Negative control. Four teeth of each experimental group were evaluated by culture and 4 by scanning electron microscopy (SEM). In all teeth, the root canals were dried and filled with 17% EDTA (pH 7.2) for 3 min for smear layer removal. Samples from the infected root canals were collected and immersed in 7 mL of Letheen Broth (LB), followed by incubation at 37°C for 48 h. Bacterial growth was analyzed by turbidity of culture medium and then observed with a UV spectrophotometer. The irrigating solutions were further evaluated for antimicrobial effect by an agar diffusion test.The statistical data were treated by means, standard deviation, Kruskal-Wallis test and analysis of variance. Significance level was set at 5%. The results showed the presence of E. faecalis after root canal sanitization. The number of bacteria decreased after the use of CPC. In the agar diffusion test, CPC induced large microbial inhibition zones, similar to 2% chlorhexidine and large than 2.5% NaOCl. In conclusion, cetylpyridinium chloride showed antibacterial potential in endodontic infection with E. faecalis.

Beschreibung einer im Winter 1841 gemachten Reparatur einer Schleuse des Schleswig-Holsteinischen Canals : nebst allgemeinen Bemerkungen über Winterbauten steinerner Werke an und im Wasser

von J. C. v. Lund

In vitro activity of photoactivated disinfection using a diode laser in infected root canals

OBJECTIVE To investigate the lethal activity of photoactivated disinfection (PAD) on Enterococcus faecalis (ATCC 29212) and mixed populations of aerobic or anaerobic bacteria in infected root canals using a diode laser after the application of a photosensitizer (PS). MATERIALS AND METHODS First, the bactericidal activity of a low power diode laser (200 mW) against E. faecalis ATCC 29212 pre-treated with a PS (toluidine blue) for 2 min were examined after different irradiation times (30 s, 60 s and 90 s). The bactericidal activity in the presence of human serum or human serum albumin (HSA) was also examined. Second, root canals were infected with E. faecalis or with mixed aerobic or anaerobic microbial populations for 3 days and then irrigated with 1.5% sodium hypochlorite and exposed to PAD for 60 s. RESULTS Photosensitization followed by laser irradiation for 60 s was sufficient to kill E. faecalis. Bacteria suspended in human serum (25% v/v) were totally eradicated after 30 s of irradiation. The addition of HSA (25 mg/ml or 50 mg/ml) to bacterial suspensions increased the antimicrobial efficacy of PAD after an irradiation time of 30 s, but no longer. The bactericidal effect of sodium hypochlorite was only enhanced by PAD during the early stages of treatment. PAD did not enhance the activity of sodium hypochlorite against a mixture of anaerobic bacteria. CONCLUSIONS The bactericidal activity of PAD appears to be enhanced by serum proteins in vitro, but is limited to bacteria present within the root canal.

Voyage à la Nouvelle Guinée, dans lequel on trouve la description des lieux, des observations physiques & morales, & des détails relatifs à l'histoire naturelle dans le regne animal & le regne végétal

par M. Sonnerat, sous-commissaire de la marine, naturaliste, pensionnaire du roi, correspondant de son cabinet & de l'Académie Royale des Sciences de Paris, associé de celles des Sciences, des Beaux-Arts et Belles-Lettres de Lyon

Furs, capitols, prouisions e actes de cort fets y atorgats per la S.C.R.M. del rey Don Phelip ... : en les Corts generals per aquell celebrades als regnicols de la ciutat y regne de Valencia en la vila de Monço en lo any MDLXIIII

Hay un ejemplar encuadernado con: Furs, capitols, prouisions e actes de Cort (XVI/6).

Furs nous del regne de Valencia e capitols ordenades per lo rey don Fernando II en la Cort general de Oriola XXXI de juliol de Any de la natiuitat de nostre senyor ... M.cccc.lxxxvIII

Incunable de la Biblioteca de Nicolau Primitiu

Furs, capitols, prouisions e actes de cort fets y atorgats per la S.C.R.M. del rey don Phelip ... : en les corts generals per aquell celebrades als regnicols de la ciutat y regne de Valencia en la vila de Monço en lo any MDLXXXV

Hay un ejemplar encuadernado con: Furs, capitols, prouisions e actes de Cort (XVI/4).

Institucions dels furs y privilegis del regne de Valencia eo summari e reportori de aquells

Colofón

Reportori general y breu sumari per orde alphabetich de totes les materies dels Furs de Valencia, fins les Corts del any 1604 inclusiue y dels priuilegis de dita ciutat y regne ab vna taula al principi ...

Colofón

Canals Ilustrada : historia de las personas venerables y Varones Ilustres que han avido (sic) naturales de la Universidad de Canals en el Reyno de Valencia

Sign.: [calderon]-2[calderon]4, 3[calderon]2, A-G4, H3

Trobes de mosen Jaume Febrer ... : en que tracta dels llinatges de la conquista de la Ciutat de Valencia e son Regne ...

Incluye 14 h. con los escudos de los apellidos de los conquistadores

Sentencia donada per lo inclit, y serenissim Rey en Iaume, sobre los delmes, è primicies ab vna summa de la presa de Valencia, y de tot lo Regne

Contiene: pequeña biografía del rey Jaime I y una Real Carta sobre Real patrimonio de 1696