Evaluation of two shaping systems and two sonic irrigation devices in removing root canal filling material from distal roots of mandibular molars assessed by micro CT.

AIM: To compare two preparation systems and two sonic irrigation devices during the removal of root filling material from oval distal canals of extracted mandibular molars. METHODOLOGY: The distal canals in 40 extracted mandibular molars were shaped using the ProTaper Next system (Dentslpy Sirona, Ballaigues, Switzerland), filled with Gutta Percha X2 (Dentsply Sirona), along with AH Plus sealer (Dentsply De Trey, Konstanz, Germany) and randomly divided into two groups (n = 20) according to volume of initial filling, preparation diameter and working length. One group was retreated using the Reciproc system (VDW, Munich, Germany), and the other using the 2Shape system (Micro-Mega, Besançon, France). A micro-CT scan was taken after the initial root filling and after retreatment to evaluate the volume of filling material remnants. The teeth were divided into four groups to test the supplementary effect of two sonic irrigation devices on removing filling material: Eddy (VDW) and MM1500 (Micro-Mega). In the first and second groups, 2Shape was followed subsequently by MM1500 and Eddy; in the third and fourth groups, Reciproc was followed by MM1500 and Eddy. A third micro-CT was taken to compare the remaining root filling material in all groups. Wilcoxon's signed rank tests, Mann-Whitney and Kruskal-Wallis tests were used for statistical analysis. RESULTS: No significant difference was found for the volume of filling material removed between the Reciproc and 2Shape in the entire canal (P = 0.355). The volume dropped significantly from its initial value after removing the bulk of the root filling by 95.8% (from 4.71 to 0.22 mm3 ) with the 2Shape (P < 0.001) and by 94.0% (from 5.05 to 0.33 mm3 ) with the Reciproc (P < 0.001). Sonic activation significantly decreased the residual volume of filling material remnants by 3.21% (P = 0.013) in the first group, 1.38% (P = 0.012) in the second group, 1.83% (P = 0.008) in the third group and 1.83% (P = 0.012) in the fourth group. At the end, the percentage of residual material was not significantly different among the groups in the entire canal (P = 0.163). CONCLUSION: In the distal oval canals of extracted mandibular molar teeth, there was no significant difference between the 2Shape and Reciproc systems in removing gutta-percha/sealer. Sonic activation with MM1500 and Eddy significantly improved filling material removal.

[Pulmonary mucormycosis: difficulties in diagnosis and treatment]. / Mucormycoses pulmonaires: difficultés diagnostiques et thérapeutiques.

INTRODUCTION: Mucormycosis is a rare opportunistic fungal infection due to filamentous fungi of the order Mucorales in the class Zygomycetes. Rhino-cerebral and pulmonary manifestations predominate on account of the airborn spread of the spores. Gastro-intestinal, cutaneous and disseminated disease is less common. The principal risk factors are immuno-suppression and diabetic keto-acidosis. CASE REPORTS: One case of fatal pulmonary mucormycosis and two cases of colonisation illustrate both the extreme severity of this disease and the diagnostic difficulties facing the physician. The ubiquitous nature of the organism leads to frequent colonisation and, moreover, the symptomatology readily mimics that of invasive pulmonary aspergillosis. The diagnosis of mucormycosis can only be confirmed by pathological and mycological examination of biopsy specimens. These requirements conflict with the need for urgent treatment with surgical debridement, amphotericin B and control of the underlying pathology. Sadly the mortality remains very high, between 50 and 80% in published series. CONCLUSION: Currently there is hope of new therapeutic approaches with posaconozole but the ineffectiveness of voriconozole and the echinocandines, used more and more against aspergillus, raises the possibility of an increase in mucormycosis by selection.

Influence of cone beam CT parameters on the output of an automatic edge-detection based endodontic segmentation.

OBJECTIVES: To determine the optimal cone beam computed tomography settings for an automatic edge-detection based endodontic segmentation procedure by assessing the accuracy of the root canal measurements. METHODS: Twelve intact teeth with closed apexes were cut perpendicular to the root axis, at predetermined levels to the reference plane (first section made before acquisition). Acquisitions of each specimen were performed with the "9000 3D®" (76µm, 14 bits) by using different combinations of milliamps and kilovolts. 3 dimensional images were displayed and root canals were segmented with the MeVisLab software (edge-detection based method). Histological root canal sections were then digitized with a 0,5 to 1µm resolution and compared with equivalent 2 dimensional cone-beam reconstructions for each pair of settings using Pearson correlation coefficient, regression analysis and Bland-Altman method for the canal area and Feret's diameter. After a ranking process, a Wilcoxon paired test was done to compare the pair of settings. RESULTS: The best pair of acquisition settings was: 3.2mA/60kV. Significant differences were found between 3.2mA/60kV and other settings (p <0.05) for root canal area and for Feret's diameter. CONCLUSIONS: The quantitative analyses of the root canal system with edge-detection based method could depend on acquisition parameters. Improvements in segmentation still need to be done to ensure the quality of the reconstructions when we have to deal with closer outlines and because of the low spatial resolution.

Influence of CBCT parameters on the output of an automatic edge-detection-based endodontic segmentation.

OBJECTIVES: To determine the optimal CBCT settings for an automatic edge-detection-based endodontic segmentation procedure by assessing the accuracy of the root canal measurements. METHODS: 12 intact teeth with closed apexes were cut perpendicular to the root axis, at pre-determined levels to the reference plane (the first section made before acquisition). Acquisitions of each specimen were performed with Kodak 9000(®) 3D (76 µm, 14 bits; Kodak Carestream Health, Trophy, France) by using different combinations of milliamperes and kilovolts. Three-dimensional images were displayed and root canals were segmented with the MeVisLab software (edge-detection-based method; MeVis Research, Bremen, Germany). Histological root canal sections were then digitized with a 0.5- to 1.0-µm resolution and compared with equivalent two-dimensional cone-beam reconstructions for each pair of settings using the Pearson correlation coefficient, regression analysis and Bland-Altman method for the canal area and Feret's diameter. After a ranking process, a Wilcoxon paired test was carried out to compare the pair of settings. RESULTS: The best pair of acquisition settings was 3.2 mA/60 kV. Significant differences were found between 3.2 mA/60 kV and other settings (p < 0.05) for the root canal area and for Feret's diameter. CONCLUSIONS: The quantitative analyses of the root canal system with the edge-detection-based method could depend on acquisition parameters. Improvements in segmentation still need to be carried out to ensure the quality of the reconstructions when we have to deal with closer outlines and because of the low spatial resolution.

[Inhalation route for administration of systemic drugs]. / Voie inhalée pour l'administration de médicaments à visée systémique.

With aerosolized administration of medicines, direct access to the lung is possible. Depending on the intrapulmonary behavior of each molecule, the aerosol mode of administration makes possible either a pulmonary topical action or a systemic action, thanks to the lung's wide vascular network. An inhaled molecule's pulmonary behavior is not predictable and must be studied on its own. Some medicines with a systemic aim have a topical effect after aerosol administration: furosemide, amiloride, morphine, interferons, cyclosporin and prostacyclin. Other medicines have systemic effects after aerosol administration: insulin, growth hormone, LHRH, calcitonin and nicotine. Heparin can be classified in either group depending on the dose and type of use.

[Legionnaires' disease with acute respiratory insufficiency. Clinical and biological characteristics, comparison with pneumococcal pneumonia]. / Légionelloses avec insuffisance respiratoire aiguë. Particularités cliniques et biologiques, comparaison avec les pneumopathies à pneumocoque.

OBJECTIVES: Legionnaires' disease is one of the main etiologies of bacterial pneumonias because of its frequency as well as its potential severity. The therapeutic choice implies the need to look for distinctive clinical, biological or radiological signs, due to the unreliability of rapid immunological criteria. Pneumococcus is the first cause of bacterial pneumopathy. Thus, identifying the distinctive signs between these two etiologies may be necessary. METHODS: In our restrospective study, nine Legionnaires' disease-related pneumonias were compared with nine pneumococcus-related pneumonias with acute respiratory failure and comparable level of severity. Patients were recruited over a two year period in a medical intensive care unit. RESULTS: Four criteria were found more frequently in pneumonia related to Legionnaires' disease: high-grade fever at the time of admission, elevated transminases, presence of Miller's criteria (converging clinical and biological signs) and increasing creatine kinase. CONCLUSION: In patients with severe pneumonia, both Pneumococcus and Legionella should be entertained as possible diagnoses before starting treatment. A prospective analysis of precise diagnostic criteria is needed to distinguish between these two bacterial diseases.

[Leukotriene antagonists]. / Les antileucotriènes.

Today, medicinal treatment of asthma over the long term is well codified and involves inhaled corticosteroid therapy, in association or not with beta 2-mimetic substances. Numerous studies have demonstrated the importance of leukotrienes in bronchoconstriction and in the delayed inflammatory reaction of asthma. At the same time, antileukotriene molecules are being introduced. Several are sold in different countries. At present, only one product is available in France: Montelukast. It is officially indicated as a complementary treatment of mild to moderate persistent asthma, not sufficiently balanced by inhaled corticosteroid therapy and as a treatment of exercise-induced asthma. In the future, studies should further define the position of these substances in the long term treatment of asthma.

[Aerosols: a re-emerging treatment]. / Les aérosols: thérapeutique en renouveau.

Aerosol drug delivery is widely used by patients with asthma and chronic bronchial obstruction for beta-2 agonists and anticholinergic drugs. More recently, inhaled steroid sprays have also been introduced. The efficacy of easy to use aerosol sprays is well proven and has become an important administration route. Different models of metered dose inhalers with gas propellants or dry powder devices help improve patients compliance. Nebulizers can be used in particular situations. Aerosol administration is proposed for anti-infectious agents and for rhDNase in cystic fibrosis. Aerosol delivery of nucleotides and antiproteases are currently under evaluation. Gene therapy can also benefit from the aerosol route which may be proposed in the near future for many different types of systemic treatments. Possible drugs include cyclosporin for lung grafts, prostacyclin for primary pulmonary hypertension, insulin for diabetes or morphine in certain types of dyspnea.

[In vitro dentinogenesis of mice fetuses tooth germs in the presence of fluoride. Morphological nad historical observations]. / Etude de la dentinogenèse de germes dentaires de faetus de souris cultivés in vitro en présence de fluor. Observations morphologiques et histochimiques.

Observations show that fluoride alters dentinogenesis in vitro. Morphological and cellular alterations are greater when the tooth germs are young and/or when the time of incubation is longer and the dose of fluoride higher. In the predentine, the stainability of proteoglycans is partially reduced. The persistence of alcianophilic zones far from the site of secretion indicates some delay of the process of matricial maturation.

[Cardiac involvement in sarcoidosis. Results of a prospective study of 37 cases]. / L'atteinte cardiaque au cours de la sarcoïdose. Résultats d'une étude prospective sur 37 cas.

An evaluation of the incidence of cardiac lesions in sarcoidosis was conducted in a group of patients with progressive pulmonary signs of the disease. Five non-invasive methods: echocardiogram, ECG, Holter, effort ECG, and thallium scintigraphy were employed on a routine basis; 31 patients were investigated by all procedures, scintigraphy being performed in all 37 cases. First degree auriculoventricular block was detected in only one case, this being compatible with cardiac sarcoidosis, though the possibility of a congenital lesion could not be excluded. The ECG remains an essential investigation among those employed, other examinations not supplying superior data. Scintigraphy appears to be of positive value, as faults in localized uptake were demonstrated in 17 p. cent of cases, these possibly corresponding to intramyocardial granulomas.