Factors affecting the viscosity of sodium hypochlorite and their effect on irrigant flow.

AIM: To assess the influence of concentration, temperature and surfactant addition to a sodium hypochlorite solution on its dynamic viscosity and to calculate the corresponding Reynolds number to determine the corresponding flow regimen. METHODOLOGY: The dynamic viscosity of the irrigant was assessed using a rotational viscometer. Sodium hypochlorite with concentrations ranging from 0.6% to 9.6% was tested at 37 and 22 °C. A wide range of concentrations of three different surfactants was mixed in 2.4% sodium hypochlorite for viscosity measurements. The Reynolds number was calculated under each condition. Data were analysed using two-way anova. RESULTS: There was a significant influence of sodium hypochlorite concentration (P < 0.001) and temperature (P < 0.001) on dynamic viscosity: the latter significantly increased with sodium hypochlorite concentration and decreased with temperature. A significant influence of surfactant concentration on dynamic viscosity (P < 0.001) occurred, especially for high surfactant concentrations: 6.25% for benzalkonium chloride, 15% for Tween 80 and 6.25% for Triton X-100. Reynolds number values calculated for a given flow rate (0.14 mL s(-1)), and root canal diameter (sizes 45 and 70) clearly qualified the irrigant flow regimen as laminar. CONCLUSIONS: Dynamic viscosity increased with sodium hypochlorite and surfactant concentration but decreased with temperature. Under clinical conditions, all viscosities measured led to laminar flow. The transition between laminar and turbulent flow may be reached by modifying different parameters at the same time: increasing flow rate and temperature whilst decreasing irrigant viscosity by adding surfactants with a high value of critical micellar concentration.

Low early gallstone recurrence rate after successful extracorporeal lithotripsy in patients with solitary stones.

Piezoelectric lithotripsy with the EDAP LT-01 machine combined with adjuvant bile acid therapy results in complete clearance of radiolucent gallstones in selected patients. We assessed stone recurrence rate in 84 patients with complete clearance of stone fragments and followed up at least 12 months after cessation of bile acid therapy (mean 17 months, range 12-33). Fifty-four patients had a solitary stone and 30 multiple stones. Bile acid therapy was continued for 3 months after complete fragment stones clearance which was ascertained by two consecutive ultrasound examinations. Stone recurrence was assessed by ultrasonography at 6 and 12 months, and then at least once a year. Gallstone recurrence occurred in 5 patients (6%) between 9 and 12 months with no further recurrence up to 33 months. The rate of recurrence at one year was 3.7% in patients with a solitary stone and 10% in patients with multiple stones. Only one patient with stone recurrence had recurrent biliary pain. We concluded that early gallstone recurrence rate after successful lithotripsy seems to be low in patients with solitary stones.

[Fabry's disease. Carbamazepine therapy in acrodyniform syndrome]. / La maladie de Fabry. Traitement du syndrome acrodyniforme par la carbamazepine.

A 19 year old male affected with Fabry's disease suffered from severe nervous manifestations. Despite very peculiar pains of the extremities, the diagnosis has been missed for a long time and was painted out at this age because of sharp reconstitution of the family history. Fabry's disease was confirmed by discovering typical corneal lesion, a low leucocyte (W.B.C.) alpha-galactosidase activity and foam cells in renal glomerular epithelium. The importance of an early diagnosis is obvious in this case: 10 Instead of degrading narcotic therapy, Carbamazepin brought forward normal social and school living. 20 Familial investigations show up that all the siblings were affected (three boys including the propositus)--several symptoms were found in the heterozygous conductor mother. Despite the rarety of Fabry's disease, the authors emphasize the easiness of diagnosis on simple clinical and biochemical grounds. The authors insist on the symptomatic and therapeutic action of Carbamazepin or Diphenytoin in order to prevent painfull symptoms which often appear during initial course of the disease.