Cleaning of dental handpieces and associated parameters: Internal and external cleaning, drying and rotation.

PURPOSE: To evaluate the cleaning of dental handpieces and its associated parameters, internal, external cleaning and drying, and rotation, for two washer-disinfectors: Teon+ by W&H, and a dental rack for WD290 by Belimed. METHODS: An original method was developed with resin flags on dental burs to assess the inner rotation during the cleaning cycle. Concerning the cleaning and drying evaluation, three groups (9, 24 and 22 handpieces) were used in different conditions: soiled with Soil Test, soiled with heparinized blood, used in real conditions after a dental procedure, and clean (as control). Cycles were performed with the two washer-disinfectors, followed by a visual evaluation and a biuret reaction test. RESULTS: The method we developed was effective to assess the inner rotation of handpieces. The internal cleaning was successful for real conditions and control handpieces, but unsuccessful for all the artificially soiled handpieces except one. All the handpieces showed substantial humidity on their inner surfaces after cleaning. The internal cleaning of handpieces and its evaluation are both difficult to perform. A questioning about the relevance of some tests required in the ISO 15883 about handpieces requires further study. Cleaning devices and their parameters should be optimized to offer better cleaning skills, and testing-tools should be developed and validated to easily assess their performances. CLINICAL SIGNIFICANCE: Easy-to-use testing tools should be developed and validated, and dental handpiece cleaning tests should be redefined to fit with the reality of practices. According to the actual performance of cleaning, and even though sterilization will largely contribute to the reduction of the infectious risk of internal handpiece structures, it is unclear whether cleaning procedures can ensure totally safe practices.

Breakthrough invasive mould infections in patients treated with caspofungin.

OBJECTIVES: To describe and estimate the rate of breakthrough invasive mould diseases (IMD) in patients receiving caspofungin. METHODS: Retrospective, non-interventional study conducted in three University Hospitals. RESULTS: Nineteen breakthrough infections have been identified including 13 aspergillosis, 2 mucormycosis, a fusariosis, a Hormographiella aspergillata infection and 2 possible IMD. Cases were equally distributed between the centres. Fourteen patients had a haematologic malignancy, four were transplant recipients (allogeneic haematopoietic stem cells in three, liver in one) and one had hepatic cirrhosis. Caspofungin has been prescribed as prophylaxis (n = 3), empirical therapy (n = 9) or directed therapy for candidemia (n = 5) or aspergillosis (n = 2). Aspergillus galactomannan was positive in serum or in bronchoalveolar lavage fluid in 10 of the 13 aspergillosis. Median duration of caspofungin treatment before breakthrough IMD was 15 days. Nine patients died within twelve weeks. Rate of breakthrough IMD in onco-haematology patients has been estimated to 7.3% for all mould infections and to 4.2% when restricted to documented aspergillosis. CONCLUSIONS: Our data call for Aspergillus galactomannan monitoring and close clinical and radiological examination in case of persistence or recurrence of infection signs in high-risk patients receiving caspofungin.

Ventricular bigeminy associated with voriconazole, methadone and esomeprazole.

CASE: We report a case of ventricular bigeminy with concomitant administration of methadone, voriconazole and esomeprazole in a Caucasian woman aged 26 with acute lymphoblastic leukaemia. Plasma concentrations of voriconazole and methadone were high, 12.4 mg/l (therapeutic range: 1-4 mg/l) and 1.6 mg/l (therapeutic range: 0.2-0.4 mg/l), respectively. In the absence of esomeprazole, no more episode of cardiac arrhythmia occurred and 7 days after, methadone plasma concentration fell at 0.57 ml/l while voriconazole concentration was at 5.5 mg/l. We speculate that a pharmacokinetic interaction between methadone and voriconazole was amplified by the addition of esomeprazole. This led to the large increase of the plasma concentration of methadone and was potentially responsible for its cardiac toxicity. CONCLUSION: Physicians should be aware of the potential interaction between voriconazole, esomeprazole and methadone leading to arrhythmia. The inhibitory potential of voriconazole is possibly increased by esomeprazole.