OBJECTIVES: The purpose of our study was to determine the quality and quantity of leachable residual (co)monomers and additives eluted from various commercial dental composite resins after polymerization. METHODS: Polymerized specimens from four universal hybrid-type composite resins were eluted for 3 days with methanol resp, water. Then all extracts were analysed by gas chromatography/mass spectrometry or liquid chromatography/mass spectrometry using a particle beam interface. RESULTS: In all polymerized composite resin specimens,(co)monomers and various additives as well as contaminants from manufacturing processes were identified. Almost every compound detected in the unpolymerized resins could also be identified in the methanol extracts, but only a few of them were found in the water extracts. From these the co-monomer TEGDMA was extracted in quantities higher than those reported to be cytotoxic in primary human oral fibroblast cultures. CONCLUSIONS: From our results we conclude that the extractable quantities of composite resin components should be minimized, either by reducing the mobility of leachable substances within the set material or by applying less water-soluble components. Furthermore, all ingredients of a dental composite should be declared by the manufacturers, in order to identify those substances in a product which may cause adverse side effects in patients and dental personnel.

Reuse of electrophysiology catheters is an important cost-saving option for many laboratories. However, to be reused safely, catheters must undergo resterilization with ethylene oxide (EtO). Residual EtO levels on resterilized catheters may be high and could pose a risk to patients. Resterilized diagnostic electrophysiology catheters were tested for residual EtO using headspace gas chromatography after both a standard resterilization with an aeration process and after a resterilization process that incorporated a detoxification period. The Food and Drug Administration's maximum permissible level of EtO for implantable products, 25 parts per million (ppm), was used as the cutoff for acceptable catheter residuals. At day 2 after standard resterilization, the residual level of EtO on catheters was high at 41 +/- 6 ppm. However, these levels decreased with shelf time, decreasing to 26 +/- 3 ppm by day 7 and to 14 +/- 2 ppm by day 14 after sterilization, at which time all catheters were <25 ppm (p <0.001). Detoxification periods of 6, 12, and 15 hours were tested and 15 hours was found to be optimal. After 15 hours of detoxification, residual EtO was 19 +/- 1 ppm by day 2 and all catheters were <25 ppm. In summary, electrophysiology catheters that have undergone resterilization have residual EtO levels that are twice the Food and Drug Administration's limit for implantable products. Residual EtO levels may be substantially reduced either by allowing a 14-day waiting period after resterilization or by incorporating a detoxification period immediately after EtO exposure.

A 23-year-old comatose man who had drunk an unknown amount of ethylene glycol was admitted to the hospital 5 hours after ingestion. The initial plasma ethylene glycol concentration was 116.2 mg/100 ml. A severe metabolic acidosis was present. Despite aggressive therapy with ethanol, hemodialysis, and intensive care support, the patient died 27 hours after poisoning. The plasma ethylene glycol concentration immediately before death was 35.9 mg/100 ml. Brain edema and acute renal tubular necrosis were evident at postmortem examination. Oxalate crystals were identified in both organs. Ethylene glycol content or concentration was determined in tissues and biologic fluids.