The advantages and disadvantages of three forms of dry heat sterilization are discussed. In addition a fourth method, consisting of heating by infrared rays in vacuo, is described. This method is particularly suitable for instruments used in the operating theatre, since it can replace an autoclave where a supply of steam is not available. Recommended times and temperatures for dry heat steriliz...

The major goal of root canal treatment is to remove irritants from the root canal system, to obturate the cleaned and shaped root canals, and to prevent recontamination. Ray and Trope proposed that coronal microleakage may be a major cause of endodontic failure. Many previous studies have examined that coronal leakage might occur, even in well obturated root canals. One of the most important co...

Bacteriological examination of 1,427 samples from a poultry-processing plant over a 2-year period yielded 202 (14.2%) cultures positive for salmonellae. The results indicate that contamination is reduced by washing procedures within the plant but that recontamination of the carcasses occurred in at least two different stages of processing, i.e., during evisceration and chilling. There was evide...

Over the last 20 years chocolate products have been at the origin of several salmonellosis outbreaks involving mainly children. One of the main characteristics are the very low levels of Salmonella normally found in such contaminated products. Due to the low water activity, the pathogens are not able to grow but these conditions provide a good protection leading to increased heat resistance and...

This paper highlights the importance of root canal disinfection. It discusses the different endodontic irrigants available and comments on how these can be used most effectively. Eliminating bacteria from the root canal system is an essential stage in endodontic therapy. An objective of endodontic treatment is removal of diseased tissue, elimination of bacteria from the canal system and prevent...

Materials for wrapping surgical dressings were studied by a method which measured the recontamination rate in packs stored for periods of up to several weeks. Of the materials tested a thick crêpe paper was better than calico and balloon cloth fabrics. Dressings wrapped in paper were not significantly contaminated after storage in dusty places for periods of up to three weeks. For added protect...

The degradation of the carrier lifetime in multicrystalline silicon due to the dissolution of metal precipitates during high temperature annealing is well known. This letter presents evidence indicating that the presence of phosphorus emitters during annealing can help reduce this recontamination. Part of the degradation observed is due to increased interstitial iron concentrations caused by th...

Several point-of-use water treatment interventions have shown the beneficial health effect of drinking water treated and stored in narrow-mouthed, spigoted plastic vessels designed to reduce chlorine decay and limit recontamination.1,2 However, more than 90% of the 43 000 households targeted by the Nyanza Healthy Water Project in western Kenya, Africa, preferred traditional, wide-mouthed clay v...