Study of the aerobic contamination of four disposable materials [anesthetic cartridge, saliva ejector tip, gutta percha and cotton roll]

Today, cross infection control is an integral part of dentistry and many dental health care workers no longer question its necessity. All dental equipments and instruments could be potentially considered as a source of infection. The aim of this study was the evaluation of aerobic contaminations of four disposable materials used in routine dental practice. In this cross-sectional study, random sampling was performed and tryptone soy broth transfer culture medium was used. After 24 hours of incubation, samples were transferred to specific culture media. [Mckangy, Chocolate agar and Blood agar]. Cultured bacteria were stained and studied using gram staining method. The study was carried out in a 17 weeks period. All suction tips were infected with Bacillus cereus bacterium. Two cases of cotton roll samples showed contamination with Bacillus cereus, 2 cases with gram positive, coagulase negative cocci, 1 case with Streptococcus viridians and one case with Enterobacter class A. One case of anesthetic cartridges was contaminated with Staphylococcus epidermidis and two cases with Streptococcus viridians. Two cases of gutta-percha samples were contaminated with Bacillus cereus. Based of the findings of this study, the highest level of contamination was observed in saliva ejector tips. Contamination with Bacillus cereus was seen more frequently

Role of riverine sediment and particulate matter in adsorption of heavy metals

Riverine sediments and suspended matters have been subjected to several bench scale tests for the evaluation of adsorption potential of heavy metals. For this purpose water, sediment and suspended particulate matters of Tadjan River [southern part of the Caspian Sea] were collected. In the vicinity of the river many polluting sources were recognized; for instance, pulp and paper mill, dairy factory and municipal sewage that can introduce various amounts of heavy metals into the river water. Bottom sediments and suspended particulate matters have been individually subjected to adsorption tests. The results of analysis showed that riverine bottom sediments have greater potential for adsorbing heavy metals than suspended matters. However the trend of adsorption in both sediments and suspended matters are similar. Maximum adsorption capacity of heavy metals [in terms of mg of metal per kg of sediments and suspended matters] by sediments and suspended matters are as: Sediments: Cu [2200]> Mn [2000]> Ni [1400]> Zn [320] Suspended matters: Cu [2100]> Ni [1500]> Mn [1200]> Zn [310] Further, results revealed that increasing concentration of metals would cause desorbing Cadmium from both sediments and suspended matters