Whatever the technique used for root canal instrumentation; a layer of debris termed “smear layer” is formed. This is a layer composed of an organic and inorganic substance and it harbors bacteria and their by-products. Removing the smear layer enhances the cleaning and disinfecting of root canal walls and grant maximum adaptation of root canal filling materials. Nonetheless, the existence of smear layer can seal the dentinal tubules and decrease the probability of dentinal tubule’s invasion by bacteria and their toxins, this issue is still controversial. Smear layer removal approaches including chemical, ultrasonics, and laser have been widely studied. However, none of them is entirely efficient along the length of all canals or is universally recognized. If the decision was to remove smear layer, irrigating root canals with EDTA followed by NaOCl will fulfill the objective. It is still debatable whether the removal of smear layer will decrease the apical leakage or not. Additional research is required to determine the consequence of removing or preserving the smear layer.

Background and aims: Human immunodeficiency virus infect cell of immune system, destroying or impairing their function. Infection with virus result in progressive deterioration of the immune system, leading to immune deficiency. This study aims to assess the knowledge level of perceptions who were working with HIV patient who were attending the hemodialysis unit in Airport Road Polyclinic 2018. Methods: In this study descriptive cross-sectional survey was done in hemodialysis unit in Airport Road Polyclinic, conducted in the period from first of December 2018 to 12th December 2018. The study included 70 health workers in Airport Road Polyclinic and agreed to answer the questioner. The questioner includes socio-demographic data general knowledge, mode of transmission and prevention of HIV. Results: Out of 70 participants, 23 were males and 47 were females, general knowledge about the disease was considered to be good (73%) in the same time less than half of participants (43%) had good score regarding the mode of HIV transmission, and (65%) of participants had good score level about the prevention of HIV. Health institute was found to be the most important source of knowledge among participants in this day, followed by read material, then TV, and lastly religious institutes. Conclusion: Structured education in the form of school curricula, health talks / seminars, in service training, and continuous education should be targeted at the medical staff. The role of television channels should be emphasized in distributing accurate, active and effective massage to the population, especially the younger age groups about sexually transmitted diseases. These massages should match social norms and religious values.