A comparison on two disinfectants: Micro10+ and Deconex 53 plus on dental instruments Dr. A. Saboori*- Dr. F. Fallah** - Dr. Dastgerdi*** *- Assistant Professor of Fixed Prosthodontics Dept.-Faculty of Dentistry – Shaheed Beheshti University of Medical Sciences. **- Associate Professor of Immunology Dept. - Faculty of Medicine – Shaheed Beheshti University of Medical Sciences. **- Dentist. Background and Aim: Quaternary Ammonium (QAD) form a group of chemical disinfectants. These compounds were deleted from the list of disinfectants in 1978, but a new generation of them have been produced and presented since 1990. Micro 10+ and Deconex 53 plus are two current samples of this generation. The aim of this study was to investigate the disinfecting effects of Micro 10+ and Deconex 53 plus. Materials and Methods: This descriptive study was performed on 30 subjects referred to Shaheed Beheshti Dental Faculty. A total number of 90 sterilized RCT files were used, 3 for each patient. After oral flora sampling, all samples were transferred to the microbiology laboratory. Lab Bacillus subtilis spore was used as the witness of the study. The contaminated files were cultivated and the existing microorganisms were cleared by coloring technique. The contaminated files were contacted for one hour with Micro 10+ (2%) and Deconex 53 plus (1%) based one the manufacture's instructions. After this duration, the cultivation was prepared again. And the result was analyzed. Results: The observed microorganisms were as follows: Staphylococus aureous, Neisseriae suprophyticous, Pneumococcis, Streptococci viridans, Nonpathogenic staphylococcus, Bacillus subtilis, Candida albikans and no colony growth was observed following the cultivations contact with the mentioned solutions. Conclusion: Micro10+ (2%) and Deconex 53 plus (1%) exert acceptable disinfecting effects on dental instruments following one – hour application. Key words: Infection control – Disinfectant – Quaternary Ammonium compounds, Micro 10+, Deconex 53 plus | 
