I have read the research article entitled "Evaluation of the Amount and Type of Microorganisms in Tooth Brushes and Miswak after Immediate Brushing" by Khounganian R, Alwakeel AA, Albadah A, Almaflehi N published in ARC Journal of Dental Science (2018; 3(1): 15-21). I want to congratulate the authors for this successful study, and make some contributions.

In the research article, it has been indicated that Gram positive/negative cocci and bacilli were detected in the tooth brushes and miswak. I think these microorganisms should be identified. Since microorganisms of the oral microflora in a healthy mouth are not pathogen [1], contamination of a toothbrush is not an issue unless pathogen microorganisms contaminate the toothbrush due to enviromental conditions. Therefore I think this study should include oral health conditions of the participants [2] and instructions given about a routine after brushing [3]. Information about storing and cleaning of thoothbrush and miswak may alter the results. It would be better to standartize these factors in the study. For instance, selection of the participants could be "individuals with Oral Hygiene Indice score 1.3-3.0". By means of this selection, pathogens for oral cavity would likely to exist in the participants' mouth and contamination of toothbrush becomes important.

In the study, the participants were instructed to brush once a week. It would be better if the reason of this frequency had been mentioned. Since brushing more frequently is advised by proffesionalists [4], such a limitation may be misunderstood in terms of ethical considerations.