fa تخصصي Special مروری Review Article <div style="text-align: right;"><div style="text-align: left;"></div></div> <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Background & Aims</span></i></b><b><span style="font-size:9.0pt">: </span></b><span style="font-size:9.0pt">Opioids cause dry mouth, tooth decay, discoloration of oral tissues, and periodontal diseases. Adequate saliva flow is a prerequisite for a healthy periodontium, and the salivary urea concentration is an important parameter for the tooth and gum health. The purpose of the present study was to investigate salivary urea concentration in opioid users. </span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Materials & Methods</span></i></b><b><span style="font-size:9.0pt">:</span></b> <span style="font-size:9.0pt">This case-control study was conducted on 240 people in 2021. The case group included 120 people referred to addiction treatment centers of Birjand. The control group also consisted of 120 people with no history of addiction and was selected from clients referred to the Faculty of Dentistry of Birjand University of Medical Sciences and Samen Dental Clinic in Birjand. The control and case groups were age matched, and their demographic information and periodontal clinical data were collected. The obtained data were then analyzed using SPSS ver. 19.</span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Results</span></i></b><b><span style="font-size:9.0pt">:</span></b><span style="font-size:9.0pt"> The amount of stimulated saliva in the case group was significantly lower than the control group (P value=0.000), while the salivary urea concentration in methadone and opium users was significantly higher than the control group (P value = 0.000). </span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:16.0pt"><span new="" roman="" style="font-family:" times=""><b><i><span style="font-size:9.0pt">Conclusion</span></i></b><b><span style="font-size:9.0pt">: </span></b><span style="font-size:9.0pt">Drug addiction causes dry mouth and increased salivary urea concentration. Poor oral and dental hygiene and increase in chronic periodontitis are also observed in drug addicts, and chronic periodontitis causes a raise in salivary urea concentration. Hence, the reason for enhanced salivary urea concentration in drug addicts could increase chronic periodontitis.</span></span></span></span> Salivary urea concentration, Stimulated saliva, Opioids, Salivary biomarkers 205 209 http://hsm.umsu.ac.ir/browse.php?a_code=A-10-98-3&slc_lang=fa&sid=1 Parvin Parvaei Parvaei.parvin@gmail.com 10031947532846001700 10031947532846001700 No Dentistry Clinical Research Development Unit, Birjand University of Medical Sciences, Birjand, Iran Marziyeh Eydzade marziyeheydzadeh1377@gmail.com 10031947532846001701 10031947532846001701 Yes Student Research Committee, Birjand University of Medical Sciences, Birjand, Iran Freshteh Osmani fereshteh.osmani@gmail.com 10031947532846001702 10031947532846001702 No Assistant Professor of Biostatistic, Infectious disease Research center, Birjand University of Medical Sciences, Birjand, Iran