الملخص الإنجليزي
Objectives: This study aimed to establish lactate dehydrogenase (LDH) and β-glucuronidase as salivary
biomarkers of periodontitis among smokers and non-smokers. Methods: This cross-sectional case-control study was
conducted at the Aligarh Muslim University, Aligarh, India, between January and June 2017. A total of 200 participants
were divided into four groups based on their periodontal and smoking statuses. Unstimulated mixed saliva samples
were collected to estimate LDH and β-glucuronidase levels. In addition, total protein was estimated using Lowry's
method. Results: There was a significant increase in enzyme activity in the periodontitis groups compared to the nonperiodontitis groups (P <0.001). However, significantly lower enzyme activity was observed among smokers, irrespective
of periodontal status (P <0.001). Nevertheless, a receiver operating characteristic curve analysis indicated the diagnostic
potential of both enzymes to be fair-to-excellent. Conclusion: Although smoking was found to significantly alter enzyme
activity, LDH and β-glucuronidase were reliable salivary biomarkers of periodontitis among both smokers and nonsmoker
