[Table/Fig-4]:

Comparison of results of present study with other studies.

Present study conclusion for CKD Group	Comparative studies
A statistically highly significant difference was observed for serum urea and creatinine values between groups (p = 0.000) with CKD group subjects showing highest range of serum urea followed by diabetic group then hypertensive group as compared to controls.	1. Mittal A et al., also demonstrated almost similar results on 440 patients with a significant increase in mean serum creatinine and urea in kidney disease patients with diabetes mellitus. In non- diabetic kidney disease patients mean value of serum creatinine and urea were also moderately raised as compared to controls [15].
Present study conclusion for diabetic group	Comparative studies
Raised serum urea and creatinine in almost all diabetic patients with normal values of serum urea and creatinine in almost all controls.	1. Similar results were seen in studies done by Shrestha S et al., [20].
	2. Kamal A demonstrated that urea and creatinine levels deflects corresponding to increase blood glucose level indicating a reduction in kidney function in diabetic patients [21].
	3. Findings were also similar to the studies done by Deepa K et al., [22] and Rohitash K et al., [23].
Present study conclusion for hypertensive group	Comparative studies
1. Serum urea and creatinine values were significantly increased in hypertensive group when compared to controls 2. Mean of serum creatinine level in hypertensive subjects was significantly higher (1.62 mg/dl) than control (0.94 mg/dl)	1. AL-Hamdani IH conducted a study on 82 hypertensive patients and 43 healthy volunteers and found a significant increase in mean values of serum urea and creatinine concentration in hypertensive patients in comparison to controls [24]. 2. Similar results were obtained by study conducted by Yadav R et al., demonstrating a positive correlation in blood urea and creatinine levels with severity of renal dysfunction in hypertensive patients [25]. 3. Results of our study were consistent with the results of study conducted by Pooja and Mittal Y where the mean serum creatinine level of hypertensive cases was significantly higher as compared to controls [26].
Present study conclusion for salivary urea and creatinine values	Comparative studies
1. A statistically highly significant difference was observed for salivary urea values between groups (p = 0.000) with CKD group subjects which showed highest range of salivary urea followed by diabetic group then hypertensive group as compared to controls. 2. A statistically significant difference for salivary creatinine values between groups with CKD group patients showed highest increase followed by equal increased values in both diabetic and hypertensive groups as compared to controls.	1. Tomas I et al., conducted a study on 50 CRF (chronic renal failure) patients with 22 M-S CRF (moderate-severe chronic renal failure) and 28 TRF (terminal renal failure) patients and 64 healthy controls. Results revealed that salivary urea level of TRF patients was significantly higher than that of M-S CRF patients [27].
Present study conclusion on group wise comparison of salivary and serum values	Comparative studies
1. In all the groups serum urea and serum creatinine values were significantly higher than salivary urea and creatinine p-value = 0.000 (<0.001).	1. These findings were contradictory with the findings of Suresh G et al., in their study on 45 hemodialysis patients, 15 transplant group patients and 10 healthy controls which suggested that salivary urea levels were slightly higher than blood urea levels in all study groups. In hemodialysis group, mean blood urea level was 71.75 mg/dl and mean salivary urea level was 97.15 mg/dl and in transplant group mean blood urea and salivary urea levels were 56.8 mg/dl and 71.53 mg/dl [8].
	2. Similar findings were also obtained by study done by Ali SP et al., demonstrating that mean salivary urea levels (107.52 mg/dl) were higher than mean blood urea levels (103.57 mg/dl) in hemodialysis patients [28].
Present study conclusion on over all correlation between serum and salivary urea values	Comparative studies
1. Overall correlations (n=120) were significant between serum urea and salivary urea in all the groups and demonstrated that as serum urea value increases, salivary urea value also increases and vice versa.	1. Similar results were obtained by Cardoso EML et al., concluding that salivary urea estimation is a harmless and useful diagnostic tool [29].
Present study conclusion on over all correlation between serum and salivary creatinine values	Comparative studies
1. Overall correlations (n=120) were significant between serum creatinine and salivary creatinine and demonstrated that as serum creatinine value increases, salivary creatinine value also increases and vice versa.	1. Lloyd JE et al., conducted a study on 26 renal disease patients and 23 healthy volunteers and found a statistically significant relationship between salivary and serum creatinine concentrations for the patients and salivary creatinine concentrations are 10-15% of those in blood [30].
Present study correlation between serum and salivary values	Comparative studies
1. In CKD subjects Spearman’s rho correlation coefficient for serum urea and salivary urea was 0.958 and for serum creatinine and salivary creatinine was 0.931, which showed very strong positive relationship with p value = 0.000 (<0.001) which is a highly significant correlation.	1. Similar results were obtained by Venkatapathy R et al., [1] Seethalakshmi C et al., [10].