Table 2. Logistic regression analysis on each HU-DBI question to compare the percentage of “agree” response between civil engineering and dental students, controlling the effect of semesters attended.

Question description	Odds ratio (95% CI)	P value	Semester: frequency (%) of “agree” response
			1	2	3	4	5	6	7	8	9	10
1. I don't worry much about visiting the dentist	0.73(0.46-1.17)	0.195
Civil Engineering			13%	15%	18%	25%	14%	27%	29%	33%	26%	7%
Dental School			19%	33%	19%	13%	21%	15%	3%	5%	20%	11%
2. My gum tends to bleed when I brush my teeth	0.87(0.55-1.35)	0.523
Civil Engineering			20%	21%	27%	21%	23%	27%	15%	25%	18%	13%
Dental School			33%	22%	13%	27%	5%	0%	19%	24%	30%	11%
3. I worry about the color of my teeth	0.62(0.36-1.08)	0.092
Civil Engineering			89%	88%	92%	96%	86%	88%	94%	95%	92%	77%
Dental School			76%	85%	100%	93%	89%	92%	87%	90%	100%	22%
4. I have noticed some white sticky deposits on my teeth	0.87(0.57-1.35)	0.540
Civil Engineering			37%	19%	22%	25%	12%	18%	32%	13%	34%	27%
Dental School			5%	33%	13%	33%	16%	38%	26%	14%	30%	0%
5. I use a child sized toothbrush	1.09(0.46-2.63)	0.839
Civil Engineering			4%	0%	6%	4%	7%	6%	3%	3%	3%	7%
Dental School			10%	4%	0%	7%	0%	8%	6%	5%	0%	0%
6. I think that I can't help having false teeth when I am old	0.68(0.41-1.14)	0.148
Civil Engineering			13%	17%	20%	21%	21%	24%	15%	18%	8%	13%
Dental School			10%	7%	13%	7%	16%	15%	23%	5%	30%	0%
7. I'm bothered by the color of my gum	2.47(1.55-3.95)	0.0001*
Civil Engineering			67%	73%	73%	79%	60%	69%	68%	70%	66%	73%
Dental School			52%	93%	69%	93%	100%	100%	94%	86%	90%	67%
8. I think my teeth are getting worse despite my daily brushing	0.33(0.20-0.53)	<.0001*
Civil Engineering			24%	33%	37%	50%	23%	24%	44%	30%	21%	27%
Dental School			24%	11%	6%	7%	5%	15%	19%	14%	30%	0%
9. I brush each of my teeth carefully	1.47(0.95-2.27)	0.085
Civil Engineering			78%	77%	78%	54%	67%	82%	74%	78%	79%	63%
Dental School			67%	74%	75%	80%	84%	92%	84%	81%	90%	89%
10. I have never been taught professionally how to brush	0.48(0.30-0.79)	0.0033*
Civil Engineering			15%	27%	33%	29%	21%	29%	32%	23%	13%	20%
Dental School			5%	15%	19%	7%	11%	15%	26%	14%	20%	0%
11. I think I can clean my teeth well without using toothpaste	3.15(1.72-5.74)	0.0002*
Civil Engineering			9%	10%	2%	7%	5%	4%	9%	5%	3%	3%
Dental School			0%	15%	13%	7%	5%	31%	13%	29%	60%	0%
12. I often check my teeth in a mirror after brushing	1.46(0.97-2.19)	0.068
Civil Engineering			74%	65%	71%	54%	67%	78%	50%	88%	61%	63%
Dental School			86%	74%	56%	93%	74%	77%	68%	71%	80%	78%
13. I worry about having bad breath	1.18(0.66-2.11)	0.586
Civil Engineering			87%	92%	86%	93%	86%	88%	82%	90%	95%	87%
Dental School			81%	89%	88%	100%	95%	92%	94%	90%	80%	89%
14. It is impossible to prevent gum disease with toothbrushing alone	0.68(0.47-0.97)	0.0329*
Civil Engineering			57%	56%	67%	39%	56%	53%	65%	63%	61%	57%
Dental School			48%	59%	44%	67%	37%	38%	55%	48%	40%	33%
15. I put off going to dentist until I have a toothache	0.45(0.30-0.68)	0.0001*
Civil Engineering			26%	48%	35%	43%	40%	41%	47%	40%	32%	37%
Dental School			33%	22%	25%	20%	32%	31%	26%	14%	10%	0%
16. I have used a dye to see how clean my teeth are	3.63(2.49-5.28)	<.0001*
Civil Engineering			35%	19%	41%	21%	37%	31%	24%	23%	16%	33%
Dental School			43%	59%	56%	73%	58%	62%	61%	62%	50%	56%
17. I use a toothbrush which has hard bristles	0.41(0.28-0.61)	<.0001*
Civil Engineering			63%	48%	49%	46%	30%	51%	47%	53%	61%	40%
Dental School			43%	26%	38%	60%	26%	8%	10%	38%	40%	0%
18. I don't feel I have brushed well unless I brush with hard strokes	0.39(0.25-0.59)	<.0001*
Civil Engineering			26%	46%	27%	39%	37%	41%	44%	48%	29%	43%
Dental School			38%	26%	38%	13%	16%	8%	13%	19%	0%	11%
19. I feel I sometimes take too much time to brush my teeth	1.18(0.82-1.70)	0.381
Civil Engineering			46%	33%	41%	25%	44%	53%	29%	45%	24%	20%
Dental School			38%	33%	50%	40%	32%	38%	52%	48%	60%	11%
20. I have had my dentist tell me that I brush very well	2.77(1.91-4.02)	<.0001*
Civil Engineering			37%	46%	22%	36%	47%	39%	32%	48%	37%	53%
Dental School			52%	48%	75%	87%	79%	38%	58%	71%	80%	67%