Genetic association of the epidermal growth factor gene polymorphisms with peri-implantitis risk in Chinese population

Figures & data

Table 1. Primer sequences of EGF gene rs2237051 and rs4444903 polymorphisms

Variations	Primer sequences
rs2237051	Forward 5ʹ-TTCAAGCCTTGTCCTTTCGT-3’
	Reverse 5ʹ-TTCAAAATCAGCAAAAGCATAAA-3ʹ
rs4444903	Forward 5ʹ-CATTTGCAAACAGAGGCTCA-3’
	Reverse 5ʹ-TGCTCTGGCTGACTTCACTG-3’ʹ

Table 2. Demographic and clinical information of the clinical subjects

Parameters	Healthy implants (n = 150)	Peri-implantitis (n = 150)	p-value
Age, (mean±SD)	42.55 ± 6.93	43.37 ± 6.25	0.298
Gender, n(%)
Male	79(52.67)	83(55.33)	0.643
Female	71(47.33)	67(44.67)
Alcohol consumption, n(%)
Yes	60(40.00)	61(40.67)	0.906
No	90(60.00)	89(59.33)
History of smoking, n(%)
Yes	69(46.00)	68(45.33)	0.908
No	81(54.00)	82(54.67)
History of periodontitis, n(%)
Yes	68(45.33)	84(56.00)	0.065
No	82(54.67)	66(44.00)
Platform type, n(%)
External hex	70(46.67)	63(42.00)	0.353
Internal hex	22(14.67)	34(22.67)
Morse cone	48(32.00)	45(30.00)
Others	10(6.66)	8(5.33)
Position, n(%)
Anterior region	96(64.00)	81(54.00)	0.078
Posterior region	54(36.00)	69(46.00)
Peri-implant phenotype, n(%)
Thin	82(54.67)	70(46.67)	0.166
Thick	68(45.33)	80(53.33)
Brushing daily, n(%)
1–3 times	127(84.67)	129(86.00)	0.744
More than 3 times	23(15.33)	21(14.00)
Dental floss daily, n(%)
Yes	58(38.67)	62(41.33)	0.276
No	28(18.67)	18(12.00)
Infrequent	64(42.67)	70(46.67)
Mouth washing daily, n(%)
Yes	44(29.33)	56(37.33)	0.339
No	34(22.67)	30(20.00)
Infrequent	72(48.00)	64(42.67)

Note: Continuous variable was expressed as mean ± standard deviation (SD) and compared via one-way ANOVA; Categorical variables were expressed as the number and percentage, total numbers in each category were compared using chi square test.

Table 3. Periodontal status of the studied population

Parameters	Healthy implants (n = 150)	Peri-implantitis (n = 150)	p value
Gingival index	0.53 ± 0.50	2.44 ± 0.52	< 0.001
Plaque index	0.77 ± 0.57	2.27 ± 0.61	< 0.001
Calculus index	0.14 ± 0.35	0.49 ± 0.59	< 0.001
PPD (mm)	1.87 ± 0.51	5.38 ± 0.77	< 0.001
CAL (mm)	1.39 ± 0.49	4.58 ± 0.74	< 0.001

Note: PPD, peri-implant pocket depth; CAL, clinical attachment level. Continuous variables were expressed as mean ± standard deviation (SD) and compared via one-way ANOVA.

Table 4. Frequency distribution of EGF gene rs2237051 and rs4444903 genotype and allele in healthy implants and peri-implantitis groups

Genotype /Allele	Healthy implants n = 150 (%)	Peri-implantitis n = 150 (%)	χ^2	P value		OR (95% CI)
rs2237051
AA	57(38.0%)	69(46.0%)	-	-	1
AG	72(48.0%)	75(50.0%)	0.381	0.537	0.861 (0.534 − 1.387)
GG	21(14.0%)	6(4.0%)	9.421	0.002*	0.236 (0.089–0.624)
A	186(62.0%)	213(71.0%)	-	-	1
G	114(38.0%)	87(29.0%)	5.454	0.020*	0.666 (0.474–0.938)
P^HWE	0.819
rs4444903
GG	74(49.3%)	71(47.3%)	-	-	1
AG	68(45.3%)	70(46.7%)	0.008	0.767	0.932 (0.585–1.486)
AA	8(5.3%)	9(6.0%)	0.096	0.756	0.853 (0.312–2.333)
G	216(72.0%)	212(70.7%)	-	-	1
A	84(28.0%)	88(29.3%)	0.130	0.718	0.937 (0.658–1.335)
P^HWE	0.128

Note: OR, odds ratio; CI, confidence interval; HWE, Hardy–Weinberg equilibrium. Categorical variables were expressed as the number and percentage, the difference between groups were compared using chi square test.

Table 5. The periodontal status of cases with different CXCR2 gene polymorphisms

Parameters	rs2237051					rs4444903
	AA	AG	GG	p value	GG	AG	AA	p value
Gingival index	1.65 ± 0.96	1.44 ± 1.15	0.96 ± 1.07	0.008	1.54 ± 0.97	1.43 ± 1.17	1.47 ± 1.28	0.726
Plaque index	1.75 ± 0.82	1.44 ± 0.99	0.89 ± 1.01	< 0.001	1.62 ± 0.83	1.41 ± 1.02	1.59 ± 1.28	0.158
Calculus index	0.40 ± 0.55	0.27 ± 0.49	0.18 ± 0.40	0.031	0.32 ± 0.53	0.30 ± 0.47	0.41 ± 0.71	0.667
PPD (mm)	3.89 ± 1.89	3.54 ± 1.91	2.81 ± 1.39	0.020	3.62 ± 1.97	3.63 ± 1.85	3.53 ± 1.37	0.975
CAL (mm)	3.40 ± 1.85	2.78 ± 1.60	2.11 ± 1.09	< 0.001	3.09 ± 1.93	2.93 ± 1.53	2.47 ± 1.07	0.338

Note: PPD, peri-implant pocket depth; CAL clinical attachment level. Continuous variable was expressed as mean ± standard deviation (SD) and compared via one-way ANOVA.