唾液基质金属蛋白酶2、9与儿童龋病相关性的初步研究

目的：比较健康儿童和不同龋损程度儿童唾液中基质金属蛋白酶（matrix metalloproteinase，MMP）-2、MMP-9含量差异以及重度龋儿童治疗前后唾液中MMP 2、MMP-9的蛋白水平变化，探讨其与儿童龋病发生、发展的相关性。方法：纳入368名3~5岁儿童，根据牙齿龋坏程度分为重度龋组112人、轻度龋组98人和无龋组158人，重度龋组患儿中完成全面的龋齿治疗并随访取样的83人纳入治疗组，测定唾液中MMP-2，MMP-9水平。使用SPSS 13.0软件分析数据，重度龋组、轻度龋组与无龋组之间的比较采用SNK-q法，重度龋组与治疗组之间的比较采用配对t检验。结果：重度龋组、轻度龋组、无龋组和治疗组的年龄及性别构成差异无统计学意义。重度龋组唾液中的MMP-2含量［(141.3±32.5) μg/L］高于轻度龋组［(107.5±21.3)μg/L］和无龋组［(102.8±18.5)μg/L］（P均＜0.05），轻度龋组与无龋组间差异无统计学意义（P＞0.05）。对纳入治疗组的83人进行分析，唾液中MMP 2含量［(120.1±24.8)μg/L］低于治疗前［(144.6±30.3)μg/L］（P＜0.05），但仍高于无龋组（P＜0.05）。重度龋组［(445.8±68.1)μg/L］和轻度龋组［(428.6±59.2)μg/L］唾液MMP 9含量高于无龋组［(385.4±60.6)μg/L］（P均＜0.05），重度龋组与轻度龋组间差异无统计学意义（P＞0.05）。对纳入治疗组的83人进行分析，唾液中MMP 9含量［(432.2±64.7)μg/L］与治疗前［(440.1±75.5)μg/L］没有明显变化（P＞0.05）。结论：重度龋患儿唾液中MMP-2、MMP-9含量显著高于无龋儿童，即使经过治疗仍高于健康儿童，提示唾液中的MMP-2、MMP-9可能是儿童患龋的相关影响因素。

A preliminary study of saliva matrix metalloproteinases (MMP-2 and MMP-9) in children with caries

Objective： To investigate the correlation between matrix metalloproteinase (MMP)-2/MMP-9 levels and childhood caries, and the saliva levels of MMP-2/MMP-9 among healthy children and those with different degrees of dental caries, both before and after treatment. Methods: In the study, 368 children aged 3 to 5 years were separated into three groups: severe caries group (112 children), mild caries group (98 children) and caries free group (158 children). The children with severe caries were included in treatment group (83 children) after accepting a comprehensive treatment of caries. MMP-2 and MMP-9 levels were determined by enzyme-linked immunosorbent assay (ELISA) and the data were analyzed by the Statistics Package for Social Science (SPSS 13.0). The differences among severe caries group, mild caries group and caries free group were analyzed by SNK-q (Student Newman Keuls). The severe caries group and treatment group were compared by paired t test. The differences between each group were statistically analyzed. Results: There was no significant difference of the age and gender composition among severe caries group, mild caries group, caries free group and treatment group. The MMP-2 level of severe caries group ［(141.3±32.5) μg/L］ was higher than those of mild caries group ［(107.5±21.3) μg/L］ and caries free group ［(102.8±18.5) μg/L］ (P<0.05). There was no significant difference between mild caries and caries free group (P>0.05). After analysis of 83 children in the treatment group, the level of MMP 2 ［(120.1±24.8) μg/L］ was lower than before ［(144.6±30.3) μg/L］ (P<0.05), but was higher than that of caries free group (P<0.05). The MMP-9 levels of severe caries group ［(445.8±68.1) μg/L］ and mild caries group ［(428.6±59.2) μg/L］ were higher than that of caries free group ［(385.4±60.6) μg/L］ (P<0.05), but the difference between severe caries group and mild caries group was not significant (P>0.05). After analysis of 83 children in the treatment group, the alteration of MMP-9 ［(432.2±64.7) μg/L］ was not significant either (P>0.05). Conclusion: The saliva levels of MMP-2 and MMP-9 in children with severe caries were higher than those in caries free children, even if the treatment was implemented, which suggests that the MMP-2 and MMP-9 in saliva might be related to the caries in children.