Effects Of Different Iron Content On Mineralization And Caries Susceptibility Of Rat Teeth

Background: Dental caries is a biofilm-mediated,sugar-driven,multi-factor dynamic disease that can damage mineralized tooth tissue.The abnormal development of teeth affects the structure and quality of enamel and the formation of dentin.Anemia is a common nutritional disease and iron deficiency is the most common cause of anemia.Iron deficiency is usually caused by insufficient iron intake and absorption in the body.In severe cases,it can cause iron deficiency anemia.Clinical work found that the incidence rate of iron deficiency anemia is high among the patients suffering from dental caries.This paper will study the relationship between iron content and caries and dental development,and explore the correlation between iron deficiency anemia,iron overload,dental caries and dental development,so as to provide new ideas for the treatment of dental caries and the prevention and control of iron deficiency anemia.Methods: Forty-eight non-specific pathogen-grade SD rats at 14 days of age were randomly divided into four groups: iron deficiency anemia group(IDA),positive control group(PG),iron excess group(HG),and negative control group(NG).Animal models were established by feeding with different iron contents.Blood was collected from the iliac vein in the eyeballs of the four groups of rats after 4 weeks of feeding.The hemoglobin(HGB)and serum iron(SI)indexes were measured to evaluate whether the model was successfully established.Streptococcus mutans were implanted into the oral cavity of each group of rats successfully modeled for 5 consecutive days,and bacteria were successfully colonized in the oral cavity by mass spectrometry.Carcinogenic feeds with different iron contents were continued to be fed.Except for the NG group,which was directly fed with deionized water,the other groups were fed with a 5 wt% sucrose ultrapure aqueous solution.Iron content was monitored once a month.Three months later,rats were sacrificed by asphyxiation with sevoflurane and cervical decapitation.The caries of the molars in each group were observed under a stereo microscope.The microstructure of dental caries and the thickness of enamel were measured by scanning electron microscope(SEM).Energy dispersive spectroscopy(EDS)was used to analyze the tooth element composition.Hematoxylin-eosin(HE)staining was used to observe the histopathological characteristics of salivary glands.Results: After 4 weeks,blood samples were taken to detect HGB and SI levels.HGB and SI levels in the anemia group were significantly reduced(P <0.01);SI levels in the high-speed rail group were significantly increased(P <0.01).These data together indicate that the IDA model and the high-iron content model Created successfully.The changes in the tooth condition were recorded weekly.The anterior teeth staining between the groups was visually observed with a large difference: compared with the negative control group,the anterior teeth in the IDA group showed a chalky color,and the high-speed iron group showed a darker stained rust color.Keyes caries score of molars between the four groups: IDA group> PG group> HG group> NG group,and the difference was statistically significant(P <0.05).The structure of caries,especially superficial enamel caries,was characterized in more detail by SEM,and the results were generally consistent with the results of Keyes caries score.EDS elemental analysis showed that Ca,P,Na,Mg,C,and O were detected in the enamel and dentin of each group.Unlike the other groups,Fe elements were detected in HG group.The results of enamel thickness measurement showed that there were statistically significant differences(P < 0.05).The results of HE staining of salivary glands in the four groups of rats showed no significant difference.Conclusion: Iron deficiency significantly increased the susceptibility to caries and may be detrimental to the development and mineralization of enamel,while high iron content can inhibit the production of caries and contribute to the formation and mineralization of enamel,but it seems to have no effect on the function of salivary gland.