Keinan David, Radko Anna, Smith Patricia, Zilberman Uri
Laboratory of Bioanthropology and Ancient DNA, Hadassah School of Dental Medicine, Hebrew University, POB 12272, Jerusalem, 91120, Israel.
Open Dent J. 2009 Jun 9;3:132-6. doi: 10.2174/1874210600903010132.
This study was carried out to evaluate the extent of differences in mineralization of inner and outer enamel of the lower primary second molars of children with Down syndrome (DS) and Cerebral Palsy (CP) as revealed by acid treatment of exfoliated teeth. The results were compared to those obtained from a control group of healthy children.
The sample included 4 mandibular second molars from each group. On each tooth, a thin section was cut, bisecting the mesial cusps. The analysis was carried out on the mesio-buccal cusps. Atomic force microscopy (AMF) was used to analyze the morphological structure of the dental enamel after 10 sec of 0.1 mol% citric acid treatment. The measurements were performed on 3 points in the enamel close to the outer surface and 3 points in the enamel close to the dentin. The differences between groups were analyzed using Mann Whitney tests.
In controls and CP teeth the outer enamel was more resistant to etching than the inner enamel. In DS teeth both outer and inner enamel showed similar results for all parameters. Between group comparisons showed that roughness values were significantly higher (P<0.01) in DS teeth than in either controls or CP teeth. No significant differences were found between CP and control teeth.
The higher values obtained for DS enamel reflect increased solubility of the enamel to acid relative to controls and CP teeth together with irregularity of the organic matrix. The practical importance of the results is that DS primary molars needs reduced etching time when prepared for pit and fissure sealants or composite/compomer restorations.
本研究旨在通过对脱落牙齿进行酸处理,评估唐氏综合征(DS)和脑瘫(CP)患儿下颌乳第二磨牙内外釉质矿化程度的差异。将结果与健康儿童对照组的结果进行比较。
每组选取4颗下颌第二磨牙。在每颗牙齿上,切取一个薄片,将近中尖一分为二。分析在近中颊尖进行。使用原子力显微镜(AMF)分析0.1 mol%柠檬酸处理10秒后牙釉质的形态结构。在靠近外表面的釉质中3个点和靠近牙本质的釉质中3个点进行测量。使用曼-惠特尼检验分析组间差异。
在对照组和CP组牙齿中,外釉质比内釉质更耐蚀刻。在DS组牙齿中,内外釉质在所有参数上均显示出相似的结果。组间比较表明,DS组牙齿的粗糙度值显著高于对照组或CP组牙齿(P<0.01)。CP组和对照组牙齿之间未发现显著差异。
DS组牙釉质获得的较高值反映出相对于对照组和CP组牙齿,牙釉质对酸的溶解度增加以及有机基质的不规则性。结果的实际意义在于,DS组乳牙在制备窝沟封闭剂或复合树脂/复合体修复体时需要缩短蚀刻时间。