Department of Orthodontics, Sri Ramachandra Dental College, SRIHER, 1, Ramachandra Nagar, Porur, Chennai, 600116, India.
Clin Oral Investig. 2024 Feb 26;28(3):176. doi: 10.1007/s00784-023-05439-8.
This study aimed to evaluate the chemical composition of the proximal enamel surface and the surface characteristics subjected to different extents of interproximal reduction (IPR) in a clinical setting.
Premolars of orthodontic patients which were designated for extraction were subjected to .2 mm, .3 mm, and .5 mm of IPR. After 1 month, the teeth were extracted and the teeth were subjected to scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDX).
The SEM images of the three experimental groups (taken at magnification of 500 × and 2000 ×) showed that the enamel surfaces were irregular and rough compared to the honey comb appearance of the unstripped group. Small areas of erosion of enamel surface were seen in Group I (0.2 mm) under 2000 × magnification compared to Group IV (control) which showed typical arrangement of enamel rods in alternating orientation. The enamel surfaces of stripped and unstripped enamel contained calcium, phosphorus, carbon, oxygen, and nitrogen. The differences were not statistically significant and neither were the calcium phosphorous stoichiometric ratios between the four groups.
On analyzing the surface characteristics of enamel using SEM between the stripped and unstripped surfaces, there were irregularities and roughness seen in stripped surface whereas honey comb pattern was observed in unstripped enamel surfaces. The elements found in unstripped and stripped enamel surfaces were calcium, phosphorous, carbon, oxygen, and nitrogen. Although the calcium and phosphorus were high in the 0.5 mm IPR group, the difference between stripped and unstripped enamel surfaces was statistically not significant.
There have been concerns that IPR can remove the superficial mineral-rich layer making the deeper layers more susceptible to carious attack. No study has evaluated the mineral content in different layers of enamel in response to IPR in vivo and this study found no significant difference between pristine enamel and enamel subjected to IPR. The results of this study strengthen the validity of the clinical protocol employed.
本研究旨在评估临床环境中不同程度邻面减径（IPR）对近釉质表面的化学成分和表面特性的影响。
正畸患者的前磨牙需要拔除，分别进行.2mm、.3mm 和.5mm 的 IPR。1 个月后，牙齿被拔出，并进行扫描电子显微镜（SEM）和能谱分析（EDX）。
三组实验的 SEM 图像（放大倍数为 500×和 2000×）显示，与未经处理组的蜂窝状外观相比，釉质表面不规则且粗糙。与对照组（IV 组）相比，在 2000×放大倍数下，第 I 组（0.2mm）可见釉质表面小面积侵蚀，而对照组则显示典型的釉质棒交错排列。经处理和未经处理的釉质表面均含有钙、磷、碳、氧和氮。各组间钙磷化学计量比无显著差异，且钙磷含量也无显著差异。
通过 SEM 分析处理和未处理釉质表面的表面特性，处理后的釉质表面存在不规则和粗糙，而未经处理的釉质表面则呈现蜂窝状。在未经处理和处理后的釉质表面均发现钙、磷、碳、氧和氮。尽管 0.5mm IPR 组的钙、磷含量较高，但处理和未处理釉质表面之间的差异在统计学上无显著性。
人们一直担心 IPR 会去除富含矿物质的浅层，使深层更易受到龋齿侵袭。没有研究评估过 IPR 对体内不同釉质层的矿物质含量的影响，本研究发现处理和未处理釉质之间没有显著差异。本研究结果支持所采用的临床方案的有效性。
