Munshi Nabeel
Oral and Maxillofacial Prosthodontics Department, King Abdulaziz University, Faculty of Dentistry, Jeddah, Saudi Arabia.
Adv Med Educ Pract. 2024 Jul 9;15:649-657. doi: 10.2147/AMEP.S460140. eCollection 2024.
To determine the effect of experience and tooth location on the finish line width and angle of crown preparations performed by undergraduate students.
Eighty full metal crown preparations on typodont teeth were divided into four groups: Group 1: 20 preparations performed on mandibular first molar in the first semester. Group 2: 20 preparations performed on mandibular first molar in the second semester. Group 3: 20 preparations performed on mandibular second molar in the first semester. Group 4: 20 preparations performed on mandibular second molar in the second semester. All prepared teeth were scanned, and the finish line width and angles were measured at 8 different locations. Paired -test in the SPSS software was used to compare and determine the effect of experience and tooth location on the students' performance.
There was a statistically significant difference in the mandibular first molar finish line width between the first and second semesters for the same student in the distal, distolingual, and mesiobuccal areas of the tooth. There was a statistically significant increase in finish line width between first and second molars in the distobuccal, distal, distolingual, lingual, and mesial side of the tooth. Regarding the finish line angle, there was a statistically significant difference between the first and second semesters on the distal side of the tooth. There was a statistically significant increase in finish line angle between first and second molars in the distobuccal side of the tooth.
As students gain more experience in different types of tooth preparations, they tend to produce a wider finish line than that recommended for full metal crown preparation. The tooth location in the mouth influences the width and angle of the finish line hence the more inaccessible areas on the tooth have a wider finish line.
确定经验和牙齿位置对本科生进行全冠预备体边缘线宽度及角度的影响。
在牙模型上进行的80次全金属冠预备体被分为四组：第1组：第一学期在下颌第一磨牙上进行的20次预备体。第2组：第二学期在下颌第一磨牙上进行的20次预备体。第3组：第一学期在下颌第二磨牙上进行的20次预备体。第4组：第二学期在下颌第二磨牙上进行的20次预备体。对所有预备好的牙齿进行扫描，并在8个不同位置测量边缘线宽度和角度。使用SPSS软件中的配对检验来比较并确定经验和牙齿位置对学生操作的影响。
对于同一学生，在牙齿远中、远舌侧和近颊侧区域，下颌第一磨牙第一学期和第二学期的边缘线宽度存在统计学上的显著差异。在牙齿的远颊侧、远中、远舌侧、舌侧和近中侧，第一磨牙和第二磨牙之间的边缘线宽度有统计学上的显著增加。关于边缘线角度，在牙齿远中侧，第一学期和第二学期之间存在统计学上的显著差异。在牙齿远颊侧，第一磨牙和第二磨牙之间的边缘线角度有统计学上的显著增加。
随着学生在不同类型牙齿预备中积累更多经验，他们倾向于制备出比全金属冠预备推荐宽度更宽的边缘线。口腔内牙齿的位置会影响边缘线的宽度和角度，因此牙齿上较难操作的区域边缘线更宽。
