Nourizadeh Amin, Ghasemi Shima, Shafiee Elnaz, JafarZadeh Sevda, Bakhtiari Fatemeh
Department of Prosthodontics, Faculty of Dentistry, Tabriz University of Medical Science, Tabriz, Iran.
Department of prosthodontics, Faculty of dentistry, Tabriz Medical Sciences, Islamic Azad University, Tehran, Iran.
BMC Oral Health. 2025 May 14;25(1):724. doi: 10.1186/s12903-025-06090-3.
Dental implants are a popular and effective solution for replacing missing teeth. However, there are challenges such as screw loosening and component failure. This deformation can impact torque application and screw retention. While research has focused on implant system longevity, there is limited investigation into how different screwdriver head designs, particularly hexagonal and star-shaped, perform under repeated opening and closing cycles, which are crucial for long-term implant stability. The study compared the deformation characteristics of hexagonal and star-shaped implant screwdriver heads after multiple opening and closing cycles.
In this in vitro experimental study, abutments were placed on two implant systems mounted in die stone and torqued to 25 N/cm according to the manufacturer's recommendations, using 12 screwdrivers (n = six for each implant). The screwdriver heads underwent examination under a stereomicroscope at 50x magnification. Subsequently, the outline and deformation of the screwdriver head after 0, 50, 100, 200, and 300 opening and closing cycles were analyzed using AutoCAD software. The changes in the surface area of hexagonal and star-shaped driver heads after different cycles were statistically evaluated using SPSS 24 (α = 0.05).
The investigation revealed a reduction in the surface area of both hexagonal and star-shaped driver heads with an increase in the frequency of cycles. Notably, following all cycles, except 0-50 and 50-100, the alterations in the surface area of the star-shaped driver head were significantly greater than those observed in the hexagonal driver head (P < 0.001).
The study shows that the star-shaped driver head deformed more than the hexagonal one, especially in cycles exceeding 100.
牙种植体是一种用于替代缺失牙齿的常用且有效的解决方案。然而，存在诸如螺钉松动和部件故障等挑战。这种变形会影响扭矩施加和螺钉固定。虽然研究主要集中在种植体系统的使用寿命上，但对于不同螺丝刀头设计，特别是六边形和星形螺丝刀头在反复开合循环下的性能研究有限，而反复开合循环对种植体的长期稳定性至关重要。本研究比较了六边形和星形种植体螺丝刀头在多次开合循环后的变形特征。
在这项体外实验研究中，将基台放置在安装在石膏模型中的两种种植体系统上，并根据制造商的建议使用12把螺丝刀（每种种植体6把）将其扭矩设定为25 N/cm。螺丝刀头在50倍放大倍数的立体显微镜下进行检查。随后，使用AutoCAD软件分析螺丝刀头在0、50、100、200和300次开合循环后的轮廓和变形情况。使用SPSS 24对不同循环后六边形和星形螺丝刀头表面积的变化进行统计学评估（α = 0.05）。
研究发现，随着循环次数的增加，六边形和星形螺丝刀头的表面积均减小。值得注意的是，在除0 - 50和50 - 100之外的所有循环后，星形螺丝刀头表面积的变化均显著大于六边形螺丝刀头（P < 0.001）。
该研究表明，星形螺丝刀头的变形比六边形螺丝刀头更大，尤其是在超过100次的循环中。
