| کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
|---|---|---|---|---|
| 5434533 | 1509144 | 2017 | 6 صفحه PDF | دانلود رایگان |
کلمات کلیدی
1.مقدمه
شکل 1- نقشه وضعیت نقاط مورد تحلیل.
2- مصالح و روش ها
2- 1- ایمپلنت های اصلاح شده
شکل 2- ایمپلنت متعارف استوانه ای HE (a و c) و اصلاح شده (b و d) تحت بار محوری: a و b – 100N؛ c و d – 150N.
جدول 1- تنش برشی حداکثر (????) به kPa ایمپلنت های استوانه ای HE.
2- 2- تهیه مدل های فتوالاستیک
2- 3- تحلیل کیفی فتوالاستیک
شکل 3- ایمپلنت متعارف استوانه ای HE (a و c) و اصلاح شده (b و d) تحت بار مورب: a و b – 100N؛ c و d – 150N.
شکل 4- ایمپلنت متعارف مخروطی CM (a و c) و اصلاح شده (b و d) تحت بار محوری: a و b – 100N؛ c و d – 150N.
2- 4- تحلیل کمی فتوالاستیک
3- نتایج
3- 1- ایمپلنت های استوانه ای (EH)
3- 2- ایمپلنت های مخروطی (MT)
شکل 5- ایمپلنت متعارف مخروطی CM (a و c) و اصلاح شده (b و d) تحت بار مورب: a و b – 100N؛ c و d – 150N.
4- بحث
- Negative effect of overload and presence of non-axial forces on the increased stress
- The modified implants generally showed lower stress in the bone crest portion.
- In the middle region of the modified implants there was increased stress.
- The modified implants showed better stress distribution in the cervical region.
- The modified implants suggesting a smaller reabsorption of the bone crest
The purpose of this study was to compare, through photoelastic analysis, the stress distribution around conventional and modified external hexagon (EH) and morse taper (MT) dental implant connections. Four photoelastic models were prepared (n = 1): Model 1 - conventional EH cylindrical implant (à 4.0 mm Ã 11 mm - Neodent®), Model 2 - modified EH cylindrical implant, Model 3 - conventional MT Conical implant (à 4.3 mm Ã 10 mm - Neodent®) and Model 4 - modified MT conical implant. 100 and 150 N axial and oblique loads (30° tilt) were applied in the devices coupled to the implants. A plane transmission polariscope was used in the analysis of fringes and each position of interest was recorded by a digital camera. The Tardy method was used to quantify the fringe order (n), that calculates the maximum shear stress (Ï) value in each selected point. The results showed lower stress concentration in the modified cylindrical implant (EH) compared to the conventional model, with application of 150 N axial and 100 N oblique loads. Lower stress was observed for the modified conical (MT) implant with the application of 100 and 150 N oblique loads, which was not observed for the conventional implant model. The comparative analysis of the models showed that the new design proposal generates good stress distribution, especially in the cervical third, suggesting the preservation of bone tissue in the bone crest region.
Journal: Materials Science and Engineering: C - Volume 77, 1 August 2017, Pages 360-365