ABSTRACT
BACKGROUND: In clinical practice, the selection of dental implants with different specifications is based on the patient' s mandibular plane angle, and the long-term success rate is different in dental implants with different specifications. Therefore, it is reasonable to assume that the mandibular plane angle could affect the mandibular stress distribution of dental implants, thus affecting the success rate of dental implantation.OBJECTIVE: To perform an orthogonal experimental study on the mechanical effects of different implant specifications, mandibular plane angles and mandibular bone densities on stress distribution of the first mandibular molar implants.METHODS: A L9(33) orthogonal experiment was designed with 3 three-level factors, including mandibular plane angle (14°, 22°, 34°), implant diameter (6.6, 8.2, 9.6 mm), and mandibular bone density (types II, III, IV). Different dental implants with different combinations were implanted into an alveolar bone model, and placed onto a pressure testing machine under 500 N load. Then, strain (stress) data were collected in real-time and analyzed.RESULTS AND CONCLUSION: The optimal combination was as follows: low angle; 4.8 mm in diameter; mandibular bone with type II bone density. The relations of all the three factors were the diameter of dental implant > the mandibular plane angle > mandibular bone density. To conclude, the mandibular plane angle has some certain influences on the stability of dental implants. If the biting force is the same, dental implant bears the largest stress under the high angle,subsequently followed by the average angle and the low angle.
ABSTRACT
Purpose To investigate the correlation of Dock180 and miR-31 expression in breast cancer cells,and to observe the effect of miR-31 on the invasion of breast cancer cells by Dock180.Methods MiR-31 was transfected into breast cancer cells by liposome transfection technique.The actual binding site of miR-31 to the 3'-untranslated region of Dock180 was confirmed through luciferase assay.Western blot was performed to detect the expression of Dockl80 and other related proteins.Real-time PCR was used to measure the expression of Dock180.Matrigel invasion were performed to detect the invasion of breast cancer cell lines with miR-31 increased.Resuits The protein levels of Dock180 in breast cancer cell lines negatively correlated with miR-31 expression,and Dock180 was directly targeted by miR-31.Dock180 downregulation and miR-31 overexpression reduced breast cancer cells invasion.Conclusion Dock180 modulated by miR-31 plays an important function in breast cancer cell lines invasion.
ABSTRACT
<p><b>OBJECTIVE</b>Finite elemental analysis of the mechanical characteristics of a first mandibular implant molar under different mandibular plane angles determines the load conditions on the implant, thereby providing guidance for clinical application.</p><p><b>METHODS</b>CT data of three mandibular plane angles (low, average, high) were collected. A finite elemental combination model of a dental implant was constructed. The orthogonal experimental research was designed. Results followed data collection and analysis.</p><p><b>RESULTS</b>The optimal combination was a low angle, 4.8 mm, and type Ⅱ bone. The relations among diameter of the implant, angle of mandibular bone, and bone density were determined.</p><p><b>CONCLUSIONS</b>Mandibular plane angle influences the stability of a dental implant. Under constant biting force, dental implants bear the stress proportional to the angle, high angles cause high stress, average angles cause average stress, and low angles cause the least stress.</p>
Subject(s)
Humans , Bite Force , Dental Implants , Dental Prosthesis Design , Dental Stress Analysis , Finite Element Analysis , Mandible , MolarABSTRACT
@#Objective In the prosthetic socket design process, the high cost and radiation deficiency caused by CT scanning which is a routine way to obtain the cross section image of the residual limb remain problems. Ultrasonic measuring approach is proposed to gain the bones and skin contour of the residual limb. MethodsAn ultrasonic measuring device to get the multiple ultrasonic images of the residual limb was developed firstly, a compound algorithm to reconstruct the multiple images into 2D image was designed, and then the feature extraction on the bones and skin was made. Results Conclusion Comparing with the like-kind cross sectional scanning technique, the ultrasonic measuring method has the characteristic of no radiation and low cost.
ABSTRACT
It is an important approach for CAD/CAM of prosthetic sockets to establish digital model of residual lower limbs from amputees. In this thesis, ultrasonic imaging technology is utilized to extract the internal and external contours of residual lower limbs for their 3D modeling , and an ultrasound measurement system is developed.