ABSTRACT
Objective To evaluate the influence of different insertion torque values on stress and strain distributions at implant-bone interface. Methods The three-dimensional finite element model of the whole mandible with dental implants for immediate loading was created by CT scanning and self-developed USIS (universal surgical integration system) software. The insertion torque values of dental implants were supposed to be 0、15、25 N•cm3, respectively. The values of Von Mises stress and strain at implant-bone interface were calculated with ANSYS software, when the dental implants were loaded with vertical and buccolingual force at a 45°oblique angle of 150 N. Results When the dental implants under the three insertion torques were loaded with the vertical force, the maximum Von Mises stress was 33.6, 56.4, 69.6 MPa and the maximum strain was 5 157, 8 645, 15 630 με, respectively, while loaded with the buccolingual force, the maximum Von Mises stress was 95.3, 100.6, 108.3 MPa and the maximum strain was 17 110, 18 690, 21 380 με, respectively. Conclusions With the increased torque value of dental implants, the stress and strain at the implant-bone interface were both increased, but the increase was much slower under buccolingual loading than that under vertical loading.
ABSTRACT
<p><b>OBJECTIVE</b>To introduce a self-developed bone collector designed by the authors and evaluate its effect in clinical application.</p><p><b>METHODS</b>A self-developed bone collector was used in 38 patients who underwent the dental implant operation from May 2008 to October 2009. During the operation the bone particles were harvested, which was used for the reconstruction of the bone defects around the implant simultaneously. The defects were fenestrate in 29 regions and triangle in 23 regions on buccal or lingual side of the dental implants.</p><p><b>RESULTS</b>All cases had no surgical wound infection and dehiscence 7 - 10 days after operation. Three to six months after implantation, the X-ray showed that all the dental implants had perfect osseointergration and the alveolar bone were successfully augmented.</p><p><b>CONCLUSIONS</b>Bone debris harvested by self-developed bone collector could repair small peri-implant bone defects, which is simple to use in clinic.</p>