Current Issue : July - September Volume : 2013 Issue Number : 3 Articles : 7 Articles
Objective. To observe the intracochlear behavior of a cochlear implant electrode insertion technique (called ââ?¬Å?pullbackââ?¬Â) in temporal\r\nbones. Study Design. Experimental. Settings. Tertiary referral center. Method. The change of the intracochlear electrode position\r\nwas investigated under various conditions of an electrode pullback (N = 54) in 9 radiologically, size-estimated temporal bones\r\n(TBs). Those TBs were prepared by removal of the cochlear scalar roof to apply digital video capture procedures to monitor the\r\npullback procedures. The digitally captured pictures were analyzed with specific software. Results. An optimal pullback of the\r\nelectrode varied between 1.37mm and 2.67 mm. While a limited pullback is without risk, an extended pullback bears the risk of\r\nremoving the electrode tip out of its initial position or out of the cochlea. A correlation between cochlear size and the amount of\r\npullback was not found. Conclusion. An initial insertion to the first or the second marker on the electrode followed by a limited\r\npullback of about 1.37mm to 1.5mm can be recommended to achieve an optimized perimodiolar position. A pullback of up to\r\ntwo marker positions bears the risk of removing the electrode tip out of its initial position....
Objective. To compare two internal fixation devices clinically in stabilisation of intertrochanteric femur fractures. Methods. Eightyseven\r\npatients were randomised upon their admission to the hospital using a sealed envelope method. Forty-five were treated with\r\nproximal femur nail antirotation (PFNA) and 42 with reverse less invasive stabilisation system (LISS). The perioperative data were\r\nrecorded and compared in relation to fracture type. Results. In each type of fractures, no significant differences were found with\r\nrespect to the blood loss, the quality of reduction, the time to bony healing, and the Harris hip score between the 2 groups.The\r\nmean duration of surgery was significantly longer in reverse LISS group than in PFNA group. Conclusion. Both the PFNA and the\r\nreversed LISS are effective in the treatment of different types of intertrochanteric femur fractures. PFNA is superior to reverse LISS\r\nin terms of surgical time, weight-bearing, and perhaps fluoroscopy time....
The surface energy of the implant surface has an impact on osseointegration. In this study, 2 surfaces: nonwashed resorbable blasting media (NWRBM; control) and Ar-based nonthermal plasma 30 days (Plasma 30 days; experimental), were investigated with a focus on the surface energy. The surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and the chemistry by X-ray photoelectron spectroscopy (XPS). Five adult beagle dogs received 8 implants (n = 2 per surface, per tibia). After 2 weeks, the animals were euthanized, and half of the implants (n = 20) were removal torqued and the other half were histologically processed (n = 20). The bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were evaluated on the histologic sections. The XPS analysis showed peaks of C, Ca, O, and P for the control and experimental surfaces. While no significant difference was observed for BIC parameter (P > 0.75), a higher level for torque (P < 0.02) and BAFO parameter (P < 0.01) was observed for the experimental group. The surface elemental chemistry was modified by the plasma and lasted for 30 days after treatment resulting in improved biomechanical fixation and bone formation at 2 weeks compared to the control group....
Magnesium alloys as biodegradable metal implants in orthopaedic research received a lot of interest in recent years. They have\r\nattractive biological properties including being essential to human metabolism, biocompatibility, and biodegradability. However,\r\nmagnesium can corrode too rapidly in the high-chloride environment of the physiological system, loosing mechanical integrity\r\nbefore the tissue has sufficiently healed.Hydroxyapatite (HAp) coating was proposed to decrease the corrosion rate and improve the\r\nbioactivity of magnesium alloy. Apatite has been cathodically deposited on the surface of Mg alloy from solution that composed of\r\n3mMCa(H2PO4)2 and 7mMCaCl2 at various applied potentials.Thegrowing ofHAp was confirmed on the surface of the coatings\r\nafter immersion in SBF solution for 7 days. The coating obtained at -1.4V showed higher corrosion resistance with bioactive\r\nbehaviors....
Zygomatic implants have been used for dental rehabilitation in patients with insufficient bone in the posterior upper jaw, due to, for\r\nexample, tumor resection, trauma, or atrophy. Zygomatic implants are an alternative to complex free or vascularized bone grafting\r\nand distraction osteogenesis. A 42-year-old male patient with a severe defect in the right posterior maxilla, starting from the first\r\ncanine region, which had occurred after tumor resection 3 years earlier, was referred to our department. One zygomatic implant\r\n(Brenemark System, Nobel Biocare, Goteborg, Sweden) to the zygoma and one dental implant to the canine region were placed.\r\nAfter a 5-month osseointegration period, a fixed denture was fabricated and adapted to the implants. Although the surgical and\r\nprosthetic procedures for zygoma implants are not easy, the final outcomes can be successful with appropriate planning....
Objectives. To test the hypothesis that there would be no differences in osseointegration by reducing the number of drills for site\r\npreparation relative to conventional drilling sequence. Methods. Seventy-two implants were bilaterally placed in the tibia of 18\r\nbeagle dogs and remained for 1, 3, and 5 weeks. Thirty-six implants were 3.75mm in diameter and the other 36 were 4.2 mm. Half\r\nof the implants of each diameter were placed under a simplified technique (pilot drill + final diameter drill) and the other half were\r\nplaced under conventional drilling wheremultiple drills of increasing diameter were utilized. After euthanisation, the bone-implant\r\nsamples were processed and referred to histological analysis. Bone-to-implant contact (BIC) and bone-area-fraction occupancy\r\n(BAFO) were assessed. Statistical analyses were performed by GLM ANOVA at 95% level of significance considering implant\r\ndiameter, time in vivo, and drilling procedure as independent variables and BIC and BAFO as the dependent variables. Results.\r\nBoth techniques led to implant integration. No differences in BIC and BAFO were observed between drilling procedures as time\r\nelapsed in vivo. Conclusions.The simplified drilling protocol presented comparable osseointegration outcomes to the conventional\r\nprotocol, which proved the initial hypothesis....
Connecting teeth to osseointegrated implants presents a biomechanical challenge. This is due to the implant being rigidly fixed to the bone and the tooth being attached to the bone with a periodontal ligament. In order to overcome this problem, various connection types such as rigid and nonrigid have been proposed. However, the mechanism of attachment and the perceived problem of the differential support provided by the implant and the tooth have been discussed by many authors, and the ideal connection type is still controversial. The aim of this study was to carry out a review of all available literature addressing the tooth-implant connection and evidence-based understanding of the management of tooth-implant-retained restorations....
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