Damping characteristics of bone‐to‐implant interface; A clinical study with the Periotest® device.

The Periotest® device was used to evaluate the damping characteristics of different bone‐to‐implant interfaces of Brånemark implants. Implant and abutment lengths were found to have a significant influence on Periotest value (PTV). There was no statistical difference between PTVs of implants located in the anterior and posterior areas of the same jaw at abutment connection. No differences were found between PTVs of standard and self‐tapping implants. PTVs at abutment connection were highly influenced by the bone quality. The contact with two corticals, one at each extremity of the implant, was of a greater influence in the maxillary than in the mandibular jaw, indicating a firmer anchorage between the bicortical implants and the surrounding bone. A proaressive decrease of PTVs over time was observed, significant up to 5 years of loading.     

Guided bone regeneration for immediate non‐submerged implant placement using bioabsorbable materials in Beagle dogs

The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri‐implant defects after placement of non‐submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow‐screw non‐submerged dental implants. For each animal, the coronal peri‐implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site: 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures ( P >0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%. P <0.05) or sites grafted with HA (22.2%, P <0.02). Total BIC in sites treated with the HA‐membrane combination (43%) was only significantly different from sites treated with HA ( P <0.10). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.     

Laser Doppler flowmetry of blood perfusion in mucoperiosteal flaps covering membranes in bone augmentation and implant procedures. A pilot study in dogs.

In guided tissue regeneration (GTR) procedures, flap recession or sloughing may occur as an unwanted sequel to the placement of a membrane. This study was designed to assess the applicability of laser Doppler flowmetry (LDF) in the evaluation of blood perfusion in the mucoperiosteal flap covering the membrane. Five Labrador dogs were initially used inthe study, but one animal was later excluded due to post‐operative problems. Maxillary premolar teeth were extracted and full thickness mucoperiosteal flaps were raised. Following removal of the buccal bone plate, 4 titanium implants were placed on each side. An experimental biodegradable polylactic‐acid membrane was placed over the fixtures on one side to allow for GTR. The mucoperiosteal flap was repositioned and secured with sutures. The contralateral side served as control with no membrane. Blood perfusion was measured in the flaps before surgery, immediately after suturing and at 24, 48 and 72 h postoperatively. A laser Doppler flowmeter was used to assess the blood perfusion. In 3 animals the membrane was exposed within 2 weeks post‐operatively, and in these 3 animals the LDF values were lower on the membrane side than on the control side. The mean LDF value was lower on the membrane side for each of the 4 periods studied. The tindings suggest that LDF can be a valuable method to study blood perfusion of oral mucosal flaps and that there may be a relationship between a reduced relative LDF value and subsequent exposure of the membrane to the oral environment.     

Operative treatment of intertrochanteric hip fractures: an overview of modern advances and techniques

Hip fractures have been one of the most studied injury pattern in adults. The number of hip fractures is increasing exponentially; furthermore, the cost of treatment places great economic strain on society. There have been recent developments in hip-fracture treatment, particularly involving the intertrochanteric region, with emphasis on deformity prevention to try to optimize patient functional outcomes. In this article, we outline some of these developments with an emphasis on changes in implant design.     

CDIC人工牙种植体的临床应用

目的：探讨种植牙的临床应用及酯套冠的修复疗效。方法：对80例失牙患者植入CDIC锥状螺旋种植体94枚，术后7－10d行暂时冠修复，6个月左右行永久性酯套冠修复。结果：随访2－5年，种植成功率达91.5%（86／94)。结论：3M聚碳酸酯套冠安全可以替代烤瓷牙冠作为前牙种植体的上部结构，CDIC锥状螺旋种植体操作方法简单，配合酯套冠修复成功率高，适合在基层医院推广应用。     

A 2‐year report on maxillary and mandibular fixed partial dentures supported by Astra Tech dental implants. A comparison of 2 implants with different surface textures.

In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO‐blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1 maxillary) were found to be non-osseointegrated and were replaced. Another implant could not be restored due to a technical complication. Two FPDs were remade because of technical complications, both because of abutment fractures. Thus, after 2 years in function, the cumulative survival rates were 97.7% and 95.7% for implants and prostheses, respectively. There was no statistically significant difference in survival rate between the 2 types of implants, 100%(TiO‐blasted) vs 95.3%(machined), P =0.24. After 2 years in function, when both jaw and type of implants were combined, the mean (SD) marginal bone loss was 0.24 (0.69) mm. No statistically significant difference in bone loss was found between the 2 tvues of implant after 2 years of loading, 0.04 (0.82) mm, P >0.30.     

Multiple Implants for First Molar Prosthodontics

Problems that can occur when single implants are utilized to restore first molar teeth include the frequent loosening of screws, as well as screws and/or implant breakage. These may result from torquing and rotational movements of the prosthesis during masticatory and parafunctional mandibular movements. When sufficient bone and mesio-distal restorative space is present, the placement of two implants should be considered.     

隆乳术后27例取除假体者原因分析

通过对隆乳术后27例取除假体者的原因进行分析,进一步揭示了目前隆乳术中仍存在的某些不足,发现术后感染、疼痛、假体破裂或外露、包膜挛缩、病人心态失衡等都是造成假体取出的直接原因。认为采取高质量的假体胸大肌下间隙隆乳是降低并发症提高隆乳术质量的关键。     

胎儿骨临床应用的研究(附40例报告)

本文报告了6～9个月胎儿长骨的化学成分的测定结果及其组织特点并与成人作了比较。自1985～1987年共进行了胎儿骨移植40例,随访38例,经4～20个月(平均10.3个月)的临床观察,证实胎儿骨移植后“爬行替代”快,骨诱导能力强,排斥反应不明显,笔者认为这些特点与胎骨的形态结构及化学成分有关。胎儿骨的采取和贮存简便,应用方便,易于推广和普及。     

The long-tube single plate Molteno implant for the treatment of recalcitrant glaucoma

One hundred cases of recalcitrant glaucoma were operated with a long tube single-plate Molteno implant (LSMI). At the median follow-up of 15 months an intraocular pressure of 19 mm Hg was obtained in 64 of the 87 eyes (73%) which have a minimum follow-up of 6 months (secondary non-neovascular glaucomas=19; congenital glaucomas=26; secondary neovascular glaucomas=12). The interval probability (percentage±standard error) of obtaining a successful result (IOP19 mmHg) was 79% (±13) at twelve months from surgery, and 53% (±24) at the eighteen month interval. The least favorable results were obtained in the secondary non-neovascular glaucomas. Complications observed included choroidal detachment (24%), tube exposure (4%), tube-endothelium contact (6%), plus band keratopathy, fibrous ingrowth, traction retinal detachment and corneal ulcers.Seventeen cases needed repeate surgery for the management of complications. In order to decrease the post-operative hypotony, we have been using a tourniquet suture around the tube at the time of implantation to occlude it temporarily and limit the outflow.