Measurement of implant stability and auditory pure-tone thresholds of Baha patients comparing osteosysthesis and osseointegrated systems

With bone-anchored hearing systems the implant-bone junction is critical for the transmission of mechanical vibrations to the skull. The implant stability might differ between available and widely applied implants and can be estimated by resonance frequency analysis.The implant stability and the audiological performance of ten adult long-time users where a bone-anchored hearing system was connected by an Baha osseointegrated implant (Cochlear Ltd, Mölnlycke, Sweden) were compared with the implant stability of fourteen adult patients provided with a Ti-epiplating osteosysthesis system (Medicon, Tuttlingen, Germany). The acute implant stability was compared between these two implants with one cadaveric skull.The results show higher resonance frequencies and thus higher implant stability for the osseointegrating system of both, measuring acute and after long-time use of the implants. The audiological outcomes show frequency dependent differences between both systems as determined by comparing pure-tone bone-conduction audiometry. However, measuring thresholds by a direct stimulation of the implant reveals better hearing with low frequencies for the osseointegrated system and for high frequencies with the osteosysthesis system. At all, the implant selection has an impact on the implant stability and on the pure-tone hearing.     

骨移植牙种植体同期植入的扫描电镜观察

目的：探讨骨移植牙种植体同期植入后骨整合的效果。方法：恒河猴6只随机分三组分别行血管吻合骨移植（Vascularized Bone Graft,VBG)牙种植体同期植入；游离骨移植（Non-Vascularized Bone Graft,NVBG)牙种植体同期植入，拔牙后三个月植入牙种植体，切取标本后扫描电镜观察，结果：VBG组：术后12周移植骨与种植体之间部分为骨性结合界面，16周呈完整的骨性结合，NVBG组：术后12周其界面为纤维结缔组织，少量骨少梁，24周大部分为骨性结合界面，呈完整的骨性结合。结论：VBG或NVBG牙种植体同期植入均能形成骨性整合，但NVBG组形成较晚，临床应用中应予注意。     

Osteoporosis and Osseointegration of Implants

According to medical literature, osteoporosis and related bone pathologies are increasing in epidemic proportions. The exact etiology of the disease is unknown, but hormonal, dietary, and genetic factors all contribute to the related loss of bone density. In the disease process, bone loss occurs throughout the body. Research indicates that the mandible and maxilla are affected, and show oral manifestations. There is no scientific data to contraindicate the use of two-step osseointegrated implants in osteoporotic individuals. The purpose of this article is to review the literature regarding osteoporosis and its relationship to oral bone loss.     

受区骨膜对非血管化骨移植种植体与骨结合的作用

目的 探讨受区骨膜对非血管化骨移植种植体与骨结合的影响,为临床在非血管化骨移植 同期进行种植体植入提供依据。方法 在狗的双侧下颌骨下缘切取1.2cm×4.0cm大小的骨块原位再植,将 钛芯羟基磷灰石涂层(Ti-HA)圆柱形种植体植入移植骨块中,左侧去除骨膜为实验组,右侧为对照组。分 别于术后2周,1个月,2个月,4个月,6个月处死动物取材,进行X线摄片,组织学切片及扫描电镜观察。 结果 在各个时间点上,实验组和对照组的骨愈合情况及植种植体与骨结合情况相似无明显差异。结论 受区骨膜的存在与否对非血管化骨移植后骨的愈合及种植体与骨的结合无明显的影响。     

Assessment of Osstell? and Periotest? systems in measuring dental implant stability (in vitro study)

Objectives

The objectives of this in vitro study were to investigate the sensitivity and reliability of the Osstell™ systems (Resonance Frequency Analysis – RFA) compared to the Periotest® system in implant bone simulated conditions. Three conditions were simulated: (1) the direct fixture-bone contact and fibrous tissue fixture contact, (2) The different levels of horizontal bone loss, and (3) The hardening implant–bone interface.

Materials and methods

Forty-nine dental implant fixtures were placed in the center of acrylic cubes. In Part I seven fixtures were placed in direct contact with acrylic and another seven were placed in contact with polyvinyl siloxane impression material as soft interface. Part II: four sets of 0, 2, 4 and 6 mm horizontally exposed fixture samples were made (seven fixtures in each set). Part III: seven fixtures were placed in contact with a thin mix of autopolymerizing resin. The stability of these fixtures was measured using Osstell™ and Periotest® systems.

Results

The mean Periotest® value(PTV) and Osstell™ measurements showed a significant difference between the direct contact and soft interface (P < 0.001). These values also showed statistically significant difference between the different levels of horizontally exposed fixture groups (P < 0.001). The level of horizontal fixture exposure was strongly correlated with the PTVS (r = 0.967) and strongly negatively correlated with Implant Stability Quotient (r = −0.946). A strong correlation was found between the Osstell™ readings and the change in the stiffness of the autopolymerizing resin fixture interface group (r = 0.986).

Conclusions

Both Osstell™ and Periotest® systems proved to be sensitive in measuring dental implant stability in hard and in soft interfaces. Osstell™ also proved to be sensitive in detecting changes in the fixture interface stiffness. Osstell™ system proved to be more reliable compared to Periotest® system in measuring dental implant stability in hard and in soft interfaces.     

喷砂联合飞秒激光蚀刻对纯钛表面理化性能的影响

目的 纯钛表面喷砂处理后,利用飞秒激光蚀刻形成表面周期性微结构,初步评价其表面理化性能。方法 12个直径10 mm、厚4 mm的纯钛圆片样本,根据表面处理方式,随机分为喷砂组（S组）、喷砂酸蚀组（SA组）、喷砂飞秒激光蚀刻组（SL组）。采用扫描电镜（SEM）、X射线能谱仪（EDS）、激光共聚焦显微镜（CLSM）、高温润湿角测量仪,分析3种钛表面的表面形貌、化学成分、粗糙度及润湿性。采用 SPSS19.0 软件包对数据进行统计学分析。结果 SEM及CLSM观察显示,飞秒激光在喷砂钛表面蚀刻出均匀整齐的周期性微米级结构,SL组钛表面呈二级粗糙度复合结构。EDS分析显示,SL组钛表面Al元素减少（SL组4.37%SA组0.32>S组0）。表面粗糙度测量显示,SL组钛表面粗糙度显著增大 [SL组（7.33±0.38）μm>SA组（1.08±0.12）μm>S组（1.05±0.14）μm]（P<0.001）;表面静态接触角测量显示,SL组钛表面静态接触角显著减小 [SL组（34.4±2.5）°P<0.001）。结论 喷砂联合飞秒激光蚀刻纯钛表面具有优良的理化性能,是一种具有潜力的钛种植体表面改性技术。     

埋入式BLB种植体疗效的长期评估

目的:回顾分析埋入式种植体BLB种植系统修复缺牙的临床效果。方法:一期埋置式植入BLB种植体,对骨量不足者进行自体骨或人造骨粉移植及上颌窦提升以曾宽手术适应症。3个月X线复诊检查,5-6个月进行二期暴露的手术方式,二期手术两周后进行上部义齿修复。结果:对232人共412枚种植体追踪观察6个月-七年,有明确记录的共8枚种植体脱落,原因不明的2枚脱落,追踪观察修复体螺丝松动6枚,螺丝固位紧而冠与基台间出现转动2枚,种植体与基台连接处螺纹脱丝1枚,烤瓷冠崩瓷5枚。结论:BLB种植系统存留率达到98.05%,骨结合性能良好,是比较理想的种植系统。