Stability of the implant/abutment joint in a single-tooth external-hexagon implant system: clinical and mechanical review

Rigorous efforts have recently been made to reduce the recurrence of implant/abutment joint failure in single‐tooth implant restorations. However, the current knowledge about the stability of implant/abutment joints in an external hexagon implant system is incomplete. We reviewed clinical data regarding single‐tooth implant treatment with Brånemark implants, specifically the CeraOne abutment system (Nobel Biocare AB, Göteborg, Sweden). In vitro studies on joint stability were systematically assessed. Bending overload and the presence of misfit at the implant/abutment joint interface are the critical mechanical conditions that can make the joint unstable. Appropriate joint fitness and proper alignment of the implant should be assessed, and occlusal adjustment by narrowing the restoration width and flattening cuspal inclination should be applied to avoid bending moments caused by the lateral component of occlusal forces. Sufficient clinical reports of longer duration that evaluate and verify longer‐term success of the newly manufactured joint components were unavailable.     

重度侵袭性牙周炎正畸种植修复联合治疗的临床修复效果1例报告及文献复习

探讨侵袭性牙周炎患者经口腔多学科联合治疗后的临床修复效果,阐述多学科联合治疗对口腔功能恢复的重要意义。     

雷奈酸锶治疗人工关节磨损颗粒诱导骨溶解的实验研究

目的研究雷奈酸锶治疗人工关节磨损微粒诱导骨溶解的作用,探讨防治人工关节置换术后假体松动的可能性。方法采用小鼠建立Co—Cr-Mo微粒诱导骨溶解的颅骨模型,分为4组：A组为空白组,B组为颗粒对照组,C组为低剂量治疗组,D组为高剂量治疗组。28d后取出颅骨进行HE染色观察颅骨骨溶解面积,通过EUSA方法检测TNF—α和RANKL的表达,qRT-PCR方法检测RANKL和OPG的表达并分析RANKL／OPG比率变化。结果雷奈酸锶可以明显抑制微粒诱导的骨溶解,对下调TNF-α和RANKL蛋白有确切的疗效,而且这种改变与雷奈酸锶的剂量有关。虽然其对OPG基因转录的抑制作用不太明显,但是对RANKL基因转录和RANKL／OPG基因转录比率的调节与HE染色切片上骨溶解程度相一致。结论雷奈酸锶能够抑制小鼠颅骨骨溶解模型中TNF-α和RANKL的表达,并下调RANKL/OPG基因转录比率,从而抑制了由微粒诱导的骨溶解,为临床预防人工关节置换术后假体松动提供了理论依据。     

Inhibitory effect of icariin on Ti-induced inflammatory osteoclastogenesis

Background

Wear particle-induced periprosthetic osteolysis that results in aseptic loosening is the most common cause of long-term failure after total joint replacement.

Materials and methods

Icariin (ICA), a flavonoid isolated from Epimedium pubescens, inhibits osteoclast formation, but its effects on wear particle-induced inflammatory osteoclastogenesis remains unclear. We investigated the role of ICA in the regulation of osteoclast differentiation in a murine macrophage cell line (RAW264.7), which is stimulated by titanium (Ti) particles and the receptor activator of NF-κB ligand.

Results

ICA effectively inhibited osteoclast formation and bone resorption in the differentiation medium. ICA (10⁻⁷ mol/L) significantly reduced the number of tartrate-resistant acid phosphatase-positive cells compared with the control, and significantly reduced the percentage of the surface covered by resorption lacunae. Quantitative real-time polymerase chain reaction analysis showed that ICA inhibited messenger RNA expression for the receptor activator of nuclear factor-κB, cathepsin K, tartrate-resistant acid phosphatase-positive, and matrix metalloproteinase-9 in RAW264.7 cells stimulated by Ti particles and receptor activator of NF-κB ligand. ICA also reduced pro-inflammatory cytokine expression of interleukin-1β and tumor necrosis factor-α in RAW264.7 cells cultured with Ti particles. In addition, incubation with cholecystokinin-8 showed that ICA had no toxic effects on RAW264.7 cells.

Conclusions

ICA possibly elicited inhibitory effects on inflammatory osteoclastogenesis induced by Ti particles, indicating that ICA may be useful for the prevention and treatment of wear particle-induced osteolysis.     

High Failure Rates of the Spectron EF Stem at a Minimum of 10 Year's Follow-up

We prospectively followed 112 hips, undergoing THA with a Spectron EF stem. At mean follow-up of 11.2 years, 21 patients had died. We obtained radiological follow-up in 99% and clinical follow-up in 100% of the surviving 91 hips. Fifty-four percent demonstrated osteolysis in at least one Gruen zone. Twenty-two hips required revision for all causes, with a further five stems radiologically loose. With endpoint being stem revision for aseptic loosening or radiological failure, survivorship at 11 years was 0.783. We believe the addition of a rougher surface finish has contributed to the high levels of osteolysis and stem failure seen with the Spectron EF.     

界膜与人工髋关节松动的相关性分析

目的：通过对松动假体界膜的研究分析人工髋关节松动的原因。方法：通过对28例人工髋关节翻修术中松动假体周围界膜组织进行肉眼外观及扫描电镜对表面超微结构的观察来分析人工髋关节无菌性松动与界膜之间的相关联系。结果：所有本组28例松动假体周围均充填有薄厚大小不一的界膜组织,多数颜色为暗红色,约1／3的界膜部分有黑色;界膜较厚处质韧类似瘢痕结缔组织,薄处似纤维薄膜。扫描电镜观察可以见到大量的粗细不等排列无序的胶原纤维组织和大小不一分布不均的异物颗粒和骨碎屑,胶原纤维内有成纤维细胞分布。结论：人工假体与骨骼形状不完全匹配,空隙的产生导致纤维瘢痕组织（界膜）充填,磨损微粒沿空隙扩散至界膜刺激界膜释放炎性细胞因子导致骨溶解而出现假体松动,松动后的假体与骨髓腔空隙加大导致更多界膜组织充填、释放溶骨性细胞因子而形成恶性循环。     

针刀松懈术联合手法治疗脊柱侧弯的临床观察

目的:探讨针刀松懈术联合手法对脊柱侧弯的治疗有效性,并做随访记录。方法:选取2012年1月至2016年9月期间宜昌市中心人民医院收治的脊柱侧弯患者34例,并分为2组,观察组使用针刀松懈术配合手法进行治疗,对照组佩戴支具进行治疗,比较2组患者的治疗总有效,以及在治疗前后VAS评分差异和Cobb角矫正效果,对针刀松懈术联合手法使用的有效性和可行性进行深入探讨。结果:观察组的优良率为94.12%高于对照组的82.35%,且前者的治疗效果为优的患者高达70.59%远远大于后者的29.41%,P0.05;但是观察组平均评分更低为(2.6±0.5),对照组为(4.8±1.9)分,P0.05;观察组矫正率为50.4%,对照组的平均矫正率为20.7%,P0.05,2组治疗前后Cobb角比较均有统计学意义,P0.05;术后半年进行随访,观察组平均身高增加了(5.1±0.6)cm,对照组为(4.6±0.7)cm,P0.05。结论:针刀松懈术联合手法治疗不但可以有效缓解患者疼痛,还能起到一个良好的矫正效果,增加身高,提高预后,是一个可靠的、有效的治疗脊柱侧弯的方案。