骨整合义耳修复创伤性全耳廓缺损

目的探讨骨整合义耳修复创伤性全耳廓缺损的可行性和临床效果。方法回顾性分析19例创伤性全耳廓缺损采用骨整合义耳修复患者。其中先天性小耳畸形全耳再造失败者12例,硫酸烧伤1例,高温铝水烫伤1例,车祸所致4例,刀砍伤1例。所有病例得到随诊,时间3～5年。结果所有患者均1次治愈,有一个形态逼真、色泽自然的外观,用骨整合方法固位的义耳配戴稳定,对日常生活无影响。结论骨整合义耳修复方法简便、创伤小、治疗周期短,无并发症,效果满意。对全耳再造失败者是一有效的治疗补救,对耳廓连同周围组织大面积缺损后瘢痕愈合者是可优先选择的方法。     

种植硅橡胶义耳在临床中的应用

目的对耳廓缺损的患者使用种植硅橡胶义耳,种植体是解决义耳的支持与固定的关键。方法在患耳（其中包括耳外伤1例和先天性耳廓畸形4例）颞骨乳突皮质骨处植入2枚钛钉种植体,采用杆卡式结构作为义耳的固位装置,完成种植义耳的修复。结果术后经3～6个月观察,钛钉种植体的骨亲和性良好,种植义耳外形逼真,患者满意。结论种植硅橡胶义耳是耳缺失的修复方法之一。     

Surface Roughness of Dental Implant and Osseointegration

IntroductionDental implants are a usual treatment for the loss of teeth. The success of this therapy is due to the predictability, safety and longevity of the bone–implant interface. Dental implant surface characteristics like roughness, chemical constitution, and mechanical factors can contribute to the early osseointegration. The aim of the present article is to perform a review of the literature on surface roughness of dental implant and osseointegration.MethodologyThis work is a narrative review of some aspects of surface roughness of dental implant and osseointegration.ConclusionDespite technological advancement in the biomaterials field, the ideal surface roughness for osseointegration still remains unclear. In this study about surface nanoroughness of dental implant and osseointegration, the clinical relevance is yet unknown. Innovative findings on nanoroughness are valuable in the fields of dental implantology, maxillofacial or orthopedic implant surfaces and also on cardiovascular implants in permanent contact with patient’s blood.     

种植体掺离子表面改性技术及其促进骨结合的研究进展

种植牙因其在解决牙列缺损方面巨大的优势,已成为许多缺牙患者首选的治疗方式。在临床应用中,如何促进种植体与骨组织界面的骨结合是种植治疗成功的关键,因此种植体表面改性一直是研究的热点。骨组织中含有钙、磷、锌、镁、锶等大量微量元素,这些微量元素对于骨组织的生长发育必不可少。因此可以通过将微量元素掺入种植体表面来促进种植体骨结合。本文着重介绍了种植体表面改性的相关技术以及微量元素促进骨结合的具体机制。     

An in vitro assessment and comparative effectiveness of silanized-glutaraldehyde functionalized titanium surfaces with phosphatidylcholine and type I collagen grafts

ObjectiveThis study aims to evaluate sequence-modified Ti surfaces functionalized with silanized glutaraldehyde and further grafted with the active biomolecules of phosphatidylcholine and type I collagen (COL I).MethodsThe properties of the functional surfaces were investigated by various surface analysis techniques and characterized their capability in osteogenic cell attachment, differentiation, and mineralization in vitro.ResultsThe Ti surfaces grafted with phosphatidylcholine and COL I effectively improved the hydrophilicity. In addition, an effect of COL I concentrations (higher than 2.5 μg/mL) do not stimulate subsequent alkaline phosphatase (ALP) activity during osteogenesis in vitro. However, the result is different in phosphatidylcholine, that is, as the concentration of phosphatidylcholine increased enhances subsequent osteogenetic properties. The Ti groups with bioactive molecules affected cell characteristics in vitro in contrast to the controlled Ti group. The proliferation and differentiation levels of osteoprogenetor cells were enhanced and ALP was strongly expressed in the groups grafted with phosphatidylcholine and COL I.SignificanceThis modification promotes progenitor bone cell adhesion, proliferation, and differentiation and thus drastically improves the success rate for implant modification by accelerating surface osseointegration.     

Atomic layout of an orthodontic titanium mini-implant in human tissue: Insights into the possible mechanisms during osseointegration

Objectives:To evaluate nanoscale molecular interactions in the interface between human bone and orthodontic titanium implants.Materials and Methods:An orthodontic implant (sandblasted with large grit and with an acid-etched surface treated with Ti6A14V alloy) retrieved from the mandible of human after 2 months of healing was used to analyze the molecular interactive mechanism between the implant and the surrounding bone tissue. To preserve the natural state of the sample as much as possible, cryofixation and scanning electron microscope/focused ion beam milling without any chemical treatment were used during sample preparation. Atom probe tomography was used to investigate the chemical composition and structure at the interface between the implant and human bone tissue.Results:Three-dimensional (3D) reconstruction of the whole sample revealed a 20 × 50-nm² plate-like bony element diffusion layer in the sample. The iso concentration analysis of the diffusion layer indicated that the bony element, calcium, and the implant element, titanium oxide, were interspersed with each other. Detailed ionic distribution was illustrated by 3D reconstruction with partial region of interest and one-dimensional concentration profiles of the implant-bone interface.Conclusions:The study results advance nanoscale understanding of osseointegration and suggest a potential nanostructure for increasing bond strength of biomaterials to bone.     

nHA/BG涂层与Bio-Oss骨粉修复种植体骨缺损的实验研究

目的:评价生物玻璃/纳米羟基磷灰石(nHA/BG)涂层与Bio-Oss骨粉在种植体骨缺损中引导骨再生的效果。方法:选取6只Beagle犬,拔除两侧下颌前磨牙。3个月后预备种植窝,同时颊侧制造裂隙状骨缺损(2.25 mm×3 mm×4 mm)。按照分组植入种植体和骨粉,A组为nHA/BG+Bio-Oss,B组为nHA/BG+血凝块愈合,C组为微米级HA+Bio-Oss。术后2周、处死前2周和3 d分别进行四环素、钙黄绿素和茜素红荧光标记。术后8周和16周处死动物,行大体观察和组织学测量。采用SPSS13.0软件包对数据进行统计学分析。结果:3组骨-种植体结合率(BIC)在8周时分别为30%、18%、21%,16周时分别为61%、53%、46%;缺损区新骨面积(RA)在8周时分别为(2.1±0.6)mm3、(1.4±1.0)mm3、(0.6±0.1)mm3,16周时分别为(4.2±0.7)mm3、(2.2±1.2)mm3、(1.2±0.6)mm3。各组8周与16周的BIC和RA相比均有显著差异(P<0.05);8周时,A、C 2组的BIC和RA相比有显著差异(P<0.05),16周时,A、B 2组的RA相比有显著差异(P<0.05)。结论:在种植体周围2.25 mm骨缺损区,nHA/BG涂层能促进种植体-Bio-Oss替代骨-骨的骨结合。     

Effect of placement angle on the stability of loaded titanium microscrews in beagle jaws

Objective:To evaluate the effect of insertion angle on stability of loaded titanium microscrews in beagle jaws.Materials and Methods:Forty-eight microscrews were inserted at four different angles (30°, 50°, 70°, and 90°) into the intraradicular zones of the mandibular first molars and third premolars of 12 beagles and immediately loaded with a force of 2 N for 8 weeks. Microcomputed tomography (micro-CT) and biomechanical pull-out tests were used to assess osseointegration of the interface.Results:All micro-CT parameters and maximum pull-out force (F_MAX) of the microscrews were affected by insertion angles of microscrews. Higher micro-CT parameters and F_MAX were seen for implants inserted at angles between 50° and 70° (P < .05). Excessive oblique and vertical insertion angles resulted in reduced stability (P < .05).Conclusion:An insertion angle of 50° to 70° is more favorable than excessive oblique or vertical angles to achieve stability of microscrews.     

Dental implants in the medically compromised patient

Objective

It has been suggested that some local and systemic factors could be contraindications to dental implant treatment. The objective of this paper was to evaluate whether success and survival rates of dental implants are reduced in the medically compromised patient.

Data/sources

An extensive literature search was conducted using PubMed/Medline, Scopus, Scirus and Cochrane databases up to November 8, 2012.

Conclusions

There are very few absolute medical contraindications to dental implant treatment, although a number of conditions may increase the risk of treatment failure or complications. The degree of systemic disease-control may be far more important that the nature of the disorder itself, and individualized medical control should be established prior to implant therapy, since in many of these patients the quality of life and functional benefits from dental implants may outweigh any risks.     

In vivo monitoring of the bone healing process around different titanium alloy implant surfaces placed into fresh extraction sockets

Objectives

Increasing surface roughness and coating with tricalcium phosphate of titanium and titanium alloy implants has been proposed to provide better rates of osseointegration. However, how these changes in surface topography and chemistry influence the osseointegration process of immediate implants placed in fresh extraction sockets is unclear. This study investigated the influence of three clinically employed implant surfaces on the early bone healing events in vivo.

Methods

Machined smooth implants were milled from grade 5 Ti6Al4V titanium. Surfaces were moderately roughened by grit blasting, which were then coated with tricalcium phosphate. Implants were placed into freshly extracted incisor sockets of mandibles of normal Wistar rats and left for 1, 3 and 9 weeks. Healing bone tissue around the implants was examined by histochemistry and immunocytochemistry to localise PCNA proliferative cells, and osteoblast differentiation markers osteopontin and osteocalcin. Positive synthesising cells were counted using image analysis.

Results

Histology indicated no differences in the amount or pattern of bone formation within the healing tissue surrounding the different implant surfaces. Bone healing occurred predominantly on exposed bone surfaces (distance osteogenesis) and not on the implant surface (contact osteogenesis). No differences were observed in the number or timing of PCNA, osteopontin and osteocalcin positive cells within the bone healing tissue around each of the implant analysed.

Conclusion

For immediately placed implants, the surface modifications investigated appeared to have little influence on the activity of bone forming cells surrounding the implant, probably due to the high level of distance osteogenesis seen within this scenario.

Clinical significance

For immediate placement of implants into fresh extraction sockets, titanium implants with roughened surfaces and coating with tricalcium phosphate have negligible influence in accelerating the early bone healing events of osseointegration.