关于提高牙种植体成功率的探讨

作者基于246只牙种植体植入的临床经验，获得近期疗效为97.1%的成功率，提出在目前的普通设备及条件下，提高牙种植体成功率的一些切实可行的有效措施。提示了进行牙种植体植入手术的几项成功要点，为在我国各基层医疗单位更好普及口腔种植修复技术，提供参考依据。     

Evaluation of Strain at the Terminal Abutment Site of a Fixed Mandibular Implant Prosthesis During Cantilever Loading

Purpose Cantilever lengths from 10 mm to 20 mm have been empirically recommended for Brånemark fixed mandibular implant prostheses. However, functional stresses generated within the framework and at the crestal bone associated with various cantilever lengths have not been well researched. The purpose of this investigation was to evaluate the strain generated within an implant-supported prosthesis and on a simulated bone surface during functional cantilever loading. Materials and Methods A symmetrical mandibular fixed-implant framework supported by six Nobelpharma 7.0 × 4.0-mm abutments and 15.0 × 4.0-mm fixtures was fabricated. The fixtures were embedded in a simulated bone matrix of polymethyl methacrylate resin. Fourteen different arrangements of active supporting abutments were tested during 15 Ib unilateral static cantilever loading 7 mm, 14 mm and 20 mm distal to the terminal abutments. T-rosette strain gauges were placed immediately distal to the terminal abutment site on the right side of the framework and on the corresponding simulated bone surface. Results There was no difference in framework microstrain as abutment number and arrangement were varied. Microstrain distal to the terminal abutment increased significantly with increasing cantilever length. Distal abutment microstrain increased 213% (63 με to 197 με) when cantilever length was increased from 7 mm to 14 mm and an additional 55% (197 με to 306 με) when cantilever length was increased from 14 mm to 20 mm. Overall, microstrain increased 306% when cantilever length was increased from 7 mm to 20 mm. Microstrain on the framework was always tensile (positive). Microstrain at the simulated bone reached higher maximum levels than on the framework (-588 με versus 314 με) and was compressive in nature (negative). In contrast to framework microstrain, microstrain at the simulated bone site varied dramatically with changes in abutment arrangement. Strains observed at the simulated bone surface increased dramatically as the distance to the adjacent active abutment increased or as the anterior-posterior span of abutments decreased. Distal abutment microstrain also increased significantly at the bone site as cantilever length increased, however, percent increases were less (7 mm to 14 mm, 55%; 14 mm to 20 mm, 30%; 7 mm to 20 mm, 101%). Conclusions The results of this study indicate that an optimum biomechanical environment should exist when cantilever spans exceeding 7 mm are planned regardless of the number of supporting abutments. Strain transmitted to the crestal bone can be decreased by maximizing the number and anterior-posterior spread of supporting fixtures while minimizing the distance between the distal abutment and its adjacent abutment.     

牙种植外科技术探讨

牙种植外科技术是牙种植学的重要组成部分之一，它直接关系到牙种植的成功与失败。本文结合几年来的临床实践，介绍了牙种植患者的术前评估、治疗设计，重点对于该手术的外科手术问题进行探讨。文章还对该手术的注意事项，如何保证正确的种植部位与方向，防止副损伤等问题介绍了作者的体会。     

种植体数目与分布对下颌种植覆盖义齿骨组织应力变化的影响

目的：建立下颌种植覆盖义齿三维有限元模型,研究咬合力作用下种植体数目与位置分布对牙槽骨组织应力分布的影响因素。方法：临床采集患者下颌骨及其原有义齿CT数据,使用逆向工程软件建立种植体数目与位置不同的下颌种植覆盖义齿实体模型。通过Abaqus有限元软件分析咬合力作用下种植体数目与位置分布对种植体周围以及下颌后端牙槽骨应力变化的影响。结果：在咬合力作用下,下颌骨Mises应力主要分布在种植体周围骨组织,种植体远中颈部呈现应力集中,下颌后端区域应力较小且分布均匀。随着种植体数目的增加,后端种植体周围骨应力上升,远端牙槽骨应力降低。当牙弓前、后端种植体距离增加时,种植体周围骨应力增大,远端牙槽骨应力降低。结论：采用2植体支持的下颌种植覆盖义齿种植体周围骨吸收风险较小,但远端牙槽嵴骨吸收风险增大。4植体义齿所承受的咬合力主要由植体承担,修复时应注意前后植体的距离和咬合力在义齿上的合理分布。     

全颌种植覆盖义齿修复的临床应用初探

采用传统的方法修复牙槽嵴萎缩的无牙患者，常难以达到满意的临床垃果。近年来由于种植义齿的临床应用，使常规活动义齿难以修复的患者得以修复，义齿的稳固性有所加强，咀嚼功能有明显改善。1994年以来，对49例不同程度牙槽嵴萎缩的全颌失牙患者，采用颌骨内植入CDIC系列种植体．上部用杆-卡固位结构的种植覆盖义齿修复。经修复后短期临床观察显示，这种修复方式增强了支持力，使义齿获得良好的稳定固位性，患者的咀嚼效率有所提高，临床效果满意。     

Cantilever and Implant Biomechanics: A Review of the Literature, Part 2

In Part 2 of this literature review, a summary of the literature regarding the determination of acceptable cantilever lengths for fixed implant prostheses is presented. Studies examining the possible effects of biomechanical stress on both the implant prosthesis and the supporting bone are also discussed.     

Influence of surface roughness and shape on microdamage of the osseous surface adjacent to titanium dental implants

Objectives: To assess the relationship between smooth and roughened implant surfaces of straight and narrow configurations with respect to microdamage of the bone surface during placement of dental implants Materials and methods: Straight and tapered, rough and smooth surface Nobel Biocare implants were placed into sheep mandibles. Microdamage within the bone adjacent to the implant surface was quantitated using a semi‐automated digitized histomorphometric method. Results: Independent of implant type, microdamage, microcracks, cross‐hatch damage and diffuse damage were significantly higher close to the implants compared with far from the implants. Microcracks and cross‐hatch damage were higher for the rough cylindrical implants than all the other implant types. Conclusions: Insertion of a rough cylindrical implant type results in an increased fraction of microdamaged bone matrix in comparison to rough tapered, smooth cylindrical and smooth tapered implants. To cite this article:
Bartold PM, Kuliwaba JS, Lee V, Shah S, Marino V, Fazzalari NL. Influence of surface roughness and shape on microdamage of the osseous surface adjacent to titanium dental implants.
Clin. Oral Impl. Res. 22 , 2011; 613–618
doi: 10.1111/j.1600‐0501.2010.02024.x     

Influence of the Connector and Implant Design on the Implant–Tooth‐Connected Prostheses

Purpose: The purpose of this study was to evaluate stress transfer patterns between implant–tooth‐connected prostheses comparing rigid and semirigid connectors and internal and external hexagon implants. Materials and Methods: Two models were made of photoelastic resin PL‐2, with an internal hexagon implant of 4.00 × 13 mm and another with an external hexagon implant of 4.00 × 13 mm. Three denture designs were fabricated for each implant model, incorporating one type of connection in each one to connect implants and teeth: 1) welded rigid connection; 2) semirigid connection; and 3) rigid connection with occlusal screw. The models were placed in the polariscope, and 100‐N axial forces were applied on fixed points on the occlusal surface of the dentures. Results: There was a trend toward less intensity in the stresses on the semirigid connection and solid rigid connection in the model with the external hexagon; among the three types of connections in the model with the internal hexagon implant, the semirigid connection was the most unfavorable one; in the tooth–implant association, it is preferable to use the external hexagon implant. Conclusions: The internal hexagon implant establishes a greater depth of hexagon retention and an increase in the level of denture stability in comparison with the implant with the external hexagon. However, this greater stability of the internal hexagon generated greater stresses in the abutment structures. Therefore, when this association is necessary, it is preferable to use the external hexagon implant.     

Efficacy of two antibiotic regimens in the reduction of early dental implant failure: a pilot study

The purpose of this study was to compare the efficacy of two antibiotic regimens in reducing early dental implant failure. A preoperative single-dose regimen and a 3-day antibiotic course were compared. Eighty subjects needing dental implant placement were randomly allocated to one of the two antibiotic prophylaxis regimen groups. In the first group, dental implants were placed after the administration of a single preoperative dose of antibiotic (1 g of amoxicillin); no postoperative antibiotics were given. In the second group, dental implants were inserted in patients who received the same preoperative dose of antibiotic as the first group, but the antibiotic was then continued postoperatively for 3 days. Patients returned for postoperative evaluation at 3 days, 7 days, and 12 weeks. The surgical sites were assessed for pain, swelling, wound dehiscence, and pus formation. No statistically significant difference was observed between the two groups, probably because of the limited number of patients. Although minor complications were seen in a few patients, all implants were successfully osseointegrated. Until a study with a larger population rules definitively on the role of antibiotics in implant surgery, a single dose of antibiotic before implant placement may be sufficient.     

上颌前牙区应用根膜技术即刻种植的临床效果观察

目的 观察上颌前牙区应用根膜技术即刻种植1年后的临床效果。方法 选取10例上颌前牙区牙齿不能保留的患者,应用根膜技术保留唇侧根片并同期植入种植体,术后6个月行永久冠修复,术后1年复查。术后1年统计种植体存留率;测量术后即刻和术后1年种植体唇侧硬组织厚度;统计术后1年种植修复体牙间乳头外形,并对修复体的红白美学进行评分;统计并发症发生情况及患者对治疗过程的满意度。结果 术后1年复查,种植体存留率为100%;种植体唇侧颈、中、根部硬组织厚度相较于术后即刻分别减少（0.27±0.21）、（0.19±0.20）、（0.28±0.29） mm;术后1年3个测量位点唇侧硬组织的厚度与术后即刻相比,差异均有统计学意义（P<0.05）,但3个位点硬组织厚度的变化量无明显差异（P>0.05）;修复体牙间乳头大多充满邻间隙,粉红色美学指数为9.10±0.54,白色美学指数为9.00±0.63;术后无明显并发症,患者满意度高。结论 根膜技术应用于上颌前牙区无法完全避免种植体唇侧硬组织的吸收,但短期修复美学效果良好,长期的临床效果仍需进一步随访观察。     

上颌前牙区应用根膜技术即刻种植的临床效果观察

目的 观察上颌前牙区应用根膜技术即刻种植1年后的临床效果。方法 选取10例上颌前牙区牙齿不能保留的患者,应用根膜技术保留唇侧根片并同期植入种植体,术后6个月行永久冠修复,术后1年复查。术后1年统计种植体存留率;测量术后即刻和术后1年种植体唇侧硬组织厚度;统计术后1年种植修复体牙间乳头外形,并对修复体的红白美学进行评分;统计并发症发生情况及患者对治疗过程的满意度。结果 术后1年复查,种植体存留率为100%;种植体唇侧颈、中、根部硬组织厚度相较于术后即刻分别减少（0.27±0.21）、（0.19±0.20）、（0.28±0.29） mm;术后1年3个测量位点唇侧硬组织的厚度与术后即刻相比,差异均有统计学意义（P<0.05）,但3个位点硬组织厚度的变化量无明显差异（P>0.05）;修复体牙间乳头大多充满邻间隙,粉红色美学指数为9.10±0.54,白色美学指数为9.00±0.63;术后无明显并发症,患者满意度高。结论 根膜技术应用于上颌前牙区无法完全避免种植体唇侧硬组织的吸收,但短期修复美学效果良好,长期的临床效果仍需进一步随访观察。     

Rescue implant concept: the expanded use of the zygoma implant in the graftless solutions

The use of "anteriorly or posteriorly" tilted implants in a graftless approach for immediate loading the edentulous maxillae has been well documented in the literature. This treatment concept allows for rehabilitation of the edentulous maxillae with a fixed prosthesis. The purpose of this article is to describe criteria for the use of the zygomatic implant, including the expanded use of the zygoma implant in cases where failure of one of the anterior or posterior tilted implants has occurred in the All-on-Four treatment concept. Zygomatic implant placement becomes a "rescue procedure", which allows for continuity of care without resorting to a removable denture.     

All-on-Four技术在口腔种植领域中的应用进展

种植修复是恢复无牙颌患者咀嚼功能和美观的有效治疗方法,但因可用骨量的不足、上颌窦和下牙槽神经血管束等解剖问题而面临巨大挑战。对该类患者行种植体植入术时,常需要进行相关的骨增量手术。All?on?Four技术是指在无牙颌前牙区植入两颗轴向种植体,在远中端植入两颗角度种植体,并即刻负重,且在4～6个月后完成最终修复的新种植修复技术。该技术避免了人工骨粉植入术及上颌窦提升术等骨增量过程,患者心理反应及术后反应较轻,同时节省了患者的时间和金钱成本。这种联合应用倾斜种植体和直种植体来共同完成无牙颌患者的固定修复治疗被认为是一种可行的治疗方式。本文将就All?on?Four概念、常规技术、评价研究以及近年来提出的一些新的观点进行阐述。     

To what extent does the crown–implant ratio affect the survival and complications of implant-supported reconstructions? A systematic review

Objective: To evaluate the occurrence of biological and technical complications with respect to the crown–implant ( C/I ) ratio of implant-supported reconstructions.
Material and methods: Electronic (MEDLINE) and hand searches were conducted for longitudinal prospective studies with a follow-up period of at least 4 years. One reviewer performed screening and data abstraction. The following complications were evaluated: implant survival, peri-implant crestal bone loss, implant fracture, and technical complications related to implant components and suprastructure.
Results: The search provided 41 articles and abstracts, seven of which were selected for full-text analysis. Only two articles were finally included. A qualitative data analysis revealed that the survival rate of implant-supported reconstructions with a C/I ratio of more than 2 was 94.1%. In addition, peri-implant crestal bone loss seemed not to be influenced by the C/I ratio of the implant rehabilitation, except in one study, which noted greater crestal bone loss with lower (<1) compared with higher (>2) C/I ratios. Technical complications related to implant components and suprastructure according to different C/I ratios were not found in any of the studies.
Conclusions: Despite the diversity among studies with respect to data collection and study design, the current literature shows that the C/I ratios of implant-supported reconstructions do not influence peri-implant crestal bone loss.     

68枚Xive种植体的临床应用效果

目的：评价Xive种植体用于修复牙列缺损的临床应用效果。方法：对32例牙列缺损的患者,采用68枚Xive种植体修复治疗,术后随访,记录周围软组织状态、种植体松动度、X线检查种植体周围骨组织情况、患者满意度等指标。结果：68枚种植体所有植体均未发生感染,无松动脱落;全冠修复后,除有2枚修复体出现水平嵌塞,其余患者均较为满意。结论：Xive种植体用于修复牙列缺损效果较为满意。     

Immediate Nonfunctional Loading of NobelPerfect Implants in the Anterior Dental Arch in Private Practice – 5‐Year Data

Background: The concept of scalloped implants to maintain the natural contour of the alveolar ridge has been a source of controversy for many years. Purpose: This study examined the long‐term clinical performance of the scalloped NobelPerfect implant in a one‐stage procedure (immediate loading in the esthetic zone). Materials and Methods: In 20 patients, immediate prosthetic restorations were placed on 31 NobelPerfect implants in a private practice and followed for up to 78 months. Twenty‐one implants were placed immediately after extraction, seven implants were placed after osseous consolidation of the extraction sockets, and three implants were placed secondary to extended alveolar ridge augmentation procedures. All implants were provisionalized on the day of implant placement and adjusted to clear all contacts in centric occlusion and during eccentric movements. Outcome variables were success rates, marginal bone levels, and pink esthetic score (PES) assessed per implant. Results: One implant failed after 1.4 months. Five patients with six implants in total were scored in the 5‐year follow‐up as dropouts. Mean follow‐up period of remaining 24 implants was 65 months (range, 55–78 months). Cumulative success rates according to the criteria specified by Smith and Zarb were 96.8%. Marginal bone levels averaged 1.1 mm above the first thread. Mean PES ratings were 10.5 (range, 3–13). Conclusions: Survival rates, marginal bone levels, and esthetic results suggest proof of principle for the preservation of the interproximal bony lamella with a scalloped implant design in long‐term data.     

美学区即刻种植牙槽嵴及唇侧骨壁宽度变化的CBCT研究

目的利用CBCT研究上前牙即刻种植后牙槽嵴的宽度及唇侧骨壁的变化。方法即刻种植患者术后（T1）、术后6个月（T2）、术后1年（T3）行CBCT检查,测量位点包括从种植体肩台到根尖点（0、2、4、6、8mm）的5个距离,测量线与种植体长轴垂直,测量数据包括牙槽骨厚度及种植体唇侧骨厚度。结果 T2-T1为-1.21±0.39mm,T3-T1为-1.42±0.56mm,6个月时唇侧骨壁变化为-1.11±0.24mm,占牙槽骨变化的91.73%,12个月时唇侧骨壁变化为-1.26±0.37mm,占牙槽骨变化的88.65%。结论即刻种植后牙槽骨宽度变化主要在拔牙后的6个月内,其中唇侧骨壁的变化量约占总宽度变化的90%。