Management of a partially edentulous patient with malpositioned implants, using all-ceramic abutments and all-ceramic restorations: A clinical report

A 57-year-old man with missing permanent maxillary right first and second premolars presented for treatment. Two axially misaligned implants had been previously placed in the edentulous area and had successfully integrated, resulting in significant mechanical and esthetic restorative challenges. The prosthodontic treatment included placing 2 custom all-ceramic implant abutments and all-ceramic crowns. This treatment resulted in functional and esthetic restorations despite axial malposition of the implants.     

A zirconia implant-crown system: a case report

Exposed metal crown margins in the porcelain-fused-to-metal technique might be an esthetic problem. Therefore, all-ceramic crown systems are used for restoring teeth and dental implants. In addition, the gray color of a titanium implant might hamper the esthetic appearance of the entire reconstruction in cases of thin peri-implant soft tissue or tissue retraction. To further improve the esthetic aspect of dental implants, efforts are undertaken to develop implant systems fabricated out of tooth-colored materials that are biocompatible and able to withstand masticatory forces. One such material may be zirconia. The present article presents a case in which an all-ceramic custom-made zirconia implant-crown system was used for the replacement of a single tooth.     

The influence of intracrevicular crown margins on gingival health: preliminary findings

STATEMENT OF PROBLEM: The effect on gingival tissue of various crown materials in combination with different abutment biomaterials should be investigated. PURPOSE: This in vivo study determined the gingival health and subgingival levels of periodontal inflammation-associated bacteria adjacent to various crown and abutment material combinations. MATERIAL AND METHODS: . Patients in the study received 1 of 5 treatments: an all-ceramic crown luted to a natural tooth, a metal-ceramic (titanium) crown luted to natural tooth, a metal-ceramic (high noble alloy) crown luted to natural tooth, an all-ceramic crown luted to a titanium implant abutment, or a metal-ceramic (high noble alloy) crown luted to a titanium implant abutment. Plaque was collected at least 6 months after luting by paper point from the gingival sulcus of each crown and an adjacent unrestored (control) tooth. DNA probe analysis was performed to determine the levels of Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. In addition, plaque, gingival redness, swelling, and bleeding scores were recorded with use of the California Dental Association scale. Statistical analysis was used to determine the effect of restoration/abutment type on levels of the bacterial species and clinical parameters pertaining to gingival health. RESULTS: None of the sulci sampled contained detectable levels of the 3 bacteria. Plaque levels and gingival redness, swelling, and bleeding scores were low. All treatment groups had similar soft tissue response as measured by gingival redness, swelling, and bleeding. Plaque scores from all-ceramic crown/implant abutment sites were higher than plaque scores from all-ceramic crown/natural tooth sites. However, differences between experimental and control sites within the same treatment group were not observed (P>.05) with any of the 4 clinical measures. CONCLUSION: In patients with suitable oral hygiene, tooth-supported and implant-supported crowns with intracrevicular margins were not predisposed to unfavorable gingival and microbial responses.     

牙尖斜度对种植体支持全瓷单冠应力分布的影响

目的：分析不同牙尖斜度对种植体支持全瓷单冠应力分布的影响。方法：利用COSMOS 2．85参照相关文献建立5个种植体支持的下颌第一磨牙全瓷单冠三维有限元模型,全瓷冠的颊尖斜度分别设计为20°、25°、30°、35°和40°,采用垂直和水平两种加载方式,分析不同牙尖斜度对全瓷冠、基台、种植体以及周围骨组织内部的应力影响。结果：全瓷冠内部的张应力和等效应力主要集中在全瓷冠颊侧颈部,压应力主要集中在全瓷冠表面加载部位。最大张应力在垂直加载下随牙尖斜度增加而增加,水平加载下随牙尖斜度增加而减小;最大压应力和等效应力在牙尖斜度为25°时最小。基台内部的应力主要集中在种植体-基台衔接处的颊侧：种植体应力集中部位在颈部颊侧;骨组织应力集中部位在种植体颈部皮质骨,垂直加载时在颊侧,水平加载时在颊舌侧。不同牙尖斜度时基台、种植体及骨组织内部的最大等效应力在垂直加载时无明显差异,在水平加载时随牙尖斜度的增加而增大。结论：不同牙尖斜度时种植体支持全瓷单冠的应力集中部位相似,最大应力与加载方式有密切关系。     

Improving darkened anterior peri-implant tissue color with zirconia custom implant abutments

Tissue discoloration in the cervical third of anterior implant restorations may result from implant abutment material show-through. As an alternative to metal abutments that may compromise the appearance of tissue color in the esthetic zone, zirconia abutments can be used. When zirconia abutments are combined with all-ceramic crowns, the appearance of the peri-implant tissue can be noticeably improved. This article describes two cases where a zirconia abutment replaced an existing metal abutment in a single anterior implant restoration.     

基于CT数据制作的上前牙种植个体化全瓷冠的应用

目的 探讨基于CT数据制作的个体化全瓷冠在上前牙区种植修复的临床应用.方法 选择15例上前牙单牙缺失患者,通过CT扫描获取颌骨和牙齿数据,参照对侧同名天然牙制作种植修复全瓷冠,并完成最终修复.随访期2~7年.结果 种植体获得100%成功率,软组织外观稳定.所有患者对最终修复满意.结论 基于CT数据制作的上前牙个体化全瓷冠具有良好的软硬组织界面,可以获得可预期的美学效果.     

Marginal Discrepancy of All-Ceramic Crowns Cemented on Implant Abutments

Purpose The purpose of this investigation was to determine the mean marginal discrepancy of all-ceramic crowns cemented on implant abutments. Materials and Methods Five Brånemark CeraOne abutments were connected to implant fixtures embedded in acrylic resin blocks. The marginal discrepancy was measured using a video camera connected to a digitizing board at four locations on each abutment for five samples in each of the following groups: all-ceramic caps (caps), all-ceramic crowns (crowns), and all-ceramic crowns cemented with zinc phosphate cement (cemented crowns). Results The mean marginal discrepancies were as follows: caps, 99.0 μm (SD, 16); crowns, 117.8 μm (SD, 20); and cemented crowns, 168.8 μm (SD, 23). Statistically significant differences were found between all three groups at the 99% level of confidence. In addition there were two significant differences between abutments. Conclusions Subgingival marginal discrepancies of the magnitude measured in this study have been shown to cause periodontal problems. It is probable that the marginal discrepancy of CeraOne restorations, as tested, can be improved. Efforts should be made to enhance the marginal accuracy of these restorations.     

Glass fiber-reinforced abutments for dental implants. A pilot study

Titanium abutments in dental implants shine through all-ceramic crowns and therefore limit excellent esthetic results. Prototypes of tooth-colored fiber-reinforced abutments were investigated to avoid the shining-through effect. In vitro, the fracture strength was determined after thermal cycling and mechanical loading of all-ceramic single crowns and four-unit bridges made of a fiber-reinforced composite. The suprastructures were adhesively fixed onto fiber-reinforced implant abutments and compared with those fixed on standard titanium abutments. The median of the fracture strength of the titanium-supported all-ceramic crowns was significantly higher than the median of crowns fixed onto the prototypes. But this value was still more than twice as high as the maximum loading force under oral conditions. No statistical difference was found between four-unit bridges made by fiber-reinforced composite inserted onto titanium abutments and those inserted onto fiber-reinforced abutments. Fiber-reinforced abutment prototypes for dental implants avoided the shining-through effect associated with metal abutments. Their load-bearing capacity after in vitro stress simulation was higher than the maximum oral loading force. With some improvements, the fiber-reinforced implant abutments are therefore a promising alternative to titanium abutments.     

根管治疗后下颌切牙瓷贴面与全瓷冠两种修复方式的抗折裂性对比研究

目的:比较根管治疗后下颌切牙瓷贴面与全瓷冠修复后的抗折裂强度。方法:选择离体下颌切牙30颗,统一经过体外根管治疗,3M纤维桩加固后随机分为3组:瓷贴面修复组、全瓷冠修复组(经牙体预备后采用IPS e.max Press铸瓷系统进行修复)和树脂充填组(直接采用复合树脂充填)。在万能材料试验机上分别测试3组样本的抗折裂载荷值,对结果进行统计分析。结果:瓷贴面组、全瓷冠组、直接充填组的抗折裂载荷分别为(439.59±56.97)N、(719.98±43.03)N和(597.74±50.35)N,各组值之间存在统计学差异(P<0.01)。结论:根管治疗后下颌切牙经纤维桩加固后,全瓷冠修复后的抗折裂强度高于瓷贴面修复。二者的抗折裂载荷值都可以满足临床修复的要求。     

Current ceramic materials and systems with clinical recommendations: a systematic review

STATEMENT OF PROBLEM: Developments in ceramic core materials such as lithium disilicate, aluminum oxide, and zirconium oxide have allowed more widespread application of all-ceramic restorations over the past 10 years. With a plethora of ceramic materials and systems currently available for use, an overview of the scientific literature on the efficacy of this treatment therapy is indicated. PURPOSE: This article reviews the current literature covering all-ceramic materials and systems, with respect to survival, material properties, marginal and internal fit, cementation and bonding, and color and esthetics, and provides clinical recommendations for their use. MATERIAL AND METHODS: A comprehensive review of the literature was completed seeking evidence for the treatment of teeth with all-ceramic restorations. A search of English language peer-reviewed literature was undertaken using MEDLINE and PubMed with a focus on evidence-based research articles published between 1996 and 2006. A hand search of relevant dental journals was also completed. Randomized controlled trials, nonrandomized controlled studies, longitudinal experimental clinical studies, longitudinal prospective studies, and longitudinal retrospective studies were reviewed. The last search was conducted on June 12, 2007. Data supporting the clinical application of all-ceramic materials and systems was sought. RESULTS: The literature demonstrates that multiple all-ceramic materials and systems are currently available for clinical use, and there is not a single universal material or system for all clinical situations. The successful application is dependent upon the clinician to match the materials, manufacturing techniques, and cementation or bonding procedures, with the individual clinical situation. CONCLUSIONS: Within the scope of this systematic review, there is no evidence to support the universal application of a single ceramic material and system for all clinical situations. Additional longitudinal clinical studies are required to advance the development of ceramic materials and systems.     

The ray setting procedure: a new method for implant planning and immediate prosthesis delivery

This paper introduces a new system for planning implant positions directly on the working cast, called the ray setting procedure. It allows clinicians to obtain, on a master cast, the correct implant positions through the correction of previously planned expected positions. The device used is the Ray Set, a machine that can be used to precisely define, on the plaster working cast of the mouth, hard and soft tissue anatomy and correlate it with an articulator and computed tomographic data from the patient. This cast is used to build an individual surgical stent that perfectly matches the teeth and soft tissues as well as a provisional or definitive implant-supported prosthesis for partially or completely edentulous patients. A clinical case is presented to explain the procedure. A definitive all-ceramic cemented and screw-retained prosthesis, fabricated from a rigid material and with passive fit, was created before implant surgery and was placed with an immediate occlusal load applied a few minutes after implant placement. The prosthesis was retained with both cement and screws so as to make removal easy for accurate finishing of the margins immediately before cementation. The prosthesis was built, before implant surgery, according to the PIP method (presurgical implant prosthesis). The ray setting procedure can be used for planning immediate or delayed loading of implants.     

氧化锆基台在种植体支持的全瓷修复中的应用

目的探讨氧化锆基台的应用及种植体支持的全瓷修复体的临床效果。方法选择安多键内连接种植系统φ4.0×10mm种植体植入缺牙区,上颌植入6个月、下颌植入3个月后安装自制的氧化锆基台;将基台予以磨改预留修复间隙,取印模,灌制石膏模型;应用CAD/CAM制作全瓷冠、桥;将全瓷修复体与基台粘接固位;应用MINRAY口内数字X线摄片系统和X线摄片定位仪,拍摄安装氧化锆基台时和全瓷修复体粘接后36个月时的X线片进行测量,对比分析。结果自制的氧化锆基台能与种植体顺利装配,应用该基台和CAD/CAM制作的全瓷冠、桥修复体完成的15例患者18颗种植义齿全瓷修复的即刻效果满意,追踪30~36个月,所有患者的种植义齿使用良好,修复体和基台均无松动脱落与折裂、折断,牙周无炎症及牙槽骨吸收,部分患者的牙槽骨显示增高,患者满意度高。结论应用氧化锆基台配合CAD/CAM氧化锆全瓷冠、桥修复体,不仅可获得满意的美学效果,还有益于种植义齿周围组织的健康。     

The influence of prosthetic material on implant and prosthetic survival of implant-supported fixed complete dentures: a systematic review and meta-analysis

PurposeEvaluating the impact of the prosthetic material on implant- and prosthetic survival of implant-supported fixed complete dentures.Study selectionElectronic and hand searches were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to identify clinical studies including at least 10 patients restored with implant-supported dentures. The primary outcome was to evaluate the implant survival rate according to the applied restorative materials. The prosthetic survival rate was evaluated as secondary outcomes.ResultsForty-one of 2254 studies were ?nally selected. A statistically significant difference (p = 0.0337) was found between implant survival rates in the main restorative groups (metal-ceramic:97%(95%CI [0.96;0.98]), all-ceramic:99%(95%CI [0.98;1.00]), metal-resin:97%(95%CI [0.96;0.98])). Prosthetic survival rates were: (metal-ceramic:95%(95%CI [0.89;0.97]), all-ceramic:97%(95%CI [0.92;0.99]), metal-resin:97%(95%CI [0.95;0.98]), with no statistically significant difference (p = 0.3796) between the groups. Chipping incidence rates were as follows: metal-ceramic:8%(95%CI[0.03;0.20]), all-ceramic:15%(95%CI [0.06;0.32]), and metal-resin:22%(95%CI [0.13;0.33]).Five types of exact restorative materials were identified (porcelain-fused-to-non-precious alloy, porcelain-fused-to-zirconia, precious-metal-acrylic-resin, non-precious-metal-acrylic resin, and PMMA). Again, implant survival rates were statistically significantly influenced by the applied restorative materials (p = 0.0126), whereas, no significant differences were reported regarding prosthetic survival rate.ConclusionsProsthetic material selection seems to have no clinically relevant influence on implant- and prosthetic survival rate in implant-supported fixed complete dentures. Due to the high chipping rate, quantifying prosthetic survival alone does not seem to be a reliable tool for evaluating the outcome of the restorations and providing recommendations. These results, along with the obvious lack of evidence, suggest that clinicians must exercise caution whenever porcelain-fused-to-zirconia or metal-resin restorations are considered.     

Strength and mode of failure of single implant all-ceramic abutment restorations under static load.

The strength and mode of failure of three different designs of custom-made all-ceramic implant abutments fabricated by milling of In-Ceram sintered ceramic blocks were compared with the conventional CeraOne system under static load. Four test groups were formed with different locations of abutment screws. In three test groups, In-Ceram crowns were fabricated for placement on the all-ceramic abutments, and in one test group, a veneer porcelain was fired directly on the abutment; crowns in the control group were fabricated using the CeraOne system. Ten-mm-long Br?nemark implants were placed into a brass block that allowed loading at a 30-degree angle to the long axis. The test group in which the veneer porcelain was fired directly on the all-ceramic abutments was the weakest, and it showed fractures at a mean value of 236 N. The fracture strength of the three other test groups was dependent on the extension of the crown margin relative to the location of the screw head. The test group that had the screw on the top compressing the entire ceramic abutment showed a mean value of 422 N that was similar to the results that were achieved with the CeraOne system (427 N). The weakest link in the all-ceramic single implant restorations was the abutment screw in which the bending began at approximately 190 N.     

CEREC 3不同光学印模在后牙种植修复中的临床研究

目的：比较CEREC3直接法光学印模和间接法光学印模在后牙种植修复中临床效果的差别.方法：选取80颗后牙种植CEREC全瓷冠修复病例,其中实验组40例使用CEREC直接法制取光学印模,对照组40例使用间接法制取光学印模,然后根据印模数据分别制作全瓷冠并口内粘接.修复后追踪观察2年,调查患者的满意度,并按照改良的USPHS标准进行临床评价.结果：实验组和对照组总体满意度分别为100.0％和97.5％,在外形,表面质地和颜色上无明显差别,在边缘适合性方面分别为90.0％和100.0％,两者比较有统计学差异（P＜0.05）.结论：在后牙种植CEREC全瓷冠修复时,间接光学印模优于直接光学印模.     

Use of abutment-teeth vs. dental implants to support all-ceramic fixed partial dentures: an in-vitro study on fracture strength

The aim of the present in-vitro study was to compare the fracture strength of all-ceramic Fixed Partial Dentures supported by tooth-analogues and periodontal membrane with the same supported by dental implants. As ceramics are highly brittle, they cannot withstand deformations of more than 0.1% without fracturing. Hence, when planning an all-ceramic FPD, it is essential to evaluate abutment support, as the fracture strength of all-ceramic constructions depends on the stability of the support to reduce strain in the beam of the prosthesis. The support provided by implants differs, however, from the support provided by natural teeth as the implants are anchored directly in the bone with no intermediate tissue. One question that arises is whether strain and stress in the prosthesis are lower when the prosthesis is loaded on implants compared to natural teeth and hence if all-ceramic FPDs benefit from implant support. Twenty-four three-unit all-ceramic FPDs-12 supported by two dental implants and 12 by two tooth-analogues serving as end abutments-were made. All FPDs were subjected to preloading in a preloading procedure and subsequently subjected to load until fracture occurred. Load at fracture were registered and comparisons between the two groups were made. The loads at fracture were statistically significant higher in the group supported by implants compared to the group supported by tooth-analogues (p = 0.003). Within the limitations of this in-vitro study, the following conclusions can be drawn: All-ceramic fixed partial dentures can be used in combination with dental implants. The solid support gained from implants might thus be beneficial for the outcome of such treatment due to decreased strain and stress levels in the prosthesis when loaded on implants compared to when loaded on natural teeth. Clinical studies are, however, needed to confirm these findings as there are more factors that influence the final clinical outcome.     

Clinical and esthetic outcomes of single-tooth implants in the anterior maxilla

The aim of this study was to evaluate the clinical and esthetic outcomes of 10 consecutive single-tooth implant restorations in the anterior maxilla. A specific treatment protocol consisting of (1) atraumatic extraction of the failing tooth, (2) placement of an SLActive bone-level implant with simultaneous guided bone regeneration at 6 to 8 weeks postextraction, (3) loading of a provisional restoration at 2 to 3 months following implant placement, (4) production of a customized impression coping, and (5) loading of the definitive all-ceramic abutment and crown 6 months after delivery of the provisional restoration was utilized in all cases. The outcomes were assessed 1 year after loading of the definitive restoration using standard clinical parameters: pink (PES) and white esthetic scores (WES). All implants were successfully integrated, accounting for a 100% survival and success rate. Besides clinical success, the application of the specific treatment protocol may be able to provide esthetically pleasing single-tooth implant restorations in the anterior maxilla, as was demonstrated by the results for PES (7.9 ± 1.7) and WES (7.0 ± 1.5).     

A prospective clinical evaluation of different single-tooth restoration designs on osseointegrated implants. A 3-year follow-up of Brånemark implants

Since single-tooth implant restorations were introduced 12 years ago (Jemt 1986), there has been continuous development both in the technical design and the aesthetic outcome of the treatment. In order to ensure high quality in single-tooth implant treatments a clinical follow-up study was carried out on patients treated with modifications to the original regimen. In this study 69 consecutive patients were provided with 80 single-tooth implant restorations. The patients were followed for 3 years. There was continuous development of the prosthetic design during the time of the study, allowing us to analyse possible prognostic differences for the different prosthetic treatments. This study confirms earlier reports which describe the single-tooth implant treatment as a safe method with few surgical complications and minimal marginal bone loss. Only 1 implant was lost during the follow-up period and the average marginal bone loss was 0.48 mm over the 3-year follow-up period. Crowns veneered with acrylic and with gold casted directly to the abutments, screwed onto the implants, led to recurring prosthetic complications and gave an appearance of rapid ageing. The first generation of crowns made following the Cera-One design, sometimes produced a gap between the crown and the abutment associated with significant marginal bone loss during the first year. Few surgical or prosthetic complications were noted with cemented all-ceramic constructions, although the number of these crowns in this study was limited.     

Immediate tooth extraction,placement of a Tapered Screw-Vent implant,and provisionalization in the esthetic zone: a case report

PURPOSE: This clinical report describes an immediate tooth extraction, followed by placement and provisional restoration of a dental implant in the prepared socket of a right maxillary central incisor. MATERIALS AND METHODS: The tooth was extracted with minimal hard and soft tissue trauma and without flap reflection. A flapless, transmucosal surgical approach was used to prepare the socket and insert a tapered implant. The implant was immediately restored with a provisional abutment and crown without occlusal contacts. An impression was made 22 days after implant insertion, and a definitive, all-ceramic restoration was placed 3 days later. RESULTS: During the period of provisional progressive loading, no significant soft tissue contraction was observed related to noninvasive operating techniques and the immediate insertion of the provisional restoration. The patient exhibited no clinical or radiologic complications through 8 months of clinical monitoring after loading. CONCLUSION: The Tapered Screw-Vent implant and all-ceramic restoration provided the patient with immediate esthetics, function, and comfort without any complications during the postloading follow-up period.     

78例氧化锆种植体边缘骨吸收5年随访观察

目的：观察氧化锆全瓷修复种植体边缘骨吸收变化,评估氧化锆全瓷修复体长期临床效果。方法：将首都医科大学电力教学医院2014年1月—2016年1月间78例采用氧化锆全瓷修复系统进行固定义齿修复的病例纳为研究对象,随访5年,检测修复体完整性、密合性、种植体存留情况,并检测改良龈沟出血指数（mSBI）、改良菌斑指数（mPLI）及牙周探诊深度（PD）,应用X线片评估种植体边缘骨吸收,使用多元线性回归分析影响骨吸收的相关因素。采用SPSS 19.0软件包对数据进行统计学分析。结果：随访期间,6例患者未按规定复诊,随访脱落,脱落率为7.69%(6/78),剩余72例患者（共80颗种植体,63个修复体）完成随访,种植体均未出现松动、折断、脱落,种植体存留率为100.00%。6个修复体出现崩瓷,2个修复体冠边缘与基台间不密合,无修复体脱落。全口曲面体层片与根尖片提示,边缘骨吸收0～2.03 mm,平均（0.23±0.04）mm。统计分析显示,糖尿病史、修复体种植方式、崩瓷及对颌牙类型影响种植体边缘骨吸收量（P<0.05）。结论：长期随访结果显示,氧化锆种植体存留率高,软组织美学效果好,边缘骨稳定,...