In order to investigate the influence of abutment material on the stress of implant-supported all-ceramic single crown, a 3D finite element model of implant-supported mandibular first premolar was computed by COSMOS/M...In order to investigate the influence of abutment material on the stress of implant-supported all-ceramic single crown, a 3D finite element model of implant-supported mandibular first premolar was computed by COSMOS/M 2.85 software. Alumina, zirconia, and titanium were used as abutment materials respectively. Vertical 600 N and horizontal 225 N load was applied on the occlusal surface. The results show that the stress distribution of implant-supported single crown was similar for different abutment materials. Maximum stresses within the crown were higher when titanium abutment was used. Maximum stress of titanium abutment was lower than that of ceramic abutment. Within the screw and fixture, maximum stresses had no difference under vertical loading but higher as titanium abutment was used under horizontal loading. There was no difference of maximum stress within the bone when different abutment materials were used. The present findings indicate that the abutment material had no influence on the stress distribution of implant-supported all- ceramic single crown but maximum stress when the titanium abutment was lower than that of ceramic abutment.展开更多
The purpose of this study was to investigate the influence of different luting agents on the stress distribution within the crown, abutment and peri-implant bone of implant-supported all-ceramic single crown. A three-...The purpose of this study was to investigate the influence of different luting agents on the stress distribution within the crown, abutment and peri-implant bone of implant-supported all-ceramic single crown. A three-dimensional finite element model of an implant-supported single crown for the first premolar of mandible was created by COSMOS 2.85. Resin-modified glass ionomer and two different resin adhesives were used to cement the crown and abutment. Vertical 600 N and horizontal 225 N loads were applied to stimulate the condition of chewing. The stress distributions within the all-ceramic crown, abutment and peri-implant bone were analyzed. The experimental results show that the stress distributions of all-ceramic crown, abutment, implant and peri-implant bone were similar when different luting agents were used. The result of present study indicated that luting agents had no influence on the stress distributions of implant-supported all-ceramic single crown.展开更多
The purpose of the present study was to evaluate the effect ofA1203 content on the fracture property of all-ceramics ZrO2. To improve the all-ceramics ZrO2 restoration mechanics properity ,96 samples containing 0,5,10...The purpose of the present study was to evaluate the effect ofA1203 content on the fracture property of all-ceramics ZrO2. To improve the all-ceramics ZrO2 restoration mechanics properity ,96 samples containing 0,5,10 and 15 wt% of A1203 particles were prepared by cold isostatic pressing （200 MPa） and 1 550 ℃ sintered .The phase was analyzed by X-ray diffraction analysis and the bulk densities of the samples were made using Archimedes principle. Samples were randomly divided into four groups. In each group, 24 specimens were prepared so that the angle between notch and specimen＇s long axis is 90° and 60°. Notch depths were 1 mm for all samples. Samples were loaded with three-point bending method. 90° cut samples were used to measure fracture toughness while 60°cut samples were used to observe fracture curve by taking points on the fracture extension path under microscope, plotting points on coordinates, generating fitting curve by software ＂Origin＂, and analyzing the microstructure of the specimen fracture surfaces by scanning electron microscopy （SEM）.The results show that the increment ofA1203 has insignificant effect on the densification of all-ceramic ZrO2.XRD analysis shows that the specimen is comprised of t-ZrO2 and a- A1203 before fracture while fracture surface is m-ZrO2, t-ZrO2 and a-A1203. ZrO2 containing 10% A1203 has the optimum mechanical properties and unconspicuous crack propagation and distribution. The observations may provide a reference for the materials selection, shaoe design, and production orocess of all-ceramic crown and bridge.展开更多
Since the last two decades, restorative dentistry has been witnessing an increased acceptance of the use of the well-known all-ceramic materials for the fabrication of single dental restorations, such as inlays, onlay...Since the last two decades, restorative dentistry has been witnessing an increased acceptance of the use of the well-known all-ceramic materials for the fabrication of single dental restorations, such as inlays, onlays, crowns, anterior and posterior fixed partial dentures (PFPDs). These restorations certainly offer the potential for better biocompatibility coupled with superior aesthetic qualities, especially when compared with the conventional prostheses made from porcelain that is fused with metal ceramic restorations. However, brittleness and extreme sensitivity of all-ceramic materials to micro-like defects or cracks that are inherently present, or may grow, in their microstructure during different laboratory fabrication steps, during necessary clinical adjustments, or from post-placement chewing activity, remain major shortcomings of these dental restorations. In fact, many researchers are of the opinion that the improved mechanical properties can significantly improve the lifetime of all-ceramic restorations and result in enhanced reliability. Therefore, efforts of researchers, as well as manufacturers, have been directed towards the improvement of the mechanical properties in order to overcome such limitations. This article reviews the characterization of the most important mechanical properties that can delineate the behavior of all-ceramic dental materials upon loading. These include fracture mechanics, the brittle nature of ceramics, the relationship between microstructural features and fracture behavior, sources of cracks and flaws that may initiate a fracture and the effect of different fabrication procedures and/or clinical adjustments on the mechanical behavior of dental ceramics are also reviewed and discussed.展开更多
The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was conducted to identify studies on tooth wear against cer...The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was conducted to identify studies on tooth wear against ceramic crowns in posterior region. The selected studies were analyzed in regard to type of crowns, natural antagonist, measuring protocol and outcome. From a yield of 1 000 titles, 43 articles were selected for full-text analysis; finally, no in vitro and only five in vivo studies met the inclusion criteria. As there is heterogeneity in design, used measuring method, ceramics and analysis-form, a meta-analysis was not possible. Results of these studies are very controversial which makes a scientifically valid comparison impossible. This review indicated that some all-ceramic crowns are as wear friendly as metal-ceramic crowns. Up to now, it has been impossible to associate tooth wear with any specific causal agent. The role of ceramic surface treatment that might be responsible for the changing in rate of tooth wear seems undetermined as yet through clinical trials. The literature reveals that studies on this topic are subject to a substantial amount of bias. Therefore, additional clinical studies, properly designed to diminish bias, are warranted.展开更多
[Objectives]To explore the difference between the CAD/CAM customized zirconia abutment and the finished titanium abutment in the maxillary anterior region.[Methods]A total of 60 implants were selected from 60 patients...[Objectives]To explore the difference between the CAD/CAM customized zirconia abutment and the finished titanium abutment in the maxillary anterior region.[Methods]A total of 60 implants were selected from 60 patients who had undergone maxillary single anterior implant implantation in the Department of Oral and Maxillofacial Surgery,Affiliated Hospital of Qingdao University from July 2017 to July 2018.They were randomly divided into an observation group and a control group(30 patients/group).The observation group used CAD/CAM customized zirconia abutment and all-ceramic crown,while the control group used finished titanium abutment and all-ceramic crown.Twelve months after the crown restoration,mechanical complications,pink esthetic(another spelling of aesthetic)score(PES)and white esthetic score(WES),and patient satisfaction were used as clinical observation indicators to evaluate the restoration effect.[Results]For 12 months after crown restoration,the implant survival rate of the two groups of patients was 100%,and there was no abutment breakage,loosening,falling off,or screw loosening and breakage.The PES and WES of the observation group were significantly higher than those of the control group(P<0.05).The patient satisfaction of the observation group was significantly higher than those of the control group(P<0.05).[Conclusions]CAD/CAM customized zirconia abutment implant restoration in the maxillary anterior region can obtain good esthetic restoration effect in a short term,and has good clinical application effect.展开更多
目的:探讨不同树脂水门汀对氧化锆陶瓷修复体粘接强度的影响。方法:制备牙本质粘接面样本30个随机分为3组(n=10),并选择Cercon氧化锆陶瓷系统分别与3种树脂水门汀进行配伍,制备相应剪切强度试件和拉伸强度试件,分别记为RU组(Cercon氧化...目的:探讨不同树脂水门汀对氧化锆陶瓷修复体粘接强度的影响。方法:制备牙本质粘接面样本30个随机分为3组(n=10),并选择Cercon氧化锆陶瓷系统分别与3种树脂水门汀进行配伍,制备相应剪切强度试件和拉伸强度试件,分别记为RU组(Cercon氧化锆与RelyX U200)、CS组(Cercon氧化锆与Clearfil SA Luting)、ME组(Cercon氧化锆与Maxcem Elite Chroma)。采用万能力学试验机检测各试件的最大剪切载荷值及最大拉伸载荷值,计算剪切强度及拉伸强度并进行统计学分析。结果:在剪切强度测试实验中,剪切强度CS组>RU组>ME组;在拉伸强度测试中,拉伸强度CS组>RU组>ME组;CS粘接剂在剪切强度和拉伸强度测试中粘接效果均优于RU和ME组。结论:在氧化锆陶瓷的剪切强度测试及拉伸强度测试中,含有10-MDP的树脂水门汀(Clearfil SA Luting)的粘接强度最大,粘接效果最好,对于氧化锆陶瓷推荐使用含MDP的树脂水门汀。展开更多
基金the National Natural Science Foundation of China (No.30801312)
文摘In order to investigate the influence of abutment material on the stress of implant-supported all-ceramic single crown, a 3D finite element model of implant-supported mandibular first premolar was computed by COSMOS/M 2.85 software. Alumina, zirconia, and titanium were used as abutment materials respectively. Vertical 600 N and horizontal 225 N load was applied on the occlusal surface. The results show that the stress distribution of implant-supported single crown was similar for different abutment materials. Maximum stresses within the crown were higher when titanium abutment was used. Maximum stress of titanium abutment was lower than that of ceramic abutment. Within the screw and fixture, maximum stresses had no difference under vertical loading but higher as titanium abutment was used under horizontal loading. There was no difference of maximum stress within the bone when different abutment materials were used. The present findings indicate that the abutment material had no influence on the stress distribution of implant-supported all- ceramic single crown but maximum stress when the titanium abutment was lower than that of ceramic abutment.
基金Funded by the National Natural Science Foundation of China(No.81100784)
文摘The purpose of this study was to investigate the influence of different luting agents on the stress distribution within the crown, abutment and peri-implant bone of implant-supported all-ceramic single crown. A three-dimensional finite element model of an implant-supported single crown for the first premolar of mandible was created by COSMOS 2.85. Resin-modified glass ionomer and two different resin adhesives were used to cement the crown and abutment. Vertical 600 N and horizontal 225 N loads were applied to stimulate the condition of chewing. The stress distributions within the all-ceramic crown, abutment and peri-implant bone were analyzed. The experimental results show that the stress distributions of all-ceramic crown, abutment, implant and peri-implant bone were similar when different luting agents were used. The result of present study indicated that luting agents had no influence on the stress distributions of implant-supported all-ceramic single crown.
基金Funded by the Technology Department Science Fund of Sichaun(No.2011GZ011520)
文摘The purpose of the present study was to evaluate the effect ofA1203 content on the fracture property of all-ceramics ZrO2. To improve the all-ceramics ZrO2 restoration mechanics properity ,96 samples containing 0,5,10 and 15 wt% of A1203 particles were prepared by cold isostatic pressing （200 MPa） and 1 550 ℃ sintered .The phase was analyzed by X-ray diffraction analysis and the bulk densities of the samples were made using Archimedes principle. Samples were randomly divided into four groups. In each group, 24 specimens were prepared so that the angle between notch and specimen＇s long axis is 90° and 60°. Notch depths were 1 mm for all samples. Samples were loaded with three-point bending method. 90° cut samples were used to measure fracture toughness while 60°cut samples were used to observe fracture curve by taking points on the fracture extension path under microscope, plotting points on coordinates, generating fitting curve by software ＂Origin＂, and analyzing the microstructure of the specimen fracture surfaces by scanning electron microscopy （SEM）.The results show that the increment ofA1203 has insignificant effect on the densification of all-ceramic ZrO2.XRD analysis shows that the specimen is comprised of t-ZrO2 and a- A1203 before fracture while fracture surface is m-ZrO2, t-ZrO2 and a-A1203. ZrO2 containing 10% A1203 has the optimum mechanical properties and unconspicuous crack propagation and distribution. The observations may provide a reference for the materials selection, shaoe design, and production orocess of all-ceramic crown and bridge.
文摘Since the last two decades, restorative dentistry has been witnessing an increased acceptance of the use of the well-known all-ceramic materials for the fabrication of single dental restorations, such as inlays, onlays, crowns, anterior and posterior fixed partial dentures (PFPDs). These restorations certainly offer the potential for better biocompatibility coupled with superior aesthetic qualities, especially when compared with the conventional prostheses made from porcelain that is fused with metal ceramic restorations. However, brittleness and extreme sensitivity of all-ceramic materials to micro-like defects or cracks that are inherently present, or may grow, in their microstructure during different laboratory fabrication steps, during necessary clinical adjustments, or from post-placement chewing activity, remain major shortcomings of these dental restorations. In fact, many researchers are of the opinion that the improved mechanical properties can significantly improve the lifetime of all-ceramic restorations and result in enhanced reliability. Therefore, efforts of researchers, as well as manufacturers, have been directed towards the improvement of the mechanical properties in order to overcome such limitations. This article reviews the characterization of the most important mechanical properties that can delineate the behavior of all-ceramic dental materials upon loading. These include fracture mechanics, the brittle nature of ceramics, the relationship between microstructural features and fracture behavior, sources of cracks and flaws that may initiate a fracture and the effect of different fabrication procedures and/or clinical adjustments on the mechanical behavior of dental ceramics are also reviewed and discussed.
文摘The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was conducted to identify studies on tooth wear against ceramic crowns in posterior region. The selected studies were analyzed in regard to type of crowns, natural antagonist, measuring protocol and outcome. From a yield of 1 000 titles, 43 articles were selected for full-text analysis; finally, no in vitro and only five in vivo studies met the inclusion criteria. As there is heterogeneity in design, used measuring method, ceramics and analysis-form, a meta-analysis was not possible. Results of these studies are very controversial which makes a scientifically valid comparison impossible. This review indicated that some all-ceramic crowns are as wear friendly as metal-ceramic crowns. Up to now, it has been impossible to associate tooth wear with any specific causal agent. The role of ceramic surface treatment that might be responsible for the changing in rate of tooth wear seems undetermined as yet through clinical trials. The literature reveals that studies on this topic are subject to a substantial amount of bias. Therefore, additional clinical studies, properly designed to diminish bias, are warranted.
文摘[Objectives]To explore the difference between the CAD/CAM customized zirconia abutment and the finished titanium abutment in the maxillary anterior region.[Methods]A total of 60 implants were selected from 60 patients who had undergone maxillary single anterior implant implantation in the Department of Oral and Maxillofacial Surgery,Affiliated Hospital of Qingdao University from July 2017 to July 2018.They were randomly divided into an observation group and a control group(30 patients/group).The observation group used CAD/CAM customized zirconia abutment and all-ceramic crown,while the control group used finished titanium abutment and all-ceramic crown.Twelve months after the crown restoration,mechanical complications,pink esthetic(another spelling of aesthetic)score(PES)and white esthetic score(WES),and patient satisfaction were used as clinical observation indicators to evaluate the restoration effect.[Results]For 12 months after crown restoration,the implant survival rate of the two groups of patients was 100%,and there was no abutment breakage,loosening,falling off,or screw loosening and breakage.The PES and WES of the observation group were significantly higher than those of the control group(P<0.05).The patient satisfaction of the observation group was significantly higher than those of the control group(P<0.05).[Conclusions]CAD/CAM customized zirconia abutment implant restoration in the maxillary anterior region can obtain good esthetic restoration effect in a short term,and has good clinical application effect.
文摘目的:探讨不同树脂水门汀对氧化锆陶瓷修复体粘接强度的影响。方法:制备牙本质粘接面样本30个随机分为3组(n=10),并选择Cercon氧化锆陶瓷系统分别与3种树脂水门汀进行配伍,制备相应剪切强度试件和拉伸强度试件,分别记为RU组(Cercon氧化锆与RelyX U200)、CS组(Cercon氧化锆与Clearfil SA Luting)、ME组(Cercon氧化锆与Maxcem Elite Chroma)。采用万能力学试验机检测各试件的最大剪切载荷值及最大拉伸载荷值,计算剪切强度及拉伸强度并进行统计学分析。结果:在剪切强度测试实验中,剪切强度CS组>RU组>ME组;在拉伸强度测试中,拉伸强度CS组>RU组>ME组;CS粘接剂在剪切强度和拉伸强度测试中粘接效果均优于RU和ME组。结论:在氧化锆陶瓷的剪切强度测试及拉伸强度测试中,含有10-MDP的树脂水门汀(Clearfil SA Luting)的粘接强度最大,粘接效果最好,对于氧化锆陶瓷推荐使用含MDP的树脂水门汀。
