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 multi-piece post-crown technique is more effective in restoring residual root than other restoration techniques.Various types of adhesives have different material properties that affect restoration.Therefore,the c...The multi-piece post-crown technique is more effective in restoring residual root than other restoration techniques.Various types of adhesives have different material properties that affect restoration.Therefore,the choice of adhesive is particularly important for patients.However,the effect of different kinds of adhesives was not too precise by experimental methods when concerning about individual differences of teeth.One tooth root can only be restored with one type of adhesive in experiment.After the mechanical test,this tooth root cannot be restored with other adhesives.With the help of medical imaging technology,reverse engineering and finite element analysis,a molar model can be reconstructed precisely and restored using different types of adhesives.The same occlusal and chewing loads were exerted on the same restored residual root models with different types of adhesives separately.Results of von Mises stress analysis showed that the adhesives with low Young’s modulus can protect the root canal effectively.However,a root canal concentration is apparently produced around the root canal orifice when chewing.Adhesives with large Young’s modulus can buffer the stress concentration of the root canal orifice.However,the root canal tissue may be destroyed because the adhesive is too hard to buffer the load.展开更多
We report the case of 27-year-old female patient applied to our clinic with several pain at her upper teeth and weakness complaints. Anamnesis revealed that she experienced laser gingivectomy to have remarkable teeth....We report the case of 27-year-old female patient applied to our clinic with several pain at her upper teeth and weakness complaints. Anamnesis revealed that she experienced laser gingivectomy to have remarkable teeth. Clinical examination showed that maxillar alveolar bone was partially uncovered with gingivae and periosteum. Interproximal necrosed area was observed. She had sensitivity at her maxillar anterior teeth. Furthermore, she was so anxious and depressed. In order to ensure more blood supply and clot formation, perforations on uncovered cortical bone was prepared. Avoiding from infection antibiotic, antiseptic gel and for epithelization vitamin E gel were prescribed. During one month she was recalled every third day. Recall times diminished periodically, as new tissue evolves. Although laser's irreversible photothermal effects on soft and hard tissue, after a year all denuded areas were covered with healthy tissues without any surgical procedures. Histopathologic comparing showed severe lymphocyte infiltration and increased fibrosis and kollagenization in restored gingiva, additionally epithelial loss was observed. Since there is not a case report about the complications of laser gingivectomy in litera-ture, we tried to represent a treatment plan that may be elucidative for clinicians.展开更多
目的:对比高嵌体与全冠在修复牙体缺损中的美学效果及预后。方法:选取2020年6月-2022年1月笔者医院收治的牙体缺损患者120例(共229颗患牙),采用随机数字法分为对照组(60例,113颗患牙)和观察组(60例,116颗患牙),对照组采用常规全瓷冠修...目的:对比高嵌体与全冠在修复牙体缺损中的美学效果及预后。方法:选取2020年6月-2022年1月笔者医院收治的牙体缺损患者120例(共229颗患牙),采用随机数字法分为对照组(60例,113颗患牙)和观察组(60例,116颗患牙),对照组采用常规全瓷冠修复治疗,观察组采用CAD/CAM全瓷高嵌体修复治疗,观察两组的修复时间(备牙时间、取模时间和总体操作时间),治疗后第6个月、12个月及18个月的修复效果,以及治疗前、治疗后第3个月牙周指标及龈沟液生化指标[C反应蛋白(C-reactive protein,CRP)、人CXC趋化因子配体16(CXC chemokine ligand 16,CXCL16)、白细胞介素1β(Interleukin-1β,IL-1β)]变化,对比两组牙齿美观满意度。结果:观察组备牙时间、取模时间和总体操作时间均显著低于对照组(P<0.05);观察组、对照组治疗后第6个月、12个月、18个月修复优良率分别为100% vs 100%、97.41% vs 85.84%、96.55% vs 83.19%,两组治疗后12、18个月比较差异有统计学意义(P<0.05);治疗后第3个月,两组出血指数(Bleeding index,BI)、菌斑指数(Plaque index,PLI)、牙龈指数(Gingival index,GI)及龈沟液CRP、CXCL16、IL-1β水平均显著降低(P<0.05),且观察组显著低于对照组(P<0.05),两组咀嚼能力显著升高,且观察组显著高于对照组(均P<0.05);观察组患者对修复体满意度(98.34%)显著高于对照组(81.67%)(P<0.05)。结论:CAD/CAM全瓷高嵌体技术应用于修复牙体缺损临床效果显著,可明显改善牙周情况及炎症反应,远期修复效果好,美观度高,患者满意度高,值得临床推广应用。展开更多
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 multi-piece post-crown technique is more effective in restoring residual root than other restoration techniques.Various types of adhesives have different material properties that affect restoration.Therefore,the choice of adhesive is particularly important for patients.However,the effect of different kinds of adhesives was not too precise by experimental methods when concerning about individual differences of teeth.One tooth root can only be restored with one type of adhesive in experiment.After the mechanical test,this tooth root cannot be restored with other adhesives.With the help of medical imaging technology,reverse engineering and finite element analysis,a molar model can be reconstructed precisely and restored using different types of adhesives.The same occlusal and chewing loads were exerted on the same restored residual root models with different types of adhesives separately.Results of von Mises stress analysis showed that the adhesives with low Young’s modulus can protect the root canal effectively.However,a root canal concentration is apparently produced around the root canal orifice when chewing.Adhesives with large Young’s modulus can buffer the stress concentration of the root canal orifice.However,the root canal tissue may be destroyed because the adhesive is too hard to buffer the load.
文摘We report the case of 27-year-old female patient applied to our clinic with several pain at her upper teeth and weakness complaints. Anamnesis revealed that she experienced laser gingivectomy to have remarkable teeth. Clinical examination showed that maxillar alveolar bone was partially uncovered with gingivae and periosteum. Interproximal necrosed area was observed. She had sensitivity at her maxillar anterior teeth. Furthermore, she was so anxious and depressed. In order to ensure more blood supply and clot formation, perforations on uncovered cortical bone was prepared. Avoiding from infection antibiotic, antiseptic gel and for epithelization vitamin E gel were prescribed. During one month she was recalled every third day. Recall times diminished periodically, as new tissue evolves. Although laser's irreversible photothermal effects on soft and hard tissue, after a year all denuded areas were covered with healthy tissues without any surgical procedures. Histopathologic comparing showed severe lymphocyte infiltration and increased fibrosis and kollagenization in restored gingiva, additionally epithelial loss was observed. Since there is not a case report about the complications of laser gingivectomy in litera-ture, we tried to represent a treatment plan that may be elucidative for clinicians.
文摘目的:对比高嵌体与全冠在修复牙体缺损中的美学效果及预后。方法:选取2020年6月-2022年1月笔者医院收治的牙体缺损患者120例(共229颗患牙),采用随机数字法分为对照组(60例,113颗患牙)和观察组(60例,116颗患牙),对照组采用常规全瓷冠修复治疗,观察组采用CAD/CAM全瓷高嵌体修复治疗,观察两组的修复时间(备牙时间、取模时间和总体操作时间),治疗后第6个月、12个月及18个月的修复效果,以及治疗前、治疗后第3个月牙周指标及龈沟液生化指标[C反应蛋白(C-reactive protein,CRP)、人CXC趋化因子配体16(CXC chemokine ligand 16,CXCL16)、白细胞介素1β(Interleukin-1β,IL-1β)]变化,对比两组牙齿美观满意度。结果:观察组备牙时间、取模时间和总体操作时间均显著低于对照组(P<0.05);观察组、对照组治疗后第6个月、12个月、18个月修复优良率分别为100% vs 100%、97.41% vs 85.84%、96.55% vs 83.19%,两组治疗后12、18个月比较差异有统计学意义(P<0.05);治疗后第3个月,两组出血指数(Bleeding index,BI)、菌斑指数(Plaque index,PLI)、牙龈指数(Gingival index,GI)及龈沟液CRP、CXCL16、IL-1β水平均显著降低(P<0.05),且观察组显著低于对照组(P<0.05),两组咀嚼能力显著升高,且观察组显著高于对照组(均P<0.05);观察组患者对修复体满意度(98.34%)显著高于对照组(81.67%)(P<0.05)。结论:CAD/CAM全瓷高嵌体技术应用于修复牙体缺损临床效果显著,可明显改善牙周情况及炎症反应,远期修复效果好,美观度高,患者满意度高,值得临床推广应用。
