<strong>Objective: </strong>The present work aimed to identify the most common edentulousness and prosthesis type (prosthetic treatment), to improve the management in oral prosthetic rehabilitation in DR C...<strong>Objective: </strong>The present work aimed to identify the most common edentulousness and prosthesis type (prosthetic treatment), to improve the management in oral prosthetic rehabilitation in DR Congo. <strong>Material and Methods: </strong>It was a documentary, longitudinal, and retrospective study of the medical records of edentulous patients admitted to the prosthetic service of the Dental Department/Kinshasa University from January 1983 to December 2020. Age, sex, cause of teeth loss, and prosthetic treatment (partial removable prosthesis, complete removable prosthesis) were evaluated. The Chare square test was performed to compare significant differences between the variables and the P-value < 0.05 was set as significant. <strong>Results:</strong> One thousand six hundred and ninety patients in that 901 were men (47 ± 16 years) and 789 women (42 ± 15 years) had undergone prosthetic treatment. One thousand eight hundred and forty-four edentulous teeth were viewed according to the Kennedy classification. Kennedy class 1 was the most predominant (61.4%) followed by Kennedy class 3 (24.8%). Two thousand one hundred and ninety-one prostheses were performed. The removable partial prosthesis with plate (acrylic resin) was the most performed (78.8%;n = 1727) and followed by the joint (17.4%;n = 384). Dental caries (52.6%) and periodontitis (36.4%) were the main causes of these edentulous teeth. <strong>Conclusion: </strong>The present study showed that edentulism is becoming a concern for the implementation of a real oral health policy.展开更多
Aim This paper deals with the treatment of an atrophied toothless mandible with a fixing bridge carried by two nonstandard implant systems. Methodology Four bicortical screws were implanted into the frontal part of th...Aim This paper deals with the treatment of an atrophied toothless mandible with a fixing bridge carried by two nonstandard implant systems. Methodology Four bicortical screws were implanted into the frontal part of the mandible and one implant on each side was placed into the distal area of the mandible as a support for a fixing bridge. Results During the years 2002–2007 the authors placed a total of 256 bicortical screw and 84 blade implants. During this period only four bicortical screws and one blade implant failed. The primary and secondary surgical success rate was therefore above 98%, while the prosthetic success rate was 100%. (Bridges which had to be re-fabricated due to implant failure were not taken into account.) Conclusion This approach is recommended as a highly successful and affordable option for a wide range of patients.展开更多
AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1...AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations(bone quantity and density), radiographic techniques, implant selection(number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.展开更多
Objective: To evaluate the association between type 2 diabetes mellitus and the reduction of mandibular residual ridge in completely edentulous patients wearing complete dentures and to investigate the ef-fect of gend...Objective: To evaluate the association between type 2 diabetes mellitus and the reduction of mandibular residual ridge in completely edentulous patients wearing complete dentures and to investigate the ef-fect of gender, age and years of edentulousness / den-ture wearing on ridge resorption on both groups. Methods: Seventy-two (36 men and 36 women) with a mean age 63.5 years (range of 52 to 73 years) com-pletely edentulous denture-wearing patients were included in this study. Of these, there were 40 patients with type 2 diabetes mellitus and 32 control subjects participated in the study. Resorption in the mandibular residual ridges was assessed by using the mental foramen and the inferior border of the mandible, as they appear in panoramic radiographs, as reference points using Wical and Swoope Analysis method. Measurements were performed using “Dijite” Digital Caliper. The amount of mandibular ridge resorption was calculated and correlated with type 2 diabetes mellitus and the results were compared with control group. Differences in gender, age and years of edentulousness were investigated. Statistical analysis was performed using SPSS (V11.0). A 2-sample t-test was used to evaluate the differences in mean values of mandibular ridge resorption between diabetics and controls. Level of significance was set at 0.05. Results: The mean mandibular residual ridge resorption of all participants is 8.0 mm (26.9%), diabetic group significantly (P < 0.01) had two times more resorption compared with control group (35.8% versus 18.0%). Females recorded greater amount of resorption in diabetics 49.7% versus 21.8% (P < 0.001) and in controls 22.3% versus 13.7%, (P < 0.05) compared to males, respectively. There were no differences in both groups regarding the age of subjects and the length of time they have been edentulous and years of denture wearing. The amount of mandibular residual ridge resorption was directly related to the number of years of edentulousness. Conclusion: Completely edentulous, denture-wearing diabetics, women in particular, are at more risk to have ridge resorption than “nondiabetic” subjects. Reduced mandibular height is directly related to years of edentulousness and denture wear-ing with greater amount of resorption among diabet-ics.展开更多
The influence of free-end torsion on compressive behavior of an extruded AZ31 rod at various temperatures was studied.Pre-torsion generates a high density of dislocations and a large number of{1012}twins in the matrix...The influence of free-end torsion on compressive behavior of an extruded AZ31 rod at various temperatures was studied.Pre-torsion generates a high density of dislocations and a large number of{1012}twins in the matrix,which can largely enhance the compressive yield strength at RT and 100℃.However,with increasing temperature,hardening effect via pre-torsion gradually decreases.When the compressive temperature reaches 300℃,pre-torsion reduces the compressive yield strength.Moreover,initial dislocations and twins via torsion help to refine the sub-structure and accelerate the continuous dynamic recrystallization during compression at 200℃.Thus,twisted sample exhibits more rapid flow softening behavior than the as-extruded sample at 200℃.When compressed at 300℃,the twins and dislocations via torsion were largely eliminated during the holding time,and the discontinuous dynamic recrystallization was enhanced.It is found that the compression curves of twisted sample and as-extruded sample tended to be coincident at 300℃.Related mechanisms were discussed in detail.展开更多
Objective The magnetic retainer was used to respair combined defects including edentous jaw,zygoma and orbit defects to recover patients mastication,language and swallow functions.Method Impression models of jaw,zygom...Objective The magnetic retainer was used to respair combined defects including edentous jaw,zygoma and orbit defects to recover patients mastication,language and swallow functions.Method Impression models of jaw,zygoma and orbit were taken.Two prosthesis were connected by magnetic retainer.Result Fixation,and recovery of language and face shape were favorable for patients with magnetic retainer.Mastitating function was completely recovered in health side and partially in affected side.Conclusion The magnetic retainer provide sufficient retention and reliable connection.It can recover mastication with convenient wearing and taking.展开更多
背景:随着无牙颌修复需求增加,“All-on-4”技术被广泛应用。种植体与天然牙的载荷传递方式不同,三维有限元分析可研究功能载荷作用下种植体及周围骨组织的应力分布,并在此基础上为寻找适合的种植体材料、优化种植体的几何结构、设计临...背景:随着无牙颌修复需求增加,“All-on-4”技术被广泛应用。种植体与天然牙的载荷传递方式不同,三维有限元分析可研究功能载荷作用下种植体及周围骨组织的应力分布,并在此基础上为寻找适合的种植体材料、优化种植体的几何结构、设计临床手术方案提供了研究方法。目的:对三维有限元分析法在“All-on-4”技术方面的相关研究作一综述。方法:检索中国知网和PubMed数据库2003-2023年相关文献,英文检索词为“Finite Element Method,All-on-4,edentulous,Biomechanics”,中文检索词为“有限元,All-on-4,无牙颌,生物力学”,根据纳入排除标准筛选符合标准的文献,最终纳入65篇文献进行综述。结果与结论:①对水平骨量不足的情况,研究者们可以选择应用窄直径种植体,但需要注意悬臂的存在对应力分布的影响,降低失败的风险。②“All-on-4”概念通过倾斜远中种植体的方法,减少骨的应力分布,但在不同的颌骨类型中,远中种植体倾斜的理想角度还需要进一步的研究。③悬臂的存在会增加种植失败的风险,将悬臂长度/AP距(CL/AP)的比值控制在0.9时,有助于减少机械并发症的发生。④用弹性模量较低的材料制作支架时,支架自身的应力较小,但会增加种植体、中央螺丝、基台及种植体周围骨组织的应力,相反使用弹性模量较大的材料,会降低修复体组件和种植体周围骨组织的应力,但支架本身的应力较高。⑤“All-on-4”概念可以实现较好的力学平衡,但需结合患者自身的具体情况制定一个长期有效的治疗方案。⑥合理的咬合设计是影响种植治疗成功的关键,尖牙引导牙合和组牙功能牙合在修复体的寿命方面无差异。然而,影响咬合设计的原因有很多,未来还需要进一步的体外实验以及大量临床研究来探索“All-on-4”理想的咬合设计。展开更多
文摘<strong>Objective: </strong>The present work aimed to identify the most common edentulousness and prosthesis type (prosthetic treatment), to improve the management in oral prosthetic rehabilitation in DR Congo. <strong>Material and Methods: </strong>It was a documentary, longitudinal, and retrospective study of the medical records of edentulous patients admitted to the prosthetic service of the Dental Department/Kinshasa University from January 1983 to December 2020. Age, sex, cause of teeth loss, and prosthetic treatment (partial removable prosthesis, complete removable prosthesis) were evaluated. The Chare square test was performed to compare significant differences between the variables and the P-value < 0.05 was set as significant. <strong>Results:</strong> One thousand six hundred and ninety patients in that 901 were men (47 ± 16 years) and 789 women (42 ± 15 years) had undergone prosthetic treatment. One thousand eight hundred and forty-four edentulous teeth were viewed according to the Kennedy classification. Kennedy class 1 was the most predominant (61.4%) followed by Kennedy class 3 (24.8%). Two thousand one hundred and ninety-one prostheses were performed. The removable partial prosthesis with plate (acrylic resin) was the most performed (78.8%;n = 1727) and followed by the joint (17.4%;n = 384). Dental caries (52.6%) and periodontitis (36.4%) were the main causes of these edentulous teeth. <strong>Conclusion: </strong>The present study showed that edentulism is becoming a concern for the implementation of a real oral health policy.
文摘Aim This paper deals with the treatment of an atrophied toothless mandible with a fixing bridge carried by two nonstandard implant systems. Methodology Four bicortical screws were implanted into the frontal part of the mandible and one implant on each side was placed into the distal area of the mandible as a support for a fixing bridge. Results During the years 2002–2007 the authors placed a total of 256 bicortical screw and 84 blade implants. During this period only four bicortical screws and one blade implant failed. The primary and secondary surgical success rate was therefore above 98%, while the prosthetic success rate was 100%. (Bridges which had to be re-fabricated due to implant failure were not taken into account.) Conclusion This approach is recommended as a highly successful and affordable option for a wide range of patients.
文摘AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations(bone quantity and density), radiographic techniques, implant selection(number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.
文摘Objective: To evaluate the association between type 2 diabetes mellitus and the reduction of mandibular residual ridge in completely edentulous patients wearing complete dentures and to investigate the ef-fect of gender, age and years of edentulousness / den-ture wearing on ridge resorption on both groups. Methods: Seventy-two (36 men and 36 women) with a mean age 63.5 years (range of 52 to 73 years) com-pletely edentulous denture-wearing patients were included in this study. Of these, there were 40 patients with type 2 diabetes mellitus and 32 control subjects participated in the study. Resorption in the mandibular residual ridges was assessed by using the mental foramen and the inferior border of the mandible, as they appear in panoramic radiographs, as reference points using Wical and Swoope Analysis method. Measurements were performed using “Dijite” Digital Caliper. The amount of mandibular ridge resorption was calculated and correlated with type 2 diabetes mellitus and the results were compared with control group. Differences in gender, age and years of edentulousness were investigated. Statistical analysis was performed using SPSS (V11.0). A 2-sample t-test was used to evaluate the differences in mean values of mandibular ridge resorption between diabetics and controls. Level of significance was set at 0.05. Results: The mean mandibular residual ridge resorption of all participants is 8.0 mm (26.9%), diabetic group significantly (P < 0.01) had two times more resorption compared with control group (35.8% versus 18.0%). Females recorded greater amount of resorption in diabetics 49.7% versus 21.8% (P < 0.001) and in controls 22.3% versus 13.7%, (P < 0.05) compared to males, respectively. There were no differences in both groups regarding the age of subjects and the length of time they have been edentulous and years of denture wearing. The amount of mandibular residual ridge resorption was directly related to the number of years of edentulousness. Conclusion: Completely edentulous, denture-wearing diabetics, women in particular, are at more risk to have ridge resorption than “nondiabetic” subjects. Reduced mandibular height is directly related to years of edentulousness and denture wear-ing with greater amount of resorption among diabet-ics.
基金the National Natural Science Foundation of China(No.51601154)Southwest University Undergraduate Innovation Project(No.zsm2021026).
文摘The influence of free-end torsion on compressive behavior of an extruded AZ31 rod at various temperatures was studied.Pre-torsion generates a high density of dislocations and a large number of{1012}twins in the matrix,which can largely enhance the compressive yield strength at RT and 100℃.However,with increasing temperature,hardening effect via pre-torsion gradually decreases.When the compressive temperature reaches 300℃,pre-torsion reduces the compressive yield strength.Moreover,initial dislocations and twins via torsion help to refine the sub-structure and accelerate the continuous dynamic recrystallization during compression at 200℃.Thus,twisted sample exhibits more rapid flow softening behavior than the as-extruded sample at 200℃.When compressed at 300℃,the twins and dislocations via torsion were largely eliminated during the holding time,and the discontinuous dynamic recrystallization was enhanced.It is found that the compression curves of twisted sample and as-extruded sample tended to be coincident at 300℃.Related mechanisms were discussed in detail.
文摘Objective The magnetic retainer was used to respair combined defects including edentous jaw,zygoma and orbit defects to recover patients mastication,language and swallow functions.Method Impression models of jaw,zygoma and orbit were taken.Two prosthesis were connected by magnetic retainer.Result Fixation,and recovery of language and face shape were favorable for patients with magnetic retainer.Mastitating function was completely recovered in health side and partially in affected side.Conclusion The magnetic retainer provide sufficient retention and reliable connection.It can recover mastication with convenient wearing and taking.
文摘背景:随着无牙颌修复需求增加,“All-on-4”技术被广泛应用。种植体与天然牙的载荷传递方式不同,三维有限元分析可研究功能载荷作用下种植体及周围骨组织的应力分布,并在此基础上为寻找适合的种植体材料、优化种植体的几何结构、设计临床手术方案提供了研究方法。目的:对三维有限元分析法在“All-on-4”技术方面的相关研究作一综述。方法:检索中国知网和PubMed数据库2003-2023年相关文献,英文检索词为“Finite Element Method,All-on-4,edentulous,Biomechanics”,中文检索词为“有限元,All-on-4,无牙颌,生物力学”,根据纳入排除标准筛选符合标准的文献,最终纳入65篇文献进行综述。结果与结论:①对水平骨量不足的情况,研究者们可以选择应用窄直径种植体,但需要注意悬臂的存在对应力分布的影响,降低失败的风险。②“All-on-4”概念通过倾斜远中种植体的方法,减少骨的应力分布,但在不同的颌骨类型中,远中种植体倾斜的理想角度还需要进一步的研究。③悬臂的存在会增加种植失败的风险,将悬臂长度/AP距(CL/AP)的比值控制在0.9时,有助于减少机械并发症的发生。④用弹性模量较低的材料制作支架时,支架自身的应力较小,但会增加种植体、中央螺丝、基台及种植体周围骨组织的应力,相反使用弹性模量较大的材料,会降低修复体组件和种植体周围骨组织的应力,但支架本身的应力较高。⑤“All-on-4”概念可以实现较好的力学平衡,但需结合患者自身的具体情况制定一个长期有效的治疗方案。⑥合理的咬合设计是影响种植治疗成功的关键,尖牙引导牙合和组牙功能牙合在修复体的寿命方面无差异。然而,影响咬合设计的原因有很多,未来还需要进一步的体外实验以及大量临床研究来探索“All-on-4”理想的咬合设计。