An in vitro Investigation into Retention Strength and Fatigue Resistance of Various Designs of Tooth/Implant Supported Overdentures

Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration. The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis. Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study. These included: O-Rings with mini-dental implants (MDIs), Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex. The study was divided into four test groups: groups A and B, controls, and groups C and D, experimental groups. Control group A contained three overdenture supports: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with Dalbo Rotex screwed in. Control group B contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position, but on the left side of the model. Experimental group C contained three overdenture support foundations: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with MDI screwed in. Experimental group D contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with MDIs screwed in at the same MDI position, but on the left side of the model. Each group was further divided into two subgroups according to attachment type used. Five samples were prepared for each group. Retention force (N) values were recorded initially (0 cycles) and after 360, 720, 1440 and 2880 insertion and removal cycles. During the tensile test a cross-head speed of 10 mm/min was applied. Values of absolute force (AF) and relative force (RF) were statistically analyzed by two-way ANOVA and multiple comparison Tukey’s tests between groups and cycles periods. The results of fatigue tests showed a 50% reduction in retention force in the subgroups with flexible attachments. A triangular design of overdenture support foundations with O-Ring attachments revealed the lowest value of AF and a relatively high reduction in RF. The four overdenture support designs with flexible acrylic attachments improved the retention force and reduced the fatigue retention. Furthermore, the results of the investigation demonstrate that flexible acrylic attachments for both teeth and implant-supported overdentures offer a wide range of retention forces.

A Research on Hydroxyapatite Front Tooth Implantation

Hydroxyapatite (HA) bio-ceramics implant tooth was tested through animal experiment and clinical application. HA tooth was placed into the fresh extraction socket. At first, HA tooth was chosen and implanted as fixed maxillary front tooth in domestic rabbit immediately after extraction of tooth. Three to six months later satisfactory osseointegration between implanted HA teeth and periodontinum was observed. Clinically, 28 teeth in 25 patients were implanted with suitable HA teeth, chosen according to dental X-ray and models of different kinds of HA dental root. Crowning prosthesis with visible lightsolidfied material made the HA tooth wholesome and nice looking. Implantation and fixation of the HA teeth into the fresh extraction sockets of all the patients were successful.

The Behavior of New Hydrophilic Composite Bone Cements for Immediate Loading of Dental Implant

We introduced the hydrophilic groups to acrylic bone cement to improve compliance and achieve more interdigitation between the bone and the acrylic bone cement in order to create better substrates for immediate loading. FTIR-ATR, contact angle, and maximum breach torque were employed for measurement. The results reveal that the introduction of hydrophilic functional groups has increased PMMA＇s surface hydrophilicity after contact angle test. FTIR-ATR results suggest the hydrophilic groups participate in the polymerization reactions, and maximum breach torque of the hydrophilic acrylic bone cements is near 110 Ncm torque. Those effects make it possible for conventional acrylic bone cement application in immediate loading of dental implant.

不同材料种植体修复单颗上前牙缺失的三维有限元分析

背景:种植修复已成为治疗前牙缺失的重要手段,选取合适的种植修复材料尤为重要,但目前临床应用的种植体材料均存在一定的不足,研究者们一直在探索合适的种植体材料。目的:对比不同材料种植体修复单颗上前牙缺失的生物力学特征。方法:将1例单颗上颌中切牙缺失患者的锥形束CT数据导入3-matic软件建立单颗上前牙缺失的三维有限元分析模型,将模型导入Marc Mentat中,根据不同的种植体材料(聚醚醚酮、钛锆合金、钛合金和氧化锆,4种材料的弹性模量依次升高)及松质骨密度(高密度、低密度)共设计8组种植体修复模型,模拟正中咬合时上前牙受力情况,比较分析种植体位移、应力以及骨皮质应力和骨松质应变。结果与结论:(1)随着种植体材料弹性模量的增加,种植体的最大位移逐渐降低,聚醚醚酮组种植体最大位移数值超过了10μm;模型中种植体应力集中于唇侧颈部,随着种植体材料弹性模量的增加,种植体最大应力逐渐增大,其中氧化锆-低密度骨质组模型种植体应力最高,达21.31 MPa;所有模型的皮质骨应力均集中于与种植体交界的唇侧皮质骨,聚醚醚酮-低密度骨质组皮质骨应力最高,为29.90 MPa。(2)从生物力学角度来看,钛锆合金、钛合金、氧化锆均可用作修复单颗上前牙缺失的种植体材料,但单纯聚醚醚酮材料在上前牙区种植修复时可能会引起种植体位移过大,导致种植失败。

Mechanical Experiment for 3D Printing of Titanium Bone Bionic Dental Implants

[Objectives] To explore the flexural strength of 3D printed titanium bone bionic dental implants and provide a scientific basis for the clinical application of 3D printed porous bionic bone dental implants. [Methods] The cone-beam CT( CBCT) image information of 20 premolars extracted by orthodontic requirement was collected,and a new porous bone bionic dental implant was produced using modeling software and 3D printer. The premolars were divided into two groups( A and B). The universal testing machine was used to test the flexural strength of the two groups and the difference in flexural strength between the two groups was compared through statistics. [Results]Twenty 3D printed porous titanium bone bionic implants were accurately produced; the morphology of group A and group B were extremely similar to each other; the average flexural strength of group A was 2 767. 92 N,while the average flexural strength of group B was 778. 77 N,showing that the average flexural strength of group A was significantly higher than that of group B,and the difference was statistically significant( P < 0. 05).[Conclusions]The personalized porous structure root implants produced by 3D printing technology are very similar to the target tooth morphology,and show high accuracy and small error of production. Besides,the flexural strength of 3D printed personalized porous structure root implants can fully meet the requirements of the maximum occlusal force for dental implant restoration. It is expected to provide a scientific basis for clinical application of 3 D printed porous bionic bone tooth implants.

Tooth regeneration: a revolution in stomatology and evolution in regenerative medicine

A tooth is a complex biological organ and consists of multiple tissues including the enamel, dentin, cementum and pulp. Tooth loss is the most common organ failure. Can a tooth be regenerated？ Can adult stem cells be orchestrated to regenerate tooth structures such as the enamel, dentin, cementum and dental pulp, or even an entire tooth？ If not, what are the therapeutically viable sources of stem cells for tooth regeneration？ Do stem cells necessarily need to be taken out of the body, and manipulated ex vivo before they are transplanted for tooth regeneration？ How can regenerated teeth be economically competitive with dental implants？ Would it be possible to make regenerated teeth affordable by a large segment of the population worldwide？ This review article explores existing and visionary approaches that address some of the above-mentioned questions. Tooth regeneration represents a revolution in stomatology as a shift in the paradigm from repair to regeneration： repair is by metal or artificial materials whereas regeneration is by biological restoration. Tooth regeneration is an extension of the concepts in the broad field of regenerative medicine to restore a tissue defect to its original form and function by biological substitutes.

Flapless immediate implant placement into fresh molar extraction socket using platelet-rich fibrin: A case report

BACKGROUND There are some challenges concerning immediate implant placement in the molar region.Platelet-rich fibrin(PRF),an autologous biomaterial,has been used widely for periodontal intra-bony defects,sinus augmentation,socket preservation,and gingival recession.However,the literature remains scarce for reports on immediate implants with PRF,particularly in the case of fresh molar extraction socket.CASE SUMMARY The patient was a 43-year-old woman with maxillary molar vertical crown-root fracture.She underwent flapless immediate implant placement into the fresh molar socket with PRF.At the follow-up visit 15 d post procedure,the vascularization of soft tissue was visible.There was no swelling or pain after the surgery.Six months postoperatively,the regeneration of bone and soft tissues was visible.Subsequently,the definitive restoration was placed.The patient was satisfied with the aesthetic outcomes.CONCLUSION The flapless immediate implant placement into the fresh molar socket with PRF is a feasible procedure.This case report demonstrates that PRF promotes bone and soft tissue regeneration apart from having an enhanced anti-inflammatory ability.Furthermore,the procedure involves a minimally invasive technique,thus reducing the surgical complexity.

倾斜种植在上颌后牙区的应用现状

上颌后牙区缺牙患者通常由于牙槽骨病理性吸收萎缩、增龄性骨丧失、上颌窦气化等原因导致牙槽骨高度降低,在对这类患者进行种植修复时,因骨量的不足,导致种植修复方案的设计与实施难度增大。为了解决此类问题,有学者提出倾斜种植的治疗方案来满足骨量不足患者的种植修复需求。文章从应用类型、优势、生物力学等方面出发,对倾斜种植进行阐述。

先天缺牙患者的种植治疗

先天缺牙患者主要表现为牙数目不足、上下颌骨牙槽突发育不全、颌面部发育不良等,可导致口腔或全身功能异常,危害性大,治疗难度高。种植义齿因其良好的稳定性和舒适度,是修复此类患者缺失牙的理想选择。本文旨在通过分析先天缺牙患者种植治疗中面临的挑战,提出先天缺牙患者口腔功能重建策略。

牙槽突扩张术联合GBR植骨术同期种植牙在牙齿发育异常患者中的应用效果

目的:探讨牙槽突扩张术联合骨引导再生(GBR)植骨术同期种植牙在牙齿发育异常患者中的应用效果。方法:纳入87例(94牙)牙齿发育异常患者为研究对象,根据治疗方式不同分为常规组(n=37,40牙)和GBR组(n=50,54牙)。常规组行牙槽骨劈开术治疗;GBR组行牙槽突扩张术联合GBR植骨术治疗,术后随访1年。比较两组患者治疗有效率、手术基本情况(手术时间、离院时间及骨愈合时间);术后1个月及6个月种植体稳定性[稳定系数(ISQ)];术后1年种植体周围软组织情况[红色美学标准(PES)评分]、种植体周围牙槽骨吸收值及种植体周围牙整齐度;手术并发症及术后1年修复体并发症发生情况。结果:GBR组患者治疗有效率高于常规组(P<0.05);骨愈合时间短于常规组(P<0.05);两组患者手术时间及离院时间比较,差异无统计学意义(P>0.05)。术后1个月及6个月,GBR组患者种植体ISQ高于常规组(P<0.05)。术后1年,GBR组患者种植体周围软组织PES评分、种植体周围牙槽骨吸收值、牙整齐度高于常规组(P<0.05)。两组患者手术并发症比较,差异无统计学意义(P>0.05);GBR组患者术后1年修复体并发症总发生率低于常规组(P<0.05)。结论:牙槽突扩张术联合GBR植骨术同期种植牙治疗有效率高,且牙齿发育异常患者预后效果更好。

个案追踪管理模式配合回馈教育对外伤性牙缺失患者即刻种植修复效果的影响

目的:观察个案追踪管理模式配合回馈教育对外伤性牙缺失患者即刻种植修复效果的影响。方法:选取2011年3月-2013年3月笔者医院收治的62例外伤性牙缺失患者为研究对象,患者均接受即刻种植修复治疗,依照区组随机化分组法将其分为对照组31例和追踪组31例。对照组实施常规护理,追踪组在对照组基础上应用个案追踪管理模式配合回馈教育。比较修复1年后两组种植体修复效果及满意度(前牙隐形义齿修复满意度),对比随访1、3、6年后两组种植体留存率及牙美观程度(牙美观指数)。结果:修复1年后,追踪组种植体修复效果优于对照组(P<0.05);追踪组前牙隐形义齿修复满意度评分高于对照组(P<0.05)。随访1、3年后,两组种植体留存率比较差异无统计学意义(P>0.05)。随访6年后,追踪组种植体留存率高于对照组(P<0.05)。随访1、3、6年后,追踪组牙美观指数评分均低于对照组(P<0.05)。结论:个案追踪管理模式配合回馈教育能提高外伤性牙缺失患者即刻种植修复后种植体修复效果,提升修复满意度,同时还有利于种植体留存,保持牙美观,具有较高临床应用价值。

即刻修复与延期修复前牙缺损的美学和牙周健康指标观察

目的探讨前牙缺损采用即刻种植后即刻修复与延期修复的临床应用效果差异。方法选取采用即刻种植治疗的前牙缺损患者120例(120颗牙)进行临床随机试验,其中60例患者种植术后采用即刻修复(即刻组),另外60例患者种植术后采用延期修复(延期组);对比两组患者的美学效果(修复体边缘匹配、完整性、牙龈健康状况、颜色一致性和牙齿敏感性)、牙周健康指标(牙周探诊断深度、龈沟出血指数、龈沟液量、菌斑指数)、种植体边缘骨吸收情况、种植修复成功率。结果在修复治疗12个月后,即刻组的牙龈健康程度、牙敏感状况优于延期组(P<0.05);修复12个月后,即刻组的龈沟出血指数、龈沟液量、菌斑指数均低于延期组(P<0.05);即刻组在修复12个月后的近中、远中骨吸收量低于延期组(P<0.05)。两组种植修复成功率均较高,但差异无显著性(P>0.05)。结论前牙缺损采用即刻种植后即刻修复与延期修复成功率均较高,但是前者有利于牙周健康维持,减少骨吸收量,美学效果更好。

外胚层发育不良重度缺牙青少年种植干预的研究现状

缺牙是青少年口腔颌面部常见的发育畸形。外胚层发育不良(ectodermal dysplasia,ED)是造成青少年重度缺牙的最主要原因。对重度缺牙的青少年进行干预可能有利于患者咀嚼、语言功能的恢复以及颌面部的美观。种植义齿修复相比于传统可摘义齿具有更好的固位和稳定性。本文对ED患者青少年时期种植的可行性进行分析,着重介绍这一类特殊患者种植修复的考量因素以及常见方法;同时对该领域的进一步研究进行展望。

先天性缺牙治疗的研究进展

先天性缺牙是人类最常见的牙发育异常,影响患者的咀嚼、发音、美观及颌面部发育。由于该疾病的特殊特点,其治疗历时久、花费高,给患者带来心理和经济的双重负担。治疗方法包括儿科、正畸、颌面外科、修复、种植等多学科协作的序列治疗,以及靶向分子治疗和组织工程技术等新兴手段。本文综述了先天性缺牙的疾病特点、传统治疗方式的新进展以及新兴的治疗方法,简述了不同治疗方法的治疗效果,旨在为先天性缺牙患者的临床治疗提供有意义的信息。

种植牙修复中保留拔牙位点对患者修复后美观度及中远期骨缺失的影响

目的:探讨种植牙修复中保留拔牙位点对患者修复后美观度及中远期骨缺失的影响。方法:选取鹰潭市人民医院2021年1月—2022年3月收治的种植牙修复患者81例为研究对象。采用随机数字表法将其分为对照组(40例)和观察组(41例)。两组均采用微创拔牙,对照组采用常规种植牙修复,观察组采用保留拔牙位点的种植牙修复。比较两组拔牙前、拔牙6个月及12个月后牙槽骨骨密度、骨高度、骨宽度变化,比较两组美观度、满意度评分及种植成功率情况。结果:拔牙前,两组牙槽骨骨密度、骨高度、骨宽度组间比较,差异均无统计学意义(P>0.05);拔牙6、12个月后,两组牙槽骨骨密度、骨高度均低于拔牙前,骨宽度均小于拔牙前(P<0.05);但观察组拔牙6、12个月后牙槽骨骨密度、骨高度均高于对照组,骨宽度均大于对照组,差异均有统计学意义(P<0.05);两组拔牙前、拔牙6个月及12个月后牙槽骨骨密度、骨高度、骨宽度比较存在交互作用,差异均有统计学意义(P<0.001);观察组美观度与满意度评分均高于对照组,差异均有统计学意义(P<0.001);两组种植成功率比较,差异无统计学意义(P>0.05)。结论:种植牙修复中拔牙位点保留技术可减少患者骨吸收,保护牙槽骨骨密度、骨高度、骨宽度,提升拔牙修复后的美观度和满意度,值得临床推广和应用。

罹患重度牙周炎上颌磨牙拔牙微翻瓣牙槽嵴保存效果评价:一项回顾性初步研究

目的采用临床回顾性研究的方式,探讨罹患重度牙周炎上颌磨牙拔牙微翻瓣牙槽嵴保存效果。方法纳入80例患者95颗上颌磨牙,拔牙后分别经过自然愈合或者微翻瓣牙槽嵴保存后种植,通过影像学评价骨高度、宽度变化和上颌窦气化量,记录种植时需要骨增量手术的比例。结果拔牙窝愈合后,牙槽窝中央骨高度在牙槽嵴保存组和自然愈合组分别增加了4.94 mm和2.20 mm。高骨壁侧嵴顶下1 mm骨宽度牙槽嵴保存组增加了约4 mm,而自然愈合组减少了约1 mm。自然愈合组上颌窦气化后的上颌窦底高度变化量为(0.50±0.35)mm,牙槽嵴保存组为(0.23±0.44)mm(P=0.003)。自然愈合组种植时骨增量比例为67.6%,牙槽嵴保存组为29.5%。结论罹患重度牙周炎上颌磨牙拔牙微翻瓣牙槽嵴保存可以改善牙槽骨高度、骨宽度及上颌窦气化,从而减少种植治疗阶段进行骨增量手术的比例,减少种植治疗阶段的创伤性和复杂性。

微创拔牙后即刻种植技术在前牙修复中的应用价值研究

目的:探讨微创拔牙后即刻种植技术在前牙修复中的应用价值。方法:选取2022年1月—2024年1月在济南市章丘区口腔医院治疗的270例前牙修复患者,采用随机数字表法将其分为观察组与对照组,各135例。对照组采用微创拔牙后延期种植,观察组采用微创拔牙后即刻种植。比较两组的临床疗效、种植体稳定性、种植体周围探诊深度、美学评分及患者满意度。结果:两组临床总有效率比较,差异无统计学意义(P>0.05)。种植后3、6个月,观察组种植体稳定性高于对照组,种植体周围探诊深度均低于对照组,差异均有统计学意义(P<0.05)。种植后6个月,观察组红色美学评分(PES)、白色美学评分(WES)均高于对照组,差异均有统计学意义(P<0.05)。观察组总满意度高于对照组,差异有统计学意义(P<0.05)。结论:微创拔牙后即刻种植技术在前牙修复中具有显著优势,能够提高种植体稳定性,改善种植体周围软组织状况及美学效果,同时提高患者的满意度。

富血小板纤维蛋白植入牙槽窝保存术对后牙拔除患者牙槽嵴吸收的影响

目的 探讨后牙拔除富血小板纤维蛋白(PRF)植入牙槽窝保存术对患者牙槽嵴吸收的影响。方法 回顾性选取2021年10月至2023年10月宣城市人民医院收治的后牙拔除患者66例作为研究对象,依据拔牙后牙槽窝保存术所用种植材料不同分为PRF植入牙槽窝保存术组(PRF植入组)、海奥胶原膜植入牙槽窝保存术组(海奥胶原膜植入组)两组,每组各33例。比较两组患者的拟可种种植体长度、直径分布情况、早期软组织愈合情况、骨密度、牙槽嵴宽度、牙槽嵴高度、牙槽嵴骨量、牙龈乳头高度、疼痛程度、矿化骨部分填充量和创面愈合时间。结果 PRF植入组患者的拟可种种植体长度8 mm比例为9.09%,低于海奥胶原膜植入组(45.45%),10、12 mm比例分别为63.64%、27.27%,均明显高于海奥胶原膜植入组(42.42%,12.12%),差异均有统计学意义(P<0.05)。PRF植入组患者拟可种种植体的直径4.1 mm比例为39.39%,明显低于海奥胶原膜植入组(66.67%),4.8 mm比例为60.61%,明显高于海奥胶原膜植入组(33.33%),差异均有统计学意义(P<0.05)。两组患者早期软组织愈合情况比较,差异无统计学意义(P>0.05)。PRF植入组患者修复后的骨密度、牙槽嵴宽度、牙槽嵴高度、临床附着水平(CAL)均高于海奥胶原膜植入组,牙龈退缩低于海奥胶原膜植入组,差异均有统计学意义(P<0.05)。PRF植入组患者的牙龈乳头高度0~Ⅰ级比例为60.61%,明显高于海奥胶原膜植入组(36.36%),Ⅱ级、Ⅲ级、Ⅳ级比例分别为33.33%,3.03%,3.03%,均明显低于海奥胶原膜植入组(45.45%,12.12%,6.06%),差异有统计学意义(P<0.05)。PRF植入组患者的视觉模拟评分法(visual analogue scale, VAS)评分明显低于海奥胶原膜植入组,矿化骨部分填充量明显多于海奥胶原膜植入组,创面愈合时间明显短于海奥胶原膜植入组,差异均有统计学意义(P<0.05)。结论 后牙拔除PRF植入牙槽窝保存术较海奥胶原膜植入牙槽窝保存术更能减少患者牙槽嵴的吸收。

黏膜支持式导板和牙支持式导板的应用对美学区前牙种植精准度及美学效果的影响

目的探讨黏膜支持式导板和牙支持式导板的应用及护理配合对美学区前牙种植精准度和美学效果的影响。方法选取2021年5月至2023年9月在我院接受美学区前牙种植的72例前牙缺损患者为研究对象,随机将其分为A组(36例58牙)和B组(36例49牙),A组运用黏膜支持式导板,B组运用牙支持式导板,实施专业护理配合进行牙种植,种植结束后进行锥形束CT(CBCT)拍摄,提取牙冠顶部、根尖部、牙根深度及角度等相关参数,计算出与种植前偏差值进行两组比较;同时运用红色美学评分(PES)和白色美学评分(WES)对两组美学效果进行评价。结果两组患者均顺利完成美学区前牙种植,A组牙冠顶部偏差、根尖部偏差、牙根深度偏差分别为(0.53±0.18)mm、(0.67±0.21)mm、(0.41±0.13)mm、角度偏差为(2.46±0.73)°,B组牙冠顶部偏差、根尖部偏差、牙根深度偏差分别为(0.41±0.13)mm、(0.45±0.17)mm、(0.32±0.11)mm、角度偏差为(1.97±0.55)°,组间比较差异均具有统计学意义(P<0.05)。术后随访3个月,A、B组WES评分分别为(8.62±1.72)分VS(8.79±1.75)分,差异无统计学意义(t=0.505,P=0.614);A、B组PES评分分别为(9.05±2.26)分VS(8.16±2.17)分,差异有统计学意义(t=2.067,P=0.041)。结论黏膜支持式导板和牙支持式导板对美学区前牙种植均可获得较好效果,牙支持式导板种植精准度优于黏膜支持式导板,美学区红色美学评分黏膜支持式导板优于牙支持式导板;临床应根据患者具体情况选择合适的数字化导板支持,以获得更为精准的种植精度和美学效果。

数字化导板在美学区多牙缺失种植修复中的应用效果分析

目的 研讨数字化导板在美学区多牙缺失种植修复中的应用效果。方法 选取2022年1月至2023年12月因上前牙美学区多牙缺失于合肥市口腔医院行种植修复的60例患者,根据治疗方法的不同分为2组,每组30例。对照组患者采用自由手进行常规种植修复;观察组患者采用数字化导板辅助进行种植修复。比较两组修复后种植体位置偏差情况、修复前后美学效果评分。结果 修复后种植体颈部、根尖、深度及角度偏差:对照组患者分别为(1.36±0.18) mm、(1.56±0.21) mm、(1.47±0.15)mm、(6.87±1.78)°,观察组患者分别为(0.45±0.14) mm、(0.69±0.16) mm、(0.54±0.11) mm、(2.96±1.49)°,观察组患者均小于对照组,差异均有统计学意义(P<0.05)。修复后红、白美学评分:对照组为(11.09±1.86)、(7.46±1.41),观察组为(14.09±1.74)、(8.89±1.35),观察组明显高于对照组,差异均有统计学意义(P<0.05)。结论 在上前牙美学区多牙缺失种植修复中辅助应用数字化导板技术,有助于提高种植体植入的精准性及获得更好的美学效果,值得在临床上进一步推广和应用。