Implant-supported mandibular overdentures retained with ball or telescopic crown attachments: a 3-year prospective study

PURPOSE: The aim of the present study was to evaluate implant survival, peri-implant conditions, and prosthodontic maintenance requirements for implant-supported mandibular overdentures in atrophic mandibles retained with ball or resilient telescopic crown attachments during a 3-year period. MATERIALS AND METHODS: Twenty-five patients with edentulous mandibles each received 2 Camlog root-form dental implants in the mandibular interforaminal (canine) region. The denture attachment system was chosen randomly; 13 patients received ball attachments and 12 patients received resilient telescopic crowns. Implant survival, implant mobility (Periotest values), and peri-implant conditions such as bone resorption, pocket depth, Plaque Index, Gingiva Index, Bleeding Index, and Calculus Index values were assessed for each implant. In addition, detailed prosthodontic maintenance was evaluated during the follow-up period and the 2 retention modalities were compared. RESULTS: There were no differences in implant survival, implant mobility (Periotest values), and peri-implant conditions between the 2 retention modalities. During the 3-year period significantly more complications/interventions for maintenance purposes were registered in the ball group (62 interventions) than in the telescopic crown group (26 interventions; P < .01). CONCLUSION: The results indicate that both ball attachments and resilient telescopic crowns used on isolated implants in the edentulous mandible are viable treatment options. Implant success and peri-implant conditions did not differ between ball attachments and telescopic crowns used as retention modalities for implant overdentures, but the frequency of technical complications was significantly higher with ball attachments than with resilient telescopic crowns.     

Telescopic crowns as attachments for implant supported restorations: a case series

The use of dental implants to support mandibular or maxillary overdentures is a widely used treatment modality. Advantages are an increase in retention, an increase in chewing ability, and easy access for oral hygiene procedures. While telescopic and conical crowns have been used for decades to connect natural teeth to overdentures, not many cases have been reported in the literature of telescopic crowns placed on implants to support overdentures. This article describes 7 patients with overdentures supported by telescopic crowns who received 65 implants (ITI Straumann). The cases presented in this report have been in function for up to 4.5 years. During that time no adverse events were reported. The use of telescopic crowns as attachments for implant-supported overdentures may be a viable treatment option.     

种植套筒冠义齿修复无牙颌的临床效果观察

目的 探讨种植套筒冠义齿修复无牙颌的临床效果.方法 15例无牙颌患者,采用种植套筒冠义齿修复.共完成26件修复体,其中上颌义齿11件,下颌义齿15件.共植入种植体104颗,修复基台研磨后直接作为套筒冠内冠,套筒冠外冠采用失蜡铸造技术加工.修复后平均回访32个月,对所有种植体及上部结构进行临床及影像学检查,并对原总义齿和种植套筒冠义齿满意度进行比较.结果 完成种植体支持修复的26件覆盖义齿,所有上部修复体的外冠与种植体基台间固位较好、义齿稳定,患者对覆盖义齿的舒适度和咀嚼功能满意,在舒适度和咀嚼功能方面,患者的种植套筒冠义齿满意度要高于常规总义齿,差异有统计学意义(P<0.05),而发音方面二者差异无统计学意义(P>0.05).覆盖义齿在观察时间内未发生松动、折断及损坏,种植体无松动或脱落.随访期内,种植体周围牙槽骨平均垂直骨吸收量约1 mm.结论 本研究结果表明,种植套筒冠义齿修复无牙颌是一种可靠的方法,但仍需要进一步长期观察.     

种植套筒冠覆盖义齿在无牙颌修复中的应用

目的探讨以种植套筒冠覆盖义齿修复无牙颌的临床效果。方法对北京大学口腔医学院·口腔医院口腔种植中心就诊的21例无牙颌患者,采用种植套筒冠覆盖义齿修复。共28件修复体,其中上颌全颌覆盖义齿13件,下颌全颌覆盖义齿15件。共植人种植体139枚,其中Camlog 74枚,IMZ 28枚,Frialit-2 37枚。种植体修复基台切削后直接作为套筒冠内冠,套筒冠外冠分别采用金沉积技术和失蜡铸造技术加工。修复后平均追踪26．5个月(12-39个月)。以临床检查和影像学检查评价修复效果。结果至最后一次复查,21例患者临床检查未见修复体松动、折断、损坏,修复体固位好、稳定,种植体周围软组织健康。19例患者曲面断层X线片显示种植体周围骨组织稳定,无吸收。仅2例在修复3年后发现少量骨吸收,约1 mm。修复后至最后一次复查未见种植体脱落。结论种植套筒冠覆盖义齿稳定,种植体周围骨组织稳定,可用于无牙颌修复。     

27例磁性附着体固位种植覆盖义齿临床体会

目的：评价磁性附着体固位种植覆盖义齿在牙槽骨严重吸收的无牙颌患者中运用的临床效果。方法：27例牙槽骨严重吸收的无牙颌患者,植入2—4枚牙种植体,3-6个月后进行种植体支持式磁性附着体固位覆盖义齿修复,定期复查,随访8—79个月。采用临床检查、x线检查和患者主观感受问卷来评价此类义齿的修复效果。结果：27例患者61枚种植体,1枚在修复前由于种植体周围炎松动被拔除,3枚在覆盖义齿修复后发生种植体周围炎松动被拔除,其余种植体均稳固无松动;27件种植覆盖义齿的固位、稳定、咀嚼功能均良好,患者满意度高。结论：运用磁性附着体固位种植覆盖义齿修复牙槽骨严重吸收的无牙颌能很好的恢复咀嚼功能,且制作方法简单,值得临床大力推广。     

Mandibular overdentures stabilized by Astra Tech implants with either ball attachments or magnets: 5-year results

PURPOSE: The purpose of this work was to report on the use of implant-stabilized overdentures in the mandible using the Astra Tech implant system with either ball attachments or magnets as the retentive mechanism. MATERIALS AND METHODS: Mandibular overdentures that used ball attachments on 2 implants were provided for 13 edentulous patients; 12 edentulous patients were provided with mandibular overdentures with magnet retention, using 2 implants in 10 patients and 3 implants in 2 patients. Once they were comfortable, the participants were placed on annual recall. Any other visits were initiated by the patients. Detailed records were kept for all visits. At the annual recall the following parameters were monitored: plaque levels, mucosal health, marginal bone levels, and the patients' assessment of the treatment. The patients were followed for 5 years. RESULTS: There was no statistical difference between the 2 groups for mucosal health and postinsertion maintenance. The magnet group had more abutment surfaces covered with plaque. Statistical analysis of the patients' subjective assessment of their treatment showed that the magnet group was less comfortable and chewing was less effective. CONCLUSION: The results indicate that both ball attachments and magnets used on isolated Astra Tech implants in the mandible are viable treatment options. Both attachment mechanisms provided patient satisfaction, although the ball attachments were better in this respect than the magnets.     

种植覆盖义齿临床疗效的回顾性研究

目的:回顾性分析评价无牙颌患者采用种植覆盖义齿修复后的临床疗效.方法:对行种植覆盖义齿修复的57 名无牙颌患者进行临床复诊,检查种植体周围菌斑指数、探诊深度、探诊出血、牙龈增生、种植体边缘骨吸收以及义齿修复后并发症的发生情况;采用VAS视觉模拟评分方法测量患者对种植覆盖义齿修复的满意度,并对相关影响因素进行分析,综合评价种植覆盖义齿的临床疗效.结果:经过(48±11.3) 个月的随访观察,4 枚种植体在愈合期内失败,存留率为98.1%;种植体的边缘骨吸收为(1.38±0.74) mm,不同类型附着体(杆卡、球帽、磁性)修复后种植体边缘骨吸收差异无统计学意义(P>0.05);杆卡组的菌斑指数、探针深度均高于磁性和球帽组(P<0.05);探针出血无明显差异(P>0.05);牙龈增生多见于杆卡组.并发症主要包括:上部基台折裂、义齿折裂、螺丝松动等等.患者对种植覆盖义齿的总体满意度较高,仅在"清洁方便程度"一项,磁性和球帽组患者的满意度高于杆卡组(P<0.05),其他各项均无明显差异(P>0.05).结论:种植覆盖义齿有较高的种植体存留率及患者满意度,但修复后需对义齿及种植体进行定期清理维护以减少后期并发症的发生,尤其是杆卡式种植覆盖义齿.     

球帽式和Locator式下颌种植覆盖总义齿的临床效果观察

目的：评价球帽式和Locator式下颌种植覆盖总义齿的临床应用效果。方法：共完成2颗种植体支持的球帽下颌覆盖总义齿9例,Locator下颌覆盖总义齿11例,上颌均制作可摘局部义齿。修复完成后于3、6、12、24个月进行随访,对各组种植体周围边缘骨吸收（MBL）进行评估,同时进行义齿满意度调查。结果：Locator组、球帽组在咀嚼功能、固位功能和舒适程度的满意度均高于治疗前,有显著性差异（P〈0.05）;Locator组与球帽组患者满意度、种植体周牙槽骨吸收量差异无统计学意义。结论：使用球帽、Locator附着体种植覆盖义齿在下颌无牙颌的应用中临床效果明显。     

非埋藏式种植体支持球型固位覆盖义齿在下颌无牙(牙合)修复中的应用

目的 评价非埋藏式种植体支持球型固位下颌覆盖义齿的临床效果。方法 39例下颌牙He病人，种植98颗TTI种植体，表面喷涂钛离子（TPS）的种植体于种植后3个月行上部结构修复，表面喷涂酸蚀－喷沙（SLA）的种植体于种植后6周行上部结构修复，上部结构采用球型固位设计。种植后及义齿修复后的观察期为1－11a。结果 种植成功率为99％，义齿修复后行使功能的成功率为100％。结果 非埋藏式种植体（ITI）支持球型固位覆盖义齿在下颌无牙He修复中有很高的成功率。     

Maxillary overdentures retained by splinted and unsplinted implants: a retrospective study

The purpose of this retrospective study was to evaluate the clinical performance of and patients' satisfaction with maxillary overdentures retained by splinted and unsplinted implants. Patients who had been treated with maxillary implant-retained overdentures because of functional problems with conventional complete dentures were identified and invited to participate in the study. A total of 16 patients fulfilled the enrollment criteria and agreed to participate. Eleven patients were treated with bar-retained overdentures with 3 to 6 clips (mean follow-up 32 months), and 5 patients wore overdentures retained by 2 to 6 ball attachments (mean follow-up 54 months). All subjects were satisfied with their prostheses, and most subjects experienced improvement in their oral function after treatment with implant-retained overdentures. At the time of clinical examination, 92% (n = 77) of the 84 implants placed were functioning satisfactorily. The cumulative survival rate for the implants after 72 months was 90%. Loss of bone support correlated with peri-implant probing depth (r = 0.29; P < .02). No differences in mean bone loss between the subjects with ball-retained or bar-retained overdentures were found. The presence of plaque or peri-implant bleeding was not associated with the type of attachment.     

Mandibular two-implant telescopic overdentures

To stabilize mandibular overdentures in edentulous patients, various connector types which can be attached to between two and four implants placed in the anterior mandible are possible. Treatment using non-rigid telescopic connectors on two interforaminal implants for overdenture stabilization began in 1989. The objective of this study is to investigate soft- and hard-tissue conditions as well as prosthesis function after a period of 10 years. This also involved an evaluation of correlations between radiographic and clinical parameters. Twenty-three subjects with 46 interforaminal implants (ITI solid screw implants, 12 mm in length, 4.1 mm in diameter; 10.4 years in situ, range, 8-12.8 years) were investigated. Modified plaque index (mPI), sulcus fluid flow rate (SFFR), modified sulcus bleeding index (mBI), probing depth (PD), distance from implant crown margin to the coronal border of the peri-implant mucosa (DIM), attachment level (AL), width of keratinized mucosa (KM), Periotest values (PTVs) and prosthesis function were evaluated. In the radiographic evaluation, the distance between implant shoulder and first crestal bone-implant contact (DIB) in mm and the horizontal bone loss (HBL) in mm were measured. The relatively high mPI scores (mean, 0.82; score, 0 in 44.4%; SD, 0.83) did not result in increased SFFR scores (mean, 12; min, 3, max, 38; SD, 7.43) or higher mBI scores (mean, 0.35; score, 0 in 70.8%; SD, 0.59), which was commensurate with healthy peri-implant mucosa. A mean PD value of 2.15 mm (min, 1 mm; max, 5 mm; SD, 0.96) and a mean DIM value of 0.28 mm (min, 0 mm; max, 2 mm; SD, 0.52) were measured. The implants were stable, showing a mean Periotest value of -1.91 (max, 02, min, -6; SD, 1.76). A mean DIB of 3.19+/-0.95 mm (range, 1.3-5.16 mm) and a mean HBL of 1.6+/-1.52 mm (range, 0.28-8.33 mm) were calculated. A correlation was found between DIB and the parameters SFFR (P=0.060), DIM (P=0.042), AL (P=0.050) and especially PTV (P<0.01), leading to the assumption that these clinical parameters may be useful indicators of peri-implant bone loss. The results of the 10-year follow-up examination show that non-rigid telescopic connectors with two interforaminal implants for overdenture stabilization appear to be an efficient and effective long-term treatment modality in severely resorbed edentulous mandibles. Particularly in geriatric patient treatment this concept may provide advantages in terms of handling, cleaning and long-term satisfaction.     

磁性附着体在下颌种植覆盖义齿的修复效果观察及患者满意度调查

目的:评价磁性附着体在下颌种植覆盖义齿修复中的临床效果及患者的满意度。方法 :选择2012-06—2013-07期间,选用种植体支持磁性附着体修复下颌牙列缺失的32例患者(32个磁性附着体,每位患者植入2~4枚种植体,共102枚种植体),随访观察12个月并对患者的满意度进行问卷调查。记录种植体的失败数量、失败类型,磁性附着体的失败数量、失败类型及各种并发症情况。结果:32例共32个磁性附着体、102枚种植体进行随访12个月。在随访病例中,2个磁性附着体(6.3%)出现基托正中折断,3个磁性基台出现松动(2.9%),6枚种植体(5.9%)存在种植体周围黏膜炎症。磁性附着体的存留率为87.5%,种植体的存留率为100%。患者对磁性附着体的舒适性和美观性满意度较高,言语功能和咀嚼功能次之,然后是固位能力。结论:种植体支持的磁性附着体,修复下颌牙列缺失的临床修复效果可靠,并可以获得良好的患者满意度。     

双种植体支持的下颌覆盖义齿的临床应用

目的:评价双种植体支持的覆盖义齿的临床应用及其效果。方法:2003年11月至2010年10月间,选择下颌无牙患者52例,其中男性39例,女性13例,年龄46-72岁,在下颌两侧尖牙区植入2枚种植体,共104枚种植体,制作覆盖义齿,其中球帽式附着体30例,磁性附着体11例,Locator附着体11例。采用临床检查和x线检查评估。结果:所有种植体在观察期内未出现松动脱落,均保持稳定的骨结合,未见种植体周围炎发生。覆盖义齿的固位、稳定及咀嚼效果的满意度良好。3例球帽附着体2年后出现固位力下降、松动,经调整后固位力增强。4例磁性附着体患者磁体脱落,重新粘固后使用正常。4例患者义齿基托出现折断,折断部位均位于植体-附着体处。未出现基台的松动、折断或变形。结论:双种植体支持的下颌覆盖义齿临床效果可靠,制作方法简单,尤其适合牙槽骨吸收严重的无牙患者。     

球帽固位下颌双种植体覆盖义齿修复效果的前瞻性研究

目的 评价球帽固位的下颌双种植体覆盖义齿的临床修复效果及其修复并发症。 方法 对下颌牙槽骨重度萎缩的10例无牙颌患者,在前牙区与中线等距平行植入2枚种植体,3个月后采用球帽附着体固位方式制作下颌种植覆盖义齿。在覆盖义齿戴入后1周、1年、2年、3年进行随访,评价种植体边缘骨吸收情况、种植体周围软组织健康状况、患者满意度及义齿并发症情况。 结果 10例两球帽固位的下颌种植覆盖义齿经过3年观察,种植体存留率100%,边缘骨吸收<1 mm,种植体周围软组织健康,患者满意度显著提高且维持稳定,义齿无重衬或折断现象,义齿并发症主要是球帽附着体O型圈的置换或固位金属簧的固位力再激活,修理频次0.67次/(年·人)。 结论 在种植体植入位置、方向合适的情况下,球帽附着体固位的下颌双植体覆盖义齿,可获得长期稳定的临床修复效果。     

Marginal bone resorption around immediate and delayed loaded implants supporting a locator‐retained mandibular overdenture. A 1‐year randomised controlled trial

The aim of this 1‐year study was to evaluate and compare crestal bone loss and clinical outcomes of immediate and delayed loaded implants supporting mandibular overdentures with Locator attachments. In a randomised controlled clinical trial, 36 completely edentulous patients (mean age 59·6 years) who desired to improve the stability of their mandibular dentures were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible after a minimal flap reflection. Implants were loaded by mandibular overdentures either 3 months (delayed loading group, G1) or the same day (immediate loading group, G2) after implant placement. Locator attachments were used to retain all overdentures to the implants. Peri‐implant vertical (VBL) and horizontal (HBLO) bone losses and clinical parameters [plaque scores (PI), gingival scores (GI), probing depths (PD) and implant stability (ISQ)] were assessed at time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. After 12 months of overdenture insertion, two implants (5·5%) failed in G2. Vertical bone loss was significantly higher in G2 compared with G1, while HBLO demonstrated insignificant differences between groups. All clinical parameters (PI, GI, PD and ISQ) did not differ significantly between groups. Vertical bone loss was significantly correlated with PD and HBLO. Immediately loaded two implants supporting a Locator‐retained mandibular overdenture are associated with more vertical bone resorption when compared to delayed loaded implants after 1 year. Clinical outcomes do not differ significantly between loading protocols.     

Mandibular overdentures supported by two or four endosteal implants: A prospective, comparative study

The aim of this prospective study was to evaluate the effect of the number of implants supporting a mandibular overdenture on the condition of the peri-implant tissues. Sixty edentulous patients (Cawood class V–VI) participated in this study. After randomization, thirty patients were treated with an overdenture supported by two IMZ implants (group A) and thirty patients with an overdenture on four IMZ implants (group B). The implants were inserted in the anterior region of the mandible. After three months overdentures were constructed, supported by round bar and clip attachments. A standardized clinical and radiographic evaluation was performed 0, 6 and 12 months after insertion of the denture. One implant was lost (group A) during the healing period. There were no significant differences with regard to any of the studied clincial or radiographic parameters of the peri-implant tissues, neither were significant differences found between the lateral and central implants in group B. None of the patients reported a sensory change in lip or chin region. From this study it is concluded that there seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion.     

Influence of implant number on the biomechanical behaviour of mandibular implant-retained/supported overdentures: A three-dimensional finite element analysis

Objective

The aim of this study was to evaluate strain distribution in peri-implant bone, stress in the abutments and denture stability of mandibular overdentures anchored by different numbers of implants under different loading conditions, through three-dimensional finite element analysis (3D FEA).

Methods

Four 3D finite element models of mandibular overdentures were established, using between one and four Straumann implants with Locator attachments. Three types of load were applied to the overdenture in each model: 100 N vertical and inclined loads on the left first molar and a 100 N vertical load on the lower incisors. The biomechanical behaviours of peri-implant bone, implants, abutments and overdentures were recorded.

Results

Under vertical load on the lower incisors, the single-implant overdenture rotated over the implant from side to side, and no obvious increase of strain was found in peri-implant bone. Under the same loading conditions, the two-implant-retained overdenture showed more apparent rotation around the fulcrum line passing through the two implants, and the maximum equivalent stress in the abutments was higher than in the other models. In the three-implant-supported overdenture, no strain concentration was found in cortical bone around the middle implant under three loading conditions.

Conclusions and clinical significance

Single-implant-retained mandibular overdentures do not show damaging strain concentration in the bone around the only implant and may be a cost-effective treatment option for edentulous patients. A third implant can be placed between the original two when patients rehabilitated by two-implant overdentures report constant and obvious denture rotation around the fulcrum line.     

二或四枚种植体支持的Locator覆盖义齿修复五年回顾

目的:比较下颌牙列缺失患者分别采用2枚或者4枚种植体支持的Locator覆盖义齿,修复5年后的临床效果。方法:选取采用2枚种植体(A组)和4枚种植体(B组)支持Locator覆盖义齿患者分别为20例、15例。评估2组患者满意度(整体满意度、咀嚼能力、说话适合性、固位和稳定性、舒适度),并检测咀嚼效率和边缘骨吸收值。结果:两组病人在整体满意度、咀嚼能力、说话适合性、固位和稳定性、舒适度及咀嚼效率、边缘骨吸收方面均无显著性差异(P>0.05)。结论:Locator种植覆盖义齿无论是采用2枚还是4枚种植体,5年后均能获得很好的临床效果,患者满意度高,但对其远期临床效果还有待观察。对于有可能出现义齿旋转的患者建议种植4枚种植体。     

Masticatory function with implant-supported overdentures

The type of attachment that is used in implant-supported mandibular overdentures may influence the retention and stability of the prosthesis and, thus, masticatory function. In this within-subject cross-over clinical trial, we examined the hypothesis that greater retention and stability of the overdenture improve the masticatory function. Eighteen edentulous subjects received 2 oral implants, a new overdenture, and, successively, 3 different suprastructure modalities: magnet, ball, and bar-clip. Masticatory performance, masticatory efficiency, and swallowing threshold were measured. The masticatory function significantly improved after implant treatment with each of the 3 attachments. We observed small differences in masticatory function among the 3 attachment types: slightly better masticatory performance with ball and bar-clip than with magnet attachments. The number of chewing cycles until swallowing hardly decreased after implant treatment. We conclude that significantly better masticatory performance, combined with a slightly smaller number of chewing cycles after implant treatment, results in smaller food particles being swallowed.     

A clinical comparison of prosthetic complications of implant-supported overdentures with different attachment systems

OBJECTIVES: The objective of this clinical study was to evaluate the prosthetic complications of patients with 2 to 4 implants splinted with a round bar or with 2 to 4 unsplinted implants with ball attachments during the follow-up period. METHODS: A total of 26 patients were included in this study. Patients were randomly provided with a round bar or with ball attachments that were used to retain overdentures. During follow-up visits, the following prosthetic complications were recorded: round bar fracture, fractured overdenture, hygiene complications, abutment screw loose, worn O-ring or replacement of O-ring attachment, and fractured retention clip. The functioning period of overdentures in the round bar group ranged from 12 to 72 months (mean 49), and from 12 to 40 months (mean 23) in the ball attachment group. RESULTS: A total of 20 prosthetic complications were recorded in both groups. No differences in prosthetic complications were observed for 2 attachment systems. CONCLUSION: Implant-supported overdentures with bar or ball attachments may be considered to be reliable methods in the treatment of the edentulous individuals.