Maintenance requirements of implant-supported fixed prostheses opposed by implant-supported fixed prostheses, natural teeth, or complete dentures: a 5-year retrospective study

PURPOSE: The purpose of this study was to compare the maintenance requirements of implant-supported fixed prostheses with cantilever arms in edentulous jaws when opposed by fixed prostheses of similar design, by natural teeth, or by complete dentures. MATERIALS AND METHODS: The maintenance requirements for the 5-year follow-up period were obtained by examining the dental records of 37 people. Six were provided with fixed prostheses in both arches, 22 with a fixed prosthesis in the mandible opposed by a complete denture, and 9 with a fixed prosthesis opposed by natural teeth. Everyone was treated with Nobel Biocare implants using standard implant and prosthetic protocols. RESULTS: The denture teeth and acrylic resin were repaired on 44 occasions in the group with implants in both jaws, on 14 occasions in the group with implants opposed by natural teeth, and twice in the group in which the implants were opposed by a complete denture. The group with implants in both jaws was more likely to fracture the gold-alloy framework, which occurred on six occasions. The group with implants in both jaws was significantly different from the other two groups in relation to higher incidence of fracture of the teeth and gold-alloy framework. CONCLUSION: The maintenance requirements of implant-supported fixed prostheses with cantilever arms opposed by fixed prostheses of similar design were much greater than when opposed by natural teeth or complete dentures.     

A prospective randomized clinical study comparing implant-supported fixed prostheses and overdentures in the edentulous mandible: prosthodontic production time and costs

Purpose

This work compared implant-supported fixed prostheses and overdentures in the edentulous mandible in a randomized prospective study of treatment results, clinical working hours, laboratory working hours, and laboratory costs including materials.

Materials and Methods

Seventeen subjects agreed to participate. Three standard Brånemark implants were placed between the mental foramina in each patient. After the connection of standard abutments, subjects were randomly assigned to the fixed prosthesis group (n=11) or overdenture group (n=6). Subjects in the fixed group were provided with prostheses according to the All-in-One concept. Subjects in the overdenture group received a conventional denture retained by a Dolder bar system.

Results

One implant was lost in the fixed prosthesis group after 1 year. A new implant was placed, and the prosthesis was refitted. Mean clinical working hours were 3.1 in the fixed prosthesis group and 4.1 in the overdenture group. Mean laboratory working hours were 12.5 in the fixed prosthesis group and 7.7 in the overdenture group. Total laboratory costs, including materials, were on average about 1,700 US dollars for the fixed prosthesis and 1,350 US dollars for the overdenture.

Conclusion

A fixed implant-supported prosthesis in the edentulous mandible could be provided at about the same cost as an overdenture using the method described. Provided that the early survival results prove to be long lasting, the choice between a fixed and a removable prosthesis need not be a matter of economy.—Reprinted with permission of Quintessence Publishing.     

Fracture analysis of randomized implant-supported fixed dental prostheses

Objective

Fractures of posterior fixed dental all-ceramic prostheses can be caused by one or more factors including prosthesis design, flaw distribution, direction and magnitude of occlusal loading, nature of supporting infrastructure (tooth root/implant), and presence of adjacent teeth. This clinical study of implant-supported, all-ceramic fixed dental prostheses, determined the effects of (1) presence of a tooth distal to the most distal retainer; (2) prosthesis loading either along the non-load bearing or load bearing areas; (3) presence of excursive contacts or maximum intercuspation contacts in the prosthesis; and (4) magnitude of bite force on the occurrence of veneer ceramic fracture.

Methods

89 implant-supported FDPs were randomized as either a three-unit posterior metal–ceramic (Au–Pd–Ag alloy and InLine POM, Ivoclar, Vivadent) FDP or a ceramic–ceramic (ZirCAD and ZirPress, Ivoclar, Vivadent) FDP. Two implants (Osseospeed, Dentsply) and custom abutments (Atlantis, Dentsply) supported these FDPs, which were cemented with resin cement (RelyX Universal Cement). Baseline photographs were made with markings of teeth from maximum intercuspation (MI) and excursive function. Patients were recalled at 6 months and 1–3 years. Fractures were observed, their locations recorded, and images compared with baseline photographs of occlusal contacts.

Conclusion

No significant relationship existed between the occurrence of fracture and: (1) the magnitude of bite force; (2) a tooth distal to the most distal retainer; and (3) contacts in load-bearing or non-load-bearing areas. However, there was a significantly higher likelihood of fracture in areas with MI contacts only.

Clinical significance

Because of the absence of a periodontal ligament, this clinical study demonstrates that there is a need to evaluate occlusion differently with implant-supported prostheses than with natural tooth supported prostheses. Implant supported prostheses should have minimal occlusion and lighter contacts than those supported by natural dentition.

Clinical Trials.gov No

K23 D2007-46.     

The stereognostic ability of natural dentitions versus implant-supported fixed prostheses or overdentures

A stereognostic ability test was performed in 60 patients. Forty patients were rehabilitated by means of osseointegrated implants. One group consisted of 20 patients with fixed prostheses on implants in both the upper and lower jaws. The other 20 patients had a maxillary denture while in the mandible an overdenture was retained by means of two implants connected by a bar. They were compared to a group of 20 subjects (controls) with a non-restored natural dentition. For the stereognostic ability test, subjects had to recognise ten different test pieces by manipulating them with two antagonistic incisor teeth, avoiding any contact with other oral structures. Both response time and percentage accuracy of recognition were evaluated. The present findings indicated that subjects with an overdenture on implants did not score significantly different from those with an implant-supported fixed prosthesis. In contrast, subjects with teeth had a significantly better stereognostic ability. The percentage of correct responses was 52% for overdentures, 56% for fixed prostheses on implants and 75% for natural dentitions. From these results, it could be concluded that the stereognostic ability is impaired in subjects rehabilitated with osseointegrated implants by about one-third to one-quarter compared to subjects with natural teeth.     

Cost-effectiveness of endodontic molar retreatment compared with fixed partial dentures and single-tooth implant alternatives

Introduction

One of the most challenging situations in dentistry is a failed root canal treatment case. Should a failed root canal-treated tooth be retreated nonsurgically or surgically, or should the tooth be extracted and replaced with an implant-supported restoration or fixed partial denture? These four treatment alternatives were compared from the perspective of cost-effectiveness on the basis of the current best available evidence.

Methods

The costs of the four major treatment modalities were calculated using the national fee averages from the 2009 American Dental Association survey of dental fees. The outcome data of all treatment modalities were retrieved from meta-analyses after electronic and manual searches were undertaken in the database from MEDLINE, Cochrane, ISI Web of Knowledge, and Scopus up to April 2010. The treatment strategy model was built and run with TreeAge decision analysis software (TreeAge Software, Inc, Williamstown, MA).

Results

Endodontic microsurgery was the most cost-effective approach followed by nonsurgical retreatment and crown, then extraction and fixed partial denture, and finally extraction and single implant-supported restoration.

Conclusions

The cost-effectiveness analysis showed that endodontic microsurgery was the most cost-effective among all the treatment modalities for a failed endodontically treated first molar. A single implant-supported restoration, despite its high survival rate, was shown to be the least cost-effective treatment option based on current fees.     

Stress analysis of a fixed implant-supported denture by the finite element method (FEM) when varying the number of teeth used as abutments

Objectives

In some clinical situations, dentists come across partially edentulous patients, and it might be necessary to connect teeth to implants. The aim of this study was to evaluate a metal-ceramic fixed tooth/implant-supported denture with a straight segment, located in the posterior region of the maxilla, when varying the number of teeth used as abutments.

Materials and Methods

A three-element fixed denture composed of one tooth and one implant (Model 1), and a four-element fixed denture composed of two teeth and one implant (Model 2) were modeled. A 100 N load was applied, distributed uniformly on the entire set, simulating functional mastication, for further analysis of the SEQV (Von Mises) principal stresses, which were compared with the flow limit of the materials.

Results

In a quantitative analysis, it may be observed that in the denture with one tooth, the maximum SEQV stress was 47.84 MPa, whereas for the denture with two teeth the maximum SEQV stress was 35.82 MPa, both located in the region between the pontic and the tooth.

Conclusion

Lower stresses were observed in the denture with an additional tooth. Based on the flow limit of the materials, porcelain showed values below the limit of functional mastication.     

CAD-CAM acrylic resin prosthesis superstructure: A technique for fabricating an implant-supported fixed complete denture

The implant-supported fixed complete denture is a common treatment option in implant prosthodontics but has shortcomings that include the high wear rate of the acrylic resin denture material and the displacement of denture teeth from the denture base. This report describes a method for fabricating implant-supported fixed dental prostheses using computer-aided design and computer-aided manufacturing technology.     

Complications after treatment with implant-supported fixed prostheses: a retrospective study

PURPOSE: The aim was to retrospectively evaluate the frequencies of different complications, as well as the number of visits to dentists because of such complications, after treatment with implant-supported fixed prostheses. MATERIALS AND METHODS: The study group comprised 75 patients who had been treated with implant-supported fixed prostheses 3 years earlier. All case records were scrutinized, and notes of complications in association with implants and superstructures were registered. RESULTS: The most common intervention made was occlusal adjustment/selective grinding of the prostheses. Complications in association with both implants and superstructures were fairly common. The most frequent complication was fractures of the acrylic resin matrix, including artificial acrylic resin teeth. Consultations because of periimplant mucosal inflammation were much more common among women compared to men, while complications that could be attributed to heavy loading tended to be more common in men. CONCLUSION: Complications with both implants and superstructures are fairly common after treatment with implant-supported fixed prostheses. Regular follow-ups to maintain optimal function in these patients are thus mandatory.     

Laser-welded titanium frameworks for implant-supported fixed prostheses: a 5-year report

The 5-year results from a multicenter study of implant-supported, laser-welded titanium frameworks are reported here as a complement to earlier reported 2-year results. Implant survival rates were satisfactory for patients with titanium frameworks and for a control group of patients with gold-alloy frameworks. At the 5-year review, more patients with titanium frameworks had lost implants than the patients with gold-alloy frameworks, but this difference was not statistically significant. More fractures of the titanium frameworks occurred, compared to the gold-alloy frameworks; again, this difference was not statistically significant. No significant differences in marginal bone levels were found between the 2 groups of patients. Slightly more fractures of artificial teeth occurred in patients with titanium frameworks than in patients with gold-alloy frameworks. Overall results for the titanium frameworks after 5 years in function are encouraging.     

金沉积技术在种植固定修复中的临床应用效果观察

目的:探讨金沉积技术在种植固定修复中的临床应用效果。方法:7例牙列缺失与牙列缺损的患者(男性3例,女性4例,年龄22-58岁),共9个修复体,其中单冠6个,无牙颌固定桥3个,植入种植体34个。观察方法为临床检查及x线检查。修复后平均追踪27个月(14-37个月)。结果:所有病例在修复后至最后一次复查未见种植体脱落。所有修复体无折断、松动或破损,修复效果良好,患者满意。一例行金沉积烤瓷单冠修复患者的一个烤瓷单冠在紧固横向螺钉时发生瓷面裂纹,经再次烧结后固定。结论:本研究结果提示金沉积技术用于制作种植体支持的修复体具有良好的生物相容性,美学效果好,同时还可以通过金沉积冠作为固位体解决种植修复体多个固位体之间的被动就位问题,近期临床效果满意。     

Evaluation of speech in patients rehabilitated with various oral implant-supported prostheses

In the present study, speech function was assessed in edentulous patients wearing fixed or removable dental prostheses supported or not by oral implants. A total of 138 patients participated in the present research. The experimental group (n=113) was divided in 4 subgroups. Subgroup FD/FFPi comprised 22 patients with a maxillary full denture (=FD) and a mandibular fixed full prosthesis on implants (=FFPi). Subgroup FFPi/ND consisted of 27 patients with a maxillary fixed full prosthesis on implants and a natural dentition (=ND) in the mandible. Subgroup FD/ODi included 49 patients wearing a maxillary full denture and a mandibular overdenture on 2 implants (=ODi). Subgroup FFPi/FFPi comprised 15 patients having a fixed full prosthesis on implants in both jaws. The outcome of the logopedic screening of the experimental group was compared with that of a control group of subjects having a natural dentition (ND/ND; n=25). A standard clinical procedure for evaluation of speech was carried out by a speech pathologist. Besides, specific oral and prosthetic parameters were scored in all patients. It was established that one or more pronunciation difficulties occurred in 84% of the patients of the experimental group. This was significantly more than in the control group, where half the number of subjects had some speech deficiencies. No clear influence of specific oral and prosthetic parameters could be identified. From the present results, it could be concluded that in patients rehabilitated with oral implant-supported prostheses speech disorder is more frequently observed than in subjects with a natural dentition.     

A study of 589 consecutive implants supporting complete fixed prostheses. Part II: Prosthetic aspects

In 91 consecutive edentulous patients, 103 jaws were treated with complete fixed prostheses supported by Br?nemark Implants (n = 589). As a result of fixture loss in each of two patients (two jaws), an overdenture instead of a fixed prosthesis was installed. For one patient (two jaws), data were not available after abutment connection. At the end of the seventh year, the cumulative failure rates for the remaining 99 prostheses reached 4.9% for mandibles and 10.1% for maxillae. After loading, 12 fixtures showed signs of nonintegration, but only one patient had to revert to complete dentures. Neither the fixture location nor the cantilever length revealed a significant difference in marginal bone loss around the supporting fixtures. Patients with fixture-supported fixed prostheses in both jaws showed significantly more marginal bone loss than did those with only one fixed prosthesis opposed by either natural dentition (50%) or a complete denture (50%). Component complications were limited to fixture fracture (3/564), abutment screw fracture (5/564), and gold screw fracture (7/564). The predictability of Br?nemark implants in the treatment of completely edentulous jaws is confirmed.     

Comparing the efficacy of mandibular implant-retained overdentures and conventional dentures among middle-aged edentulous patients: Satisfaction and functional assessment : Manal A. Awad, James P. Lund, Eric Dufresne, Jocelyne S. Feine. Int J Prosthodont 2003;16:117-122

Purpose

The aim of this randomized clinical trial was to compare the relative efficacy of mandibular overdentures retained by only two implants and a bar attachment with conventional dentures.

Materials and methods

Edentulous adults, aged 35 to 65 years, were randomly assigned to two groups that received either a mandibular conventional denture (n = 48) or an overdenture supported by two endosseous implants with a connecting bar (n = 54). All subjects rated their general satisfaction and other features of their original dentures and their new prostheses (comfort, stability, ability to chew, speech, esthetics, and cleaning ability) on 100-mm visual analogue scales prior to treatment and 2 months postdelivery. Oral health-related quality of life was also evaluated pre- and posttreatment.

Results

Multiple regression analysis revealed that the mean general satisfaction was significantly higher in the overdenture group than in the conventional denture group (P=.0001). Age, gender, marital status, and income were not significantly associated with ratings of general satisfaction. Furthermore, the implant group gave significantly higher ratings on three additional measures of the prostheses (comfort, stability, and ease of chewing; P<.05).

Conclusion

A mandibular two-implant overdenture opposed by a maxillary conventional denture is a more satisfactory treatment than conventional dentures for edentulous middle-aged adults.     

A survey of the use of mandibular implant overdentures in 10 countries

Purpose

This preliminary international survey compared provision of implant-retained overdentures to fixed implant-supported prostheses for edentulous mandibles.

Materials and Methods

Questionnaires based on a 2001 Swedish study were sent to prosthodontists and specialist clinics in nine additional countries.

Results

Response rate varied from 53% to 100% in 10 national surveys and should allow careful comparison of results. The relationship between implant overdentures and fixed implant-supported prostheses in treatment of edentulous mandibles varied much; in Sweden, the proportion of overdentures was 12%, whereas it was 93% in the Netherlands. In all countries, the most common reason for choice of the overdenture was reduced cost. In all but two countries, the majority of respondents thought that patients with implant overdentures were equally or more satisfied with overdentures as those with fixed implant-supported prostheses.

Conclusion

There were great differences among the 10 countries in choice of implant treatment of the edentulous mandible. The relative proportion of mandibular overdentures to fixed prostheses was low in Sweden and Greece and varied from one to two thirds in the other countries, except the Netherlands.     

Strain of implants depending on occlusion types in mandibular implant-supported fixed prostheses

PURPOSE

This study investigated the strain of implants using a chewing simulator with strain gauges in mandibular implant-supported fixed prostheses under various dynamic loads.

MATERIALS AND METHODS

Three implant-supported 5-unit fixed prostheses were fabricated with three different occlusion types (Group I: Canine protected occlusion, Group II: Unilaterally balanced occlusion, Group III: Bilaterally balanced occlusion). Two strain gauges were attached to each implant abutment. The programmed dynamic loads (0 - 300 N) were applied using a chewing simulator (MTS 858 Mini Bionix II systems, MTS systems corp., Minn, USA) and the strains were monitored. The statistical analyses were performed using the paired t-test and the ANOVA.

RESULTS

The mean strain values (MSV) for the working sides were 151.83 µε, 176.23 µε, and 131.07 µε for Group I, Group II, and Group III, respectively. There was a significant difference between Group II and Group III (P < .05). Also, the MSV for non-working side were 58.29 µε, 72.64 µε, and 98.93 µε for Group I, Group II, and Group III, respectively. One was significantly different from the others with a 95% confidence interval (P < .05).

CONCLUSION

The MSV for the working side of Groups I and II were significantly different from that for the non-working side (Group I: t = 7.58, Group II: t = 6.25). The MSV for the working side of Group II showed significantly larger than that of Group III (P < .01). Lastly, the MSV for the non-working side of Group III showed significantly larger than those of Group I or Group II (P < .01).     

上颌全口固定式种植义齿组织面牙菌斑附着的研究

目的 分析使用复合基台的全口固定式种植义齿组织面菌斑附着的特点,为指导患者口腔卫生的维护提供依据.方法 选取上颌全口固定式种植义齿修复患者21例,永久修复后3个月对修复体的组织面进行菌斑染色,收集图片通过Image J 2.1.4.7软件评估菌斑附着的特点.结果 永久修复体组织面菌斑附着面积百分比为(46.13±7.23)%.颊侧和腭侧菌斑附着面积百分比分别为(41.53±3.08)%和(53.76±3.07)%,腭侧菌斑附着面积百分比显著大于颊侧(t=16.750,P<0.001);游离端菌斑附着面积百分比为(71.86±2.00)%,显著高于前部(48.85±2.09)%(t=40.445,P<0.001)和中部(49.33±0.98)%(t=47.124,P<0.001).种植体间距离越小,永久修复体的组织面菌斑附着面积越大.结论 缩小腭侧组织面延伸、扩大种植体之间的距离、尽可能减小游离端面积有助于减少上颌全口固定式种植义齿组织面的菌斑附着.     

Retrospective,cross-sectional study on immediately loaded implant-supported mandibular fixed complete-arch prostheses fabricated with the passive fit cementation technique

Statement of problem

Mandibular fixed complete-arch dental prostheses on dental implants have been benefiting patients for a long time, but problems with passive fitting between the metallic framework of the prostheses and the implants might influence its long-term success.

Peri-implant mucosal level in patients treated with implant-supported fixed prostheses: a 1-year follow-up study

PURPOSE: The purpose of this follow-up study was to quantify the change in the peri-implant mucosal level after treatment of edentulous patients with fixed prostheses on osseointegrated endosseous implants. MATERIALS AND METHODS: Twenty patients were included in the study: 10 were treated in the maxilla, and 10 were treated in the mandible. Both groups had fixed prostheses on osseointegrated Br?nemark implants. Peri-implant mucosal level was measured with a calibrated probe after removal of the prostheses at the 1-year follow-up. These measurements were compared to those made on the original master casts. RESULTS: A larger mean retraction (-) was observed in the mandible (-1.6 mm) compared to the maxilla (-0.8 mm), but there was great variation. The individual values varied from -4.5 to +1.0 mm in the mandible and from -6.0 to +6.0 mm in the maxilla. CONCLUSION: Peri-implant soft tissue recession occurs during the first year in edentulous jaws after treatment with implant-supported fixed prostheses and more so in the maxilla than the mandible.     

Fabrication of a functionally generated, implant-retained fixed partial denture

Partially edentulous patients are frequently restored with implant-supported restorations between and opposing natural teeth. Differences in horizontal and vertical mobility of teeth and dental implants necessitate occlusal contact modification to create prostheses that harmonize with the opposing dentition. This article describes a functionally generated path technique to achieve optimal articulation between an implant-retained fixed partial denture and the patient's dentition.     

CAD-CAM high-density polymer implant-supported fixed diagnostic prostheses

Computer-aided design and computer-aided manufacturing (CAD-CAM) complete-arch implant-supported fixed prostheses have become popular in recent years and offer several advantages over traditional fabrication techniques. However, they also present challenges, and careful treatment planning is required, particularly for zirconia implant-supported fixed prostheses layered with feldspathic porcelain. This clinical report describes the use of a CAD-CAM high-density polymer implant-supported diagnostic prosthesis to verify the accuracy of the implant impression and evaluate the maxillomandibular relationship, esthetics, and phonetics of the planned CAD-CAM definitive implant-supported fixed prosthesis before CAM processing.