Prosthodontic complications in a prospective clinical trial of single-stage implants at 36 months

PURPOSE: The present material reports on prosthodontic complications in a trial of 51 patients with prostheses supported by single-stage implants over a period of 36 months. MATERIALS AND METHODS: One hundred eighty-six single-stage implants were placed in 51 patients over a 3-year period in 2 carefully controlled prospective clinical trials. Nineteen of the patients (103 implants) were completely edentulous and restored with a maxillary complete denture and a mandibular fixed-detachable complete prosthesis. Single metal-ceramic crowns or fixed partial dentures were fabricated for the remaining 32 patients (83 implants). The fixed restorations were either screw-retained or cemented. RESULTS: All patients/implants were followed for a minimum of 3 years. Complications in the edentulous patients included fracture of denture teeth, fracture of the maxillary denture, and occlusal screw loosening. Occlusal screw loosening and loss of the resin composite access plug were the only complications observed in the patients treated with screw-retained restorations. No complications were found in the patients restored with cemented restorations on solid abutments. DISCUSSION: Problems with prostheses were very common in the completely edentulous patients (13 of 19 patients encountered complications), possibly a result of increased bite force or inadequate laboratory technique. Tooth fractures were seen more frequently in men than in women. Complications occurred in only 5 of the 32 partially edentulous patients. CONCLUSION: Complications were associated with laboratory-related procedures rather than the implant system itself.     

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.     

Early functional loading at 5 days for Brånemark implants placed into edentulous mandibles: a prospective,open-ended,longitudinal study

BACKGROUND: Traditionally, implants placed in the mandible heal for 3 to 4 months before they are loaded. In maxillae, healing time usually takes 5 to 6 months. The purpose of this study was to evaluate placement of 4 to 6 implants in edentulous mandibles. The implants were placed between mental foramina for support of non-metal, reinforced, fixed, implant-supported provisional prostheses. A unique method was used to convert existing dentures into fixed, implant-supported appliances. The implants were functionally loaded early (5 days). METHODS: Twenty patients with edentulous mandibles or with 2 to 3 remaining mandibular teeth were enrolled in this open-ended, prospective study. Existing dentures without porcelain teeth were modified for use as a surgical guide. These dentures were used as temporary fixed prostheses. Patients were to have metal-reinforced appliances fabricated by the referring dentists after 3 to 4 months of healing. After implant installation, prosthetic abutments were fixed to the implants and tightened to 20 Ncm without counter torque. Bone quality and quantity as well as implant size and position were entered into a computer database. Impression copings were attached to the abutments, and the modified denture was used for a pick-up impression. After the impression was made, implant replicas were fitted to the impression copings and casts were poured. Gold cylinders were processed into the tissue side of the denture. Laboratory screws were used to attach the denture with gold cylinders to abutment replicas. The dentures were processed, polished, and inserted 5 days after implant surgery. Radiographs were taken to verify proper fit of the gold cylinders to the prosthetic abutments (baseline). Radiographs were taken at each follow-up visit and were used to measure changes in crestal bone levels. RESULTS: Twenty patients received 92 machined-surface commercially pure titanium implants in fully edentulous mandibles. Of the total number of implants placed, two were lost between 0 to 1 year and one between 1 to 2 years. Twenty patients with a total of 90 implants were followed between 0 to 1 year. Fourteen patients have been followed between 1 to 2 years, 7 between 2 to 3 years, and 2 between 3 to 4 years. One patient died after 9 months of loading (4 implants loaded, 2 sleeper implants); another died between 1 to 2 years. A total of 6 implants remained buried (sleepers). At 2 years, the cumulative success rate is 96.3%. Survival of the implant bridges is 100.00%. The mean crestal bone level at 5 days for 11 patients was 2.1 mm (SD 0.526, SE mean 0.159) (measurements were not available for the deceased patient), while the mean level at an average of 15 months was 1.96 mm (SD 0.585, SE mean 0.176). Differences between the measurements taken at 5 days with those taken at an average of 15 months were not significant (P < 0.683). CONCLUSIONS: Results of this study indicate that 4 to 5 implants can be placed and loaded within 5 days of implant insertion with high success (96.3%). Success rates for the interim and final prosthesis are 100%. A simple, possibly cost-effective method of using non-metal reinforced dentures as interim fixed, provisional dentures has been described. Impressions and registrations for making the prosthesis can be made at the time of implant installation, and this method is accurate enough to make provisional restorations. The modified denture can function as an interim fixed, implant-supported prosthesis for up to 30 months. Results of x-ray measurements indicate stable crestal bone levels for up to an average of 15 months.     

Maxillary interim overdentures retained by splinted or unsplinted provisional implants

PURPOSE: The survival rate of splinted and unsplinted provisional implants for anchoring removable interim overdentures, as well as handling and maintenance of the interim dentures, was evaluated. MATERIALS AND METHODS: Eighteen edentulous maxillae were provided with 72 provisional implants for anchoring interim overdentures. For 10 patients, 40 unsplinted implants were used with conical copings to retain the provisional prostheses, while for 8 patients 32 implants had a splinted bar architecture for supporting the interim prostheses. Failure rate of provisional implants, as well as handling and behavior of the anchored interim overdentures, was followed until definitive prosthetic restoration and compared between groups. RESULTS: Eighteen (25.0%) of the 72 provisional implants were prematurely lost. The loss rate of unsplinted implants (37.5%) was significantly higher than that of splinted implants (9.3%). Patient handling and maintenance of maxillary interim overdentures during the follow-up period was found to be easier with the splinted bar-retained method than with the unsplinted prosthodontic method. CONCLUSION: Placement of provisional implants fulfilled the requirements for initiating immediate prosthetic rehabilitation and showed that removable interim overdentures can be adequately stabilized and provide added patient comfort and satisfaction. The results suggest benefits of the splinted retention modality over the unsplinted method because of advantages regarding failure rate, patient handling, and interim denture maintenance.     

Use of an Immediate Provisional Implant to Support a Full-Arch Interim Restoration: A Clinical Report

The use of provisional implants as the sole or adjunct mean of stabilization for interim fixed partial dentures has gained popularity in implant prosthodontic treatment. These implants can be used between submerged implants during the healing phase to provide support for interim fixed or removable partial dentures. In this clinical report, a provisional implant used to provide support for a full-arch fixed interim restoration is described. Positioned between adjacent conventional implants, the provisional implant was placed during the same surgical procedure. As a result, an immediate acrylic fixed partial denture supported by natural teeth and the provisional implant provided a comfortable and esthetic interim restoration during the osseointegration period.     

Treatment planning: implant-supported partial overdentures

When multiple anterior teeth are missing, many options of replacement are available. Traditionally, the choice was between a fixed or removable prostheses. Today, with the predictability of dental implants, the options of tooth replacement range from removable partial dentures to implant-supported fixed prostheses. The choice of which restoration that will best provide occlusion and esthetics depends on multiple factors including the number and location of missing teeth, the residual ridge form in relation to the replacement teeth, the relationship of the maxillary and mandibular anterior teeth, the condition of teeth adjacent to the edentulous span, the amount of bone available for implant placement, the patients "smile line" and display of teeth, lip support, and financial constraints. When there is minimal loss of the ridge contour, restorations that emerge from the ridge are the most functional and esthetic restorations, adhesive-type fixed partial dentures, conventional fixed partial dentures, and implant-supported restorations can be indicated with the choice of restoration dependent on a risk benefit and cost benefit analysis. When there is a loss of ridge contour due to residual ridge resorption or trauma, the decision becomes more complex as not only does the tooth structure need to be replaced, the ridge form also has to be replaced. (Figures 1 and 2). This can be assessed clinically as illustrated by Figures 1 and 2 where a dis crepancy in arch form and ridge form in relation to the adjacent teeth and/or opposing arch can be observed. Other considerations are lip support and display of the teeth when smiling. This article presents a case and rationale for implant-supported par tial overdentures. Many authors have written on the merits of com plete overdentures. The complete overdenture has proven to be an improvement over conventional complete prostheses with respect to chewing efficiency, patient comfort and satisfaction. In partial edentulism, the implant-supported overdenture has several advantages, some in common with a removable partial denture.     

无牙颌种植后即刻负重的临床回顾研究

目的探讨无牙颌患者种植后进行即刻负重修复技术的可行性和临床效果。方法从2012年1月至2015年3月间,共22例无牙颌患者合计140枚种植体植入后行即刻负重,均于48 h内完成种植体支持的临时义齿修复,4~6个月后行永久修复。对该修复方案下的种植体留存率、种植体边缘骨吸收情况、种植体稳固性及周围龈组织状况以及患者应用的临床效果进行观察和研究。结果 22例共140枚种植体行即刻负重,其中有3枚种植体失败,种植体留存率为97.9%。种植体负重后6个月和12个月的边缘骨吸收量分别为(0.62±0.11)mm和(0.74±0.13)mm。通过对患者的病例回顾发现共有4例发生不同程度的机械并发症,包括修复体折裂、重衬、人工牙脱落等。种植体周围龈组织健康,未出现明显的红肿。临时义齿固位良好,患者满意度高。结论选择适当的病例,应用种植外科和修复技术对无牙颌患者行即刻负重修复是可行的,可获得理想的临床效果,近期疗效可靠。     

Immediate loading of 190 endosseous dental implants: a prospective observational study of 40 patient treatments with up to 2-year data

PURPOSE: The present study was undertaken to determine the feasibility of using primary stability as a predictor of implant success in patients whose implants were immediately loaded. MATERIALS AND METHODS: The study included 40 patients, in whom a total of 190 implants were placed, 102 in maxillary sites and 88 in mandibular sites. All were loaded within 72 hours of placement. Sixteen patients were completely edentulous in the mandible and/or the maxilla. The remaining 24, who were partially edentulous, received fixed partial dentures or single-implant restorations. All of the definitive implant restorations were screw retained. The criterion for loading was clinical judgment of primary stability, verified by a "screw test." Impressions were made after implant placement to facilitate the fabrication of a laboratory-made heat-processed provisional restoration from acrylic resin. Following a 4-month period for osseointegration and soft tissue healing, definitive fixed prostheses were fabricated. RESULTS: There were no surgical complications. After 1 to 2 years, all 190 implants had survived and were considered 100% successful, as determined by independent testing of mobility and radiographic evidence of osseointegration. In 4 patients, fracture of the provisional restoration occurred during the healing period. DISCUSSION: Clinical research has shown that immediate loading is a viable treatment modality. The favorable success rate reported in this study for rough-surfaced implants suggests that adherence to a protocol, an important parameter of which is primary stability above 32 Ncm, can lead to osseointegration. CONCLUSION: The results of this limited investigation suggest that patients who are partially or completely edentulous may be immediately restored with implants and fixed provisional restorations, provided that the dental implants are adequately stable immediately after their surgical placement. This alternative therapeutic approach did not appear to affect the up-to-2-year survival of the implants in this patient population.     

不同排牙方法对全口义齿修复影响的临床研究

目的 探讨不同的排牙方法对无牙颌患者满意度和全口义齿咀嚼效能的影响.方法 采用上颌排牙法、下颌排牙法和综合排牙法为10例无牙颌患者分别制作3副全口义齿.戴用3个月后,测试无牙颌患者对3种全口义齿的满意度,同时通过吸光度法测定咀嚼效率及咀嚼次数,比较三种排牙方法的全口义齿咀嚼效能的异同.结果 无牙颌患者在戴用3个月后对下颌排牙法和综合排牙法全口义齿的满意度均好于上颌排牙法义齿.本实验3组全口义齿中下颌排牙法和综合排牙法全口义齿的咀嚼次数和咀嚼效能无显著差异,但均好于上颌排牙法义齿.结论 下颌排牙法和综合排牙法的全口义齿排列的人工牙有利于无牙颌患者在咀嚼过程中稳定地使用义齿,提高咀嚼效能,而且无牙颌患者对下颌排牙法和综合排牙法的全口义齿也更满意.     

Esthetic potential of single-implant provisional restorations: selection criteria of available alternatives

Provisional implant restorations are essential tools used to optimize the esthetic outcomes for single-tooth implant restorations. This article describes three groups of available alternatives and the specific options within each group including removable prostheses (interim removable partial denture, vacuum-formed appliance), tooth-supported prostheses (bonded extracted or denture teeth, cast metal or fiber-reinforced resin-bonded fixed partial denture [FPD], wire-retained resin-bonded FPD, acrylic resin provisional FPD), and implant-supported fixed prostheses (implant-retained provisional restoration). Advantages and disadvantages as well as fabrication guidelines for each option are provided. The author proposes that the restorative dentist consider eight criteria in selecting the most appropriate type of provisional prosthesis for a specific patient situation including the esthetic potential, patient comfort, treatment time, laboratory cost, occlusal clearance, ease of removal, durability, and ease of modification. The patient's esthetic expectations are critical in determining the most suitable type of provisional restoration. Esthetically pleasing provisional restorations are part of the evolving implant continuum, making implant dentistry more appealing to practicing dentists and potential patients. CLINICAL SIGNIFICANCE: Provisional restorations for single implants have evolved from temporary expedients during osseous and soft tissue integration to critical therapeutic tools used to assess patient expectations, communicate with the laboratory, and optimize definitive implant treatment. The selection of the type of provisional restoration may significantly influence esthetics during the period of implant integration and soft tissue healing. However, it is unlikely that there is a direct correlation between the type of provisional restoration used and the esthetic outcome of the definitive prosthesis.     

Checking the occlusal relationships of complete dentures via a remount procedure

Correct occlusal relationships are part of the successful prosthetic treatment of edentulous patients. Occlusal checking should be performed via a remount procedure because denture base materials and fabrication procedures cannot provide dimensionally accurate complete dentures. Occlusal errors caused by the adjustment of denture bases to the denture foundation after a certain period of wearing can also be corrected by means of remounting. The following remount procedures for complete dentures are described: fabrication of transfer casts, transfer of a maxillary denture with a facebow, centric relation record, and mounting of dentures with transfer casts in an articulator with a dental stone. Deflective occlusal contacts of denture teeth in centric occlusion can be eliminated by selective grinding and by tooth-guided excursive movements. In complete denture treatment, priority is given to anterior/canine-guided occlusion.     

Implant-supported overdenture with prefabricated bar attachment system in mandibular edentulous patient

Implant-supported overdenture is a reliable treatment option for the patients with edentulous mandible when they have difficulty in using complete dentures. Several options have been used for implant-supported overdenture attachments. Among these, bar attachment system has greater retention and better maintainability than others. SFI-Bar® is prefabricated and can be adjustable at chairside. Therefore, laboratory procedures such as soldering and welding are unnecessary, which leads to fewer errors and lower costs. A 67-year-old female patient presented, complaining of mobility of lower anterior teeth with old denture. She had been wearing complete denture in the maxilla and removable partial denture in the mandible with severe bone loss. After extracting the teeth, two implants were placed in front of mental foramen, and SFI-Bar® was connected. A tube bar was seated to two adapters through large ball joints and fixation screws, connecting each implant. The length of the tube bar was adjusted according to inter-implant distance. Then, a female part was attached to the bar beneath the new denture. This clinical report describes two-implant-supported overdenture using the SFI-Bar® system in a mandibular edentulous patient.     

Transforming an existing fixed provisional prosthesis into an implant-supported fixed provisional prosthesis with the use of healing abutments

Maintaining a fixed provisional prosthesis through all phases of complex implant prosthodontic therapy for a soon-to-be completely edentulous arch is a difficult task. This article focuses on the treatment phase in which teeth and/or transitional implants supporting a provisional fixed partial denture are removed. The described technique makes use of healing abutments to support a modified provisional fixed partial denture. This protocol ensures patient comfort and allows proper soft tissue healing before definitive implant abutment selection. It also eliminates the placement of interim implant abutments.     

义齿黏附剂与线性殆在牙槽嵴重度吸收无牙颌患者中的应用

目的：评价义齿黏附剂和线性胎在牙槽嵴吸收严重的无牙颌患者全口义齿修复中的应用效果。方法：选择15例牙槽嵴吸收严重的无牙颌患者,为每位患者制作解剖式骀和线性胎2副全口义齿,3个月后更换使用。每副义齿于戴用3个月时检测其使用义齿黏附剂前后的咀嚼效率,并采用满意度问卷调查获取患者的主观评价。结果：使用义齿黏附剂后,线性胎和解剖式胎全口义齿的咀嚼效率均较使用前得到改善（P〈0．05,P〈0．01）。义齿黏附剂使用前后,两种骀型全口义齿的咀嚼效率间差异无统计学意义（P〉0．05）。义齿黏附剂使用前,线性骀全口义齿的固位稳定和舒适程度满意度高于解剖式骀全口义齿（P〈0．05,P〈0．01）;使用义齿黏附剂后,两种胎型全口义齿的固位稳定、咀嚼功能和舒适程度满意度均有显著性提高（P〈0.01）。结论：对牙槽嵴吸收严重的无牙颌患者,应用线性骀全口义齿和义齿黏附剂均可改善义齿的治疗效果。     

Transition from failing dentition to a fixed implant-supported restoration: a staged approach

This article describes a staged approach to provide a fixed restoration to patients with a hopeless dentition without a removable provisional phase. The rehabilitation protocol, which includes initial conservative periodontal care, starts with strategic extraction of some of the remaining teeth. The aim of the first step is to permit implant placement and to strategically keep residual teeth as abutments for a provisional fixed denture during the implant healing period. After the implants have osseointegrated, abutment connection is performed, residual teeth are extracted and, simultaneously, a second group of implants is placed. A second fixed provisional restoration is delivered to the patient. After the second group of implants has healed, the patient is ready to undergo normal prosthetic treatment. Advantages of the technique include no removable provisional prosthesis, soft tissue management, preserved function and enhanced esthetics during treatment, and prosthetically driven implant placement. The main drawbacks are extended treatment time, adjustments of the provisional restorations, and no less than two surgical steps.     

无牙颌患者个人因素对全口义齿审美的影响

目的：探讨无牙颌患个人因素对全口义齿审美的影响。方法：用Cattell's16项个性因素问卷评定136名无牙颌患的个性特点、期望度、问卷了解患的义齿外观期望值。常规法制作全口义齿，戴牙一月后，按5级评定患对全口义齿的外观满意程度。结果：约40％患希望有理想的义齿外观，约85％患对全口义齿外观满意。年龄与满意度呈正比，个性中的世故性、独立性与外观满意度呈反比关系。结论：常规排牙法制作的全口义齿满足大部分患才的审美要求。对一些年龄、个性突出、有特殊要求的患，可运用个性排牙法，使患戴用义齿后，容貌生动自然。     

Patient expectations of oral implant-retained prostheses in a UK dental hospital

STATEMENT OF PROBLEM: The loss of the natural dentition leads to severe functional impairment in many edentulous adults. A prosthesis retained and supported by osseointegrated dental implants may provide a satisfactory solution for people who have lost all their natural teeth. However, little information is available as to what patients requesting implants expect of implant-retained prostheses. AIM: The aim of this study was to assess the expectations of a group of edentulous patients requesting implant therapy. METHOD: The study included two groups: (1) a group of edentulous adults who requested implant therapy ('implant group'); and (2) an edentulous control group, of similar age and gender distribution as the implant group, receiving conventional complete dentures. Following a clinical and radiographic examination of the patients, data were collected using validated questionnaires. Both groups made a subjective assessment of current dentures. The implant group also completed a questionnaire which assessed expectations of implant-retained prostheses. RESULTS: Baseline satisfaction with current dentures was low in both groups, with the implant group being significantly less satisfied with comfort and stability of their mandibular dentures. Perceived ability of the implant group to chew hard foods was less than the control group. The implant group's expectations of an implant-retained prosthesis were significantly greater than for a conventional denture. CONCLUSION: Careful assessment of patient expectation of implant therapy is essential to determine appropriate treatment need, and to highlight unrealistic expectations.     

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目的    比较中性区全口义齿和传统全口义齿在患者满意度方面的差异。方法    选择2007年12月至2009年2月就诊于河南省信阳市第四人民医院口腔科需做全口义齿修复的15例患者,每例患者均戴用传统全口义齿3个月后再改戴用中性区全口义齿。分别在戴用两种全口义齿1个月和3个月时采用问卷的形式了解患者的满意度。结果    患者戴用中性区全口义齿1个月和3个月的固位稳定和舒适程度满意度明显高于戴用传统全口义齿（P < 0.01）。结论    患者戴用中性区全口义齿在固位稳定和舒适程度方面优于传统全口义齿。     

Clinical evaluation of overdenture restorations supported by osseointegrated titanium implants: a retrospective study

This paper reports the results of using osseointegrated titanium implants as abutments for overdenture restorations in the mandibles of 62 edentulous patients. All of these patients were edentulous for several years and required complete dentures. Six months after prosthodontic treatment, two implants (ITI, Straumann) were placed with consideration of the denture base and morphologic aspects of the mandibular residual ridge. The retention devices consisted of a bar connector or single ball-shaped precision attachments. Three or four implants splinted with a bar were placed in a control group of 11 patients. Attached keratinized gingiva (greater than or equal to 2 mm) surrounded approximately 48% of the buccal and 55% of the lingual implant sites. Evaluation after periods of 6 to 66 months postoperatively revealed good clinical results with five patients lost to recall in 1989. Two implants were lost after overdenture insertion. The findings suggest that two implants may adequately serve as retention for a mandibular complete denture and that attached gingiva surrounding the implants does not seem to be prerequisite for healthy function.     

Maintenance of Implant Hybrid Prostheses: Clinical and Laboratory Procedures

Fixed implant hybrid prostheses have been used for the last 40+ years in the treatment of edentulous patients. These prostheses have provided long‐term masticatory function for thousands of patients. The original treatment protocol included fabrication of cast metal frameworks that fit accurately on the restorative platforms or abutments and/or endosseous implants. Frameworks were designed to splint implants together; they also provided retention and support for the functional and esthetic portions of the fixed hybrid prostheses. Initially, edentulous patients were treated with maxillary complete dentures and mandibular fixed, hybrid prostheses. Denture teeth were used in both prostheses. Over the span of many years, occlusal surfaces of the denture teeth in the mandibular prostheses exhibited signs of occlusal abrasion and wear, sometimes completely abrading the teeth and denture bases, resulting in framework exposures. Ultimately, this resulted in decreased chewing efficiency and loss of vertical facial height. Patients would then return to clinicians and ask for retreatment. In certain instances, the underlying frameworks would have to be remade. This involved replicating the original series of appointments and significant additional expense to patients and clinicians alike. The protocol presented in this article avoids having to remake the most expensive portion of fixed implant prostheses—the frameworks. The protocol identifies the clinical and laboratory procedures involved in using existing frameworks and replacing preexisting denture bases and denture teeth, with minimal inconvenience to patients.