Evaluation of anterior maxillary alveolar ridge resorption when opposed by the transmandibular implant

Fifteen edentulous patients with complaints regarding denture comfort and/or function were treated with the transmandibular implant. All patients were restored with conventional maxillary dentures opposed by implant-supported removable prostheses. Two to 4 years after surgery, these patients were evaluated for vertical and horizontal maxillary bone loss with a radiographic analysis developed by the authors. With this technique, attention was focused on vertical alveolar ridge resorption in the anterior maxilla. Although the sample size was small, the findings from this study indicate that vertical bone loss in the anterior maxilla does occur when a maxillary denture is opposed by an implant-supported overdenture. Comparison of these results with a previous study that evaluated anterior maxillary resorption when a complete maxillary denture opposed natural mandibular anterior teeth and a distal extension removable partial denture demonstrated no statistically significant difference.     

The effect of different mandibular dentures on antagonistic maxillary ridge

PURPOSE: Is to evaluate the antagonistic, maxillary ridge resorption for different prosthetic modalities mainly mucosa-supported mandibular complete overdentures, combined mucosa implant-supported mandibular complete overdenture, and lower conventional complete dentures. MATERIALS AND METHODS: Fifteen completely edentulous patients were divided into 3 groups; 5 patients each. Group I patients received maxillary conventional denture and mandibular overdentures retained by magnet attachment on 2 implants (mainly mucosa-supported overdenture). Group II patients received maxillary conventional denture and mandibular overdentures retained by bar attachment on 2 implants (combined mucosa implant-supported overdenture). Group III patients received upper and lower conventional complete denture. All patients were evaluated clinically and radiographically immediately after insertion and after 1 and 2 years. Panoramic radiographic film was used to evaluate the antagonistic maxillary ridge resorption. RESULTS: Indicated a more pronounced annual bone resorption of the antagonistic maxillary ridge after 2 years in patients with conventional complete denture wearers when compared with patients with combined mucosa implant-supported mandibular complete overdenture and mainly mucosa-supported mandibular complete overdenture groups. CONCLUSION: Using a combined mucosa implant-supported mandibular complete overdenture the amount of antagonistic maxillary alveolar bone resorption increases when compared with the mainly mucosa-supported complete overdenture.     

Maxillary implant-supported bar overdenture and mandibular implant-retained fixed denture using CAD/CAM technology and 3-D design software: a clinical report

The implant-supported bar overdenture and the implant-retained fixed complete denture are appropriate treatment choices for patients with inadequate bone volume in the posterior maxilla and mandible, respectively. Computer-aided design/computer-aided manufacturing (CAD/CAM) technology has broadened the scope and application of those treatment options, allowing for prosthodontically-driven implant placement and ideal substructure design for optimal esthetics and biomechanics. This report describes the fabrication of a maxillary implant-supported milled titanium bar with attachments and an overdenture, and a mandibular implant-retained fixed complete denture with milled titanium substructure.     

Long-term marginal periimplant bone loss in edentulous patients

PURPOSE: The aim of this study was to examine the long-term periimplant bone loss in patients treated with implant-supported fixed prostheses in both jaws. MATERIALS AND METHODS: The participants comprised 44 edentulous patients who have been followed for a 15-year period after treatment with a fixed implant-supported prosthesis in the mandible. Thirteen of them also received an implant-supported fixed prosthesis in the maxilla, on average 4.5 years after the mandibular treatment. The periimplant bone level was measured on intraoral radiographs. RESULTS: The long-term results of the implant treatment were successful, and only 1% (3/273) of the implants were lost in the mandible and 7% (5/75) in the maxilla. All but one of the failures occurred before the connection of the prostheses. The mean marginal bone loss around the implants was small (less than 1 mm for a 10-year period after implant placement), and was of similar magnitude in both jaws. However, the individual variation was relatively great. There was no significant difference in marginal bone loss between those who had a maxillary complete denture during the entire observation period and those who had received a fixed implant-supported maxillary prosthesis. Smokers lost more periimplant bone than did the nonsmokers; the difference was significant in the mandible but small and nonsignificant in the maxilla. CONCLUSION: The long-term periimplant bone loss was small and of similar magnitude in the mandible and the maxilla in subjects who had received implant-supported fixed prostheses in both jaws. The prosthetic status in the maxilla, i.e., complete denture or fixed implant-supported prosthesis, had no significant influence on the mandibular periimplant bone loss.     

Maxillary anterior and mandibular posterior residual ridge resorption in patients wearing a mandibular implant-retained overdenture

The mandibular implant-retained overdenture could improve masticatory function compared to the conventional complete denture. However, increased forces exerted by the overdenture could increase residual ridge resorption of the maxillary anterior and mandibular posterior areas. The aim of this study was to compare the effect of the mandibular implant-retained overdenture using two or four dental implants, or the conventional complete denture on resorption of the residual ridge of the maxillary anterior and mandibular posterior areas over a period of 10 years. In total, 120 patients, 30 patients treated with an overdenture on two implants (two-implant group), 30 patients with an overdenture on four implants (four-implant group) and 60 patients treated with a conventional full denture (conventional group), participated in this study. On panoramic radiographs, made before and 10 years after treatment, proportional area measurements were applied to determine changes in bone height. After 10 years, a statistically significant amount of bone resorption had occurred in the anterior maxilla in the two-implant group and in the four-implant group. A significant amount of bone resorption had occurred in the posterior mandible in all three groups. There were no statistically significant differences between the groups in both areas. Patients presented large individual differences. It is concluded that patients rehabilitated with implant-retained mandibular overdentures are not subjected to more residual ridge resorption in the anterior maxilla when compared to patients wearing a conventional full denture. Regarding the mandibular posterior residual ridge, resorption was irrespective of wearing an implant-retained mandibular overdenture or a conventional mandibular denture.     

The prosthodontic rehabilitation of malpositioned implants in a patient with basal cell carcinoma: a clinical report

This clinical report describes the prosthodontic rehabilitation of a patient with a partially edentulous maxilla and compromised mandibular anatomy caused by resection of bone due to basal cell carcinoma. Placement of a fibula bone graft was followed by placement of 2 implants. The implants were malpositioned in the anteroposterior plane due to the altered form of the alveolar bone. Prosthodontic treatment included a maxillary removable partial denture and a mandibular partial overdenture supported by implants and remaining teeth.     

Attachment of clips in a bar-retained maxillary implant overdenture: a clinical report

Implant-supported overdentures are a good alternative for patients with conventional dentures that lack retention and stability. The most common prosthetic complications in mandibular and maxillary implant-supported overdentures are fracture and loosening of the attachment system. This clinical report describes the treatment of a completely edentulous patient with sinus floor elevation by using bone from the iliac crest and the insertion of 4 implants in the maxilla and mandible followed by implant-supported overdentures. The technical procedure for the attachment of clips to an acrylic resin overdenture base with the use of metal reinforcement is described. The advantage of this attachment procedure is an improved attachment system with less fracture and less loosening of the clips.     

An alternative method to treat a case with severe maxillary atrophy by the use of angled implants instead of complicated augmentation procedures: a case report

Several treatment options with implants have been described for maxillary edentulous patients. Maxillary implant-supported overdentures have been shown to be a predictable, accepted treatment option for the edentulous maxilla. Patients with severe bone resorption present additional difficulties, and implant treatment in the atrophic maxilla represents a challenge. Anatomical limitations and patient desires in this case have forced the treatment to be 4 angulated implants supporting an upper overdenture. Since conventional single-retention mechanisms such as ball (O-ring), locator, or telescopes would transfer too much force to the implants, especially because of their angulation, an individual bar was fabricated. One-year follow-up of the case showed a stable peri-implant condition on bone as well as soft tissue level. Although further follow-up and higher case numbers will give more information about this treatment modality, the actual result is encouraging and can be recommended for similar cases.     

A survey of implant-retained superstructure types in the edentulous mandible in The Netherlands

Treatment of mandibular edentulousness with endosseous permucosal implants has evolved to a common treatment option during the last decades. In The Netherlands, the relative cheap prosthetic treatment of implant-supported overdentures is considered a qualitatively adequate treatment. The aim of the study described in this article was to survey the treatment of edentulous mandibles by fixed implant-supported prostheses and implant-supported overdentures, and to register the different mesostructures used. All clinics of special dental care and all larger clinics for implant dentistry in The Netherlands received a questionnaire. The data provided showed that more than 90% of patients treated with implants because of mandibular edentulousness, were provided with an overdenture. In 85% of cases a bar-clip mesostructure was used. Cost control was the most important reason to choose an overdenture above a fixed implant-supported prosthesis.     

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.     

Rehabilitation of severe maxillary atrophy with zygomatic implants. Clinical report of four cases

Rehabilitation of the severely resorbed maxilla poses a difficult challenge, for both restorative and surgical colleagues, as the typically large maxillary sinuses in this group of patients require extensive bone grafting if root form dental implant placement is considered. Acceptance is low, due to disadvantages associated with: i) an additional surgical procedure for an iliac bone graft harvesting and, ii) an overall delay in delivery of the final implant-supported prosthesis. The zygomatic implant placement procedure does not require any adjunctive procedures. Furthermore, the ability to immediately use existing dentures and the lack of need for bone grafting and prolonged hospitalisation makes this treatment modality more acceptable to the patient. Four cases are reported that demonstrate the successful treatment of a severely atrophic maxilla with either a fixed prosthesis supported by two zygomatic and a minimum of three standard dental implants or an overdenture supported by two zygomatic and one standard dental implant.     

A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part II. Comparisons of masticatory performance

Statement of problem. Convincing evidence is lacking to demonstrate the functional superiority of mandibular implant-supported overdentures over conventional dentures.Purpose. This randomized clinical trial was conducted to compare masticatory functional effectiveness of mandibular implant-supported overdentures and conventional dentures in diabetic denture wearers with clinically acceptable metabolic control.Methods. A total of 102 edentulous diabetic patients, treated with or without insulin, were randomized to receive a new maxillary and either a mandibular conventional denture or an implant-supported overdenture. Treatment was completed in 89 patients, 37 with conventional dentures and 52 with Hader bar-clip attachment overdentures supported by two IMZ implants. Besides data from medical and dental histories, oromaxillofacial examinations, and questionnaires, masticatory tests were performed by patients before and at 6 and 24 months after treatment completion. Although 78 patients (28 in the conventional, 50 in the overdenture group) performed tests at 6 months after treatment, 68 (25 in the conventional, 43 in the overdenture) had performance data for both entry and 6-month posttreatment intervals.Results. The two treatment groups were highly comparable in terms of general characteristics, quality of original dentures, tissue support, and past denture experience. No significant differences were found between patients treated for diabetes with or without insulin. All four masticatory performance scores with original dentures were higher in the conventional denture group than the overdenture group. The posttreatment performance scores for the two treatment groups became similar because of the higher gains in the overdenture group. Patients with low initial performance scores showed greater posttreatment gains with both conventional dentures and overdentures.Conclusions. The implant-supported overdenture showed no significant advantage over the conventional denture for improving the ability to comminute food in this group of diabetic patients with higher than average initial functional levels observed for other groups of denture wearers in previous studies. (J Prosthet Dent 1998;79:632-40.)     

The management of a severely resorbed edentulous maxilla using a bone graft and a CAD/CAM-guided immediately loaded definitive implant prosthesis: a clinical report

Functional reconstruction of an occlusion with severe residual ridge resorption is a clinical challenge. Removable prostheses are unsuccessful in situations with severe bone resorption. A patient with an edentulous maxilla received bone grafts from the anterior iliac crest to augment the maxillary alveolar residual ridges. The maxilla underwent bilateral sinus lift in the posterior area and onlay bone graft on the anterior maxilla using platelet-rich plasma. Eight endosseous implants were placed using a CAD/CAM surgical template approximately 6 months after the bone augmentation procedure. A prefabricated definitive implant-supported fixed complete denture was connected immediately after implant placement using a CAD/CAM-guided surgical implant placement protocol.     

Successful outcome of splinted implants supporting a 'planned' maxillary overdenture: a retrospective evaluation and comparison with fixed full dental prostheses

Objective: Whereas an overdenture concept is generally accepted for the mandible, the outcome of this therapy for the maxilla remains less documented. This retrospective analysis evaluated the peri-implant parameters of implants supporting a 'planned' overdenture in the maxilla, and compared these data with those of an age-matched control group, with a fixed full dental prosthesis.
Material and methods: All patients with an implant-supported overdenture in the maxilla from the Leuven University Hospital (at least 12 months in function) were recalled for a thorough examination. Forty-four patients (162 implants, Brånemark type) could be enrolled.
Results: The mean loading time was 9 years (range: >1 to >20 years). The cumulative survival rate after 10 years of function was 99.3% if four to six interconnected implants supported the overdenture, but only 85.7% in case two non-connected implants were used as support. The marginal bone level in the former group remained stable, with changes comparable with those observed for implants supporting fixed full dental prostheses.
Conclusions: These results fully support the overdenture treatment concept for the maxilla, at least when ≥4 splinted implants are used.     

Replacement of a mandibular implant-fixed prosthesis with an implant-supported overdenture to improve maintenance and care

PatientsA 69-year-old woman presented to the Osaka University Dental Hospital. She had two chief complaints, (a) food accumulation under the lower teeth and (b) poor maxillary denture retention while eating. On clinical examination the patient presented with a maxillary complete denture and fixed mandibular implant prosthesis. For preventing food accumulation under the fixed implant prosthesis and to keep the maxillary denture stable by providing posterior occlusal contact for bilaterally balanced occlusion, the use of a mandibular implant-supported overdenture with self-adjusting magnetic attachments provided a prosthetic solution for this patient. After provided the new dentures, the patient was pleased and was comfortable with the aesthetic, stability and retention of the dentures. There were no discernable clinical or radiographic changes after 1 year of use.DiscussionTo prevent food accumulation beneath the fixed implant prosthesis and maintain the stability of the maxillary denture by providing posterior occlusal contact for bilaterally balanced occlusion, a mandibular implant-retained overdenture with magnetic attachments was used to provide a prosthetic solution for this patient.ConclusionIn this clinical case, an implant-fixed prosthesis in the edentulous mandibular region was replaced into an implant-supported overdenture with considerations for (a) preventing the food accumulation beneath the lower prosthesis, (b) achieving the proper occlusion in the posterior part for maxillary denture stability and (c) ease of maintenance and care for the prostheses.     

Dental rehabilitation using an implant-carrying plate system in a severely resorbed edentulous maxilla: a case report

This clinical article describes a case of dental rehabilitation using an implant-carrying plate system (EPITEC) for a patient with severely resorbed edentulous maxilla and microstomia. In this case, the presence of microstomia prevented bone augmentation procedures through an intraoral approach. Treatment using 2 endosseous implants inserted in the canine regions and an implant-supported overdenture was planned. However, endosseous implants were not feasible on the right side because of insufficient available bone volume. An implant-carrying plate system was then utilized on the right side. Four months later, an implant-supported ball-attachment overdenture was fabricated. At the 2-year follow-up, the clinical course remained uneventful, and the patient remained satisfied with the treatment.     

Prosthodontic treatment with implant fixed prosthesis for a patient with ectodermal dysplasia: A clinical report

Oral characteristics of ectodermal dysplasia (ED) include hypodontia or anodontia of the primary or permanent teeth, impacted teeth, malformed and widely spaced peg-like teeth, and underdeveloped alveolar ridges. Patients with this disease often need a multidisciplinary approach to treatment planning and dental treatment to regain appropriate function, esthetics, and comfort. The definitive treatment plan may include removable, fixed, or implant-supported prostheses or a combination of these options. Depending on the remaining available alveolar bone and the pattern of missing teeth, the ideal treatment option for an adult ED patient often includes the use of implants. This clinical report describes the multidisciplinary approach to diagnosis and treatment of ED in a 37-year-old woman. The treatment included a mandibular implant-supported fixed denture and a maxillary conventional overdenture fabricated to establish acceptable occlusal vertical dimension, esthetics, and oral function.     

6颗种植体支持的上颌无牙颌固定义齿应力分布研究

目的:分析种植体位置变化时,6颗种植体支持的上颌无牙颌固定义齿的应力分布.方法:选择一名牙列缺失、牙槽骨中度吸收的志愿者,对其头颅部进行CBCT扫描,并利用一系列计算机软件进行数据转换,完成上颌骨三维实体模型的重建.设计8种不同位置种植体支持的固定义齿,建立8个三维有限元模型,分析种植体、上颌骨和固定义齿的应力分布情况.结果:远中没有悬臂的模型比有悬臂的模型的应力差值小;8种位点设计的模型都是应力集中在磨牙区种植体,种植体的应力集中点都是种植体颈部,且是偏向于颊侧.种植体的应力都是磨牙＞前磨牙＞前牙;在8种位点设计的模型中,种植固定义齿和颌骨位移都是集中在前牙区,种植固定义齿的位移是从前牙区向后牙区逐渐变小;8种模型的种植体应力都表现为以压应力为主.模型Ⅰ种植体(位点13、15、17、23、25、27)分散型排列,避免了远中悬臂的设计,6颗种植体的应力分布最均匀.结论:种植体植入位点于13、15、17、23、25、27,是8种方案中最佳的植入位点方案.     

The implant-supported overdenture as an alternative to the complete mandibular denture

BACKGROUND: Approximately one-third of Americans older than 65 years of age are fully edentulous, requiring replacement of missing teeth. While the conventional denture may meet the needs of many patients, others require more retention, stability, function and esthetics, especially in the mandible. The implant-supported prosthesis is an alternative to the conventional removable denture. METHODS: This article describes the strengths of the implant-supported mandibular overdenture. The authors also outline the risks of this approach. They performed a review of recent literature to summarize the reported success rate of implants used to support a mandibular overdenture. RESULTS: The literature review indicates that implants placed in the anterior mandible (anterior to the foramen) have a success rate better than 95 percent. Patients have reported a high degree of satisfaction with the implant-supported overdenture. CONCLUSIONS: The literature indicates that implant-supported overdentures in the mandible provide predictable results with improved stability, retention, function and patient satisfaction compared with conventional dentures. Implants placed in the anterior mandible have a success rate equal to or greater than 95 percent. CLINICAL IMPLICATIONS: When planning treatment for patients with edentulous mandibles, clinicians should consider the implant-supported prosthesis.     

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.