Improving oral rehabilitation through the preservation of the tissues through alveolar preservation

When performing a tooth extraction, imminent collapse of the tissue by resorption and remodeling of the socket is a natural occurrence. The procedure for the preservation of the alveolar ridge has been widely described in the dental literatures and aims to maintain hard and soft tissues in the extraction site for optimal rehabilitation either with conventional fixed or removable prosthetics or implant-supported prosthesis.     

消极吻合技术在下颌前牙种植修复中的应用

目的：探讨种植修复消极吻合的重要性。方法：32例下颌前牙缺失骨量不足患者种植85颗种植体,取模,制作金属基底冠桥,分开其连接处,试戴就位,分开处在口内以成型塑料连接,重新二次印模,激光焊接,再试基底冠桥,检查其颈部密合性和翘动情况,制作烤瓷牙,粘固固位种植修复体,定期牙周维护。分别于种植修复后3、6、12月临床检查修复体稳定性与牙龈情况,X线检查种植体-骨界面与牙槽嵴情况。结果：种植修复成功31例,失败1例。结论：消极吻合是保证口腔种植修复成功的要素之一。     

Restoration with implants in patients with recessive dystrophic epidermolysis bullosa and patient satisfaction with the implant-supported superstructure

PURPOSE: The use of endosseous implants in the prosthetic restoration of edentulous patients with recessive dystrophic epidermolysis bullosa (RDEB) may provide improved outcomes when compared with traditional prosthetic methods. The aim of this study was to evaluate the feasibility of placing endosseous implants in patients with RDEB and to compare the treatment outcomes of fixed and removable implant-supported restorations in the edentulous maxilla or mandible with the main emphasis on patient response. MATERIALS AND METHODS: Six patients with RDEB were treated with implants. All patients were completely edentulous in either the maxilla or mandible and had marked oral involvement, with alterations in the soft and hard tissues in all cases. Three patients were treated with fixed, screw-retained implant-supported prostheses, and 3 were treated with removable implant-supported prostheses. Six months after prosthetic restoration, patients were given a questionnaire to assess their psychologic well-being and satisfaction with the implant-supported restoration marked on a visual analog scale. RESULTS: A total of 38 dental implants (21 maxillary, 17 mandibular) were placed in 6 patients. The implant success rate was 97.9%. The average follow-up from implant placement was 5.5 years (range, 1 to 9). The fixed and removable implant-supported prostheses were associated with improvements in comfort and retention, function, esthetics and appearance, taste, speech, and self-esteem. The level of satisfaction was slightly higher in patients with a fixed prosthesis. CONCLUSION: These findings suggest that endosseous implants can be successfully placed and provide support for prostheses in patients with RDEB. Patients with fixed prostheses and overdentures were satisfied with their implant-supported prostheses in the edentulous maxilla and mandible.     

后牙种植修复体咀嚼效能的初步比较研究

目的:将后牙常规义齿与种植义齿的修复效果进行定量比较。方法:选择单侧后牙缺失4颗以下,无其他口腔疾病者无口腔修复史者90例,牙位等同,分为活动组,固定组,种植组各30例。正常牙列对照组30例。用改良吸光度法测量并比较单侧后牙缺失患者行活动义齿,固定义齿及种植义齿修复前后的咀嚼效能。结果:活动修复后咀嚼效能与正常牙列人群咀嚼效能之间有显著性差别(P<0.05);固定修复后,种植修复后与正常牙列咀嚼效能无显著差别(P>0.05)。结论:活动义齿、固定义齿、种植义齿修复均能有效提高后牙缺失患者的咀嚼效能,但活动义齿效果最差。固定义齿和种植义齿修复均能使后牙缺失患者的咀嚼效能提高至与正牙列人群相似。     

Unconventional implants for distal cantilever fixed full-arch prostheses: a long-term evaluation of four cases

Excessive cantilever lengths of fixed implant-supported prostheses may have functional and biomechanical disadvantages. This study reports the clinical outcomes of unconventional implants placed for distal support of a fixed implant-supported prostheses. Seven extraoral implants with intraosseous lengths of 2.5 to 4.0 mm were placed in four patients. Distal cantilevers had a mean length of 29.8 mm (range, 18.6 to 39.3 mm). No bone loss or other adverse events were found. The prosthetic plan was maintained in all patients. Within the limits of the employed research design, this concept seems to be a successful option for fixed complete implant-supported prosthesis treatment.     

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.     

Treatment outcomes of fixed or removable implant-supported prostheses in the edentulous maxilla. Part I: patients' assessments

STATEMENT OF PROBLEM: Distinct clinical parameters determine whether fixed or removable implant-supported prostheses are indicated to restore the edentulous maxilla. However, there is a strong belief that fixed implant prostheses meet with greater patient acceptance and satisfaction, but this may differ from the patients' perceptions, their psychological responses to treatment, and their assessments of the treatment outcome. PURPOSE: This prospective clinical study compared the treatment outcomes of fixed and removable implant-supported restorations in the edentulous maxilla with the main emphasis on the patient's point of view.Material and methods: Twenty patients who requested an implant-supported superstructure to restore the edentulous maxilla were asked to complete a questionnaire measuring their satisfaction with the present situation and the psychologic impact of their oral health status with their responses marked on a Visual Analog Scale (VAS). Ten patients were treated with a fixed, screw-retained implant prosthesis (group 1), and 10 were treated with a removable, implant-supported and bar-retained overdenture (group 2). Six months after prosthetic rehabilitation, patients were again given the questionnaire to assess their psychologic well-being and satisfaction with the implant-supported restoration. RESULTS: Both prosthesis designs were associated with significant improvements in comfort and retention, function, esthetics and appearance, taste, speech, and self-esteem. No difference was found between the 2 groups with respect to how the patients assessed the implant therapy. However, the results indicated that patients in group 2 experienced greater differences between pretreatment and posttreatment scores for the parameters esthetics, taste, and speech. Treatment costs per unit were significantly higher in group 1 than in group 2. CONCLUSION: Patients in groups 1 and 2 were similarly satisfied with their implant-supported prostheses in the edentulous maxilla with regard to their well-being and the cost-utility, irrespective of whether the restoration was fixed or removable.     

下颌无牙颌种植修复设计体会

目的:探讨下颌无牙颌种植体植入位置、数目与修复设计的关系。方法:采用Frialit-2种植体36枚和Endo-pore种植体6枚对8例下颌无牙颌患者进行了种植修复,其中2例进行了杆卡覆盖义齿修复,2例球帽覆盖义齿修复,4例种植固定义齿修复。结果:二期手术时,42枚种植体均形成了良好的骨性结合。经6~24个月的临床修复观察,种植体负重6个月时骨吸收平均0.5mm±0.02mm,戴义齿12个月后骨吸收平均0.1mm±0.03mm。修复的种植义齿能较好地行使咀嚼功能,收到了满意的临床效果。结论:对于下颌无牙颌的种植患者,合理的治疗计划,对于保障种植义齿的修复效果及维持种植体的长期成功率是重要的。     

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 fixed cantilever prostheses in partially edentulous arches. A seven-year prospective study

The purpose of the following study was to evaluate the medium- to long-term prognosis of implant-supported cantilever fixed prostheses, and to establish to what degree this is influenced by factors such as length, type of cantilever (mesial or distal), and opposite dentition versus cantilever prostheses. This study was performed on a sample of 38 partially edentulous patients treated between January 1994 and March 2001 with 49 partial cantilever fixed prostheses supported by 100 implants. Marginal bone resorption (MBL) has been studied and used as a reference parameter to define therapeutic success. The MBL measurement was made possible by transposing X-ray images of patients selected on a PC and then using a software program. Statistical analysis was carried out for possible correlation between peri-implant bone resorption and the parameters considered in this study: length and type (mesial or distal) of cantilever and opposite dentition to cantilever prostheses. Seven years after loading cantilever prostheses, the overall cumulative implant survival rate (OCSR) was 97%, and the prostheses success rate is 98%. Mesial cantilever prostheses registered a lower success rate (97.1%) than distal cantilever prostheses (100%). Furthermore, a better prognosis was not observed when the opposite dentition of the prostheses comprised natural teeth, or fixed prostheses on natural teeth, when compared with the cases in which opposite teeth were implant-supported fixed prostheses. The authors concluded that medium-term prognosis of implant-supported cantilever fixed prostheses and traditional implant-supported fixed prostheses was comparable. However, a thorough pre-treatment analysis of risk factors regarding implant-supported prosthesis survival is important.     

Neuromuscular coordination of masticatory muscles in subjects with two types of implant-supported prostheses

OBJECTIVES: To compare the electromyographic (EMG) characteristics of masticatory muscles in patients with fixed implant-supported prostheses and implant overdentures. MATERIAL AND METHODS: Nineteen subjects aged 45-79 years were examined. Fourteen were edentulous and had been successfully rehabilitated with (a) maxillary and mandibular implant-supported fixed prostheses (seven patients); (b) mandibular implant overdentures and maxillary complete dentures (seven patients). Five control subjects had natural dentition or single/partial (no more than two teeth) tooth or implant fixed dentures. Surface EMG of the masseter and temporal muscles was performed during unilateral gum chewing and during maximum teeth clenching. To reduce biological and instrumental noise, all values were standardized as percentage of a maximum clenching on cotton rolls. RESULTS: During clenching, temporal muscle symmetry was larger in control subjects and fixed implant-supported prosthesis patients than in overdenture patients (analysis of variance, P=0.005). No differences were found in masseter muscle symmetry or in muscular torque. Muscle activities (integrated areas of the EMG potentials over time) were significantly larger in control subjects than in implant-supported prosthesis patients (P=0.014). In both patient groups, a poor neuromuscular coordination during chewing, with altered muscular patterns, and a smaller left-right symmetry than in control subjects were found (P=0.05). No differences in masticatory frequency were found. CONCLUSION: Surface EMG analysis of clenching and chewing showed that fixed implant-supported prostheses and implant overdentures were functionally equivalent. Neuromuscular coordination during chewing was inferior to that found in subjects with natural dentition.     

Level of satisfaction in patients with maxillary full-arch fixed prostheses: zygomatic versus conventional implants

PURPOSE: To evaluate the satisfaction of patients with maxillary fixed prostheses supported by conventional and/or zygomatic implants. MATERIALS AND METHODS: Patients restored with complete maxillary implant-supported fixed prostheses were included in the study. They were divided into 2 groups: those with at least 1 zygomatic implant (the zygomatic group) and those with no zygomatic implants (the nonzygomatic group). Twelve months after prosthesis delivery, subjects indicated their satisfaction with the new prosthesis on a visual analog scale. Prostheses were rated in terms of general satisfaction, comfort and stability, ability to speak, easy of cleaning, esthetics, self-esteem, and functionality. RESULTS: Forty-six patients participated in the study (23 in each group). The mean level of satisfaction was high; the groups differed significantly only in satisfaction with esthetics. Patients in the zygomatic group had a higher average score for esthetics than those in the nonzygomatic group. Those who had previously worn conventional removable prostheses gave a higher score for functionality to the implant-supported fixed prosthesis compared to the removable prosthesis. CONCLUSION: Patient satisfaction with zygomatic implant-supported fixed prostheses was similar to that for fixed prostheses supported by conventional implants.     

Implant-supported fixed prosthesis improves nutrient intake in patients with partial edentulous posterior regions

PurposeThis study investigated changes in food and nutrient intake after implant-supported fixed prosthesis treatment in patients with partial edentulous posterior regions.MethodsThis study included 30 patients who received implant treatment with fixed prostheses in the posterior region. Food and nutrient intake was evaluated using a brief self-administered diet history questionnaire at baseline and post-implant treatment, and the results were statistically analyzed.ResultsTreatment with implant-supported fixed prostheses in patients with posterior edentulous conditions tended to increase the amounts of soy products and vegetables consumed: in particular, intake of carrot and squash was significantly increased. The total energy, protein, lipid, and carbohydrate intakes were comparable between baseline and post-implant treatment. On the other hand, the vegetable protein, α-carotene, daidzein, and genistein intakes were significantly increased, and dietary fiber and β-carotene intakes tended to be increased in patients with implant-supported fixed prostheses.ConclusionsImplant-supported fixed prostheses in patients with posterior edentulous conditions affected food intake, resulting in improved nutrient intake.     

Analysis of influence of lip line and lip support in esthetics and selection of maxillary implant-supported prosthesis design

The lip line and lip support influence esthetics and selection of implant-supported prosthetic designs for maxillary edentulous patients. This article describes a procedure to analyze the influence of lip line and lip support on the esthetics of an existing maxillary complete denture, revealing potential limitations when planning a fixed implant-supported prosthesis.     

Implant-supported maxillary denture retained by a telescopic abutment system: A clinical report

An implant-supported fixed dental prosthesis is one of the treatment options for an individual with a completely edentulous maxilla. However, a screw-retained or cemented prosthesis can make oral hygiene difficult, especially for patients with a history of periodontal disease or disabilities. Compared with maxillary fixed dental prostheses, implant-supported overdentures offer similar retention and function and facilitate esthetics, phonetics, and hygiene. This report describes the prosthetic rehabilitation of a patient with an edentulous maxilla and a severe maxillomandibular discrepancy that involved the use of a novel prefabricated telescopic system to retain an implant-supported removable dental prosthesis.     

Oral rehabilitation considerations for partially edentulous periodontal patients

Traditional tooth-supported and implant-supported fixed/removable restorations are currently used to replace teeth lost due to periodontal disease. This article reviews the existing literature for oral rehabilitation of partially edentulous periodontal patients with various designs of removable dental prosthesis (RDP), fixed dental prosthesis (FDP) and implant-supported single crown (SC), by addressing their (a) general features, (b) survival and complication rates, along with considerations for treatment planning in periodontal patients, and (c) preference by patients. To answer these issues, relevant articles were searched and critically analyzed, and their data were extracted. Data reviewed indicated that despite many advantages, implant-supported restorations have higher complication rates than tooth-supported restorations. Systematic reviews on conventional RDPs are lacking, but existing literature reviews provide limited evidence suggesting the use of RDPs with design modifications along with strict periodontal care in periodontal patients. Numerous systematic reviews on conventional FDPs and implant-supported restorations provide a moderate level of evidence favoring their survival in periodontal patients; however, for long-term success of these restorations, the patient's periodontal condition needs to be stabilized. In terms of patient preference, no restoration is superior, as they all are governed by their cost, advantages, and disadvantages. Thus, in the wake of existing weak evidence for prosthodontic rehabilitation of periodontal patients by these restorations (especially, conventional RDPs and for FDPs and SCs in implant-supported restorations), longitudinal studies with standardized treatment protocol and methodology are needed to evaluate and compare tooth-supported and implant-supported restorations in periodontal patients with regard to survival rates, cost, maintenance, and patient-centered outcomes.     

Prosthetic outcome of cement-retained implant-supported fixed dental restorations: a systematic review

The aim of the article is to assess the current literature in terms of the prosthetic outcome of cement-retained implant-supported fixed restorations, as well as to determine the type of cement that can be recommended for clinical application. A review of the literature published up to May 2010 was conducted to identify clinical studies about cement-retained implant-supported fixed restorations. The search strategy applied was a combination of MeSH terms and free text words, including the following keywords: implants, implant-supported fixed dental prostheses (FDPs), bridges, implant-supported single crowns (SCs), cement-retained, cement fixation, cement, cementation, cement failure, retention, and loss of retention, technical complications, mechanical complications, prosthetic complication, retrievability and maintenance. Thirty-two studies met the inclusion criteria. The studies were divided into two categories: 15 short-term clinical studies with an observation period of less than 5 years, and 17 long-term clinical studies with an observation period of 5 years and more. The most common technical complications of cement-retained implant-supported fixed restorations were loss of retention, chipping and abutment screw loosening. The results of the current review revealed no guidelines about cement or cementation procedures. It may be stated that despite the questionable retrievability of cement-retained implant-supported fixed restorations, this treatment modality is a reliable and effective option, especially for implant-supported SCs and short-span FDPs. The literature does not provide accurate information about the clinical outcome of cement-retained implant-supported fixed restorations nor about the ideal type of cement that facilitates stability and maintains retrievability. Standardised randomised clinical trials will provide valuable information to this issue.     

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.     

全颌固定式种植义齿

目的：牙列缺失的种植义齿修复多采用覆盖义齿方式，但某些患者仍希望得到固定修复。Branemark的可拆卸固定全颌种植义齿技术复杂，美观清洁卫生等也不理想。本研究要建立一种牙列缺失的固定种植我齿修复模式。方法：11例有条件的无牙颌患者，在CDIC种植体支持基础上，用常规烤瓷溶附冠桥技术完全成颌固定式种植义齿修复。结果：1至5年的观察表明，该修复模式在咀嚼功能，美观性，舒适感及清洁卫生维护均获得满意结果。     

Clinical and technical aspects of implant-supported restorations in the edentulous maxilla: the fixed partial denture design

PURPOSE: The aim of the present article was to describe the treatment planning for an implant-supported maxillary fixed prosthesis and the clinical procedure involved, including the laboratory fabrication sequence. MATERIALS AND METHODS: If patients request a fixed prosthesis to restore the edentulous maxilla, it is essential to decide as soon as possible whether this prosthesis design can satisfy the requirements of esthetics, phonetics, comfort, and function. Thus, the crucial clinical factors need to be checked during examination. Furthermore, the relationships between ideal implant angulation, available bone, and intended crown should be assessed using reformatted computed tomography. RESULTS: In patients with minimal bone resorption and limited intermaxillary space, implants can usually be placed in the prosthetically driven implant position for a fixed prosthesis. To evaluate and optimize esthetics, biology, and function, a fixed provisional restoration should be inserted for a 6-month diagnostic period. The ideal provisional then serves as a guide for the final restoration. CONCLUSION: If clinical and radiologic diagnostics indicate that an implant-supported fixed complete denture is feasible, meticulous presurgical planning, precise execution of implant positioning, and a progressive prosthetic treatment sequence are required. The ceramometal fixed implant-supported restoration can then be established in an ideally prepared and matured oral environment.