Treatment of edentulism using Astra Tech implants and ball abutments to retain mandibular overdentures.

The goal of this study was to provide evidence to support simplified treatment of mandibular edentulism using denture fabrication and implant placement to circumvent the need for second-stage surgeries or prosthodontic superstructures. A 5-year prospective clinical trial is reported, which involved treatment of mandibular edentulism using the single-stage surgical placement of a TiOblast microthreaded titanium screw implant with immediate replacement of a relieved mandibular overdenture and eventual retention of the overdenture with reduced ball abutments. Fifty-eight patients were treated; 116 implants were placed using a single-stage surgical approach, with a duplicate mandibular denture as the tomographic/surgical template. Mandibular dentures were relieved and relined with a tissue conditioning material and placed immediately after implant surgery. After 3 months, Conical Seal Design ball abutments were placed and attachments were secured in the overdentures by heat-polymerizing laboratory reline methods. Five of the 116 consecutively placed implants failed at 2 to 4 months, providing an immediate implant survival rate of 95.69% at the time of attachment connection. Pain and inflammation were not common to all failures, and infection was not reported in any of the 5 failures. The immediate placement of implants by a single-stage surgical procedure in the parasymphyseal region of the mandible, followed by placement of a relined mandibular denture, results in predictable and asymptomatic healing of implants that display the clinical and radiographic features of osseointegration. Encouraging results at the immediate observation period (attachment connection) must be tempered by the need for prudent and detailed clinical and radiologic evaluation over the 5-year trial period.     

Solutions for Severely Angulated Implants in the Mandibular Overdenture: A Clinical Report

Results of randomized clinical trials have confirmed that implant overdentures provide patients with better outcomes than do conventional complete dentures. Several designs have been introduced for the mandibular implant-retained removable prosthesis. The most commonly used prosthesis design for the mandibular overdenture is two implants in the canine areas with a stud attachment mechanism (i.e., ball attachments). This design is the least expensive, and therefore can service more patients and is now considered to be the "Standard of Care" for the mandibular edentulous patient. Proper treatment planning and execution lead to favorable implant placement and a successful prosthetic restoration and ultimately patient satisfaction; however, implant malposition may occur, which can lead to an unsuccessful prosthesis. This clinical report describes an implant overdenture design used for severely angled implants. Prosthodontic techniques that enabled this patient to have a successful outcome included the use of cast-to attachments and abutments along with a sectional matrix used to locate these components within the bulk of the prosthesis. For this patient the prosthodontic compromises were preferred over another surgical procedure with the additional time, discomfort, increased cost, and possible surgical morbidity. It is important that the patient understand the compromises and potential problems when implant placement is not ideal, especially the potential for implant overload and failure.     

An overview of the O-ring implant overdenture attachment: clinical reports

The O-ring is used to increase retention of implant complete and partial overdenture prostheses. They possess a number of advantages, including ease of use and maintenance, low cost, and possible elimination of a superstructure bar. O-rings wear over time, gradually lose retention, and must be replaced periodically. It is essential that O-ring abutments be parallel to each other. Two cases are presented showing the use of O-rings with a complete mandibular implant overdenture and a maxillary removable partial denture.     

Correcting a nonparallel implant abutment for a mandibular overdenture retained by two implants: a clinical report

A mandibular overdenture supported by 2 implants is an effective treatment alternative for the maladaptive denture wearer. The implants may be either splinted, using a bar, or nonsplinted and retained by attachments, such as balls or magnets. When the use of a ball attachment is contemplated, the implant abutments should be parallel to one another along the path of insertion. The following report describes the procedure to correct a nonparallel implant abutment to retain a mandibular overdenture.     

A Simplified Chair-Side Technique with Pre-Fabricated Directional Rings in a Case of Divergent Root Retained Overdenture

Precision attachments have been largely ignored by most dental professionals for trivial reasons such as cost and reluctance of a practitioner to grasp the intricacies of its indications and applications. Precision attachments offer considerable advantages such as increased retention of a denture, preservation of teeth which are otherwise indicated for extraction, as a viable alternative to implant retained overdenture and the ability to obtain parallelism in divergent abutments. A prosthodontist who familiarizes himself with precision attachments will be in a position to suggest a better treatment options in retaining teeth which might otherwise be considered for extraction or immediate implant placement. In this clinical report, we have described an overdenture placed on a previously unfavourable abutment made favourable by placing directional rings to maintain parallelism thus facilitating easy insertion and removal of the prosthesis.     

Use of a dental surveyor to ensure optimal seating of implant overdenture attachments

Many implant overdenture attachments accommodate divergent abutments. However, there can be instances where the denture base resin surrounding the abutment may impede seating by binding on the axial surface(s) of the abutment. This article describes the use of a dental surveyor to aid clinicians in determining where the resin denture base might be preventing the seating of overdenture attachments. The surveyor can be used for judicious adjustment to allow optimal seating of the attachments.     

A comparative clinical investigation of 2 early loaded ITI dental implants supporting an overdenture in the mandible

The purpose of this prospective clinical study was to evaluate the efficacy of early loading of implants and to provide evidence to support simplified treatment of mandibular edentulism by using an implant designed for 1-stage surgery, combined with ball abutments to circumvent the need for a fixed prosthodontic superstructure. Historically, the recommended time between the placement and functional loading of dental implants has been 3 months in the mandible. This recommendation is the result of a systematically chosen healing time during development of implant treatment. In recent years, histologic and experimental studies have shown that specially designed implants can result in increased bone-to-implant contact at earlier healing times. Accordingly, these implants can be placed into function faster than previously recommended. In this study, 21 patients aged between 61 and 85 years with edentulous mandibles were included. All received 2 titanium plasma-sprayed, solid-screw dental implants in the interforaminal region. Ten patients had the implants loaded with an overdenture connected with ball abutments after 3 months (control group). The other 11 patients (test group) had prostheses connected to the ball abutments after a maximum of 3 weeks. Marginal bone resorption, Periotest values, and patient satisfaction were evaluated. The cumulative post-loading implant survival rate was 100% for both groups after 24 months. Marginal bone resorption after 1 year around all implants ranged from 0 to 2 mm (no significant differences between groups; P < .05). Periotest values for all implants 1 year after loading were below zero (range -1 to -6). The results of this clinical trial suggest that successful early loading of 2 implants is possible provided there is uncomplicated implant placement.     

The mandibular complete overdenture

Mandibular complete overdenture treatment has been available for decades, but its use was limited when the treatment relied on retained teeth as overdenture abutments. This treatment, however, is currently experiencing more popularity than ever before. In fact, dentistry may be experiencing a philosophical shift, in which mandibular implant overdenture treatment may become the new standard of care for the treatment of the edentulous mandible. Practitioners are looking for simplified treatments that can provide cost-effective alternatives to more complex implant prosthodontic procedures. Implant overdentures provide a strong return for the investment in treatment time and expense and are a treatment suited to the lower socioeconomic status of many edentulous patients. The clinical outcome of this treatment is significantly better than that achieved with conventional mandibular dentures, especially when patients are experiencing technical problems because of compromised prosthesis retention or stability.     

Mucosal and radiographic aspects during the healing period of implants placed in a one-stage procedure

PURPOSE: The aim of this prospective clinical trial was to compare peri-implant clinical and radiographic parameters following the placement of nonsubmerged two- and one-stage implants. MATERIALS AND METHODS: Patients were randomly assigned to the IMZ group (20 patients receiving two IMZ two-stage implants in a one-stage procedure) or ITI group (20 patients receiving two ITI implants in the conventional one-stage procedure). The healing period was defined as an 18-week unloaded osseointegration period and a 1-year functional period during which maturation of bone took place. Twelve weeks after implant placement, fabrication of an overdenture with a bar-clip attachment system was started; it was placed at 18 weeks. RESULTS: None of the implants were lost during the osseointegration period; one IMZ implant was removed during the functional period because of mobility. There was no significant difference in Gingival Index between the two groups at all evaluation periods. The mean bone loss during the functional period was 0.6 mm in both groups. A high number of healing abutments loosened in the IMZ group. CONCLUSION: Clinical and radiographic parameters of two-stage implants placed in a one-stage procedure and one-stage implants are comparable during the healing period. Healing abutments of the IMZ implant system loosen easily.     

Simplified procedure for replacement of retentive clips in a bar-retained implant overdenture

Replacing the retentive elements in a bar-retained overdenture can be a difficult and time-consuming procedure. This article describes an impression procedure that allows the matrices in a bar-retained implant overdenture to be replaced in the laboratory using a heat-cured rebase procedure. Long waxing screws are used, which allows the bar to be removed in the rebase impression and incorporated in a new master cast. After completion of the laboratory phase, the bar is screwed back onto the implant abutments and the denture, with new retentive matrices, is inserted.     

Management of misangulated implants for a maxillary overdenture with spherical abutments: a clinical report

Misangulated and malpositioned implants pose a significant challenge for the prosthodontic treatment of edentulous patients. Most reports of maxillary overdenture patients have described the use of a bar to splint malaligned implants, followed by successful fabrication of the prosthesis. Few reports have discussed the use of individual abutments in such situations. This clinical report describes the successful use of spherical/ball abutments for the management of 4 malaligned implants in the edentulous maxilla for an overdenture. The rationale and technique for the use of spherical abutments for overdenture fabrication in such situations are described.     

Clinical evaluation of the Biocomp-implant system. Results after 1,3 and 5 years in a general practice

A population of 107 consecutive patients was treated with a new HA-coated, screw-type dental implant (n = 384 implants), the Biocomp implant. Treatment was performed in a general dental practice by one and the same dentist. The implants were utilized for various types of prosthetic constructions, sometimes in challenging conditions with respect to patient selection, jaw bone quantity and quality. A clinical and radiographical evaluation was performed after 1, 3 and 5 years. After 5 years, the chance on implant survival was 87.1% (standard error 3.4%). Implant loss occurred predominantly within the first 1.5 year after implant placement. Particularly short implants, placed in the atrofic maxilla, frequently failed. Biocomp implants that served as abutments for an overdenture in the edentulous mandible or as a single tooth replacement in the upper anterior region had an excellent prognosis.     

Management of a failed mandibular staple implant: a clinical report

A 48-year-old woman sought treatment because her staple implant-retained overdenture was no longer retentive, and the denture was worn over the abutments. After unsuccessfully attempting to move the retentive nuts along the transosseous posts of the staple implant, the posts were cut off at the level of the bone. Two endosseous implants were placed around the staple implant, and a new implant-retained overdenture was fabricated and inserted using ball attachments for retention. This article describes the treatment for this patient, who has been wearing the new dentures successfully for the past 4 years.     

A prospective evaluation of Frialoc implants with ball-abutments in the edentulous mandible: 1-year results

Several surgical and prosthetic concepts for the treatment of patients with mandibular atrophy and related lower denture problems are proposed and described in the literature. The present study discusses and evaluates the use of a new single-stage implant and overdenture with ball-attachment for this purpose. This study evaluates the clinical performance of the implants and abutments and addresses surgical and prosthetic complications that were encountered. Eighteen fully edentulous patients received two, single-stage Frialoc implants (Friadent, Mannheim, Germany). The implants were left to osseointegrate for 3 months and were subsequently provided with ball-abutments and loaded through a mandibular overdenture. After 1-year of clinical service, two implants were lost, which accumulated to a 1-year survival rate of 93.9% (SE 4.2%). Patient satisfaction was high, and prosthetic complications and postinsertion maintenance were minimal. Three abutments loosened, one of which subsequently broke after 5 months of loading. Retightening of the attachment (gold matrix) was performed on seven occasions in four patients. Soft tissue response was excellent. Although minor hypertrophy of the peri-implant mucosa was observed, hardly any marginal bone loss between baseline and 1-year observations occurred. Short-term results indicate that mandibular implant overdenture treatment by means of two ball-abutments, using Frialoc implants and prosthetic components, leads to good clinical results, both from an objective and a subjective perspective.     

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.     

Overdentures and the periodontium

Many reasons have been clarified for the retention of teeth in the oral cavity for use as overdenture abutments. The benefits afforded the patient by the preservation of the periodontium have been explained, and methods have been discussed to evaluate the zone of attached gingiva around overdenture abutments. Finally, some research has been discussed to compare some representative overdenture attachments and provide some guidelines for their use in order to more carefully preserve the periodontium.     

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

Objective

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

Methods

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

Results

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

Conclusions and clinical significance

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

Prosthodontic Management of a Combination Transosteal/ Endosteal Implant Reconstruction: A Clinical Report

This is a clinical report of a patient who was not referred for prosthodontic evaluation and treatment until after undergoing Bränemark endosseous implant placement to supplement the previously existing mandibular staple bone plate implant. This supplemental treatment was the surgeon's attempt to resolve the patient's complaint of loose dentures. Creativity with implant biomechanics and prosthodontic design were necessary to restore the patient, in a predictable manner, to normal function. A fixed, detachable cast overdenture bar rigidly connected to all the implants was constructed utilizing resilient attachments to retain the tissue-supported mandibular overdenture. A presurgical prosthodontic evaluation could have averted many of the problems encountered with treatment. More effective conventional prosthodontic treatment may have resolved the patient's complaints and eliminated the need for additional implant placement.     

The Role of Abutment-Attachment Selection in Resolving Inadequate Interarch Distance: A Clinical Report

A critical factor that needs to be evaluated during the diagnosis and treatment planning phase for patients seeking an implant-tissue-supported overdenture or metal-resin implant fixed denture is the presence of adequate interarch distance. The amount of interarch distance is critical to the selection of appropriate implant abutments and attachments for both implant-tissue-supported overdentures and metal-resin implant fixed complete dentures. This clinical report describes a patient with complications related to the failure to diagnose inadequate interarch distance, and the methods used to resolve the patient's chief complaint. A guide for abutment-attachment selection using one commercially available implant system is given.     

A prospective study of single stage surgery for implant supported overdentures

OBJECTIVEs: To investigate the clinical and psychological outcomes with ball attachment supported mandibular overdentures on Branemark implants placed in a single stage surgical approach. MATERIAL AND METHODS Sixteen edentulous patients aged 32-74, with atrophic (flat) mandibular residual alveolar ridges, and a history of having difficulty coping with technically adequate mandibular dentures made within the last 2 years were recruited. Mark II Branemark implants were placed using a single stage surgical technique with healing abutments placed at time of surgery. Mandibular complete dentures were modified by relieving the areas over the abutments and a resilient liner was placed. After a period of 3 months, healing abutments were replaced with ball abutments and new complete dentures were made and the patients followed for a period of 2 years. Patients completed the General Health Questionnaire (GHQ) and answered further questions relating to the functional and psychological impact of complete denture wearing before treatment and 3 months after the dentures were provided. Patients additionally completed the GHQ 2 years after overdenture insertion. RESULTS: Six patients suffered from loss of one of their two implants in the first 2 years after placement. Three of the implants had failed to osseointegrate, which was detected at initial loading 3 months after placement. General Health Questionnaire scores were statistically significantly reduced after treatment and the improvement was maintained over 2 years. Responses to the functional and psychological questions were similarly improved. CONCLUSION: Single stage surgery led to a higher rate of implant failure than expected. Patients showed significant psychological health benefits from the treatment provided.