Bar-retained Overdentures Research Articles

The Milled Bar‐Retained Removable Bridge Implant‐Supported Prosthesis: A Treatment Alternative for the Edentulous Maxilla

Restoration of the edentulous jaw with dental implants can be achieved using either an implant-supported prosthesis, such as a fixed bridge, or an implant-retained prosthesis, such as a traditional overdenture. The implant-retained prostheses use edentulous ridges as primary stress-bearing regions, and through stress-breaking mechanisms, the implants are not loaded during function. However, the success rates of maxillary overdentures do not appear to be as good as for mandibular overdentures; this may be attributable to the adverse loading conditions, short implant length, poor quality of bone, number of implants used, flexible bar design, or poor treatment planning. Many articles have also described the numerous problems and multiple visits required in maintaining a traditional bar-retained overdenture restoration, often making it more expensive in the long term than a fixed restoration. The milled bar implant-supported prosthesis offers the benefits of both fixed and removable restorations. Its infrastructure provides the same rigidity as the fixed restoration, owing to the precise fit to the superstructure, which is removable, to promote adequate access for hygiene, yet it still provides lip support and maintains close contact with the soft tissues. These advantages enhance phonetics, esthetics, correct lip support, maintenance, and patient comfort.

Prospective study on titanium bar-retained overdentures: 2-year results.

Within a monometallic concept 29 patients received titanium bar-retained mandibular overdentures on 2 IMZ implants. The study had a prospective design with 3 months recall intervals. One of 58 implants failed after 11 months. There were no significant differences of the mean plaque scores (Silness, Löe) and the mean sulcus bleeding scores (Mühlemann, Son) at the abutments between baseline, 12 months and 24 months. Less than 40% of the subjects showed plaque score zero at 24 months. However, 89% exhibited sulcus bleeding score zero indicating health of the peri-implant soft tissues in most cases. Plaque at the basal site of the bar was scored separately at additional measuring points located at the central area and the contact areas between bar and abutments. Bar plaque scores nearly doubled between baseline and 12 months and remained high at 24 months. Median maximal vertical bone loss around the implants was 1.7 mm after 2 years. Bone loss did not exceed one quarter of the implant length in 79%. The monometallic concept in bar-retained overdentures on 2 implants proved its clinical suitability except for the applicability of pure titanium for bar clips. Plaque formation beneath the bar seems to be one of the major clinical problems.

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. (J Prosthet Dent 2000;83:586-8.)

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. (J Prosthet Dent 2000;83:424-33.)

Implant supported overdentures — the Leuven experience

Objectives: This report covers a series of three different clinical longitudinal studies on the outcome of overdenture therapy when two (mandible) or four (maxilla) implants retaining a resilient overdenture are used. Conclusions: The resilient mandibular bar-retained overdenture on two implants is a very reliable treatment. Implant failure is low and the stability of the implants improves over time. Marginal bone remains stable once the first year has passed. The applied overdenture design is simple, versatile and very cost elfective. In the maxilla such implants do maintain their marginal bone level if splinted by means of a rigidly cast bar and when applied in a resilient overdenture therapy. Correct laboratory fabrication of the prosthesis is critical to the success of treatment. Clinically, overdenture aftercare is limited to renewal of used attachments. Patient satisfaction remains very positive to this form of treatment.

A comparative prospective study of splinted and unsplinted Brȧnemark implants in mandibular overdenture therapy: A preliminary report

Thirty-six edentulous patients, each provided with two Brȧnemark implants in the mandible to anchor an overdenture, were selected for this study and randomly divided into three groups of 12 patients each. In each group a different attachment system was used: (1) magnets, (2) ball attachments, and (3) straight bars with clips (control). The mean loading time was 12.4 months (range 3 to 24 months). This study investigated (1) the clinical behavior of loaded implants by means of overdentures related to their connection system (splinted versus unsplinted) and (2) the clinical performance of prosthetic treatment. Preliminary results indicate no differences; no failures occurred and the level of marginal bone height, as well as the probing attachment level, changed similarly in the three groups. Although splinted bar-retained overdentures scored better objectively, subjective satisfaction ratings did not differ. It was concluded that for the short follow-up period, the state of connection did not influence the clinical success of implants. However, no definite conclusions may be drawn until long-term data become available.

FREE GINGIVAL GRAFTING AND VESTIBULOPLASTY WITH ENDOSSEOUS IMPLANT PLACEMENT

Soft-tissue complications may occur adjacent to endosseous implants and their associated transepithelial abutments. Vestibuloplasty and connective tissue grafting techniques can be used to obtain attached keratinized tissue in the anterior endentulous mandible before implant placement in an effort to improve the long-term prognosis. A clinical case is presented that was restored with a mandibular implant-supported, bar-retained overdenture opposing a maxillary complete denture after grafting and vestibuloplasty procedures.

Free gingival grafting and vestibuloplasty with endosseous implant placement

Soft-tissue complications may occur adjacent to endosseous implants and their associated transepithelial abutments. Vestibuloplasty and connective tissue grafting techniques can be used to obtain attached keratinized tissue in the anterior edentulous mandible before implant placement in an effort to improve the long-term prognosis. A clinical case is presented that was restored with a mandibular implant-supported, bar-retained overdenture opposing a maxillary complete denture after grafting and vestibuloplasty procedures. (Implant Dent 1994;3:235–238)

Bar-retained overdentures for implants—technical aspects

The principles of the laboratory procedures for making overdentures retained by bar abutments on ITI implant fixtures are described, and details of producing the master casts, making a soldered bar, and processing a prosthesis incorporating a cobalt-chromium alloy strengthener are given.