The International Journal of Oral & Maxillofacial Implants, 04/1990

The accuracy of master casts fabricated from three impression techniques commonly used with the Brånemark System was measured. Points placed in a metal surrogate model and onto master abutments were compared after abutments were transferred to stone casts using splinted and unsplinted impression coping techniques. The mean values and standard deviations of each of the reference points on 12 total casts were compared with the values for each point from the surrogate model. Values from techniques using splinted and unsplinted squared polymer copings as well as unsplinted tapered hydrocolloid copings were not significantly different from values recorded from the master surrogate model. Tapered hydrocolloid copings yielded a higher correlation to coordinate values on the master than unsplinted squared polymer copings or splinted squared copings. Keywords: Brånemark implants, computer reference, copings, transfer impressions

The rationale and possible clinical applications of an immediate fixture placement technique are described. Although this concept may be a somewhat radical departure from the conventional mandibular protocol, there are significant potential patient benefits with no apparent change in anticipated fixture survival rates. A similar approach in the maxilla may be less practical with most presenting dentitions, but there is evidence that further research may make immediate fixture placement equally appropriate in this arch. Keywords: immediate fixture placement, mandible, maxilla, osseointegration, treatment planning

This study reviews the long-term outcome of prostheses and fixtures (implants) in 759 totally edentulous jaws of 700 patients. A total of 4,636 standard fixtures were placed and followed according to the osseointegration method for a maximum of 24 years by the original team at the University of Göteborg. Standardized annual clinical and radiographic examinations were conducted as far as possible. A lifetable approach was applied for statistical analysis. Sufficient numbers of fixtures and prostheses for a detailed statistical analysis were present for observation times up to 15 years. More than 95% of maxillae had continuous prosthesis stability at 5 and 10 years, and at least 92% at 15 years. The figure for mandibles was 99% at all time intervals. Calculated from the time of fixture placement, the estimated survival rates for individual fixtures in the maxilla were 84%, 89%, and 92% at 5 years; 81% and 82% at 10 years; and 78% at 15 years. In the mandible they were 91%, 98%, and 99% at 5 years; 89% and 98% at 10 years; and 86% at 15 years. (The different percentages at 5 and 10 years refer to results for different routine groups of fixtures with 5 to 10, 10 to 15, and 1 to 5 years of observation time, respectively.) The results of this study concur with multicenter and earlier results for the osseointegration method. Keywords: Brånemark System, long-term follow-up, oral implants, osseointegration, total edentulism

Surface analysis techniques and in vitro biologic assays were used to characterize sterilized commercially pure titanium surfaces. Significant surface alterations were observed following sterilization treatments. These alterations led to decreased fibroblast cell attachment and altered cellular spreading phenomena compared to nonsterilized control surfaces. Keywords: cell adhesion, CP titanium implants, sterilization, surface characteristics

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 (>=22 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. Keywords: edentulous mandible, overdenture, titanium implants

Computed tomography can assist the surgeon in planning the exact three-dimensional positioning of endosseous implants in the jaw bone. This study examined the reliability of three CT techniques: direct imaging (normal coronal and sagittal slices), standard reconstruction (based on axial slices), and multiplanar reconstruction and display (also based on axial slices). The three imaging techniques were used to estimate the bone height, bone width, and maximal implant length in six dissected human jaw bones. These jaws were then sawed perpendicular to their axis to enable measurement of real values for comparison. The sagittal and coronal slices frequently were overestimated, especially in the canine and premolar regions. The mean absolute deviation was 1.4 mm. Standard reconstruction offered the most reliable cross-sectional images, with a mean absolute deviation of 0.5 mm. The multiplanar reconstruction and display technique frequently demonstrated underestimations (mean absolute deviation was 2.3 mm). The standard reconstruction technique seems to be the method of choice in preoperative radiographic examination of patients before implant placement. Keywords: computed tomography, dental implants, oral surgery, osseointegration, radiography

Oral implant stability is essential for optimal function. Results obtained from the Periotest measurement of the stability of 204 commercially pure titanium implants, consecutively placed in 22 maxillae and 24 mandibles according to the Brånemark procedure, are reported. Preliminary results suggest that the Periotest value of an oral implant is an objective and easily applied criterion for stability assessment. Since osseointegration is achieved gradually over time, this test may assist the clinician in deciding whether to extend the healing period before loading fixtures that seem clinically and radiologically integrated but give borderline Periotest values. Keywords: clinical material, osseointegrated dental implants, Periotest, stability, tissue damping

Many edentulous patients who previously have undergone vestibuloplasty with split-thickness skin grafting to improve denture stability and function seek additional help with dental implants. Problems encountered following the placement of four endosseous root-form dental implants in one such patient are presented. The anatomic and surgical considerations as well as methods available to circumvent these problems are discussed. Keywords: endosseous implants, split-thickness skin graft, vestibuloplasty

A patient with a failed implant-supported prosthesis was treated with an immediate interim overdenture. After insertion of a bar modified from the prosthesis substructure, the patient was restored with an implant supported overdenture. A bar soft liner retention system was used to aid retention and stability of the overdenture. Keywords: Brånemark implant, interim overdenture, overdenture, soft liner