A four-year retrospective study of 3i threaded implants.

The use of osseointegrated implants can be considered as one of the most productive developments in dentistry during this century. Although initially introduced for use in fully edentulous patients, their present widespread use in nearly all forms of tooth loss, as well as for the rehabilitation of maxillofacial prosthetics and in orthodontics, has significantly expanded the realm of restorative dentistry. The present multicentre retrospective study evaluates the results of 327 patients rehabilitated with 1047, 3i (Implant Innovations Inc.) threaded implants over a four-year period. Eight patients with 22 implants dropped out and were excluded from the study as they could not be evaluated. A total of 319 patients with 1025 implants remained. Nine implants failed in the mandible and 14 in the maxilla. There was a success rate of 98.2 percent in the mandible and 97.3 percent in the maxilla. The mean overall success rate was 97.75 percent, with little variation between the four study centres. These results are similar to previously published studies on titanium threaded implants and indicate that, with careful adherence to accepted principles of surgery and restorative dentistry, the 3i threaded implant system can be used confidently to provide the necessary support for an osseointegrated implant-supported prosthesis.

The efficacy of two-stage titanium implants as orthodontic anchorage in the preprosthodontic correction of third molars in adults--a report of three cases.

Orthodontic movement of teeth is often required to satisfactorily treat a variety of oral rehabilitation problems. Considerable limitations in the clinical application of orthodontic treatment may result from the lack of teeth suitable for anchorage. Three patients with edentulous posterior segments are presented illustrating how implants can be utilized for preprosthodontic correction of impacted third molars rendering them suitable as bridge abutments. The patients have been followed for 8-10 years. Two-stage titanium implants were used as orthodontic anchorage as no dental anchorage was available. Edgewise orthodontic mechanics were used to move the third molars mesially with forces up to 2.5 N (about 250 g). No movement of the implants occurred and they were radiologically and clinically intact at the end of the orthodontic loading and were, therefore, subsequently used as bridge abutments.

Some characteristics of patients given dental treatment under general anesthesia.

The attitude to treatment of dental diseases under general anesthesia has been rather restricted in the dental profession in Scandinavia. Yet, some patients with certain medical conditions and patients haunted by anxiety may not be able to have conventional dental treatment. During the period 1975-1983, 1067 patients were treated in a group practice in Oslo. These patients are described with regard to gender, age, reasons for treatment, place of residence, source of referral, and type of treatment given. Some of the data are related to the year of treatment. The profile of patients changed during the observation period. At the beginning most of the patients came from Oslo and were less than 6 years old, whereas at the end most of the patients were more than 15 years old, lived outside Oslo, and had more conservative than radical treatment. It is concluded that there will probably always be a small group for whom dental treatment under general anesthesia will be necessary.

Implant-tissue interface of endosseous dental implants in dogs. validity of clinical evaluation methods.

Plaque and gingival bleeding were scored and probing, radiography, and histologic methods were used to evaluate clinical methods for estimating alterations of supporting structures at functioning endosseous dental implants. Twelve implant abutment posts in three Labrador retriever dogs were assessed. The observation period was 3 months of submerged healing followed by 6 months in function. In the presence of daily gingival cleaning, both plaque and gingival bleeding scores were reduced on implant abutments. No correlation was found between gingival scores and the degree of bone resorption. The correlation between probing and radiographic measurements was studied by comparing 136 parallel measurements. The average difference was 0.4 mm. Discrepancies were observed when evaluating bone loss that reached the shoulder area. Better accordance was obtained when moderate (2 to 4 mm) or extensive (6 to 8 mm) resorption was assessed. Histologic evaluation indicated alternating regions of implant-bone contact and fibrous encapsulation. Progressive infiltrates were observed in the permucosal area, sometimes extending into the deeper parts of the supporting bone. A combination of probing and radiographic measurements seems to give the most reliable information about the level of bone support and is recommended to be included in routine control of implant abutments.

Comparison of bone resorption at one-step and two-step mandibular endosseous implants in dogs.

Endosseous dental implants have been inserted into dog jaw bone following two different implantation principles. Using the two-step procedure, the implant is left submerged, covered by the mucoperiosteum for a healing period, before communication with the oral cavity is established. According to the one-step procedure, this communication is established peroperatively. In order to estimate radiographically the degree of bone resorption following the two-step as compared to the one-step procedure, the former was used on the right and the latter on the left side of the mandible in two dogs. Periodic identical intraoral radiographs revealed bone resorption in the neck area of all implants. After a 1-yr period with bilateral bridges, the vertical resorption varied between 3 and 5 mm. No difference was found between the two methods concerning this bone resorption. The observation seems to be contrary to the general opinion on the matter, and pertinent investigations with the present model will be performed in a human material.

Subperiosteal transmucosal porous ceramic/titanium implants. Clinical experience from three cases.

Porous ceramic (Al2O3) material was used in combination with titanium fixtures as subperiosteal transmucosal implants in three patients at the Department of Oral Surgery and Oral Medicine, Dental Faculty, University of Oslo. Ceramic pieces were furnished with titanium receptacles and matching threaded posts. The implantation approach was based upon two stages, the first for subperiosteal placement of the ceramic onlay segment containing the titanium receptacles, and the second procedure for perforation of the mucosa and insertion of the posts intended for prosthetic use. A healing period of 8 weeks was planned between the two procedures. In one of the patients, however, the implants were removed only a few weeks after placement because of inflammation and soft tissue breakdown over the ceramic material. Reoperation was performed, however, with the same negative results. The other two individuals retained the implants, with uneventful postoperative healing periods. Between 6 and 8 weeks after mucosal perforation and insertion of the titanium posts, however, subjective and objective symptoms of infection were registered in both patients. In addition, one of the cases exhibited dehiscence and exposure of the ceramic. The implants were removed in both individuals.