This retrospective study was designed to verify the factors that influence implant failures. Six prosthodontic clinics in Sweden participated in the study, and together they included a total of 54 patients treated between January 1988 and December 1996. All patients were completely edentulous in the maxilla, and received either a fixed prosthesis or an overdenture supported by at least 4 implants (Brånemark System). Half of the patients belonged to the study group, and an inclusion criterion for this group was that they had lost at least half of their implants. To reduce bias, the patients in the control group were matched to the study group, i.e. they were selected so that both groups were as identical as possible. The results of the study indicate that the control group had a better initial bone support than the study group. Furthermore, the patients in the study group suffered from circumstances that could induce implant failure, such as bruxism, personal grief, depression, as well as addictions to cigarettes, alcohol and/or narcotics. On the study form the clinicians were asked to give their own opinion of the reason for implant failure. The answers given could easily be grouped into 5 different topics, and this experience can be useful to improve patient selection. This study suggests that there are certain factors of importance to consider to prevent a cluster phenomenon of implant failures i.e. lack of bone support, heavy smoking habits and bruxism.

In this study, patient opinion on oral rehabilitation by means of Brånemark implants was investigated. All patients were referred to a periodontal clinic for implant installation and treated by one and the same operator. Prosthetic restorations were performed by dentists, who had no previous experience with prostheses on implants, but had completed a postgraduate training course. Patient opinion was obtained through questionnaires, pertaining to satisfaction and oral function. A comparison was made between pre-implant situation, short-term (< 4 months) and long-term functioning (3 years) with the implant-restorative rehabilitation. In total, 61 patients participated in the study; 23 received a full lower arch bridge and 18 a full upper arch bridge, while 20 patients got partial bridges. Of 298 installed implants, 7 failed at abutment connection (2.3%) and 1 during the 3-year follow-up interval (0.3%). The study results indicated that a great majority of patients were very satisfied with the treatment. Comfort with eating, aesthetics, phonetics and overall satisfaction improved significantly and nearly all patients said that they would undergo the treatment again or recommend it to others. Patients experienced their implants as "natural" teeth. The conclusion is that rehabilitation ad modum Brånemark, even in the hands of non-specialized dentists, can be of high quality, improving oral function and satisfying the needs and demands of patients.

Background: Originally, the Brånemark System was used as a two‐stage surgical procedure. Comparable clinical results have made one‐stage and early‐loading concepts possible alternatives in the edentulous mandible. From the patient's point of view, the financial aspect of implant treatment is important. In an attempt to decrease financial burden, the reduction of surgical interventions and reduction of the number of implants could be considered. Purpose: This prospective multicenter study evaluated (1) the 1‐and 3‐year success rates of implants loaded within 1 month after one‐stage surgery with a fixed 10‐ to 12‐unit bridge on three regular platform Brånemark System implants in the mandible, (2) the outcome of the prosthetic treatment, and (3) the opinion of patients regarding the treatment procedure. Materials and Methods: Of 20 patients, 19 received five implants in the mandible, of which three were functionally loaded with the one‐stage technique (group 1). The loaded implants were inserted in a tripodal position, one implant in the symphysis and two located anterior of the mental foramen in the bicuspid area. Two additional implants were inserted for safety reasons but were not intended to be included in the restoration. These two additional implants served as either an unloaded one‐stage control implant (group 2) or an unloaded control implant installed with the submerged technique (group 3). Immediately after surgery, the implants were loaded with a relined denture. The patients received a 10‐ to 12‐unit prosthetic reconstruction an average 31 days (range, 4‐53 d) after surgery. Implant stability was clinically checked at 3, 12, and 36 months. Radiographs were taken at corresponding follow‐up visits to calculate bone‐to‐implant level and marginal bone resorption. Results: Six of 60 functionally loaded implants (10%) and 3 of 20 prostheses (15%) failed within the first year. The cumulative implant failure rate in group 1, both after 1 and after 3 years, was 9.5%. No implant failure occurred in the control groups 2 and 3. The average marginal bone level measured at 1 and 3 years was 1.6 mm (SD = 0.8 mm) and 2.1 mm (SD = 0.2 mm), respectively, for group 1; 1.5 mm (SD = 1.3 mm) and 2.4 mm (SD = 0.6 mm), respectively, for group 2; 0.8 mm (SD = 1.4 mm) and 0.7 mm (SD = 0.9 mm), respectively, for group 3. Conclusions: The results of treatment using three regular platform Brånemark System implants supporting a fixed mandibular arch reconstruction were less favorable than the outcome that can be expected with a standard four‐ to six‐implant with one‐stage surgery.

This multicenter prospective study on the use of an implant system involved 9 centers and reports on the periodontal aspects after 3 years of observation. A total of 558 implants in 159 patients with 197 bridges all independent from natural teeth were originally included. Because of failures and patient withdrawals the number of implants was reduced to 460 and bridges to 174. The cumulative success rate for implants, starting from implant placement, is 94.3% after 2 years and 93.9% after 3 years indicating a leveling of implant loss. Failures concentrated in patients with a high plaque index. The loss of marginal bone was during the second and third years only 0.03 mm per year as an average while it was 0.4 mm during the first year. There were no reports of intense gingival inflammation in any of the patients and the plaque and gingivitis index behaved similarly around abutments and teeth. The probing pocket depth was significantly reduced over the observation time. The resistance towards marginal bone loss around these implants confirms the previous studies on fully edentulous patients.

Strain gauges were used to record in vivo and in vitro functional deformations in a fixed prosthetic appliance supported and retained by osseointegrated titanium implants. Four linear gauges were attached to each of totally 5 implant abutment cylinders and gauge signals were transferred into a computer via a digital converter. A computer program (ASYST) was used for collection, calibration and analysis of data obtained. Based on the results of a series of explorative in vitro tests, in vivo experiments were performed at maximum biting as well as during chewing on certain normally available food items. The results show fundamental differences between in vitro and in vivo testing conditions. Unexpectedly high bending of the implants was recorded in many of the in vivo loading situations.