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A proposed protocol and differentiated success criteria for long-term evaluation of oral implants are presented. The protocol and criteria were applied to a retrospective patient material treated during a 1-year period and followed for 5 years. The protocol comprised a two-stage analysis of the collected clinical data. First, a quantitative analysis of the outcome was made using a life table. Based on the information obtained during the follow-up, each implant was categorized into one of three groups: unaccounted for, failure, or survival. A qualitative analysis of the survival group was then performed by active testing against defined criteria. Depending on the modes of clinical and radiographic examinations and their results, surviving implants were either further assigned to one of three success grades or remained in the survival group. The data are presented in a four-field table at one level of success. Strict success criteria together with individual stability testing and radiographic examination of each consecutive implant should be used when a new implant system is evaluated or when a new application is explored. Radiography alone and more moderate success criteria may be used to document routine treatments, provided that an already well-documented implant system is studied. [ABSTRACT FROM AUTHOR]

The positive predictive value of radiographic identification of unstable Brånemark implants was evaluated. Based on approximately 2,000 patients with implants followed during a 3-year period, a total of 84 patients were radiographically detected to have suspected failing implants. A total of 481 implants had been placed in these patients, but because of the study design and some patient dropouts, the evaluation was carried out in only 79 of the identified patients, who had 413 implants. Calculations were performed based on the number of occasions the implants were examined (n = 482) because some patients were assessed on more than one occasion. Results indicated a high positive predictive value (83%) to radiographically identify failing implants, and only 5% were clinically found to be failing without having been detected radiographically. In nine jaws (11%), the fixed prosthetic restorations were unnecessarily detached because of inaccurate radiographic diagnosis. The study indicated that radiographic identification of unstable implants is reliable when performed as part of annual examinations and when examining patients on a long-term routine basis. The timing for these assessments should be annual during the first 3 years of follow up for the unexperienced clinician and may thereafter be individualized with more clinical experience. [ABSTRACT FROM AUTHOR]

Image quality in preimplant computerized tomography (CT) examinations made with different radiation doses (40 to 280 mAs) and scanning modes (standard and helical axial, 15-degree angled, and frontal) and in conventional spiral tomography (Scanora) was compared. Mandibular canal and alveolar bone crest visibility was evaluated in images from mandibular jaw segments. Visibility was unaffected by radiation dose in CT examinations except in frontal scanning, where a small actual difference was statistically significant. Differences among CT scanning modes and between CT and conventional spiral tomography were highly significant. Low-dose mandibular preimplant tomography can be performed with CT using lower-than-normal radiation doses or with conventional spiral tomography. [ABSTRACT FROM AUTHOR]

A new self-tapping Brånemark implant designed for denser bone qualities was evaluated with regard to insertion technique, complications, marginal bone remodeling, and survival rate. Thirty patients, representing 21 mandibles and 9 maxillae, participated in the study. In each patient both standard and self-tapping implants were placed, and a total of 179 implants, 88 self-tapping and 91 standard, were inserted. Thirteen of 62 mandibular self-tapping implants reached their correct positions only after using the screw tap or the cylinder wrench for manual insertion. No such problems were noted when using standard fixtures after bone pre-tapping. In the maxillae, neither of the two implant designs presented any problems. One standard and one self-tapping fixture failed to osseointegrate. Radiolucencies were seen in the bone around the apical portion of two fixtures, one of each design. The mean marginal bone resorption after 1 year of follow-up was 0.5 to 0.6 mm for the two fixture types. [ABSTRACT FROM AUTHOR]

A surgical technique for rehabilitation of severely resorbed edentulous maxillae using fixed prostheses or overdentures supported by osseointegrated fixtures in immediate autogenous corticocancellous bone grafts from the ilium is described. The results of the first 23 consecutively treated patients are reviewed. The mean observation time was 4.2 years (range 1 to 10 years). A total of 124 fixtures was originally placed into the grafts, supplemented with 16 fixtures inserted later into seven of the jaws. Throughout their observation period, 17 of the patients had continuously stable prostheses. The remaining five had overdentures, and one patient had resorted to a conventional complete denture. After 4 years, 12 of 16 patients had continuously stable prostheses. Corresponding values at 5 years were 7 of 8 patients. Calculated from the date of abutment connection, 82. 1% and 81.6% of the original fixtures were clinically stable and radiographically osseointegrated after 4 and 5 years in function, respectively. From the date of fixture placement, the corresponding figures were 75.3% and 73.8%, respectively. The mean marginal bone loss after the first year of prothesis function was 1.49 mm. The annual marginal bone loss thereafter was about 0.1 mm. The results indicate that this technique is worthwhile for patients with extreme maxillary atrophy and who cannot wear conventional complete dentures. [ABSTRACT FROM AUTHOR]

Fransson C, Tomasi C, Sundén Pikner S, Gröndahl K, Wennström JL, Leyland AH, Berglundh T. Severity and pattern of peri-implantitis-associated bone loss. J Clin Periodontol 2010; 37: 442–448. doi: 10.1111/j.1600-051X.2010.01537.x. Objective: The purpose of the present study was to describe the severity and pattern of peri-implantitis-associated bone loss. Material and Methods: Intra-oral radiographs from 182 subjects were analysed. Bone-level measurements were performed in 419 implants with a history of bone loss. All radiographs obtained in the interval from the 1-year follow-up to the end-point examination (5–23 years) were analysed. The amount of bone loss that occurred from 1 year after prosthesis insertion was assessed and the pattern of bone loss was evaluated. Results: The average bone loss after the first year of function was 1.68 mm and 32% of the implants demonstrated bone loss ⩾2 mm. The multilevel model revealed that the bone loss showed a non-linear pattern and that the rate of bone loss increased over time. The model also revealed that the pattern of peri-implantitis associated bone loss was similar within the same subject. Conclusion: It is suggested that peri-implantitis-associated bone loss varies between subjects and is, in most cases, characterized by a non-linear progression, with the rate of loss increasing over time. [ABSTRACT FROM AUTHOR]

Background: Fixture placement in the tuber area is one way to overcome the problem of insufficient bone volume for routine implant surgery in the posterior maxilla due to severe resorption of jawbone and an extensive enlargement of the maxillary sinus. However, little is known about the long-term results. Purpose: The aim of this study was to retrospectively evaluate the survival rate and marginal bone conditions at fixtures placed in the tuber region of the maxilla. Material and methods: Twenty-one patients previously treated with at least one implant in the tuber region of the maxilla were included in this retrospective analysis. A total of 23 standard Brånemark System fixtures with a turned surface had been surgically placed in the tuber regions and 71 additional implants in adjacent areas to support fixed dental bridges. All implants were allowed to heal for 6–8 months before abutment connection and following prosthetic treatment. The patients were radiographed after 1–12 years for evaluation of marginal bone levels. In addition, the relation between the apex of the fixture in the tuberosity area and the posterior border of the maxilla was measured. Results: Twenty of the 21 patients representing 22 tuber and 64 additional implants were radiographically evaluated. No implants in the tuber areas were lost during the follow-up whereas two fixtures in the anterior region had to be removed, one before loading and the other after 4 years of loading not interfering with the prosthesis stability. The mean marginal bone level at tuber implants was situated on average 1.6 mm (SD 1.1, n=22) from the abutment-fixture junction, whilst the other implants showed an average bone level of 1.9 mm (SD 0.8, n=64). The results were similar when comparing partially and totally edentulous patients. Conclusion: The present retrospective study shows good clinical outcome with standard Brånemark fixtures placed in the tuber region of the posterior maxilla using a two-stage procedure. In appropriate cases where bone of adequate volume and density is available, our data indicate that the technique can be used as an alternative to more extensive surgery and especially to the sinus lift procedure. However, prospective comparative studies are needed in order to evaluate the efficacy of the described technique for this purpose. [ABSTRACT FROM AUTHOR]

Background: Most long-term follow-up studies of implants in partially edentulous jaws present their outcomes as mean values of implant survival and follow-up time, and few address the fate of the remaining teeth. Purpose: The aim of this study was to investigate the results of oral implant treatment in partially edentulous jaws after 20 years, and simultaneously to assess what happens to teeth present at the time of implant placement. Materials and Methods: Seventeen partially edentulous patients, of 27 originally treated individuals, were retrospectively reviewed after receiving implants from 1983 to 1985. The parameters studied were implant survival, prosthesis stability, marginal bone loss at teeth and implants, treatment complications, need for dental treatment, and patient’s satisfaction with the outcome. Results: The cumulative survival rate was 91%, when all 27 patients were assessed, that is, including the 10 dropouts. Of the 69 inserted and followed implants (Brånemark system®; Nobel Biocare AB, Göteborg, Sweden), six failed (8.7%) during the 20-year period, four during the first decade, and the remaining two during the second. A majority ( n=4) of the losses were due to implant fractures, two after 8 years, and two after 17 years. In all, 10 of the original fixed bridges being followed ( n=24) remained in function during the entire investigation period, whereas 12 were exchanged for new constructions after an average of 7 years. The mean marginal bone loss at teeth was 0.7 mm, and at implants it was 1.0 mm. The major complication observed during the second decade was veneer material fractures, which occurred 14 times in six patients. Component loosening and abutment- and bridge-locking screw fractures were the second most common problems seen, indicating material/component fatigue. Most patients were satisfied with their treatment and many mentioned that they did not think of the constructions as anything but a part of their own body. Conclusion: Over the decades, treatment of partially edentulous jaws with turned titanium implants seems to function well and to provide patients with good support for fixed short-span bridge constructions. [ABSTRACT FROM AUTHOR]

Wennström JL, Ekestubbe A, Gröndahl K, Karlsson S, Lindhe J. Implant-supported single-tooth restorations: a 5-year prospective study. J Clin Periodontol 2005; doi: 10.1111/j.1600-051X.2005.00715.x.© Blackwell Munksgaard, 2005.Comparatively few studies are available reporting at least 5 years of follow-up data of implant-supported single-tooth replacements.To evaluate prospectively the 5-year outcome of implant-supported single-tooth prosthetic restorations.Forty subjects (mean age 41 years), 23 males and 17 females, who required single-tooth prosthetic replacement for a missing tooth were recruited. A total of 45 self-tapping implants (Astra Tech® ST-implants)– 40 in the maxilla and five in the mandible– were installed in a two-stage procedure. Abutment connection was performed 3–6 months after implant installation. Clinical and radiographic examinations were performed at the completion of the prosthetic treatment and once a year during a 5-year follow-up period. The analysis of peri-implant bone level alteration was performed on subject and implant levels and by the use of analysis of variance and binary logistic regression.Three patients were lost during the 5 years of follow-up. One implant was lost after 2.5 years in function and another four implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 2.6% (subject level) and 2.3% (implant level). The mean loss of marginal bone at the implants during the first year in function was 0.06 mm (SD 0.67) on the subject level and 0.02 mm (0.65) on the implant level. During the subsequent 4 years the annual change in peri-implant bone level amounted to−0.02 mm (0.22) on both subject and implant levels. Thus, the mean total bone level change over the 5-year interval was−0.14 mm (1.04) on subject level and−0.11 mm (1.00) on the implant level of analysis (p>0.05). The frequency of implants with a 5-year bone loss of⩾1 mm was 13%. Approximately 50% of the implants demonstrated no bone loss.The present clinical trial on single-tooth replacements with the Astra Tech® implant system demonstrated that the bone loss during the first year of function as well as annually thereafter was small. [ABSTRACT FROM AUTHOR]

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Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)