1,721,085 research outputs found
Data on implant failures will show different results depending on how patients are compiled and analyzed: A retrospective study on 3902 individual patients treated either with one single implant or implants in the edentulous upper jaw
No full textPurpose The basic aim of the present study was to analyze the results of implant failures in two different implant populations, and how these results may vary depending on how the data are compiled and analyzed. Materials and Methods Two groups of consecutively treated patients were included who had been provided with either one single implant in a partially edentulous upper jaw (1881 patients) or four to eight implants in an edentulous upper jaw (2031 patients/12 454 implants). The risk of implant failure in the two groups separately and in combination was statistically compared by using uni- and multivariable analyses. Results The two groups showed significant differences in inclusion, surgical treatment protocols, and the risk of implant failures (P < .05). Overall, 25-year patient-level cumulative survival rates (CSRs) were 75.8% and 96.3% for edentulous and single implant treatment, respectively. "Dental condition" was the variable associated with the greatest risk of implant failure (HR 6.00; edentulous). Only one variable was significantly associated with the risk of implant failure in all tested groups ("time after surgery"; a decreased risk was observed over time), and more variables were statistically associated with implant failures in the edentulous group than in the single implant group. Conclusions Edentulous patients present a significantly and substantially higher risk of implant failures than patients provided with a single implant. When patients with different clinical conditions are pooled into the same group, patients with the most common condition in the total group have greatest impact on the result of the total group. Based on the present observations, risk patterns for a certain oral condition are not necessarily comparable with the implant treatment received by other patients, and the external validity may be limited in small, homogeneous groups of patients
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Implant treatment in elderly patients
No full textA group of 48 patients, all more than 80 years old (mean age 82.7 years) at first implant surgery, who received a total of 254 implants, were followed in one clinical center. Of the exposed implants, 6 of 238 (2.5%) were found to be loose at second-stage surgery, and another 3 implants were lost during the follow-up period. Most patients had minimal postplacement problems, similar to what has been observed in younger patients. However, some patients (10%) experienced obvious problems with general adaptation and muscle control, which has not been observed in younger patients
Regeneration of gingival papillae after single-implant treatment
No full textAn index to assess the size of the interproximal gingival papillae adjacent to single implant restorations was described and preliminary tested in a pilot study of retrospective material comprising 25 crowns in 21 patients. The result indicated a significant spontaneous regeneration of papillae (P < .001) after a mean follow-up period of 1.5 years. Based on these results, the general conclusion was made that the proposed index allows scientific assessment of soft tissue contour adjacent to single-implant restorations. The results also indicated that soft tissue changed in a systematic manner during the time period between insertion of the crowns and follow-up 1 to 3 years later
Failures and complications in 391 consecutively inserted fixed prostheses supported by Brånemark implants in edentulous jaws: a study of treatment from the time of prosthesis placement to the first annual checkup
No full textA total of 391 edentulous maxillae and mandibles was consecutively treated with routine fixed prostheses, supported by 2,199 implants. The patients were followed for 1 year; the overall success rate was 99.5% and 98.1% for the prostheses and implants, respectively. The number of severe complications was low, but it was possible to identify a significantly higher ratio of problems in the maxillae throughout the observation period than for the mandibles. While many problems occurred in both the maxillae and mandibles, there were also problems more typical for each jaw. Diction and fractures of resin teeth were more common problems in maxillae; cheek and lip biting was a more frequent postinsertion complication in the treatment of mandibles. Most problems were easily resolved, and the retrievability of the prostheses was of great advantage
Measurements of tooth movements in relation to single-implant restorations during 16 years: a case report
No full textBACKGROUND: Osseointegrated implants behave as ankylotic abutments, and their positions are not affected by dentofacial changes. PURPOSE: To measure changes in occlusion in relation to single implants in one patient after more than 15 years in function. MATERIALS AND METHODS: One 25-year-old female was treated with two single implants in the upper central incisor and bicuspid area after trauma. Study casts made prior to treatment (1987) and after 16 years in function (2004) were scanned by means of an optical scanner. Using the palate as the reference, the models were placed in the same coordinate system and analyzed and compared in a computer-aided design (CAD) program. The results of the measurements of the casts were also compared with clinical photographs taken at the time of treatment (1988), after 9 years (1997), and after 16 years (2004) in function. RESULTS: The clinical photographs showed obvious signs of implant infraposition after 9 years. New crowns were made in the incisor region after 15 years (2002), but signs of infraposition were again present at the final examination (2004). Measurements of the casts indicated small tooth movements with a pattern of slight eruption of upper teeth combined with a palatal inclination, mesial drift, and lingual inclination and crowding of the lower anterior teeth. The small measured vertical eruption of the teeth was less than the observed clinical infraposition of the implant crowns, indicating that the vertical position of the palatal may have changed in relation to the implants as well. CONCLUSION: Obvious dentofacial changes may take place in adult patients. Teeth may adjust for this, and no major problems may arise in the dentate patient. However, because the positions of implants are not affected by dentofacial changes, other patterns of clinical problems can be seen when implant patients present with these changes. The character and frequency of these dentofacial changes that may compromise implant treatment in the long term are not yet known
Implant Survival in the Edentulous Jaw-30 Years of Experience. Part I: A Retro-Prospective Multivariate Regression Analysis of Overall Implant Failure in 4,585 Consecutively Treated Arches
No full textPurpose: To report retro-prospective data on the prevalence of overall implant failure in a large number of edentulous patients treated at one referral clinic over a 30-year period and to analyze possible associations between implant failure and basic clinical variables Materials and Methods: Altogether, 24,781 implants were consecutively placed in 4,585 edentulous arches between 1986 and 2015. All implant failures identified at the clinic during follow-up were consecutively recorded, and a multivariate logistic regression analysis was performed to identify possible associations between implant failure and different clinical factors. Results: Altogether, 1,333, 688, and 249 treated arches were followed up for 15, 20, and 25 years, respectively. Cumulative survival rates (CSR) for the treated arches were 86.2% and 83.8% after 15 and 25 years, respectively. Most patients lost only one implant each (58%). Loss of all implants was reported in 68 arches, with total failure rates of 1.9% and 2.2% after 15 and 25 years, respectively. The strongest associations with increased risk for implant failure were maxilla (hazard ratio [HR] 4.76: 95% confidence interval [CI] 3.70 to 6.25) and implant surface (HR 2.38: 95% CI 1.59 to 3.57). Age at surgery, implant surgeon, calendar year of surgery, and time of follow-up also showed significant associations with risk of implant failure (P < .05). A completely steady-state level in implant survival was not observed, but few implants were lost up to the last years of follow-up. Conclusion: There is a higher risk for implant failure in the maxilla compared to the mandible. Risk is reduced when using implants with a moderately rough surface. The highest risk for failure was observed during the first year. This was followed by a reduced failure rate, which never reached a steady-state level
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Implant Survival in the Edentulous Jaw: 30 Years of Experience. Part II: A Retro-Prospective Multivariate Regression Analysis Related to Treated Arch and Implant Surface Roughness
No full textPurpose: To report retro-prospective, long-term data on the prevalence of implant failures related to maxillary and mandibular arches and to different implant surfaces in a large number of edentulous patients. Materials and Methods: Altogether, 3,493 and 1,092 edentulous arches were consecutively treated with implants with turned (1986-2002) or moderately rough (2003-2015) surfaces, respectively, during two time periods at one referral clinic. All implant failures were consecutively identified during routine follow-up, and a multivariate logistic regression analysis was performed to analyze implant failure related to arch and implant surface. Results: Overall cumulative survival rates (CSR) for arches treated with turned surface implants were 75.7% and 94.6% for the maxilla and mandible, respectively. The corresponding 10-year CSRs for arches treated with implants with a moderately rough surface were 91.9% and 96.1%, respectively. The strongest significant association (P < .05) with risk for implant failure was the maxilla, and this was more pronounced for implants with a turned surface. Age at surgery, implant surgeon, calendar year of surgery, and time of follow-up also had significant associations with risk of implant failure (P < .05). Conclusion: Risk for implant failure was significantly higher for treatment in the maxilla, but this risk was decreased significantly when using implants with a moderately rough surface. The impact of surface was not so obvious for treatment in the mandible. Risk for late implant failures after the first year was lower for implants with a moderately rough surface in the maxilla, but this risk seemed to be comparable for the different surfaces in the mandible
- …
