Prefabricated shouldered abutments enable successful restoration of molar crowns on implants.

PURPOSE: This retrospective study evaluated the effect of selected clinical and patient factors on survival, success, and peri-implant bone level changes of locking taper implants supporting molar crowns on Bicon's prefabricated shouldered abutments. METHODS: A total of 234 patients, who received 274 single molar crowns supported by locking taper implants were included in this retrospective study. Kaplan-Meier survival analysis was used to assess overall implant survival, prostheses survival, and success. Crowns were either monolithic (resin based) or bilayered (milled fiber-reinforced composite coping veneered with indirect composite). Early and late changes in marginal bone levels were plotted and analyzed with equivalence testing to compare the effects of different factors on crestal bone levels. RESULTS: At 9.5 years after implant surgery, the implant survival probability was 94.2%, the probability of prosthesis survival was 91.4%, and the probability of prosthetic success was 90.4%. Neither the use of different crown materials, nor the choice of monolithic versus bilayered crown construction, significantly affected the probability of prosthetic success. Marginal bone levels, on average, trended downwards towards the top of the implant within the first 2 years after functional loading, and remained stable on average, since then. Factors affecting bone levels included the use of nonsteroidal anti-inflammatory drugs, which precluded early implant bone loss; and subcrestal implant placement, which was linked to significantly higher long-term bone levels. CONCLUSION: The implant and abutment system studied resulted in high implant and prosthetic survival rates, regardless of prosthetic material used, with stable bone levels over time.

Fiber-reinforced composite full-arch prosthetic reconstructions supported by three standard, short or extra-short implants: a two-center retrospective study.

OBJECTIVES: To evaluate the survival of implants and prostheses, and marginal bone level of fiber-reinforced composite implant supported fixed complete prostheses supported by 3 implants. MATERIALS AND METHODS: Patients with fiber-reinforced composite fixed prostheses supported by 3 standard-length, short or extra-short implants were included in this retrospective cohort study. Kaplan-Meier survival was computed for implants and prostheses. Univariate and multivariate Cox proportional hazard regressions, clustered by patient, were used to analyze bone level differences as a function of different study covariates. Linear regressions were used to investigate the relationship between distal extension lengths and bone levels. RESULTS: Forty-five patients with 138 implants were followed for up to 10 years after prosthesis insertion (mean 52.8; SD 20.5 months). Kaplan-Meier survival analysis showed overall survival rates of 96.5% for implants and of 97.8% for prostheses. The 10-year success rate for prostheses was 90.8%. Extra-short implants survived at similar rates to short and standard implants. Marginal bone levels surrounding implants remained stable over time, even showing slight bone gain on average (mean + 0.1 mm/year; SD ± 0.5 mm/year) Acrylic denture teeth, overdentures on the opposing arch, and implant placement in the posterior maxilla were correlated with bone gain. Screw retention, opposed to telescopic retention, was correlated with bone loss. Longer distal extensions were correlated with bone gain on the implants closest to the distal extensions. CONCLUSIONS: Fiber-reinforced composite fixed prostheses supported by only 3 implants, most of which were extra-short, presented high survival rates with stable bone levels. CLINICAL RELEVANCE: An encouraging prognosis can be expected for restoration of atrophic maxillary and mandibular arches, when restored with fixed fiber-reinforced composite frameworks with long distal extensions and supported on only 3 short implants.

Fiber-reinforced composite partial fixed dental prostheses supported by short or extra-short implants: A 10 year retrospective study.

INTRODUCTION: This study evaluated the 10-year survival and success of partial fixed dental prostheses (P-FDPs) fabricated with a milled fiber-reinforced composite (FRC) framework, supported by short or extra-short implants. METHODS: Patients restored with FRC P-FDPs supported by short or extra-short implants were included in this retrospective study. Kaplan-Meier analysis was used to calculate the survival and success rates of the prostheses. Univariate and multivariate Cox regression models, clustered to adjust for multiple implants and prostheses being placed in the same patient, were used to correlate changes in peri-implant bone levels with patient, implant, and prosthesis-related covariates. RESULTS: This study followed 121 FRC P-FDPs supported by 261 implants, placed in 96 patients. At 118 months in function, the P-FDP survival rate was 95.9% (95% CI: 87.5%-98.7%), and the success rate was 89.8% (95%CI: 80.4%-94.8%). Differences in prosthesis span length, abutment/pontic ratio, and the presence of distal extensions (cantilevers) did not affect the prosthetic outcomes. Bone levels around implants were stable, with an average rate of change of -0.01 ± 0.05 mm/month. Cox regression revealed that grafted sites were correlated with peri-implant bone loss, while longer prosthetic spans were correlated with bone gain. CONCLUSION: P-FDPs comprised of milled fiber-reinforced composite frameworks, supported by short and extra-short implants, had high survival and success rates for up to 10 years.

Antiresorptive therapy and dental implant survival: an up to 20-year retrospective cohort study in women.

OBJECTIVES: To investigate the effects of antiresorptive treatment on the survival of plateau-root form dental implants. MATERIALS AND METHODS: Patients undergoing antiresorptive therapy via oral or intravenous administration as well as patients not undergoing antiresorptive therapy and healthy control patients were included in this retrospective cohort study. In total, 1472 implants placed in 631 postmenopausal patients (M: 66.42 ± 9.10 years old), who were followed for a period of up to 20 years (8.78 ± 5.68 years). Kaplan-Meier survival analysis was performed, and univariate and multivariate Cox regression, clustered by each patient, was used to evaluate and study factors affecting the survival of their implants. RESULTS: Implants placed in patients undergoing oral antiresorptive treatment presented significantly higher survival rates, than implants placed in the osteoporosis/osteopenia control cohort (p value < 0.001), and similar survival rates, when compared to healthy controls (p value = 0.03). Additionally, clustered univariate and multivariate Cox regression analysis also revealed higher implant survival when oral antiresorptive drugs (p value = 0.01 and 0.007, respectively) were used, and lower implant survival in the presence of untreated osteoporosis/osteopenia (p value = 0.002 and 0.005, respectively). Overall, the 20-year implant survival in osteoporotic patients undergoing antiresorptive therapy was 94%. For the failed implants, newly replaced implants in patients under antiresorptive treatment presented a 10-year survival of 89%. CONCLUSIONS: Long-term plateau-root form implant survival in osteoporotic patients taking oral antiresorptives was similar to a healthy population and significantly higher than the untreated controls. CLINICAL RELEVANCE: These results suggest that plateau-root form implants provide a robust solution for treating tooth loss in patients, who are undergoing antiresorptive therapy.

Implants Placed in Adolescents Followed for Up to 15.5 Years: A Retrospective Case Series.

PURPOSE: To evaluate the clinical outcomes of unsplinted implant-supported single crowns placed in adolescents, ages 10 to 19 years, and followed up from 5 to 15 years. MATERIALS AND METHODS: This retrospective case series evaluated the outcomes of implant-supported single crowns placed in adolescents between June 2002 and January 2015. The patients were treated with locking-taper connection implants under a two-stage rehabilitation technique. The variables assessed included patient identification, age and reason for implant placement, implant dimensions, follow-up time, status at follow-up, and event description. To analyze peri-implant changes, bone crest level relative to the adjacent tooth was measured from periapical radiographs taken after implantation and the latest follow-up. A paired t test was performed to determine initial and follow-up differences, and data are shown as mean and 95% confidence interval. Cumulative Kaplan-Meier survival rates for implants and prostheses were calculated. RESULTS: Twenty-one adolescent patients with ages ranging from 14 to 19 years, mainly 16 to 18 years, received a total of 37 implant-supported single crowns more frequently placed in the anterior maxilla as a result of congenital aplasia and trauma. Mean changes in bone crests were 1.99 (± 0.4) mm at the day of crown insertion and 2.23 (± 0.4) mm at the latest follow-up (average: 10 years; P = .08). No implant was lost during the follow-up period, leading to 100% implant survival. A total of 34 surviving crowns and 3 crown failures at the time of the latest follow-up led to a cumulative survival rate of 70%. The most commonly observed event was loss of proximal contacts and infraocclusion, which were handled chairside by adding resin composite. CONCLUSION: Unsplinted implant-supported single crowns placed in adolescents showed high implant and prosthesis survival rates, with a mean bone crest level increase of approximately 0.23 mm relative to the adjacent teeth.

Draining orocutaneous fistula associated with a failing subperiosteal implant: report of a case.

The use of mandibular subperiosteal implants was first reported by Dahl in the 1940s. It was followed by a more comprehensive report by Goldberg and Gershkoff, who published the first case series in the United States. We describe a case of an orocutaneous fistula that developed secondary to a chronic infection attributed to a failing subperiosteal implant. Elemental analysis of the metal framework revealed an implant composed of mainly a cobalt-chromium alloy. Cobalt, which was frequently used in subperiosteal implant manufacturing, is associated with a higher corrosion rate than other metals and is no longer used to fabricate subperiosteal implants. The strength of subperiosteal implants is their ability to be used in a mandible with an atrophic alveolar ridge. Unfortunately, this feature of the hardware is also its weakness in that reconstructive procedures after their removal are difficult. The failing subperiosteal implant in our patient was subsequently removed, and primary closure of the intraoral wound and extraoral fistula as well as resolution of the patient's symptoms was obtained with no lasting complications.

Extraction, immediate-load implants, impressions and final restorations in two patient visits.

BACKGROUND: Since the advent of immediately loaded implants, patients have experienced shorter treatment times, reduced amount of surgical therapy, preserved gingival esthetics and the comfort and security of fixed prostheses. Practitioners have experienced less expense in the form of chair time and greater patient satisfaction. CASE DESCRIPTION: The authors present two cases in which, at the first clinical visit, they extracted maxillary incisors, placed hydroxyapatite-coated implants, took impressions for final restorations and stabilized the implants immediately with a fixed interim prosthesis. At the second clinical visit, the authors placed the final restorations. All of the implants were integrated clinically, and gingival esthetics appeared to have benefited from preservation of papillary form, which was made possible with fixed interim anterior restorations. The patients expressed satisfaction with the results particularly because the treatment was accomplished in two clinical visits. CLINICAL IMPLICATIONS: The cases presented demonstrate a technique that may be of value to therapists who place immediate-load implants. The long-term effectiveness of immediate-load implants requires further evidence to ensure their long-term usefulness and safety.