Prosthetic Survival Rate Research Articles

Monolithic Lithium Disilicate Full-Contour Crowns Bonded on CAD/CAM Zirconia Complete-Arch Implant Bridges With 3 to 5 Years of Follow-Up

This study was carried on to assess the clinical performance of a novel restorative concept consisting in single monolithic lithium disilicate full-contour crowns bonded on computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia complete-arch implant bridges, to overcome the drawbacks related to the chipping of porcelain fused to zirconia restorations. Sixteen patients received 18 implant-supported hybrid screw-cement-retained complete-arch restorations, consisting of single monolithic lithium disilicate full-contour crowns bonded on CAD/CAM zirconia frameworks. The restorations were supported by 4-8 implants. All patients were followed up for at least 3 years on function (range 36 to 60 months, mean 49.3 months). Clinical controls were scheduled every 4 months. The outcomes were implant and prosthetic survival and success rates, any complications, patient satisfaction, and soft tissue parameters. No dropouts occurred. The overall implant and prosthesis survival rates were 100%. One of 18 restorations (1 of 236 dental units) showed a chip-off fracture of the veneering ceramic that was polished intraorally without any additional treatment, scoring a cumulative prosthetic success rate of 100%, according to the California Dental Association index. All patients were functionally and esthetically highly satisfied with their restorations. Successful soft tissue parameters were found around all implants. Single monolithic lithium disilicate full-contour crowns, bonded on CAD/CAM screw-retained complete-arch zirconia frameworks, showed favorable preliminary outcomes with medium-term follow-up. However, randomized controlled studies of this technique are required for further conclusive recommendations.

Clinical outcomes of Kyocera Modular Limb Salvage system after resection of bone sarcoma of the distal part of the femur: the Japanese Musculoskeletal Oncology Group study

The Japanese Musculoskeletal Oncology Group have developed an original prosthesis called the Kyocera Modular Limb Salvage system (KMLS system). This prosthesis has a semi-rotating hinge joint and is particularly designed for people with an Asian body type. The metallic parts of the prosthesis are made entirely of titanium alloy. The purpose of this study is to evaluate the clinical outcomes of treatment using this system following tumour resection of primary bone sarcoma of the distal femur. Between 2002 and 2010, 82 patients with primary bone sarcomas of the distal femur were treated. Seventeen patients underwent stem cementation, while 65 patients were treated with cementless prostheses. The mean follow-up period after surgery was 61 months. Complications were observed in 28 of the 82 patients. Forty-one complications occurred in these 28 patients. Thirteen prostheses (16%) required revision surgery due to complications, including five cases of stem breakage, three deep infections, three cases of aseptic loosening, one case of displacement of the shaft cap and one case of breakage of the tibial tray. The five-year overall prosthetic survival rate was 80.0%. Four of the 82 patients underwent subsequent amputation due to local recurrence. The five-year limb salvage rate was 94.5%. The mean function score according to the scoring system of the Musculoskeletal Tumour Society was 21.8 points (72.5%). Although further follow-up is required to determine the performance, this prosthesis is considered to be satisfactory for reconstruction of the distal femur after resection of bone sarcoma.

Influence of Hospital Volume on Revision Rate After Total Knee Arthroplasty with Cement

The number of total knee replacements has substantially increased worldwide over the past ten years. Several studies have indicated a correlation between high hospital procedure volume and decreased morbidity and mortality following total knee arthroplasty. The purpose of the present study was to evaluate whether there is a correlation between procedure volume and the risk of revision following total knee arthroplasty with use of hospital volume data from the Norwegian Arthroplasty Register. Thirty-seven thousand, three hundred and eighty-one total knee arthroplasties that were reported to the Norwegian Arthroplasty Register from 1994 to 2010 were used to examine the annual procedure volume per hospital. Hospital volume was divided into five categories according to the number of procedures performed annually: one to twenty-four (low volume), twenty-five to forty-nine (medium volume), fifty to ninety-nine (medium volume), 100 to 149 (high volume), and ≥150 (high volume). Cox regression (adjusted for age, sex, and diagnosis) was used to estimate the proportion of procedures without revision and the risk ratio (RR) of revision. Analyses were also performed for two commonly used prosthesis brands combined. The rate of prosthetic survival at ten years was 92.5% (95% confidence interval, 91.5 to 93.4) for hospitals with an annual volume of one to twenty-four procedures and 95.5% (95% confidence interval, 94.1 to 97.0) for hospitals with an annual volume of ≥150 procedures. We found a significantly lower risk of revision for hospitals with an annual volume of 100 to 149 procedures (relative risk = 0.73 [95% confidence interval, 0.56 to 0.96], p = 0.03) and ≥150 procedures (relative risk = 0.73 [95% confidence interval, 0.54 to 1.00], p = 0.05) compared with hospitals with an annual volume of one to twenty-four procedures. Similar results were found when we analyzed two commonly used prosthesis brands. In the present study, there was a significantly higher rate of revision knee arthroplasties at low-volume hospitals as compared with high-volume hospitals.

Clinical Reliability of CAD/CAM Cross‐Arch Zirconia Bridges on Immediately Loaded Implants Placed with Computer‐Assisted/Template‐Guided Surgery: A Retrospective Study with a Follow‐Up between 3 and 5 Years

The purpose of this study is to retrospectively evaluate the implant and prosthetic survival and success rates of zirconia-based, implant-supported, screw-retained, cross-arch restorations up to 5 years after placement. Twenty-two consecutive edentulous patients (11 males and females, each; mean age 68.3 years) received 26 CAD/CAM cross-arch zirconia implant bridges (NobelProcera™ Implant Bridge Zirconia; Nobel Biocare AG, Zurich, Switzerland) supported by 4 to 10 implants each. All patients were followed for at least 3 years (range 36-60 months, mean 42.3 months). Clinical assessments were scheduled every 4 months during hygiene maintenance. Outcomes were implant and prosthetic survival rates, prosthetic success rate, any observed clinical complications, patient satisfaction, and soft tissue parameters. Fisher's exact test was used to assess associations between categorical variables. No dropouts occurred. The overall implant and prostheses survival rate up to 5 years was 100%. Three out of 26 restorations (five out of three hundred forty eight dental units) showed an adhesive chip-off fracture of the veneering ceramic, scoring a cumulative prosthetic success rate of 88.5% at the prosthetic level and 98.6% at the unit level. All 22 patients were functionally and aesthetically highly satisfied with their restorations. Successful soft tissue parameters were found around all implants. Industrially manufactured, zirconia-based, implant-supported, screw-retained, cross-arch restorations are a viable alternative to conventionally manufactured porcelain-fused-to-metal restorations for rehabilitating the edentulous patient.

Double Crown-Retained Maxillary Overdentures: 5-Year Follow-Up

There is a lack of data concerning implant-supported overdentures (IODs) retained by double crowns in the edentulous maxilla. To perform a retrospective evaluation of clinical outcomes (survival/success rates) of maxillary overdentures retained on four implants via double crowns. Between 1993 and 2011, 28 patients with edentulous maxillae were restored with overdentures supported by four implants with a Morse taper connection (Ankylos, Dentsply Friadent, Mannheim, Germany) and double crowns according to the Marburg Double Crown (MDC) technique in a private practice. For retrospective evaluation of implant and prosthetic survival (in situ criterion) and success (event-free observational period), only patients attending a professional maintenance program were included (n = 20). Twenty patients (13 female/ seven male, mean age: 63.45 ± 7.18 years) with 80 implants met the inclusion criteria. The mean follow-up period was 5.64 ± 3.50 years. One implant was lost (cumulative survival rate: 98.75%). Eight implants (10.1%) in two patients (10%) showed peri-implantitis; both patients were active smokers (cumulative success rate: 88.75%). All dentures were still functional (prosthetic survival rate 100%) at the time of investigation. Technical maintenance procedures (e.g., abutment loosening, screw loosening, acrylic fracture or relining) were required at a rate of 0.222/patient-year. Within the limitations of this study, we conclude that MDC-IODs are a promising treatment alternative for edentulous maxillae offering high implant and prosthesis survival rates > 98% and a limited incidence of biological and technical complications after a mean observational period of >5 years.

Conometric retention for complete fixed prosthesis supported by four implants: 2‐years prospective study

The aim of this study was to verify the reliability of a conometric system for a fixed retention of complete prostheses (CPs) on four implants followed for 2 years. Twenty-five patients received four implants and only one CPs for a total of 100 implants followed. Each prosthesis was supported by four implants. An immediate loading surgical protocol was used. The CPs were provided to be fixed to conometric abutments without prostheses removal by the patients, to test this retention for a fixed instead of a removable rehabilitation. Clinical and radiographical parameters were assessed at the yearly follow-up visit. A follow-up of 2 years was observed for each patient. Moreover, biological and technical complications were recorded. Changes overtime of clinical and radiographic parameters were analyzed as well as the satisfaction degree for each patient. No patient was classified as "dropout." The following results were observed after 2 years of follow-up: all the implants supporting the 25 CPs completed the follow-up examination. No implant, reconstruction, and abutment failure were recorded; therefore, the prosthetic survival was 100% for all the abutments and restorations. No significant differences in biological indexes were observed when compared with the baseline. No significant change of the mean marginal bone level (MBL) was found between the baseline and the last follow-up. No loss of retention was recorded for the CPs. No technical complications referred to abutments and frameworks were observed: a prosthetic survival rate of 100% can be recorded. Mucositis was recorded for two implants and successfully treated with interceptive supportive therapy. No significant differences (P < 0.05) were found between plaque index and MBi parameters at baseline and after 2 years of function. Similar results were recorded for the mean probing pocket depth Index at baseline (1.2 mm with SD of 0.3 mm) and after 2 years of function (1.2 mm with SD of 0.2 mm). The present implant-supported conometric retention system can be used to give a fixed retention to a CPs supported by four implants immediately loaded. Furthermore, costs reduction and simplified treatment procedures were provided by such a clinical approach.

A New Approach to the All-on-Four Treatment Concept Using Narrow Platform NobelActive Implants

Although a number of approaches to implant-supported restoration of severely atrophic maxillae and mandibles have been developed, most of these treatments are costly and protracted. An exception is the All-on-Four concept, which uses only 4 implants to support an acrylic, screw-retained provisional prosthesis delivered on the day of implant placement, followed by a definitive prosthesis approximately 4 months later. After the introduction of a new implant design in 2008, a new protocol was developed for provisionally treating patients with severely atrophic jaws using the All-on-Four concept and 3.5-mm-diameter implants. This article describes that protocol and reports on the results of 227 implants after 1 to 3 years of follow-up. The cumulative survival rate was 98.7% at the end of 3 years, with a 100% prosthetic survival rate. Combining the 3.5-mm-diameter NobelActive implants with the All-on-Four concept promises to become a new standard of care for severely compromised patients.

Long-term Outcome of One-Piece Implants. Part II: Prosthetic Outcomes. A Systematic Literature Review with Meta-Analysis

To evaluate the long-term clinical performance of prosthetic reconstructions on one-piece implants, with a focus on technical and biological complications. An electronic MEDLINE search complemented by a manual search was conducted to identify randomized and prospective controlled clinical trials on one-piece implants. Additional inclusion criteria were a mean follow-up period of at least 5 years and an inception cohort where more than 80% of the enrolled patients remained in the study at the 5- or 10-year observation point. Sixty-six studies from an initial yield of 597 titles were selected, and the data were extracted. Of the full-text articles examined, 46 were excluded and a total of 20 articles were finally selected. All studies were published between 1995 and 2011. Two different study designs were identified: 4 randomized controlled trials and 16 prospective cohort studies. The studies were analyzed and classified according to study type, patient characteristics, prosthetic characteristics, and biologic and technical complications after 5 and 10 years. The meta-analysis of the included studies showed a prosthetic survival rate for one-piece, one-part implants of 82.81% after 5 years and 97.85% and 98.24% in two-part implants after 5 and 10 years, respectively. Although the prosthetic survival rates were high, complications were frequent: complications of the suprastructure (18.44% to 18.75%), screw loosening/fracture (7.64%), soft-tissue complications (4.69% to 8.25%), sensory disturbances (0.36% to 6.25%), implant loss before loading (0% to 0.23%) and during function (1.10% to 3.21%), and implant fracture (0.0004%). Within the limits of this systematic review, it can be concluded that despite high long-term prosthetic survival rates, technical and biologic complications are frequent in one-piece implants, both in one-part and two-part designs. Further randomized clinical trials are needed to provide more information about the outcome of different variables associated with this type of implant design.

Minimally invasive treatment of the atrophic posterior maxilla: A proof-of-concept prospective study with a follow-up of between 36 and 54 months

In the posterior maxilla, tooth loss is usually associated with alveolar bone resorption and sinus pneumatization, limiting the placement of implants without grafting procedures. The purpose of this study was to evaluate a minimally invasive treatment of the atrophic posterior maxilla, with axial and tilted implants and immediate loading. The research hypothesis was that the combination of a guided, minimally invasive approach and the biomimetic features of computer-aided design and computer-aided manufacturing (CAD/CAM) abutments would be an effective alternative to maxillary sinus floor augmentation procedures with reduced bone resorption around implants. Twenty-seven consecutive participants (female=12, male=15) (mean age 54.18 years) with severe atrophy of the posterior maxilla were treated by using guided surgery with immediately loaded axial (39) and tilted (42) implants supporting CAD/CAM zirconia (39) and titanium (42) abutments (81 total) and partial fixed prostheses. Each participant underwent a computed tomography scan, after which 2 or 3 implants were positioned with a flapless or miniflap approach. The drilling protocol was adapted to the bone density of each implant site to obtain an insertion torque ranging between 40 and 50 Ncm. CAD/CAM customized abutments composed of zirconia or titanium were fixed to the implants with prosthetic screws tightened with a torque of 35 Ncm. An acrylic resin interim restoration reinforced with metal was placed immediately. Five to 6 months after initial loading, a zirconia framework was manufactured, and a definitive prosthesis was placed. Clinical and radiological controls were performed at baseline and after 1 and 3 years to assess implant and prosthesis survival and success rate and compare marginal bone remodeling of axial and tilted implants. Inferential statistics for radiological data were acquired by using the Mann-Whitney U-test. All statistical comparisons were conducted at the .05 significance level. The mean follow-up period was 43.3 months (ranging from 36 months to 54 months). The cumulative implant survival rate was 96.3% at 3 years. All prosthetic restorations were stable and in good function, resulting in a cumulative prosthetic survival rate of 100%. Three restorations had chipping of the veneer material; thereafter, the cumulative prosthetic success rate was 91.9%. Treatment of the posterior partially edentulous atrophic maxilla with guided surgery and immediate loading of tilted and straight implants supporting short-span partial fixed dental prostheses is effective.

What is the optimal number of implants for fixed reconstructions: a systematic review

To assess the 5-year and 10-year survival and complication rates of implant-supported fixed reconstructions in partially and totally edentulous patients with regard to the optimal number and distribution of dental implants. This review was designed as a systematic review of the literature. A search strategy was developed and executed using an electronic and selective hand search for English-language articles in Dental Journals limited to human clinical trials. Search terms were grouped into categories for "problem" - "intervention" - "outcome". For articles retrieved by this search, abstracts were screened by two reviewers based on the inclusion criteria. Selected articles were then obtained in full texts. Finally, the selection based on inclusion/exclusion criteria was repeated for the full-text articles. Of the 210 titles retrieved by the search, 51 were selected for full-text review based on the information given in the abstract. From the full-text articles, a total of nine studies were included for this systematic review. In meta-analysis, prosthetic survival rates over 5 and 10 years for partial Fixed Dental Prostheses (FDPs) on two to four implants were estimated as 98.9% (95% CI: 98.5-99.2%) and as 97.8% (95% CI: 96.9-98.4%) respectively. A survival rate for maxillary Full-Arch Fixed Dental Prostheses (FAFDPs) on four to six implants after 5 years was assessed as 97.5% (95% CI: 94.1-98.9%) and a survival rate after 10 years as 95.0% (95% CI: 88.5-97.9%). The result for the survival rates in case of mandibular FAFDPs on four to six implants after 5 years was 97.9% (95% CI: 96.3-98.8%) and after 10 years 95.9% (95% CI: 92.8-97.7%). Specific implant-to-replaced-unit-ratios were not available in any of the studies. For implant-supported FAFDPs, using 4-6 implants is a well-documented treatment option with high estimated 5-year survival of the construction. It is unclear whether three implants for supporting a FAFDP will achieve similar survival rates. The RCTs needed that report implant-to-replaced-units-ratios for partial FDPs and include 3 vs. 4-6 implants for supporting a FAFDP in the mandible.

Prosthetic limb salvage surgery for bone and soft tissue tumors around the knee

In this study, we analyzed long-term survival, limb function and associated complications after prosthetic limb salvage treatment in patients with bone and soft tissue tumors around the knee joint. A total of 63 patients treated with prosthetic limb salvage surgery around the knee were reviewed. The bone tumors involved the distal femur in 45 patients, the proximal tibia in 14 patients and the soft tissue tumors of the proximal lower leg in 4 patients. The median follow-up period after the first operation was 8.0years. The medical records of the patients, surgical reports, radiographs and histological specimens were retrospectively reviewed. The 5-year overall survival rate was 63.2% in the patients with distal femur tumors and 86.2% in those with tumors of the proximal lower leg. The 5‑year prosthetic survival rate was 72.8% in the distal femur and 74.6% in the proximal lower leg. The mean functional score according to the scoring system of the Musculoskeletal Tumor Society (MSTS) was 81% in the patients with distal femur tumors and 82% in the patients with proximal lower leg tumors. Post-operative complications occurred in 27 patients. Limb salvage surgery is considered to be an effective treatment option. However, the high complication rate is a major concern for prosthetic replacement. Future improvements of prostheses are very important.

Long‐term results of implant‐supported over‐dentures retained by double crowns: a practice‐based retrospective study after minimally 10 years follow‐up

Different concepts regarding the number of implants and attachment systems for the preparation of implant-supported over-dentures (IODs) have been discussed. Nonetheless, long-term results for double-crown-retained IODs with an observational period of more than 10 years are still rare in the literature. The aim of this practice-based study was to retrospectively evaluate the long-term clinical outcome (success/survival rates, technical/biological complications) of IODs retained by double crowns. In a private practice, 36 non-smoking edentulous patients were restored between 1991 and 2002 with double-crown-retained IODs supported by 2-6 implants. For the retrospective evaluation of implant and prosthetic survival (in-situ criterion) and success (event-free observational period), only those patients were included who regularly (at least once a year) participated in a professional maintenance programme and who had a functional period for the restoration of more than 10 years. Twenty-two patients (12 Women/10 men, mean age 60.1 ± 9.8 years) with 89 implants supporting nine maxillary and 13 mandibulary dentures (mean number of implants/prosthesis = 4) met the inclusion criteria. The mean follow-up period was 14.1 ± 2.8 years. One implant failed after 4.9 years (cumulative-survival rate: 98.9%). Seven implants in two patients showed peri-implantitis (prevalence: patient-based = 9.1%/implant-based = 8%). Five dentures were renewed (prosthetic-survival rate 77.3% Maintenance procedures (i.e. screw loosening or acrylic fractures) were required at a rate of 0.31/year and patient. This study indicates that IODs retained with double crowns offer predictable long-term performance with a limited incidence of biological and technical complications.

Immediate postextraction implant placement with immediate loading for maxillary full-arch rehabilitation: A two-year retrospective analysis

There are few studies in the literature regarding immediate postextraction implant placement with immediate loading in the maxilla. These studies have only small cohorts. Therefore, the authors conducted a retrospective study to help fill this knowledge gap. Between January 2001 and January 2009, 65 participants (32 women, 33 men) with an average age of 60.5 years (age range, 43-83 years) received 334 dental implants, which were placed in postextraction sockets and loaded immediately. The follow-up period for this retrospective study was two years. All prostheses were stable, and only seven implants failed during the follow-up, for a 100 percent prosthetic survival rate and a 97.9 percent implant survival rate at two years. The mean (standard deviation) implant bone level measured 0.50 (0.27) millimeter at insertion, 1.90 (0.51) mm at one year and 2.06 (0.49) mm at two years. The results of this retrospective study showed that the survival rate of immediately loaded postextraction implants is comparable with that reported for traditional delayed implants in the maxilla. Immediate loading of four to six implants placed in extraction sockets may be a valid way to treat the edentulous maxilla.

10-year survival of total ankle arthroplasties

Background and purpose There is an ongoing need to review large series of total ankle replacements (TARs) for monitoring of changes in practice and their outcome. 4 national registries, including the Swedish Ankle Register, have previously reported their 5-year results. We now present an extended series with a longer follow-up, and with a 10-year survival analysis.Patients and methods Records of uncemented 3-component TARs were retrospectively reviewed, determining risk factors such as age, sex, and diagnosis. Prosthetic survival rates were calculated with exchange or removal of components as endpoint—excluding incidental exchange of the polyethylene meniscus.Results Of the 780 prostheses implanted since 1993, 168 (22%) had been revised by June 15, 2010. The overall survival rate fell from 0.81 (95% CI: 0.79–0.83) at 5 years to 0.69 (95% CI: 0.67–0.71) at 10 years. The survival rate was higher, although not statistically significantly so, during the latter part of the period investigated. Excluding the STAR prosthesis, the survival rate for all the remaining designs was 0.78 at 10 years. Women below the age of 60 with osteoarthritis were at a higher risk of revision, but age did not influence the outcome in men or women with rheumatoid arthritis. Revisions due to technical mistakes at the index surgery and instability were undertaken earlier than revisions for other reasons.Interpretation The results have slowly improved during the 18-year period investigated. However, we do not believe that the survival rates of ankle replacements in the near future will approach those of hip and knee replacements—even though improved instrumentation and design of the prostheses, together with better patient selection, will presumably give better results.

Clinical Evaluation of Immediate Loading of Electroeroded Screw‐Retained Titanium Fixed Prostheses Supported by Tilted Implant: A Multicenter Retrospective Study

Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable treatment protocol. However, there is limited long-term data available in the literature, when an electroeroded definitive cast-titanium fixed prosthesis is used for this treatment protocol. The aim of this study was to evaluate the clinical effectiveness of dental implants (Astra Tech Dental, Mölndal, Sweden) in the edentulous mandible immediately loaded with an electroeroded cast-titanium screw-retained fixed prosthesis. Forty-five patients received five implants each in the interforaminal area. All the implants were inserted with torque up to 40 Ncm and the distal implants were distally tilted approximately 20 to 30 degrees to minimize the length of posterior cantilevers. Implants were loaded within 48 hours of placement with an acrylic resin-titanium screw-retained prosthesis fabricated by electroerosion. Two of the 225 inserted implants failed after 3 and 16 months of healing, respectively, with a cumulative survival rate of 99.1% and a prosthetic survival rate of 97.8%. Immediate loading of tilted dental implants inserted in the edentulous mandible with a screw-retained titanium definitive prosthesis fabricated with electrical discharge machining provide reliable and predictable results.

Reconstruction of Surgical Defects After Partial Maxillectomies: A Two-Stage Procedure

The reconstruction of the maxilla after massive excisions for cancer and tumors is a challenging problem due to the anatomical complexity of the region. Nevertheless, the reconstruction is crucial to offer the patient a functional, comfortable and aesthetic outcome. This presentation describes a treatment protocol for the reconstruction of defects after partial maxillectomy for excision of benign or malignant tumors: 1) following the resection, a temporalis myofascial flap is transposed to cover the maxillary defect, 2) 3-dimensional treatment planning is made and from a stereo lithographic model a template is manufactured, to illustrate the size, shape and volume of the bone transplant, 3) after 12 months, bone grafting from the iliac crest is performed to reconstruct the maxillary bone, 4) 4 months later dental implants are installed for rehabilitation with fixed prostheses. Three cases are presented to illustrate the treatment principles. In the first two cases, bone grafting was performed intraorally by a secondary surgical procedure through the temporalis flap. Bi-cortical bone grafts were harvested from the posterior or anterior iliac crest. In the third case it was performed as a mono-cortical bone transplantation through a modified lateral rhinotomy incision and through the temporalis flap. The implant installation was performed four months later. Case 1: A 48-year-old woman referred from the oto-rhino-laryngologists for reconstruction after hemimaxillectomy due to squamous cell carcinoma. A primary reconstruction was performed with a temporalis flap. The patient had radiotherapy and subsequently hyperbaric oxygen treatment. Bone harvesting from the anterior iliac crest was performed, and from an intraoral approach the graft was fixated as a bicortical block to the left maxilla through a dissection of the temporalis flap. Finally, the area was reconstructed with three dental implants and a titanium composite bridge. Case 2: A 38-year-old woman referred from the oto-rhino-laryngologists for reconstruction after hemimaxillectomy due to sarcoma. Primary reconstruction with a temporalis flap was performed. Bone was harvested from the anterior iliac crest and from an intraoral approach adapted as a bicortical block to the left maxilla through a dissection in the temporalis flap. Finally, a reconstruction with three dental implants and a titanium composite bridge was performed. Case 3: A 22-year-old male with a primary diagnosis of myxoma referred from the oto-rhino-laryngologists for reconstruction after hemimaxillectomy and closure with a temporalis flap. Bone was harvested from the posterior iliac crest and through an extraoral approach a monocortical block was fixated to the maxilla after dissection through the temporal flap. Final reconstruction with three implants and a titanium composite bridge was performed. The functional and aesthetic results have been satisfactory. One implant of nine was lost after 14 days. After that the implant and prosthetic survival rate was 100%. Within the limitations of these three cases, rehabilitation of the hemimaxillectomized patients with the two-stage procedure is a reliable and safe alternative to the primary reconstruction procedure. The bicortical block transplantation undergoes less resorption than the monoblock transplantation and is preferred.

Short-term effects of total hip arthroplasty using metal-on-metal prosthesis with large diameter femoral head

Objective To evaluate mid-term clinical outcomes associated with total hip arthroplasty using metal-on-metal prosthesis with large diameter femoral head. Methods From March 2007 to December 2009, 153 patients (177 hips) with advanced hip diseases undergoing large diameter femoral head metal-on-metal total hip arthroplasty in our hospital were retrospectively analyzed in this study. Clinical physical examination and radiographic examination were used to evaluate hip function and the incidence of complications (implant loosening and inflammatory pseudotumor); ICP-MS method was used to determine serum cobalt ion and chromium ion levels and compare with normal values; revision was set as the prosthesis endpoint to evaluate the five year survival rate of implant. Results A total of 145 patients (169 hips) were followed up for average 72.4 months (67-80 months), the follow-up rate was 94.8% (145/153). For the involved patients, 85 were male (104 hips), 60 were female (65 hips); age 20-78 years old, average 49.3±12.6 years old. All patients received ASRTM-XL large femoral head metal-on-metal total hip arthroplasty operation. At the end of follow-up, the average Harris hip score improved from 44.2±12.6 points preoperatively to 91.5±5.7 points. A total of 8 patients received revision, 3 for acetabular implant spinout-out and 5 for hip inflammatory pseudotumor. The prosthetic survival rate 5 years after operation was 95.3% (161/169) for revision. Serum cobalt (2.89 μg/L) and chromium (3.31 μg/L) ion levels were significantly increased compared with normal value (<0.5 μg/L). Conclusion For the fixation and friction interface disadvantages, acetabular implant spinout-out and inflammatory pseudotumor might occur for patient receiving large femoral head metal-on-metal THA. The mid-term prosthetic survival rate was also low, with metal ion levels increased significantly. For primary THA, large femoral head metal-on-metal prosthesis cannot be the first choice. Key words: Arthroplasty, replacement, hip; Prostheses and implants; Granuloma, plasma cell; Chromium alloys

Clinical outcomes of the KYOCERA Physio Hinge Total Knee System Type III after the resection of a bone and soft tissue tumor of the distal part of the femur

The KYOCERA Physio Hinge Total Knee System Type III (PHKIII) was developed to reconstruct bony defects of the distal femur. The PHKIII is originative in that the metallic parts are fully made of titanium alloy, and this prosthesis has a unique semi-rotating hinge joint and was designed especially for people with the Asian physical body-type. The clinical outcomes of the PHKIII after the resection of musculoskeletal tumors of the distal femur were evaluated. There were 41 males and 28 females with a median age of 48-years. The median duration of follow-up was 57 months. Eleven early complications and 37 late complications were observed, including 10 recurrences, 7 deep infections, 7 aseptic loosenings, 4 stem breakages, 4 displacements of shaft cap, and one wear of rotation sleeve. Twenty four prosthesis (35%) required a secondary operation because of complications. The five-year overall prosthetic survival rates, -prosthetic survival rate without aseptic loosening, and -limbs preservation rate were 85%, 90%, and 86%, respectively. The mean functional score according to the classification system of the Musculoskeletal Tumor Society was 20.5 points (68%). Although continuous follow-up is required, reconstructions using PHKIII are considered to achieve more acceptable functional results.

Implant-supported fixed prostheses in the edentulous maxilla: 8-year prospective results

The purpose of this prospective study was to evaluate the long-term survival and success rates of implants and screw-retained, full-arch prostheses placed in edentulous maxillae over 8 years of function. A total of 106 Astra Tech implants were placed in the maxillae of 17 edentulous patients in a one-stage surgical approach. After a healing period of 6 months, the patients received fixed screw-retained bridges. Follow-up visits, including clinical and radiographic examinations, were performed after 6 months and at yearly intervals. Implant survival, implant success, and marginal bone-level changes were defined as the primary outcome variables. The secondary aims were to report periodontal pathogens at 5 years' follow-up and patients' satisfaction at the 8-year follow-up. The overall observation time was 8 years. One patient died during the study and one implant failed during the healing period, yielding an 8-year cumulative implant survival rate of 99%. The prosthetic survival rate was 100%. The mean crestal bone loss amounted to 0.3 ± 0.72 mm. Patients' subjective evaluations demonstrated an overall high level of satisfaction. In all cases, except for one, microbiologic probing of the peri-implant sulcus after 5 years showed no higher incidence of periodontal pathogens. Screw-retained, full-arch restorations on six implants in an edentulous maxilla are a predictable and highly successful treatment concept as observed throughout this study with an observation period of 8 years of function, in particular with respect to low crestal bone loss and high patient satisfaction.

Guided Surgery and Presurgical Prosthesis: Preliminary Results of 33 Fully Edentulous Maxillae Treated in Accordance with the NobelGuide® Protocol

The aim of this study was to present the preliminary results of 33 edentulous maxillary patients treated using the Nobelguide (Nobel Biocare AB, Göteborg, Sweden) technique. Thirty-three patients were treated according to the conventional protocol of the Nobelguide technique in two clinical centers. This group of patients received 211 implants. Monitoring was carried out for over 12-51 months, depending on the patient. The Nobelguide protocol was used for all patients. Of the 211 implants loaded, four were lost (1.9%). The implant survival rate was therefore 98.1%. The prosthetic survival rate was 100%. There were some per-operative complications (four) and some postoperative complications (10 fractures of resin). These preliminary results seemed rather promising. These were the first cases of experienced surgeons who needed to learn a new implant placement protocol. It was clear that analysis and understanding of the system were essential in order to obtain such a success. Only one implant was replaced without there being any impact on the prosthesis survival rate which is 100%.