Clinical evaluation of the zygoma implant: 3-year follow-up at 16 clinics.

PURPOSE: The purpose of this clinical investigation was to evaluate the treatment outcome with zygoma implants with regard to implant survival, patient satisfaction, and function of prosthesis replacement after 3 years. PATIENTS AND METHODS: The treatment outcome of 76 patients treated with 145 zygoma fixtures at 16 centers was evaluated with regard to implant survival. Status of peri-implant mucosa and amount of plaque were registered annually. Patients' and dentists' evaluations of the functional and esthetic outcome of the treatment were assessed at delivery of prosthesis and thereafter at each follow-up visit. RESULTS: Sixty of 76 patients were followed for 3 years after prosthetic delivery. Five of 145 placed zygoma implants failed during the course of the study resulting in an overall implant survival rate of 96.3%. At the 3-year follow-up, 75% of the implants sites were registered with normal peri-implant mucosa and 68% with no visible plaque. The patients were fully satisfied with the esthetic and functional outcome of the treatment in 86% and 71%, respectively, at the 3-year follow-up visit. All reported data from dentists scored from acceptable to excellent. CONCLUSION: The multicenter study showed a high predictability of the zygoma implant-supported rehabilitation.

Retrieved implants from irradiated sites in humans: a histologic/histomorphometric investigation of oral and craniofacial implants.

PURPOSE: The aim of this report was to quantitatively and qualitatively evaluate the tissue response to bone-anchored implants retrieved from irradiated sites in patients. MATERIALS AND METHODS: The material consists of 23 consecutively received Brånemark implants (Nobel Biocare AB, Göteborg, Sweden) placed in pre- or postoperatively irradiated sites. Twenty-two of the 23 implants were suitable for histologic evaluation of undecalcified sections in the light microscope. RESULTS: The oral implants with shorter time in situ demonstrated sparse bone to implant contact with mainly dense connective tissue in the interface. However, for implants with longer time in situ, high amounts of bone-implant contact and bone fill of threads were noted. The mean values of bone-implant contact and bone area within the thread were calculated to 40% (16-94) and 70% (13-96), respectively. The craniofacial implants, with the exception of two implants lined with a capsular formation, demonstrated mature and newly formed bone at the bone-implant interface. The mean value for bone-metal contact was calculated to 45 and 53% for two specimens. The mean value for bone area within the thread ranged from 65 to 88% for three specimens. CONCLUSION; The possibility to achieve bone anchorage of implants in irradiated tissue was supported by the findings in this study. However, due to limited material, conclusions with regard to radiation dose and bone tissue response to implants cannot be stated.

Histologic evaluation of Brånemark clinic oral implants retrieved from grafted sites.

PURPOSE: The aim of this report is to quantitatively and qualitatively describe the bone tissue response to Brånemark implants retrieved from grafted sites in patients. MATERIALS AND METHOD: The material consists of consecutively received Brånemark implants retrieved from grafted sites. Thirty-five of these implants, retrieved from 16 patients, were suitable for the histologic evaluation of undecalcified sections in the light microscope. RESULTS: The unloaded implants were mainly lined with soft tissue, and sparse bone-implant contact was observed only in some sections. The loaded implants, with the exception of one implant removed due to mobility, had mature and new bone-implant contact. Resorption of graft through cutting cone structures was detected. Cement lines were found separating bone-like tissue albeit no cellular content and bone tissue with detectable osteocytes. CONCLUSION: In this heterogeneous group of implants from grafted sites, the unloaded implants showed limited bone-implant contact. The autografts showed seemingly mixed viability as judged by the cell content in the osteocyte lacunae and cement lines separating areas with filled and empty lacunae.

A study of 275 retrieved Brånemark oral implants.

The aim of this report was to describe the bone tissue response to Brånemark oral implants retrieved from patients. The material consisted of consecutively received Brånemark threaded oral implants and related patient data provided by clinicians. The implant samples were processed into undecalcified sections for evaluation under the light microscope. The analysis demonstrated a lower percentage of bone-to-implant contact for the unloaded implants as compared to the loaded implants. When the threads were divided into four different regions, the loaded implants had a lower percentage of bone-contacting length at the thread top as compared to the other three regions.

A descriptive study on retrieved non-threaded and threaded implant designs.

OBJECTIVES: In the light microscope compare the amount of bone saucerization for non-threaded cylindrical and threaded implant designs in retrieved samples from patients. MATERIAL AND METHOD: Consecutively received retrieved oral implants from 117 patients, whereof 85 non-threaded cylindrical and 85 Brånemark implants, have been included in the study. For 75 non-threaded cylindrical and 46 Brånemark implants was the entire implant length available for calculation. Undecalcified ground sections were investigated in the light microscope with calculation of percentage of implant length coronal to the first bone-implant contact and percentage of bone to implant contact. RESULTS: Mean value for implant length coronal to first bone-implant contact was 65%, standard error of the mean (SEM) 3 (range 0-100%), for non-threaded cylindrical implants and 43%, SEM 6 (range 0-100%) for Brånemark implants. Mean values of bone contact along the entire implant length was 23%, SEM 2 (range 0-65%), for the non-threaded cylindrical implants and 33%, SEM 5 (range 0-93%) for the Brånemark implants. CONCLUSION: Within the limitations of this retrospective, retrieval study non-threaded cylindrical implants demonstrated a greater bone saucerization when evaluated in the light microscope.

A clinical evaluation of the Zygoma fixture: one year of follow-up at 16 clinics.

PURPOSE: To evaluate treatment outcome with Zygoma fixtures (Nobel Biocare, Göteborg, Sweden) with regard to fixture survival, patient satisfaction, and function of prosthesis replacement. MATERIALS AND METHODS: The treatment outcome of 76 patients treated with 145 Zygoma fixtures at 16 centers was evaluated. Patient's and dentist's evaluations of the functional and aesthetic outcome of the treatment were assessed at delivery of prosthesis and at the 1-year follow-up visit. At the 1-year follow-up visit, the status of the peri-implant mucosa around the abutments and the amount of plaque were registered. RESULTS: Sixty-six of the 76 patients, with 124 Zygoma fixtures supporting the prosthetic restorations, were evaluated at the 1-year follow-up. The overall survival rate for the Zygoma fixtures was 97.9% after 1-year of follow-up. Eighty percent of the patients were fully satisfied with both aesthetic and functional outcome at the time of prosthetic insertion and at the 1-year follow-up. All reported data from the dentists, with the exception of one restoration with several abutment screw loosenings, scored from acceptable to excellent for the aesthetic and functional outcome of the treatment. The status of peri-implant mucosa was recorded as normal in approximately 60% of the sites. Plaque, when present, was more often detected on the palatal surfaces compared with the buccal surfaces. CONCLUSION: This 1-year follow-up of Zygoma fixtures has shown good results with an acceptable number of minor complications and a majority of satisfied patients.