Aim: Over the last decade, newer immediate provisionalization/loading protocols have demonstrated to reduce the treatment time resulting in high implant success rates. The present pilot clinical trial evaluates the outcome of a modified “Toronto prosthesis technique” placed in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prosthesis. Methods: 7 patients completely edentulous or presenting natural teeth with a hopeless prognosis seeking implant-supported prosthesis at the Istituto Stomatologico Toscano, Dentistry Department of Versilia Hospital, Italy (University of Pisa) were recruited. Eligible patients had to have sufficient bone volume allowing placement of six implants, which should be used for a full-arch implant-supported rehabilitation. A complete examination of hard and soft oral tissues was conducted for each patient to assess the bone volume of the scheduled implant sites. Each case was accurately evaluated examining diagnostic casts for the intraarch relationship, periapical and panoramic radiographs, and computed tomography if necessary. Six dental implants 3,8 mm diameter (Khono ,Sweden and Martina, Italy) were placed on each patient in healed and fresh extraction sites following a one-stage surgical protocol. Implants were inserted with a minimal torque of 45 Ncm. All prosthetic procedures were performed by the same prosthodontist and the same dental technician. Implant positions were registered intraoperatively. Provisional abutments were screwed onto the implants and then splinted to the impression template. This information was transferred to the patient’s diagnostic cast and used to make an acrylic resin provisional full-arch screw-retained metal-reinforced prosthesis with no distal cantilever, which was placed within 72 hours postsurgery. Patients were assessed by a calibrated investigator at 2, 6, and 12 months following completion of treatment. The occlusion was adjusted to provide a balanced distribution of forces. Implant success was determined according to the clinical and radiographic criteria defined as follows: (1) absence of clinically detectable implant mobility, (2) absence of pain or any subjective sensation, (3) absence of recurrent peri-implant infection, and (4) absence of ongoing radiolucency around the implant after 6 and 12 months of loading. Results: Two patients failed to attend the scheduled recall visits and were excluded from the study. The final patient sample consisted of 5 patients (2 women and 3 men) with a mean age of 51.4 ± 9.8 years (range, 38 to 69 years). The 5 patients included in the study received a total of 30 implants, all the implants fulfilled the success criteria. The implant survival rate was 100%, whereas the average marginal bone loss was of 0.42 mm of peri-implant bone (range 0.1 to 0.8 mm, standard deviation [SD] 0.23 mm) after 1 year. Conclusions: The present study, with a short follow-up period and a small sample, showed implant success and minimal peri-implant marginal bone loss after immediate loading of fixed full-arch prostheses with a modified “Toronto tecnique”. All provisional immediately loaded fixed prostheses functioned successfully. Additional studies with longer follow-up times and larger samples are required to better evaluate the influence of loading protocols on the alveolar bone response and the outcome of dental implant therapy.

Immediate loading of implants placed into fresh and healed extraction sites to support a full-arch fixed prosthesis placed with a modified “Toronto tecnique”: 1-year results from a pilot clinical trial

MARCONCINI, SIMONE;VANO, MICHELE;BARONE, ANTONIO;COVANI, UGO;
2014

Abstract

Aim: Over the last decade, newer immediate provisionalization/loading protocols have demonstrated to reduce the treatment time resulting in high implant success rates. The present pilot clinical trial evaluates the outcome of a modified “Toronto prosthesis technique” placed in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prosthesis. Methods: 7 patients completely edentulous or presenting natural teeth with a hopeless prognosis seeking implant-supported prosthesis at the Istituto Stomatologico Toscano, Dentistry Department of Versilia Hospital, Italy (University of Pisa) were recruited. Eligible patients had to have sufficient bone volume allowing placement of six implants, which should be used for a full-arch implant-supported rehabilitation. A complete examination of hard and soft oral tissues was conducted for each patient to assess the bone volume of the scheduled implant sites. Each case was accurately evaluated examining diagnostic casts for the intraarch relationship, periapical and panoramic radiographs, and computed tomography if necessary. Six dental implants 3,8 mm diameter (Khono ,Sweden and Martina, Italy) were placed on each patient in healed and fresh extraction sites following a one-stage surgical protocol. Implants were inserted with a minimal torque of 45 Ncm. All prosthetic procedures were performed by the same prosthodontist and the same dental technician. Implant positions were registered intraoperatively. Provisional abutments were screwed onto the implants and then splinted to the impression template. This information was transferred to the patient’s diagnostic cast and used to make an acrylic resin provisional full-arch screw-retained metal-reinforced prosthesis with no distal cantilever, which was placed within 72 hours postsurgery. Patients were assessed by a calibrated investigator at 2, 6, and 12 months following completion of treatment. The occlusion was adjusted to provide a balanced distribution of forces. Implant success was determined according to the clinical and radiographic criteria defined as follows: (1) absence of clinically detectable implant mobility, (2) absence of pain or any subjective sensation, (3) absence of recurrent peri-implant infection, and (4) absence of ongoing radiolucency around the implant after 6 and 12 months of loading. Results: Two patients failed to attend the scheduled recall visits and were excluded from the study. The final patient sample consisted of 5 patients (2 women and 3 men) with a mean age of 51.4 ± 9.8 years (range, 38 to 69 years). The 5 patients included in the study received a total of 30 implants, all the implants fulfilled the success criteria. The implant survival rate was 100%, whereas the average marginal bone loss was of 0.42 mm of peri-implant bone (range 0.1 to 0.8 mm, standard deviation [SD] 0.23 mm) after 1 year. Conclusions: The present study, with a short follow-up period and a small sample, showed implant success and minimal peri-implant marginal bone loss after immediate loading of fixed full-arch prostheses with a modified “Toronto tecnique”. All provisional immediately loaded fixed prostheses functioned successfully. Additional studies with longer follow-up times and larger samples are required to better evaluate the influence of loading protocols on the alveolar bone response and the outcome of dental implant therapy.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/461071
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