Standard of disocclusion in complete dentures supported by implants without free distal ends: analysis by the finite elements method

OBJECTIVE: The occlusal patterns are key requirements for the clinical success of oral rehabilitation supported by implants. This study compared the stresses generated by the disocclusion in the canine guide occlusion (CGO) and bilateral balanced occlusion (BBO) on the implants and metallic infrastructure of a complete Brånemark protocol-type denture modified with the inclusion of one posterior short implant on each side. MATERIAL AND METHODS: A three-dimensional model simulated a mandible with seven titanium implants as pillars, five of them installed between the mental foramen and the two posterior implants, located at the midpoint of the occlusal surface of the first molar. A load of 15 N with an angle of 45º was applied to a tooth or distributed across three teeth to simulate the CGO or BBO, respectively. The commercial program ABAQUS(®) was used for the model development, before and after the processing of the data. The results were based on a linear static analysis and were used to compare the magnitude of the equivalent stress for each of the simulations. RESULTS: The results showed that the disocclusion in CGO generated higher stresses concentrated on the working side in the region of the short implant. In BBO, the stresses were less intense and more evenly distributed on the prosthesis. The maximum stress found in the simulation of the disocclusion in CGO was two times higher than that found in the simulation of the BBO. The point of maximum stress was located in the neck of the short implant on the working side. CONCLUSIONS: Under the conditions of this study, it was concluded that the BBO pattern was more suitable than CGO for the lower complete denture supported by implants without free distal ends

Adherence of hip and knee arthroplasty studies to RSA standardization guidelines

Peer reviewe

Reversible, non-plaque-induced loss of osseointegration of successfully loaded dental implants

Objectives: Excess loading has been often cited as a reason for the failure of dental implants or bone loss post-osseointegration. The available data from animal studies have failed to show a clear role for excessive loading in the loss of osseointegration. The present case documentations aimed at providing a deeper insight into the medium- to long-term influence of occlusal loading on osseointegrated implants, and describe the clinical manifestations of such pathology. Material and methods: Two cases of loss of osseointegration are documented with single implants in the posterior maxilla. Implant mobility was in both cases the first and only sign of pathology, with the absence of plaque-induced inflammation and marginal bone loss. Results: Re-osseointegration of the implants was achieved after the removal of the prosthetic reconstruction. Conclusions: The two cases reported that the loss of osseointegration in the absence of plaque-induced peri-implant inflammation is possible, although the clinical manifestations were very different to these of peri-implantitis. Once the occlusal loading was withdrawn, re-osseointegration was clinically confirmed in a period of 6-8 months. © 2012 John Wiley & Sons A/S.link_to_subscribed_fulltex

Reversible, Non-plaque-induced loss of osseointegration of successfully loaded dental implants

Objectives: Excess loading has been often cited as a reason for the failure of dental implants or bone loss post-osseointegration. The available data from animal studies have failed to show a clear role for excessive loading in the loss of osseointegration. The present case documentations aimed at providing a deeper insight into the medium- to long-term influence of occlusal loading on osseointegrated implants, and describe the clinical manifestations of such pathology. Material and methods: Two cases of loss of osseointegration are documented with single implants in the posterior maxilla. Implant mobility was in both cases the first and only sign of pathology, with the absence of plaque-induced inflammation and marginal bone loss. Results: Re-osseointegration of the implants was achieved after the removal of the prosthetic reconstruction. Conclusions: The two cases reported that the loss of osseointegration in the absence of plaque-induced peri-implant inflammation is possible, although the clinical manifestations were very different to these of peri-implantitis. Once the occlusal loading was withdrawn, re-osseointegration was clinically confirmed in a period of 6-8 months. © 2012 John Wiley & Sons A/S

A finite element analysis of tilted versus nontilted implant configurations in the edentulous maxilla.

The aim of this study was to evaluate stress patterns at the bone-implant interface of tilted versus nontilted implant configurations in edentulous maxillae using finite element models of two tilted and one nontilted configuration. Analysis predicted the maximum absolute value of principal compressive stress near the cervical area of the distal implant for all models. The tilted configurations showed a lower absolute value of compressive stress compared with the nontilted, indicating a possible biomechanical advantage in reducing stresses at the bone-implant interface

Sir George and Lady Fuller holding a bouquet of flowers onboard a ship, New South Wales, ca. 1927, 1 [picture].

Title devised from accompanying information where available.; Part of the: Fairfax archive of glass plate negatives.; Fairfax number: 4589.; Also available online at: http://nla.gov.au/nla.pic-vn6247331; Acquired from Fairfax Media, 2012

Comparison of Tilted and Nontilted Implant-Supported Prosthetic Designs for the Restoration of the Edentulous Mandible: A Biomechanical Study

Purpose: The purpose of the study was to evaluate, using finite element analysis, the stress patterns induced in cortical bone by three distinct implant-supported prosthetic designs. Materials and Methods: The first two models consisted of a prosthesis supported by four implants, the distal two of which were tilted, with different cantilever lengths (5 mm and 15 mm). The third design consisted of a prosthesis supported by five conventionally placed implants and a 15-mm cantilever. Results: In the tilted model with 5-mm cantilever and in the nontilted model, the maximum value of compressive stress (-18 Mpa) was found near the cervical area of the distal implant. Higher values for compressive stress were predicted near the cervical area of the distal implant in the tilted model with a 15-mm cantilever, as compared to the tilted model with the 5-mm cantilever. For the tilted model with the 5-mm cantilever, peak values of tensile stress were predicted near the cervical area of both the distal (1.25 Mpa) and the mesial implants (2.5 Mpa). For the nontilted model, the peak value was found near the cervical area of the in-between implant (5 Mpa). For the tilted model with 15-mm cantilever, tensile stress values were higher than in the tilted model with 5-mm cantilever. Conclusions: No significant difference in stress patterns between the tilted 5-mm and the nontilted 15-mm configuration was predicted. The tilted configuration with a 15-mm cantilever was found to induce higher stress values than the tilted configuration with a 5-mm cantilever

Comparison of the periimplant bone stress distribution on three fixed partial supported prosthesis designs under different loading. A 3D finite element analysis

International Joint Conference SOCO’17-CISIS’17-ICEUTE’17 (2017. León, Spain