A Strain Gauge Analysis Comparing External and Internal Implant-Abutment Connections

Abstract

When loaded vertically, the internal implant-abutment connection produced less strain when compared with the external implant-abutment connection.

A strain gauge analysis comparing 4‐unit veneered zirconium dioxide implant‐borne fixed dental prosthesis on engaging and non‐engaging abutments before and after torque application

“…The use of dental implants is a well‐accepted and predictable treatment modality for the rehabilitation of partially or completely edentulous patients (Asvanund, ; Hegde, Lemons, Broome, & McCracken, ). Although the success rate with implants are high, biological and technical complications around the implants or implant‐borne fixed dental prosthesis (FDP) are reported to increase in long‐span FDPs (Pjetursson, Brägger, Lang, & Zwahlen, ).…”

“…Initially, upon tightening, the abutment screw exerts a compressive force to maintain the contact between the abutment and the implant surface (Nishioka, Nishioka, Abreu, de Vasconcellos, & Balducci, ). At this moment, the torque applied to the prosthesis‐abutment induces stresses that are transmitted to the supporting bone and suprastructure, which can eventually yield to bone resorption (Asvanund, ; Nishioka et al, ) or chipping in the veneering ceramic. In fact, mechanical stress may have both positive and negative consequences on the bone tissue (Abreu, Nishioka, Balducci, & Consani, ; Isidor, ).…”

“…However, to date, there is no proof whether E abutments cause more strain development compared to NE abutments in the FDPs, despite the standardized grinding procedures. Moreover, torque forces during tightening of the prosthetic screws also produces compressive forces on the suprastructure (Asvanund, ). Depending on the material type, even though the rigid suprastructure appears to fit well on each abutment, residual stresses after the torque may yield to mechanical failures in the FDP (Asvanund, ).…”

“…Complex strain fields around fixtures, implant components, or suprastructures could be typically measured using strain gauge analysis (Abduo, Bennani, Lyons, Waddell, & Swain, ; Abreu et al, ; Asvanund, ; Castro, Zancope, Verissimo, Soares, & Neves, ; Cehreli & Iplikcioglu, ; Cho et al, ; De Vasconcellos et al, ; De Vasconcellos, Nishioka, de Vasconcellos, Balducci, & Kojima, ; Heckmann et al, ; Hegde et al, ; Isidor, ; Karl, Rosch, Graef, Talyor, Heckmann, ; Karl, Graef, & Wichmann, ; Karl, Graef, Wichmann, & Krafft, ; Karl & Holst, ; Karl & Taylor, ; Karl, Wichmann, Heckmann, & Krafft, ; Nishioka, de Vasconcellos, & de Melo Nishioka, ; Nishioka, de Vasconcellos, Joias, & Rode Sde, ). With this method, an electrical resistance in the strain gauge enables the measurement of deformation with high sensitivity (μm/m) (Asvanund, ). Strain is defined as the ratio between the length of an object under stress and its original dimension; it is a dimensionless entity.…”

Análise da distribuição de tensão em protocolo mandibular confeccionado pelo sistema convencional e CAD/CAM, variando tipo, número e inclinação dos implantes

“…Assim, temse especulado que, sob altas cargas oclusais, o hexágono externo pode permitir micro movimentos do pilar, causando instabilidade da articulação que pode resultar em afrouxamento do parafuso do pilar ou fratura por fadiga (Worthington et al, 1987;Zarb & Schmitt, 1990;Adell et al, 1990;Jemt et al, 1991;Hermmings et al, 1994;Jemt & Lekholm, 1995;Becker & Becker 1995). Segundo Asvanund (2014), o sistema de conexão hexágono externo, em comparação aos outros sistemas de conexão, tem apresentado maior concentração de tensões em casos de reabilitação de mandíbulas edêntulas, por meio de próteses totais sobre implantes, suportada por quatro implantes.…”