Validation of Strain Gauges as a Method of Measuring Precision of Fit of Implant Bars

Abstract

Strain in the bar increased significantly with increasing levels of misfit. Strain measurements induced at maximum torque are not necessarily indicative of the maximum strains experienced by the bar. The presence or absence of a microgap between the bar and the platform is not necessarily indicative of passivity. These data suggest that microgap may not be clinically reliable as a measure of precision of fit.

Microfractures in metal-ceramic and all-ceramic implant-supported fixed dental prostheses caused by superstructure fixation

“…In the aforementioned studies 15,25) , assessment was based on marginal fit using gap measurements. As shown by Hegde et al 4) , microgap measurements had no correlation with increasing misfit and that the presence or absence of a microgap was not necessarily indicative of passivity.…”

“…1). The strain gages were abbreviated as "SG" and named according to their positions: Am -mesial SG at anterior implant; Ad -distal SG at anterior implant; Pm -mesial SG at posterior implant; Pd -distal SG at posterior implant 4,11) . The strains developed around the implants were recorded using a measurement amplifier (Spider 8, Hottinger Baldwin Messtechnik, Darmstadt, Germany) and an analysis software (BEAM for Spider 8, AMS Gesellschaft für Angewandte Mess-und Systemtechnik, Flöha, Germany).…”

“…It has been pointed out that superstructures fabricated by conventional methods such as casting failed to achieve a passive fit [2][3][4] . When multi-unit fixed restorations were fabricated using the computer-aided design/computeraided manufacturing (CAD/CAM) technique, greater accuracy was achieved [5][6][7][8][9] .…”

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, ).…”

“…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, ).…”