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

Abstract

This study quantified the strain development after inserting implant‐borne fixed dental prosthesis (FDP) to various implant–abutment joints. Two bone‐level implants (∅ = 4.1 mm, RC, SLA 10 mm, Ti, Straumann) were inserted in polyurethane models (N = 3) in the area of tooth nos 44 and 47. Four‐unit veneered zirconium dioxide FDPs (n = 2) were fabricated, one of which was fixed on engaging (E; RC Variobase, ∅ = 4.5 mm, H = 3.5 mm) and the other on non‐engaging (NE) abutments (RC Variobase, ∅ = 4.5 mm, H = 5.5 mm). One strain gauge was bonded to the occlusal surface of pontic no. 46 on the FDP and the other two on the polyurethane model. Before (baseline) and after torque (35 Ncm), strain values were recorded three times. Data were analyzed using Kruskal–Wallis and Mann–Whitney U tests (α = 0.05). Mean strain values presented significant increase after torque for both E and NE implant–abutment connection type (baseline: E = 4.33 ± 4.38; NE = 4.85 ± 4.85; torque: E = 196.56 ± 188.02; NE = 275.63 ± 407.7; p < .05). Mean strain values based on implant level presented significant increase after torque for both E and NE implant–abutment connection (baseline: E = 4.94 ± 5.29; NE = 5.78 ± 5.69; torque: E = 253.78 ± 178.14; NE = 347.72 ± 493.06; p < .05). The position of the strain gauge on implants (p = .895), FDP (p = .275), and abutment connection type (p = .873) did not significantly affect the strain values. Strain levels for zirconium dioxide implant‐borne FDPs were not affected by the implant–abutment connection type.

Computational Biomechanical Analysis of Engaging and Nonengaging Abutments for Implant Screw‐Retained Fixed Dental Prostheses

“…The choice for using engaging or nonengaging largely depends on the implant positions and angulations. 8,15,16 Therefore, different combinations of engaging and nonengaging abutments have been evaluated and proposed as an alternative to regain some advantages of utilizing the internal connection with an engaging abutment, while achieving the required passive fit with a nonengaging abutment. 8 Biomechanical aspects of implant-supported FDPs and stress distribution in the components have been investigated in a number of in vitro, animal and clinical studies to predict the clinical behavior of implant-supported restorations.…”

“…The caveat with nonengaging abutments is that greater stress has been reported around the abutment screws and the IAI when eccentric forces are applied. The choice for using engaging or nonengaging largely depends on the implant positions and angulations 8,15,16 . Therefore, different combinations of engaging and nonengaging abutments have been evaluated and proposed as an alternative to regain some advantages of utilizing the internal connection with an engaging abutment, while achieving the required passive fit with a nonengaging abutment 8 …”

Strain analysis of anterior resin-bonded fixed dental prostheses with different thicknesses of high translucent zirconia

“… 26 , 27 Using the strain gage method, this deformation can be measured with a high sensitivity. 28 This method can also measure the real strain on dental restorations in the oral cavity. In another previous study, there was no significant difference in strain between the in vivo and in vitro models.…”

Examination of inter-rater and intra-rater reliability during retentive force measurement of different clasps using the developed small-sized retentive force measurement device

“…Two strain gauges (gauge length of 1 mm and base size of 1.4 × 2.8 mm, Kyowa Electronic Instruments Co., Ltd., Tokyo, Japan) for transducers were provided inside and two were given to the outside, and a cable with 1.7 calibers was welded from the terminal of the gauge towards the handles. Strain gauge has characteristics such as excellent repeatability and linearity, and it is possible to measure force, load, pressure, and displacement [13,14]. After the coating process, the device was covered with silicon rubber.…”