Comparative evaluation of 3 microbond strength tests using 4 adhesive systems: Mechanical, finite element, and failure analysis

Abstract

The storage time did not affect the results, but differences were found among the adhesives and methods. For comparisons of bond strength from tests with different bonding areas, the normalization for area seemed essential. The microshear bond test should not be used for bond strength evaluation, and the microtensile test needs improvement to enable reliable results regarding stress concentration and failure mode. The micropush-out test may be considered more reliable than the microtensile in the bond strength investigation, as demonstrated by the uniform stress concentration and adhesive failure pattern.

Assessment of Bonding Effectiveness of Adhesive Materials to Tooth Structure using Bond Strength Test Methods: A Review of Literature

“…The test results in a depth profiling of different substrates and preparation of multiple specimens from a same tooth as in the case of micro-tensile tests. However, without the involvement of sectioning or trimming procedures which by themselves may induce early microcracking within the specimen [ 19 , 20 ].…”

A Comparative Study on the Mechanical Properties of a Polymer-Infiltrated Ceramic-Network Material Used for the Fabrication of Hybrid Abutment

“…This test method may be conducted in further studies. A favorable test method for bond-strength evaluation has been suggested to involve high bond-strength values, homogeneous stress distribution, and adhesive failures; however, no test method has been regarded as ideal so far [ 47 ]. Microbond-strength tests have some advantages over macro tests since microbond-strength tests demonstrate higher percentage of adhesive failures, lower coefficients of variation, and it is possible to evaluate different areas of the same specimen [ 48 , 49 ].…”

“…On the other hand, microtensile and micro-pushout tests provided more reliable results in comparison to the µSBS test since specimen configuration, direction of force, and elastic moduli of the materials involved have a significant effect on µSBS values and cause greater variation of the findings [ 52 ]. A recent study [ 47 ] that conducted finite-element and failure analyses to compare microbond tests concluded the use of a micro-pushout test for uniform stress concentration and adhesive failure pattern. A micro-pushout bond-strength test may be performed in further studies to obtain more reliable results.…”

Estudo comparativo entre diferentes cimentos endodônticos em relação à resistência de união do conjunto cimento resinoso/pino de fibra de vidro à dentina radicular

“…Além disso, durante o teste de push-out a força é aplicada paralelamente à interface dentina/cimento resinoso, simulando as condições clínicas e, por esse motivo, tem sido considerado o método mais adequado para avaliação da RU à dentina radicular (GORACCI et al, 2004;FISHER;BERZINS;BAHCALL, 2007;SOARES et al, 2008;COSTA et al, 2010;CARNEIRO et al, 2012;CAMPOS et al, 2018). Durante a realização do teste, foram selecionadas pontas aplicadoras de carga e bases metálicas com diâmetros e orifícios específicos para cada slice no intuito de favorecer a aplicação de força e distribuição de tensões de cisalhamento o mais próximo da interface cimento resinoso/dentina radicular (ZANATTA et al, 2015).…”