{"title":"Adhesive damage of class V restorations under shrinkage stress and occlusal forces using cohesive zone modeling","authors":"Youxin Li , Bingmei Shao , Zhan Liu","doi":"10.1016/j.jmbbm.2024.106880","DOIUrl":null,"url":null,"abstract":"<div><h3>Objective</h3><div>This study aims to investigate adhesive damage caused by the synergistic effects of polymerization shrinkage and occlusal forces via finite element analysis (FEA), based on damage mechanics with the cohesive zone model (CZM). The objective is to obtain the adhesive damage distribution and investigate how the material properties of resin composite impact adhesive damage.</div></div><div><h3>Methods</h3><div>A 3D reconstruction model of an mandibular first molar was constructed through CBCT imaging, and a Class V cavity was prepared using computer-aided engineering (CAE) software. Common clinical resin composite and an universal adhesive were selected for restorative filling. A 3D FEA was performed, incorporating the pre-stress induced by polymerization shrinkage of the resin composite, followed by occlusal forces. The cohesive zone model (CZM) was employed to represent the adhesive damage. To emphasize the impact of synergistic loading on adhesive damage, three types of loads were separately applied to the model: polymerization shrinkage, occlusal forces, and combined loading. Subsequently, three clinical resin composites with varying polymerization shrinkage and elastic modulus were used as restorative materials. Sensitivity analysis was conducted on dozens of hypothetical materials to provide definitive results.</div></div><div><h3>Results</h3><div>Polymerization shrinkage was undergone by the cured resin composite, resulting in extensive adhesive damage. Occlusal forces induced microdamage in regions already damaged by shrinkage stress, especially in the gingival wall. Predictably, the regions with severe adhesive damage were prone to marginal microleakage. The properties of the resin composite can affect adhesive damage. The adhesive damage with bulk-fill resin composite was milder than that with flowable and conventional resin composite. The extent of adhesive damage correlated markedly positively with the polymerization shrinkage of the resin composite and mildly positively with its elastic modulus.</div></div><div><h3>Significance</h3><div>Adhesive damage has been directly implicated in marginal microleakage. The cohesive zone model (CZM) can effectively elucidate the distribution of adhesive damage and provide a clear representation of the impact of varying material properties of resin composite on adhesive damage.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106880"},"PeriodicalIF":3.3000,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Mechanical Behavior of Biomedical Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1751616124005125","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Objective
This study aims to investigate adhesive damage caused by the synergistic effects of polymerization shrinkage and occlusal forces via finite element analysis (FEA), based on damage mechanics with the cohesive zone model (CZM). The objective is to obtain the adhesive damage distribution and investigate how the material properties of resin composite impact adhesive damage.
Methods
A 3D reconstruction model of an mandibular first molar was constructed through CBCT imaging, and a Class V cavity was prepared using computer-aided engineering (CAE) software. Common clinical resin composite and an universal adhesive were selected for restorative filling. A 3D FEA was performed, incorporating the pre-stress induced by polymerization shrinkage of the resin composite, followed by occlusal forces. The cohesive zone model (CZM) was employed to represent the adhesive damage. To emphasize the impact of synergistic loading on adhesive damage, three types of loads were separately applied to the model: polymerization shrinkage, occlusal forces, and combined loading. Subsequently, three clinical resin composites with varying polymerization shrinkage and elastic modulus were used as restorative materials. Sensitivity analysis was conducted on dozens of hypothetical materials to provide definitive results.
Results
Polymerization shrinkage was undergone by the cured resin composite, resulting in extensive adhesive damage. Occlusal forces induced microdamage in regions already damaged by shrinkage stress, especially in the gingival wall. Predictably, the regions with severe adhesive damage were prone to marginal microleakage. The properties of the resin composite can affect adhesive damage. The adhesive damage with bulk-fill resin composite was milder than that with flowable and conventional resin composite. The extent of adhesive damage correlated markedly positively with the polymerization shrinkage of the resin composite and mildly positively with its elastic modulus.
Significance
Adhesive damage has been directly implicated in marginal microleakage. The cohesive zone model (CZM) can effectively elucidate the distribution of adhesive damage and provide a clear representation of the impact of varying material properties of resin composite on adhesive damage.
期刊介绍:
The Journal of the Mechanical Behavior of Biomedical Materials is concerned with the mechanical deformation, damage and failure under applied forces, of biological material (at the tissue, cellular and molecular levels) and of biomaterials, i.e. those materials which are designed to mimic or replace biological materials.
The primary focus of the journal is the synthesis of materials science, biology, and medical and dental science. Reports of fundamental scientific investigations are welcome, as are articles concerned with the practical application of materials in medical devices. Both experimental and theoretical work is of interest; theoretical papers will normally include comparison of predictions with experimental data, though we recognize that this may not always be appropriate. The journal also publishes technical notes concerned with emerging experimental or theoretical techniques, letters to the editor and, by invitation, review articles and papers describing existing techniques for the benefit of an interdisciplinary readership.