Effect of volumetric shrinkage of restorative materials on tooth structure: A finite element analysis

2021 ◽  
pp. 095441192199013
Author(s):  
Ankit Nayak ◽  
Prashant K Jain ◽  
Pavan K Kankar ◽  
Niharika Jain
Keyword(s):  
Clinical Problem ◽  
Volumetric Shrinkage ◽  
Dental Composites ◽  
Element Analysis ◽  
Polymerization Shrinkage ◽  
Curing Conditions ◽  
Tooth Structure ◽  
Gutta Percha ◽  
Hermetic Seal ◽  
Restorative Materials

Post-treatment coronal hermetic seal of the root canal opening prevents the food or saliva which assist to achieve successful endodontic treatment. Gutta-percha is filled in the inner canal, that is, from cervical third to apical third. Gutta-percha does not provide the hermetic seal because it does not bound with dentine walls. Various new restorative materials have been developed in the last 6–7 decade but drawback related to the polymerization shrinkage of the composite resin remains a clinical problem. In general, dental composites having volumetric shrinkage of the material depends on its formulation and curing conditions. In this article, the effect of this polymerization shrinkage on the tooth structure has been studied.

Mechanical Analysis of Restored-Tooth Structure Due to Polymerization Shrinkage of Composite Restoration

2011 ◽  
Vol 474-476 ◽  
pp. 1401-1405
Author(s):  
Shui Wen Zhu ◽  
Jian Ping Fan ◽  
Guo Ping Chen
Keyword(s):  
Material Properties ◽  
Development Trend ◽  
Mechanical Analysis ◽  
Elastic Behaviour ◽  
Element Analysis ◽  
Polymerization Shrinkage ◽  
Tooth Structure ◽  
The Finite Element Analysis ◽  
The Development Trend ◽  
Composite Restoration

The finite element analysis is presented in this paper in order to investigate the influence of interphase properties on restored-tooth structure due to polymerization shrinkage of resin-based composite. The restoration-tooth interface is simulated using plane elements of varying material properties and thicknesses. The stress and displacement within restored-tooth structure built-up from the polymerization shrinkage of the restorative composite were computed accounting for the time-dependent, visco-elastic behaviour of the composite. It was found that a correlation exists between material and geometry properties at the restoration-tooth interface and higher shrinkage stresses on interphase due to polymerization shrinkage. The development trend of residual stress from polymerization shrinkage in the restored-tooth structure was discussed and forecasted.

scholarly journals Mechanical Behavior of Different Restorative Materials and Onlay Preparation Designs in Endodontically Treated Molars

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1923
Author(s):  
Ana Beatriz Gomes de Carvalho ◽  
‪Guilherme Schmitt de Andrade ◽  
João Paulo Mendes Tribst ◽  
Elisa Donária Aboucauch Grassi ◽  
Pietro Ausiello ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Mechanical Behavior ◽  
Maximum Principal Stress ◽  
Element Analysis ◽  
Tooth Structure ◽  
Cement Layer ◽  
Restorative Materials ◽  
Homogeneous Stress

This study evaluated the effect of the combination of three different onlay preparation designs and two restorative materials on the stress distribution, using 3D-finite element analysis. Six models of first lower molars were created according to three preparation designs: non-retentive (nRET), traditional with occlusal isthmus reduction (IST), and traditional without occlusal isthmus reduction (wIST); and according to two restorative materials: lithium-disilicate (LD) and nanoceramic resin (NR). A 600 N axial load was applied at the central fossa. All solids were considered isotropic, homogeneous, and linearly elastic. A static linear analysis was performed, and the Maximum Principal Stress (MPS) criteria were used to evaluate the results and compare the stress in MPa on the restoration, cement layer, and tooth structure (enamel and dentin). A novel statistical approach was used for quantitative analysis of the finite element analysis results. On restoration and cement layer, nRET showed a more homogeneous stress distribution, while the highest stress peaks were calculated for LD onlays (restoration: 69–110; cement layer: 10.2–13.3). On the tooth structure, the material had more influence, with better results for LD (27–38). It can be concluded that nRET design showed the best mechanical behavior compared to IST and wIST, with LD being more advantageous for tooth structure and NR for the restoration and cement layer.

Incremental Filling Technique and Composite Material—Part II: Shrinkage and Shrinkage Stresses

2014 ◽  
Vol 39 (2) ◽  
pp. e83-e92 ◽  
Author(s):  
AA Bicalho ◽  
ADCM Valdívia ◽  
BCF Barreto ◽  
D Tantbirojn ◽  
A Versluis ◽  
...  
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Strain Gauge ◽  
Shrinkage Stress ◽  
Element Analysis ◽  
Polymerization Shrinkage ◽  
Tooth Structure ◽  
Material Part ◽  
Von Mises ◽  
Pearson Correlations

SUMMARY Objectives Finite element analysis (FEA) was used to study polymerization shrinkage stress in molars restored with composites and to correlate those stresses with experimentally measured tooth deformation. Methods Three composites (Filtek LS, Aelite LS Posterior, Filtek Supreme) and three filling techniques (bulk, 2.0-mm increments, and 1.0-mm increments) for restoring a molar were simulated in a two-dimensional FEA. Polymerization shrinkage was modeled using post-gel shrinkage, which was measured using the strain gauge technique (n=10). Cuspal tooth deformation, measured at the buccal and lingual surfaces with strain gauges in a laboratory study, was used to validate the analysis. Residual shrinkage stresses were expressed in modified von Mises equivalent stresses. Linear Pearson correlations were determined between the laboratory and FEA results. Results Post-gel shrinkage values (in volume %) were: Filtek LS (0.11 ± 0.03) < Aelite LS Posterior (0.51 ± 0.02) < Filtek Supreme (0.62 ± 0.09). The 1.0-mm increment filling caused substantially higher stresses and strains in the cervical enamel region. Significant correlations were found between: elastic modulus and FEA strain, elastic modulus and FEA stress, post-gel shrinkage and FEA strain, post-gel shrinkage and FEA stress, FEA strain and cuspal deformation by strain gauge, and FEA stress and cuspal deformation by strain gauge (p<0.05). Conclusions Increasing the number of increments and high post-gel shrinkage and/or elastic modulus values caused higher stresses in the remaining tooth structure and tooth/restoration interface. Cuspal deformation measured with the strain gauge method validated the finite element analyses.

A Finite Element Analysis of the Residual Stress Distribution in the Interphase of Restoration-Tooth Structure

2011 ◽  
Vol 211-212 ◽  
pp. 710-714
Author(s):  
Shui Wen Zhu ◽  
Guo Ping Chen
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Residual Stress Distribution ◽  
Interfacial Stress ◽  
Elastic Behaviour ◽  
Element Analysis ◽  
Polymerization Shrinkage ◽  
Tooth Structure

The finite element analysis is presented in this paper in order to investigate residual stress distribution in the interphase of restoration-tooth structure due to polymerization shrinkage of resin-based composite. The restoration-tooth interface is simulated using plane elements of varying material properties and thicknesses. The stress within restored-tooth structure built-up from the polymerization shrinkage of the restorative composite were computed accounting for the time-dependent, visco-elastic behaviour of the composite. A sensitivity study is performed to examine the relative influence of geometric and material parameters of interphase on the shrinkage stress development. It was found that a correlation exists between material and geometry properties at the restoration-tooth interface and higher shrinkage stresses on interphase due to polymerization shrinkage. The development trend of residual stress from polymerization shrinkage in the restored-tooth structure was discussed and forecasted. The varying material and geometry properties of restoration-tooth interface seem to have conclusive effect on the interfacial stress system, as well as on the longevity of the restoration. From the purely mechanical point of view, this can result in interfacial debonding.

Vital Tooth Whitening Techniques. A literature Review

2020 ◽  
Vol 02 ◽  
Author(s):  
Pia Chatterjee Kirk
Keyword(s):  
Soft Tissues ◽  
Treatment Time ◽  
Tooth Bleaching ◽  
Tooth Whitening ◽  
Easy Method ◽  
Tooth Structure ◽  
Dental Esthetics ◽  
Total Treatment Time ◽  
Restorative Materials ◽  
Total Treatment

Background: Vital tooth whitening has become an integral part of esthetic dentistry and remains one of the safest and most economic options today to improve dental esthetics without removing tooth structure. The tooth whitening materials have evolved into three categories: dentist-prescribed/dispensed (in office and patient home-use), and over-thecounter purchased and applied by patients. Objective: This review outlines the latest advances in dentist prescribed vital teeth whitening techniques, effects on tooth structure, soft tissues, and dental restoratives. Areas requiring additional research are also discussed. Methods: Electronic and manual literature search was conducted for key words such as tooth bleaching, and dental bleaching techniques using PubMed/MEDLINE, followed by manual selection of the studies that included whitening procedures in vital teeth. Results: The two main whitening agents are carbamide peroxide (CP) and hydrogen peroxide (HP or H2O2) whose concentration, duration of contact, and total treatment time can alter results. In addition, factors including the type of stain, and age of patient can affect results. Although whitening agents can affect tooth structure, restorative materials, and gingival tissues, the changes are temporary or can be treated using minimally invasive techniques. Conclusion: Areas requiring further research include the actual mechanism of whitening, its effect on tooth structure and restorative materials, and the development of an easy method to quantitate the degree of whitening in the dental office.

scholarly journals Fractographical Analysis and Biomechanical Considerations of a Tooth Restored With Intracanal Fiber Post: Report of the Fracture and Importance of the Fiber Arrangements

2016 ◽  
Vol 41 (5) ◽  
pp. E149-E158 ◽  
Author(s):  
VF Wandscher ◽  
CD Bergoli ◽  
IF Limberger ◽  
TP Cenci ◽  
P Baldissara ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Glass Fiber ◽  
Shear Stresses ◽  
Fiber Post ◽  
Element Analysis ◽  
Parallel Fibers ◽  
Tooth Structure ◽  
Anterior Teeth ◽  
Compressive Stresses

SUMMARY Objective: This article aims to present a fractographic analysis of an anterior tooth restored with a glass fiber post with parallel fiber arrangement, taking into account force vectors, finite element analysis, and scanning electron microscopy (SEM). Methods: A patient presented at the Faculty of Dentistry (Federal University of Santa Maria, Brazil) with an endodontically treated tooth (ETT), a lateral incisor that had a restorable fracture. The treatment was performed, and the fractured piece was analyzed using stereomicroscopy, SEM, and finite element analysis. Results: The absence of remaining coronal tooth structure might have been the main factor for the clinical failure. We observed different stresses actuating in an ETT restored with a fiber post as well as their relationship with the ultimate fracture. Tensile, compression, and shear stresses presented at different levels inside the restored tooth. Tensile and compressive stresses acted together and were at a maximum in the outer portions and a minimum in the inner portions. In contrast, shear stresses acted concomitantly with tensile and compressive stresses. Shear was higher in the inner portions (center of the post), and lower in the outer portions. This was confirmed by finite element analysis. The SEM analysis showed tensile and compression areas in the fiber post (exposed fibers=tensile areas=lingual surface; nonexposed fibers=compression areas=buccal surface) and shear areas inside the post (scallops and hackle lines). Stereomicroscopic analysis showed brown stains in the crown/root interface, indicating the presence of microleakage (tensile area=lingual surface). Conclusion: We concluded that glass fiber posts with parallel fibers (0°), when restoring anterior teeth, present a greater fracture potential by shear stress because parallel fibers are not mechanically resistant to support oblique occlusal loads. Factors such as the presence of remaining coronal tooth structure and occlusal stability assist in the biomechanical equilibrium of stresses that act upon anterior teeth.

Polymerization shrinkage-strain and microleakage in dentin-bordered cavities of chemically and light-cured restorative materials

2002 ◽  
Vol 18 (7) ◽  
pp. 521-528 ◽  
Author(s):  
M. Rosin ◽  
A.D. Urban ◽  
C. Gärtner ◽  
O. Bernhardt ◽  
C. Splieth ◽  
...  
Keyword(s):  
Shrinkage Strain ◽  
Polymerization Shrinkage ◽  
Restorative Materials

The Silorane-based Resin Composites: A Review

2017 ◽  
Vol 42 (1) ◽  
pp. E24-E34 ◽  
Author(s):  
GA Maghaireh ◽  
NA Taha ◽  
H Alzraikat
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Clinical Significance ◽  
Physical And Mechanical Properties ◽  
Marginal Adaptation ◽  
Resin Composites ◽  
Restorative Material ◽  
Polymerization Shrinkage ◽  
Tooth Structure

SUMMARY This article aims to review the research done on the silorane-based resin composites (SBRC) regarding polymerization shrinkage and contraction stresses and their ability to improve the shortcomings of the methacrylate-based resin composites (MRBC). Special attention is given to their physical and mechanical properties, bond strength, marginal adaptation, and cusp deflection. The clinical significance of this material is critically appraised with a focus on the ability of SBRC to strengthen the tooth structure as a direct restorative material. A search of English peer-reviewed dental literature (2003-2015) from PubMed and MEDLINE databases was conducted with the terms “low shrinkage” and “silorane composites.” The list was screened, and 70 articles that were relevant to the objectives of this work were included.

scholarly journals Radiopacity of restorative materials using digital images

2006 ◽  
Vol 14 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Leda Maria Pescinini Salzedas ◽  
Mário Jefferson Quirino Louzada ◽  
Antonio Braz de Oliveira Filho
Keyword(s):  
Restorative Material ◽  
Radiographic Image ◽  
Equivalent Thickness ◽  
Tooth Structure ◽  
Suitable Material ◽  
Dental Tissues ◽  
Permanent Molar ◽  
Restorative Materials ◽  
Phosphor Plate ◽  
The Mean

The radiopacity of esthetic restorative materials has been established as an important requirement, improving the radiographic diagnosis. The aim of this study was to evaluate the radiopacity of six restorative materials using a direct digital image system, comparing them to the dental tissues (enamel-dentin), expressed as equivalent thickness of aluminum (millimeters of aluminum). Five specimens of each material were made. Three 2-mm thick longitudinal sections were cut from an intact extracted permanent molar tooth (including enamel and dentin). An aluminum step wedge with 9 steps was used. The samples of different materials were placed on a phosphor plate together with a tooth section, aluminum step wedge and metal code letter, and were exposed using a dental x-ray unit. Five measurements of radiographic density were obtained from each image of each item assessed (restorative material, enamel, dentin, each step of the aluminum step wedge) and the mean of these values was calculated. Radiopacity values were subsequently calculated as equivalents of aluminum thickness. Analysis of variance (ANOVA) indicated significant differences in radiopacity values among the materials (P<0.0001). The radiopacity values of the restorative materials evaluated were, in decreasing order: TPH, F2000, Synergy, Prisma Flow, Degufill, Luxat. Only Luxat had significantly lower radiopacity values than dentin. One material (Degufill) had similar radiopacity values to enamel and four (TPH, F2000, Synergy and Prisma Flow) had significantly higher radiopacity values than enamel. In conclusion, to assess the adequacy of posterior composite restorations it is important that the restorative material to be used has enough radiopacity, in order to be easily distinguished from the tooth structure in the radiographic image. Knowledge on the radiopacity of different materials helps professionals to select the most suitable material, along with other properties such as biocompatibility, adhesion and esthetic.

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