scholarly journals Functional or Nonfunctional Cusps Preservation for Molars Restored with Indirect Composite or Glass-Ceramic Onlays: 3D FEA Study

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3831
Author(s):  
Pablo Lenin Benitez Sellan ◽  
Larissa Mendes Campaner ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal de Oliveira Dal Piva ◽  
Guilherme Schmitt de de Andrade ◽  
...  
Keyword(s):  
Resin Composite ◽  
Contact Point ◽  
Tooth Structure ◽  
Traditional Design ◽  
Restorative Materials ◽  
Conservative Dentistry ◽  
3D Fea ◽  
Cad Cam ◽  
Von Mises ◽  
Preparation Design

Evidence regarding the effect of the onlay preparation design for different CAD/CAM restorative materials considering the preservation of cusps is lacking. Molars were 3D-modeled in four preparation designs for onlay restoration: traditional design with functional cusp coverage (TFC), non-retentive design with functional cusp coverage (NFC), traditional design with non-functional cusp coverage (TNFC) and non-retentive design with non-functional cusp coverage (NNFC). The restorations were simulated with two CAD/CAM restorative materials: LD—lithium disilicate (IPS e.max CAD) and RC—resin composite (GrandioBloc). A 100 N axial load was applied to the occlusal surface, simulating the centric contact point. Von Mises (VM) and maximum principal (Pmax) stress were evaluated for restorations, cement layer and dental substrate. The non-retentive preparation design reduced the stress concentration in the tooth structure in comparison to the conventional retentive design. For LD onlays, the stress distribution on the restoration intaglio surface showed that the preparation design, as well as the prepared cusp, influenced the stress magnitude. The non-retentive preparation design provided better load distribution in both restorative materials and more advantageous for molar structure. The resin composite restoration on thenon-functional cusp is recommended when the functional cusp is preserved in order to associate conservative dentistry and low-stress magnitude.

scholarly journals Functional or Nonfunctional Cusps Preservation for Posterior Onlays in Indirect Composite or Glass-Ceramic: 3D FEA Study

2021 ◽  
Author(s):  
Pablo Lenin Benitez Sellan ◽  
Larissa Mendes Campaner ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Guilherme Schmitt de Andrade ◽  
...  
Keyword(s):  
Resin Composite ◽  
Contact Point ◽  
Tooth Structure ◽  
Traditional Design ◽  
Restorative Materials ◽  
Conservative Dentistry ◽  
3D Fea ◽  
Cad Cam ◽  
Von Mises ◽  
Preparation Design

Evidence regarding the effect of the onlay preparation design for different CAD/CAM restorative materials considering the preservation of cusps is lacking. Molars were 3D modeled in four preparation designs for onlay restoration: traditional design with functional cusp coverage (TFC), non-retentive design with functional cusp coverage (NFC), traditional design with non-functional cusp coverage (TNFC), non-retentive design with non-functional cusp coverage (NNFC). Restorations were simulated with two CAD/CAM restorative materials: LD – lithium disilicate (IPS e.max CAD) and RC - resin composite (GrandioBloc). A 100 N axial load was applied to the occlusal surface simulating the centric contact point. Von Mises (VM) and maximum principal (Pmax) stresses were evaluated for restorations, cement layer and dental substrate. The non-retentive preparation design reduced the stress concentration in the tooth structure in comparison to the conventional retentive design. For LD onlays, the stress distribution on the restoration intaglio surface showed that the preparation design as well as the prepared cusp, influenced the stress magnitude. The non-retentive preparation design provided better load distribution in both restorative materials and more advantageous for tooth structure. The resin composite restoration on non-functional cusp is recommended when functional cusp is preserved, in order to associate conservative dentistry and low stress magnitude.

A Comparative Study of Light Transmission by Various Dental Restorative Materials and the Tooth Structure

2019 ◽  
Vol 45 (4) ◽  
pp. 442-452 ◽  
Author(s):  
N Ilie ◽  
G Furtos
Keyword(s):  
Optical Properties ◽  
Glass Ceramic ◽  
Light Transmission ◽  
Lithium Disilicate ◽  
Lithium Silicate ◽  
Restorative Process ◽  
Tooth Structure ◽  
Computer Aided ◽  
Restorative Materials ◽  
Cad Cam

Clinical Relevance Light transmission through dental materials and tooth structure has direct clinical implication on such factors as selecting an appropriate curing technique during a restorative process. SUMMARY Introduction: This study aims to quantify and compare the amount of light that passes through seven different types of direct and indirect restorative materials comprising light-cured resin based composites (regular and bulk-fill), computer-aided design/computer-aided manufacturing (CAD/CAM) restoratives such as resin based composites, poly(methyl methacrylate) (PMMA) resin, leucite glass-ceramic, lithium silicate glass-ceramic, feldspar ceramic, and the natural tooth structure. Methods and Materials: Individual sets (n=6) of plane-parallel test specimens (2 mm) of 32 restorative materials belonging to the aforementioned seven material types and the tooth structure were prepared. Within the analyzed materials, one leucite glass-ceramic and one lithium disilicate glass-ceramic were considered in two different translucencies. In addition, two light-cured resin composites, one CAD/CAM resin composite, and one lithium disilicate glass-ceramic were considered in two different shades. Optical properties (transmittance, T; absorbance, A; and opacity, O) of each material were calculated from the relationship between incident and transmitted irradiance [I(d)] using a violet-blue light-curing unit. Incident and transmitted irradiance were assessed in real time on a spectrophotometer. A multivariate analysis (general linear model) assessed the effects of various parameters on the optical properties. Results: A very strong influence of the parameter material was identified on I(d) (p<0.001; partial eta squared, ηP2=0.953), T (p<0.001; ηP2=0.951), A (p<0.001; ηP2=0.925), and O (p<0.001; ηP2=0.886), while the effect of the parameter material type was not significant (p=0.079, p=0.05, p=0.05, and p=0.051, respectively). Light attenuation differed significantly by material within each shade category and by shade category within the analyzed material. Conclusions: Attenuation of light through restorative materials and tooth structure is high (59.9% to 94.9%); thus, deficits in polymerization are difficult to compensate for by additional light exposure at the end of the restorative process.

scholarly journals Effect of Direct and Indirect Materials on Stress Distribution in Class II MOD Restorations: A 3D-Finite Element Analysis Study

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Şemsi Alp ◽  
Laden Gulec Alagoz ◽  
Nuran Ulusoy
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Class Ii ◽  
Element Analysis ◽  
3D Finite Element ◽  
3D Finite Element Analysis ◽  
3D Cad ◽  
Restorative Materials ◽  
Cad Cam ◽  
Von Mises

The aim of this study is to investigate the stress distributions of different restoration options for class II mesio-occluso-distal (MOD) cavities. A class II MOD cavity with proximal box gingival floor 1 mm below cementoenamel junction was designed in a mandibular first molar tooth model. 3D finite-element analysis (FEA) and 3D-CAD modelling were used to examine the occlusal stresses distributed to the remaining buccal enamel (RBE), remaining lingual enamel (RLE), adhesive surfaces, and restorative materials by direct and indirect materials resulting from a 600 N of static occlusal load stimulating foodstuff. von Mises (VM) and maximum principal (Pmax) stresses were evaluated for two CAD/CAM materials and three direct materials. CAD/CAM materials exerted less stress than the direct restorative materials. Significant von Mises and Pmax stress value differences were seen among all restoration models on RBE. Reducing RLE and including it into the cavity would be a more effective option for this model in this scenario. As VM and Pmax stresses of PIHC CAD/CAM material for RBE and dentin were significantly lower than other tested materials, it may be the choice of material for indirect MOD restorations.

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.

Mechanical degradation of contemporary CAD/CAM resin composite materials after water ageing

2021 ◽  
Author(s):  
Michael Wendler ◽  
Anja Stenger ◽  
Julian Ripper ◽  
Eva Priewich ◽  
Renan Belli ◽  
...  
Keyword(s):  
Composite Materials ◽  
Resin Composite ◽  
Mechanical Degradation ◽  
Cad Cam

The Potential of a Bioactive, Pre-reacted, Glass-Ionomer Filler Resin Composite to Inhibit the Demineralization of Enamel in Vitro

2021 ◽  
Vol 46 (1) ◽  
pp. E11-E20
Author(s):  
IF Leão ◽  
N Araújo ◽  
CK Scotti ◽  
RFL Mondelli ◽  
MM de Amoêdo Campos Velo ◽  
...  
Keyword(s):  
Resin Composite ◽  
Surface Hardness ◽  
Composition Analysis ◽  
Glass Ionomer ◽  
Material Interface ◽  
Enamel Demineralization ◽  
Restorative Materials ◽  
Ph Cycling ◽  
Group B

Clinical Relevance A prereacted, glass-ionomer filler fluoride-containing resin composite had lower remineralization potential than glass-ionomer cements but was able to inhibit enamel demineralization; thus, it may be an option for restoring dental surfaces for patients at high risk of caries. SUMMARY Evidence is lacking on the use of surface prereacted glass-ionomer filler resin composites to inhibit demineralization and that simulate real clinical conditions. The present laboratory study evaluated the potential of such composites to prevent demineralization and quantified fluoride (F) and other ions released from restorative materials after a dynamic pH-cycling regimen applied to the tooth material interface in vitro. The pH-cycling regimen was assessed by measuring surface hardness (SH) along with energy dispersive X-ray spectroscopy (EDX). Methods and Materials: Ninety blocks of bovine enamel were subjected to composition analysis with EDX, and were further categorized based on SH. The blocks were randomly divided into 6 treatment groups (n=15 each): F IX (Fuji IX Extra; GC Corporation); IZ (Ion Z, FGM); F II (Fuji II LC, GC Corporation); B II (Beautifil II, Shofu); F250 (Filtek Z250 XT, 3M ESPE); and NT (control, no treatment). The blocks were subjected to a dynamic pH-cycling regimen at 37°C for 7 days concurrently with daily alternations of immersion in demineralizing/remineralizing solutions. EDX was conducted and a final SH was determined at standard distances from the restorative materials (150, 300, and 400 μm). Results: The EDX findings revealed a significant increase in F concentration and a decrease in Ca2+ in the enamel blocks of group B II after the pH-cycling regimen (p<0.05). SH values for groups F IX, IZ, and F II were greater than those for groups B II, F250, and NT at all distances from the materials. Conclusions: The results suggest that each of 3 restorative materials, F IX, IZ, and F II, partially inhibited enamel demineralization under a dynamic pH-cycling regimen.

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