Fatigue Failure Load of Restored Premolars: Effect of Etching the Intaglio Surface of Ceramic Inlays With Hydrofluoric Acid at Different Concentrations

2018 ◽  
Vol 43 (2) ◽  
pp. E81-E91
Author(s):  
T Missau ◽  
AB Venturini ◽  
GKR Pereira ◽  
C Prochnow ◽  
LF Valandro ◽  
...  
Keyword(s):  
Fatigue Failure ◽  
Hydrofluoric Acid ◽  
Computer Aided Design ◽  
Failure Load ◽  
Acrylic Resin ◽  
Test Machine ◽  
Staircase Method ◽  
Ceramic Inlays ◽  
Computer Aided ◽  
Failure Loads

SUMMARY The aim of this study was to evaluate the effect of etching, with different hydrofluoric acid concentrations at the intaglio surface of feldspathic ceramic inlays, on the fatigue failure load of restored premolars. A total of 60 upper premolars were embedded in plastic cylinders with acrylic resin (up to 3 mm below the cement-enamel junction) and prepared using a device specially designed for that purpose. Teeth were randomly assigned to three groups (n=20): HF1, HF5, and HF10 (etching with hydrofluoric acid for 60 seconds at concentrations of 1%, 5%, and 10%, respectively). Preparations were scanned and restorations were milled by a computer-aided design / computer-aided manufacturing system. The inner surfaces of the inlays were etched and received an application of a silane coupling agent; the dentin and enamel were treated appropriately for the luting system (RelyX ARC, 3M-ESPE). The restorations were cemented and the fatigue failure load (in N) was determined using the staircase method (10 Hz; 105 cycles in each step). The initial load (585.5 N) was applied on the slopes of the cusps (labial and palatal/lingual, simultaneously) through a cylinder attached to the test machine (Instron ElectroPuls E3000). The tested samples were analyzed under a stereomicroscope for failure analysis. Fatigue data were analyzed by one-way analysis of variance. There was no statistical difference among the fatigue failure loads (in N): HF1 (448.5±79.1), HF5 (360.7±55.4), and HF10 (409.5±121.1). Regarding the fracture mode, there was a predominance of interfacial fracture (50%), followed by cusp fracture (34.6%). It may be concluded that the etching with hydrofluoric acid at the tested concentrations (1%, 5%, and 10%) does not influence the fatigue failure load of feldspathic ceramic inlays cemented on premolars.

Endodontic Access Effect on Full Contour Zirconia and Lithium Disilicate Failure Resistance

2020 ◽  
Vol 45 (3) ◽  
pp. 276-285
Author(s):  
J Mallya ◽  
N DuVall ◽  
J Brewster ◽  
H Roberts
Keyword(s):  
Computer Aided Design ◽  
Failure Load ◽  
Fatigue Testing ◽  
Resin Composite ◽  
Glass Ionomer Cement ◽  
Surface Preparation ◽  
Lithium Disilicate ◽  
Load Resistance ◽  
Core Material ◽  
Computer Aided

SUMMARY Objectives: To evaluate the effect of endodontic access on the failure load resistance of both adhesively and conventionally luted, full-contour monolithic yttria-stabilized zirconium dioxide (Y-TZP) and adhesively luted lithium disilicate (LD) crowns cemented on prepared teeth. Methods and Materials: Seventy-two human maxillary molars were prepared per respective guidelines for all-ceramic crowns with one group (n=24) restored with LD and the other (n=48) receiving Y-TZP crowns. Preparations were scanned using computer-aided design/computer-aided milling (CAD/CAM) technology, and milled crowns were sintered following manufacturer recommendations. All LD crowns and half (n=24) of the Y-TZP crowns were adhesively cemented, while the remaining Y-TZP specimens were luted using a conventional glass ionomer cement (GIC). One LD group, one Y-TZP adhesive group, and one GIC-luted group (all n=12) then received endodontic access preparations by a board-certified endodontist: the pulp chambers were restored with a dual-cure, two-step, self-etch adhesive and a dual-cure resin composite core material. The access preparations were restored using a nano-hybrid resin composite after appropriate ceramic margin surface preparation. After 24 hours, all specimens were loaded axially until failure; mean failure loads were analyzed using Mann-Whitney U test (α=0.05) Results: Endodontic access did not significantly reduce the failure load of adhesively luted LD or Y-TZP crowns, but Y-TZP crowns with GIC cementation demonstrated significantly less failure load. Conclusions: These initial findings suggest that endodontic access preparation may not significantly affect failure load resistance of adhesively luted Y-TZP and LD crowns. Definitive recommendations cannot be proposed until fatigue testing and coronal seal evaluations have been accomplished.

Fracture Strength and Precision of Fit of Implant-Retained Monolithic Zirconia Crowns

2018 ◽  
Vol 44 (5) ◽  
pp. 330-334 ◽  
Author(s):  
Pauliina Moilanen ◽  
Jenni Hjerppe ◽  
Lippo V. J. Lassila ◽  
Timo O. Närhi
Keyword(s):  
Fracture Strength ◽  
Computer Aided Design ◽  
Testing Machine ◽  
Implant Surface ◽  
Computer Aided ◽  
Cad Cam ◽  
Zirconia Crowns ◽  
Failure Loads ◽  
Monolithic Zirconia ◽  
Aided Design

New monolithic zirconia materials can be used to fabricate full-contour fixed dental prostheses with the computer-aided design/computer-aided manufacturing (CAD/CAM) method. The aim of this study was to examine the fracture strength and precision of fit of screw-retained monolithic zirconia crowns made directly on implants or by cementing on prefabricated titanium (Ti) bases. Monolithic screw-retained implant crowns (n = 6) were produced by CAD/CAM method using partially (PSZ) and fully stabilized (FSZ) zirconia. Industrially produced zirconia crowns were used as a reference. A lateral incisor study model was made onto an implant replica. Crowns were produced either directly on the implant or through cementing on a prefabricated titanium base (PSZ+Ti, FSZ+Ti). The crowns were tightened to implant replicas with a torque of 35 Ncm. The gap between the replica and the abutment or crown was measured from ×400 scanning electron microscope images for precision of fit. Mechanical testing until failure was completed with a universal testing machine with loading angle of 45°. Statistical analysis was performed (analysis of variance). Mean (±SD) failure loads were 259 ± 23 (PSZ), 140 ± 13 (FSZ), 453 ± 25 (PSZ+Ti), 439 ± 41 (FSZ+Ti), and 290 ± 39 (Procera). Mean (±SD) gap values were 2.2 ± 0.2 (PSZ), 2.5 ± 1.0 (FSZ), 7.0 ± 1.0 (PSZ+Ti), 7.7 ± 1.6 (FSZ+Ti), and 6.7 ± 1.7 (Procera). Monolithic zirconia crowns with a Ti base clearly show higher fracture strengths than the crowns fixed directly on the implant surface. Better marginal fit can be achieved with direct zirconia crowns than with crowns on a titanium base or industrially produced zirconia crowns.

scholarly journals REJUVENATING EDENTULISM USING CAD-CAM TECHNOLOGY: A COMPREHENSIVE REVIEW

2020 ◽  
Vol 8 (9) ◽  
pp. 1233-1243
Author(s):  
Suresh Kamble ◽  
◽  
Ajit Jankar ◽  
Pratiksha Somwanshi ◽  
Shirish Pawar ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Oral Care ◽  
Public Health Problem ◽  
Acrylic Resin ◽  
Cost Of Care ◽  
Complete Dentures ◽  
Denture Base ◽  
Removable Denture ◽  
Computer Aided ◽  
Cad Cam

Edentulism has been a severe public health problem in industrialized countries due to aging and poor oral care. Design and fabrication of the complete dentures are mainly using conventional methods involving an enormous series of clinical and laboratory procedures. Edentulous patients have to make several visits to the clinic for the traditional fabrication of denture. Now the unceasing developments occur over several years. Present-day technological innovations allow the use of various systems with computer‑aided design/computer‑aided manufacture (CAD/CAM) technology to produce complete dentures has seen exponential growth. There are different manufacturing techniques of CAD-CAM complete denture like AvaDent, Wieland digital denture, Baltic denture, DENTC system. CAD-CAM technology requires only two appointments for the patient to get their complete removable denture. A reduction in clinical chair time also shortens the cost of care. The improved fit of the denture was because of fewer processing errors. It simplifies the re-manufacturing of lost/broken prostheses due to the digital storage of denture data. The pre-polymerized acrylic resin used by manufacturers for the fabrication of a denture base delivers excellent fit and strength when compared to conventionally processed bases. It doesnt show any polymerization shrinkage as there is a less residual monomer. Hence, it reduces the potential infections as fewer candida albicans attach to the denture bases. The motive of this article is to highlights the benefits of CAD-CAM technology over conventional denture fabrication.

Fatigue failure load of feldspathic ceramic crowns after hydrofluoric acid etching at different concentrations

2018 ◽  
Vol 119 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Andressa B. Venturini ◽  
Catina Prochnow ◽  
Liliana G. May ◽  
Cornelis J. Kleverlaan ◽  
Luiz Felipe Valandro
Keyword(s):  
Fatigue Failure ◽  
Hydrofluoric Acid ◽  
Failure Load ◽  
Acid Etching ◽  
Ceramic Crowns

Tribological Prototype for Wear Tests on Pavement Surfaces

2014 ◽  
Vol 902 ◽  
pp. 121-128
Author(s):  
E.E. Vera Cardenas ◽  
F. González Hernández ◽  
M.A. Flores Rentería
Keyword(s):  
Computer Aided Design ◽  
Quality Function Deployment ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Test Machine ◽  
Element Analysis ◽  
Computer Aided ◽  
Static Conditions ◽  
Aided Design

In this work the design and manufacturing of a new test machine to simulate the Rolling Contact Fatigue (RCF) wear on pavement surfaces is carried out. The method of Quality Function Deployment (QFD) was used to determine the conceptual design of the machine; from this a detailed design of the machine was developed, through additional computer aided design software. The machine basically consists of a frame and two mechanisms; one is for transmitting the force and the other one the motion. The static conditions were calculated and a finite element analysis was performed by computer aided engineer software to determine the failure due to mechanical stresses. Finally it is showed the machine assembly and some preliminary tests in order to verify the performance of the tribological prototype.

Fatigue Failure Load of a Bonded Simplified Monolithic Feldspathic Ceramic: Influence of Hydrofluoric Acid Etching and Thermocycling

2020 ◽  
Vol 45 (1) ◽  
pp. E21-E31 ◽  
Author(s):  
LF Guilardi ◽  
GKR Pereira ◽  
AS Vallau ◽  
IA Silva ◽  
JC Giordani ◽  
...  
Keyword(s):  
Fatigue Failure ◽  
Fatigue Resistance ◽  
Hydrofluoric Acid ◽  
Failure Load ◽  
Statistical Tests ◽  
Resin Cement ◽  
Ceramic Surface ◽  
Adhesive Cementation ◽  
Ceramic Restorations ◽  
O 10

SUMMARY Objective: To evaluate the effect of hydrofluoric acid (HF) etching and thermocycling (Tc) on fatigue failure load of feldspathic ceramic restorations cemented with two resin cements. Methods: Disc-shaped feldspathic ceramic (Vitablocs Mark II; Ø=10 mm, 1.0-mm thick) and G10 epoxy resin (Ø=10 mm, 2.5-mm thick) specimens were made and randomly allocated considering three factors: ceramic etching (ie, with vs without 10% HF plus silane application), resin cement (ie, self-adhesive [RelyX U200; U200] or conventional [Multilink Automix; MA]), and Tc (ie, with vs without 5-55°C/12,000 cycles). Adhesive cementation followed each manufacturer's instructions. The fatigue test (n=20) was based on the staircase approach (250,000 cycles; 20 Hz). Contact angle, surface topography, and fractography analysis were also executed. Specific statistical tests were employed for each outcome (α=0.05). Results: The interaction of HF and Tc factors decreased the fatigue resistance for both cements (U200 542.63>U200/HF-Tc 495.00; MA 544.47>MA/HF-Tc 506.84). Comparing the cements associated with HF or Tc, there was statistical superiority for MA (U200-Tc 537.37<MA-Tc 561.32; U200/HF 535.79<MA/HF 557.11), and no statistical difference was detected when only cement type or its association with HF-Tc was compared (U200 542.63=MA 544.47; U200/HF-Tc 495.00=MA/HF-Tc 506.84). The fracture always originated from defects at the ceramic-intaglio surface as radial cracks. Conclusion: HF etching plus silane agent increased the ceramic surface free energy and its wettability, but it did not provide better results in terms of fatigue resistance compared with silane agent application only. The association of HF etching and aging significantly reduced the fatigue resistance of the material, regardless of the resin cement used.

scholarly journals Influence of Polymeric Restorative Materials on the Stress Distribution in Posterior Fixed Partial Dentures: 3D Finite Element Analysis

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 758
Author(s):  
Larissa Mendes Campaner ◽  
Marcos Paulo Motta Silveira ◽  
Guilherme Schmitt de Andrade ◽  
Alexandre Luiz Souto Borges ◽  
Marco Antonio Bottino ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Computer Aided Design ◽  
Resin Composite ◽  
Acrylic Resin ◽  
Element Analysis ◽  
Stress Criterion ◽  
Biomechanical Behavior ◽  
Computer Aided ◽  
Restorative Materials ◽  
Abutment Teeth

Background: This study evaluated the effect of interim restorative materials (acrylic resin (AR), resin composite (RC) or polyetheretherketone (PEEK) for dental computer-aided design/computer-aided manufacturing (CAD/CAM)) on the stress distribution of a posterior three-unit fixed partial denture. Methods: The abutment teeth (first molar and first premolar) were modeled using the BioCAD protocol containing 1.5 mm of axial reduction and converging axial walls. A static structural analysis was performed in the computer-aided engineering software, and the Maximum Principal Stress criterion was used to analyze the prosthesis and the cement layers of both abutment teeth. The materials were considered isotropic, linearly elastic, homogeneous and with bonded contacts. An axial load (600 N) was applied to the occlusal surface of the second premolar. Results: Regardless of the restorative material, the region of the prosthetic connectors showed the highest tensile stress magnitude. The highest stress peak was observed with the use of RC (129 MPa) compared to PEEK and AR. For the cement layers, RC showed the lowest values in the occlusal region (7 MPa) and the highest values for the cervical margin (14 MPa) compared to PEEK (21 and 12 MPa) and AR (21 and 13 MPa). Conclusions: Different interim restorative materials for posterior fixed partial dentures present different biomechanical behavior. The use of resin composite can attenuate the stress magnitude on the cement layer, and the use of acrylic resin can attenuate the stress magnitude on the connector region.

scholarly journals Evaluation of Fracture Resistance and Microleakage of Endocrowns with Different Intracoronal Depths and Restorative Materials Luted with Various Resin Cements

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2528 ◽  
Author(s):  
Ouqba Ghajghouj ◽  
Simge Taşar-Faruk
Keyword(s):  
Computer Aided Design ◽  
Fracture Resistance ◽  
Failure Modes ◽  
Numerical Data ◽  
Lithium Disilicate ◽  
Load Test ◽  
Test Machine ◽  
Cavity Depth ◽  
Computer Aided ◽  
Cad Cam

The aim of this study was to determine the effect of restoration design on the fracture resistance of different computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics and investigate the marginal leakage of endocrowns according to different types of cement. In total, 96 extracted mandibular first premolars were used for fabrication of endocrowns; 48 of the endocrowns were divided into 6 groups (n = 8) according to intracoronal cavity depth (2 and 3 mm) and CAD/CAM ceramics (lithium disilicate IPS e.max-CAD, zirconia-reinforced glass-ceramic Vita Suprinity, and poly-ether-ether-ketone (PEEK)). Teeth were subjected to a fracture resistance test with a universal test machine following thermo-cycling. Failure modes were determined by stereomicroscope after the load test. The rest of the endocrowns (n = 48) were produced by Vita Suprinity ceramic and divided into 6 groups (n = 8) according to the cement used (Panavia V5, Relyx Ultimate, and GC cement) with intracoronal cavity depths of 2 and 3 mm. Microleakage tests were performed using methylene blue with stereomicroscope after thermo-cycling. Numerical data for both fracture resistance and microleakage tests were obtained and evaluated by three-way ANOVA. PEEK endocrowns had higher fracture resistance compared to lithium disilicate and Vita Suprinity. Panavia V5 cement had the lowest degree of microleakage, while GC cement had the highest. Different intracoronal cavity depths had no correlation with fracture resistance and microleakage.

The effect of hydrofluoric acid concentration on the fatigue failure load of adhesively cemented feldspathic ceramic discs

2018 ◽  
Vol 34 (4) ◽  
pp. 667-675 ◽  
Author(s):  
Andressa B. Venturini ◽  
Catina Prochnow ◽  
Gabriel K.R. Pereira ◽  
Arie Werner ◽  
Cornelis J. Kleverlaan ◽  
...  
Keyword(s):  
Fatigue Failure ◽  
Acid Concentration ◽  
Hydrofluoric Acid ◽  
Failure Load
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