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.

scholarly journals Comparison of Optical Properties of Laminate Veneers Made of Zolid FX and Katana UTML Zirconia and Lithium Disilicate Ceramics

2020 ◽  
Author(s):  
Fariborz Vafaei ◽  
Alireza Izadi ◽  
Samaneh Abbasi ◽  
Maryam Farhadian ◽  
Zahra Bagheri
Keyword(s):  
Experimental Study ◽  
Optical Properties ◽  
Computer Aided Design ◽  
Composite Resin ◽  
Lithium Disilicate ◽  
Laminate Material ◽  
Computer Aided ◽  
Aided Design ◽  
Laminate Veneers

Objectives: This study aimed to compare the optical properties of Zolid FX, Katana UTML, and lithium disilicate laminate veneers. Materials and Methods: In this in-vitro experimental study, the maxillary left lateral incisor of a phantom received a laminate veneer preparation. An impression was made, and a die was fabricated using dental stone. The die was scanned using a computer-aided design/computer-aided manufacturing scanner. Ten dies were fabricated from each of the A1, A2, and A3 shades of composite resin. Laminate veneers were fabricated using A1 shade of Katana UTML, Zolid FX, and IPS e.max CAD ceramics (n=10) and placed on composite abutments using bleach and white colors of trial insertion paste (TIP). The optical properties were measured at the incisal, middle, and cervical thirds using a spectrophotometer. Data were analyzed using three-way analysis of variance and Tukey’s test. Results: The effect of laminate material on the L*, a*, and b* parameters was significant in all areas (P<0.001), except for the L* parameter in the middle and cervical thirds. All color parameters were affected by TIP color in all three regions in most samples (P<0.05). The effect of composite abutment shade was also significant in most cases (P<0.05). The effect of laminate material, abutment shade, and TIP color on the b* parameter was significant (P<0.001). The L* parameter was almost the same in the two zirconia and lithium disilicate ceramic groups. Conclusion: The composite abutment shade, TIP color, and laminate material should be carefully selected to achieve optimal aesthetics in laminate veneers.

Premolar Axial Wall Height Effect on CAD/CAM Crown Retention

2016 ◽  
Vol 41 (6) ◽  
pp. 666-671 ◽  
Author(s):  
C Gillette ◽  
R Buck ◽  
N DuVall ◽  
S Cushen ◽  
M Wajdowicz ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Failure Resistance ◽  
All Ceramic ◽  
Computer Aided ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Aided Design ◽  
Post Hoc

SUMMARY Objective: To evaluate the significance of reduced axial wall height on retention of adhesively luted, all-ceramic, lithium disilicate premolar computer-aided design/computer-aided manufacturing (CAD/CAM) crowns based on preparations with a near ideal total occlusal convergence of 10°. Methods: Forty-eight recently extracted premolars were randomly divided into four groups (n=12). Each group received all-ceramic CAD/CAM crown preparations featuring axial wall heights of 0, 1, 2, and 3 mm, respectively, all with a 10° total occlusal convergence. Scanned preparations were fitted with lithium disilicate all-ceramic crowns that were luted with a self-etching resin cement. Specimens were tested to failure at a 45° angle to the tooth long axis with failure load converted to megapascals (MPa) based on the measured bonding surface area. Mean data were analyzed using analysis of variance/Tukey's post hoc test (α=0.05). Results: Lithium disilicate crowns adhesively luted on preparations with 0 axial wall height demonstrated significantly less failure resistance compared with the crowns luted on preparations with axial wall heights of 1 to 3 mm. There was no failure stress difference between preparations with 1 to 3 mm axial wall height. Conclusions: Under conditions of this study, adhesively luted lithium disilicate bicuspid crowns with a total occlusal convergence of 10° demonstrated similar failure resistance independent of axial wall height of 1 to 3 mm. This study provides some evidence that adhesion combined with an ideal total occlusal convergence may compensate for reduced axial wall height.

Effect of Repeated Firings on Microtensile Bond Strength of Bi-layered Lithium Disilicate Ceramics (e.max CAD and e.max Press)

2016 ◽  
Vol 17 (7) ◽  
pp. 530-535 ◽  
Author(s):  
Hamid Jalali ◽  
Zeinab Bahrani ◽  
Somayeh Zeighami
Keyword(s):  
Bond Strength ◽  
Computer Aided Design ◽  
Tensile Load ◽  
Lithium Disilicate ◽  
Firing Cycle ◽  
Microtensile Bond Strength ◽  
The Core ◽  
Significant Difference ◽  
Computer Aided ◽  
Aided Design

ABSTRACT Aim To achieve acceptable contour, color, esthetics, and occlusal relations, the porcelain may be subjected to several firing cycles. This study sought to assess the effect of multiple firing cycles on the microtensile bond strength (MTBS) of lithium disilicate-based ceramics (e.max Press, e.max CAD). Materials and methods IPS e.max computer aided design (CAD) cores were fabricated using CAD/(Computer Aided Manufacturing (CAM)) technology, and IPS e.max Press cores were fabricated using the heat-pressing technique (12 × 12 × 4 mm3). Cores in each group were divided into three subgroups based on the number of firing cycles (three, five, and seven cycles). After porcelain application, the samples were sectioned into microbars and a total of 20 sound microbars in each group were subjected to tensile load in a microtensile tester at a crosshead speed of 1 mm/minute. Microtensile bond strength of the core to the veneering porcelain was analyzed using one-way analysis of variance (ANOVA). Pairwise comparisons were made using the Tukey's test (p < 0.05). Results In the e.max CAD, the mean MTBS values were 22.07 ± 6.63, 34.68 ± 7.07, and 26.05 ± 10.29 MPa following three, five, and seven firing cycles respectively. These values for the e.max Press were 34.46 ± 9.28, 23.09 ± 5.02, and 31.26 ± 12.25 MPa respectively. There was significant difference in bond strength of e.max CAD (p < 0.003) and e.max Press (p < 0.002) based on the number of firing cycles. Conclusion Increasing the number of porcelain firing cycles decreased the bond strength of the core to the veneering porcelain in both ceramics. Clinical significance It is better to decrease the number of firing cycle as much as possible. How to cite this article Jalali H, Bahrani Z, Zeighami S. Effect of Repeated Firings on Microtensile Bond Strength of Bi-layered Lithium Disilicate Ceramics (e.max CAD and e.max Press). J Contemp Dent Pract 2016;17(7):530-535.

scholarly journals Torsional strength of computer-aided design/computer-aided manufacturing–fabricated esthetic orthodontic brackets

2016 ◽  
Vol 87 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Najla Alrejaye ◽  
Richard Pober ◽  
Russell Giordano II
Keyword(s):  
Computer Aided Design ◽  
Resin Composite ◽  
Orthodontic Brackets ◽  
Computer Aided Manufacturing ◽  
Torsional Strength ◽  
Computer Aided ◽  
Ceramic Brackets ◽  
The Mean ◽  
Materials Used ◽  
Aided Design

ABSTRACTObjective: To fabricate orthodontic brackets from esthetic materials and determine their fracture resistance during archwire torsion.Materials and Methods: Computer-aided design/computer-aided manufacturing technology (Cerec inLab, Sirona) was used to mill brackets with a 0.018 × 0.025-inch slot. Materials used were Paradigm MZ100 and Lava Ultimate resin composite (3M ESPE), Mark II feldspathic porcelain (Vita Zahnfabrik), and In-Ceram YZ zirconia (Vita Zahnfabrik). Ten brackets of each material were subjected to torque by a 0.018 × 0.025-inch stainless steel archwire (G&H) using a specially designed apparatus. The average moments and degrees of torsion necessary to fracture the brackets were determined and compared with those of commercially available alumina brackets, Mystique MB (Dentsply GAC).Results: The YZ brackets were statistically significantly stronger than any other tested material in their resistance to torsion (P &lt; .05). The mean torques at failure ranged from 3467 g.mm for Mark II to 11,902 g.mm for YZ. The mean torsion angles at failure ranged from 15.3° to 40.9°.Conclusion: Zirconia had the highest torsional strength among the tested esthetic brackets. Resistance of MZ100 and Lava Ultimate composite resin brackets to archwire torsion was comparable to commercially available alumina ceramic brackets.

Monolithic Lithium Disilicate Full-Contour Crowns Bonded on CAD/CAM Zirconia Complete-Arch Implant Bridges With 3 to 5 Years of Follow-Up

2015 ◽  
Vol 41 (4) ◽  
pp. 450-458 ◽  
Author(s):  
Alessandro Pozzi ◽  
Marco Tallarico ◽  
Alberto Barlattani
Keyword(s):  
Soft Tissue ◽  
Computer Aided Design ◽  
Lithium Disilicate ◽  
Additional Treatment ◽  
Success Rates ◽  
Association Index ◽  
Randomized Controlled Studies ◽  
Computer Aided ◽  
Cad Cam

This study was carried on to assess the clinical performance of a novel restorative concept consisting in single monolithic lithium disilicate full-contour crowns bonded on computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia complete-arch implant bridges, to overcome the drawbacks related to the chipping of porcelain fused to zirconia restorations. Sixteen patients received 18 implant-supported hybrid screw-cement-retained complete-arch restorations, consisting of single monolithic lithium disilicate full-contour crowns bonded on CAD/CAM zirconia frameworks. The restorations were supported by 4–8 implants. All patients were followed up for at least 3 years on function (range 36 to 60 months, mean 49.3 months). Clinical controls were scheduled every 4 months. The outcomes were implant and prosthetic survival and success rates, any complications, patient satisfaction, and soft tissue parameters. No dropouts occurred. The overall implant and prosthesis survival rates were 100%. One of 18 restorations (1 of 236 dental units) showed a chip-off fracture of the veneering ceramic that was polished intraorally without any additional treatment, scoring a cumulative prosthetic success rate of 100%, according to the California Dental Association index. All patients were functionally and esthetically highly satisfied with their restorations. Successful soft tissue parameters were found around all implants. Single monolithic lithium disilicate full-contour crowns, bonded on CAD/CAM screw-retained complete-arch zirconia frameworks, showed favorable preliminary outcomes with medium-term follow-up. However, randomized controlled studies of this technique are required for further conclusive recommendations.

scholarly journals Spatial Distribution of the Micro-Mechanical Properties in High-Translucent CAD/CAM Resin-Composite Blocks

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3352 ◽  
Author(s):  
Nicoleta Ilie
Keyword(s):  
Spatial Distribution ◽  
Computer Aided Design ◽  
Mechanical Performance ◽  
Resin Composite ◽  
Inorganic Filler ◽  
Homogeneous Distribution ◽  
Indentation Modulus ◽  
Computer Aided ◽  
Cad Cam

Industrially cured, high-translucent computer-aided design/computer-aided manufacturing (CAD/CAM) resin-based composites (RBC) are the most recently launched dental restoratives. Clinical treatments and laboratory tests are based on a homogeneous distribution of properties within CAD/CAM blocks to obtain constant and reproducible results. The study therefore aims to determine the spatial distribution of various micro-mechanical parameters (Vickers hardness, Martens hardness, indentation modulus, creep, elastic and total indentation work) in five representative CAD/CAM RBCs. The properties of the tooth structure were evaluated under similar conditions. Filler size and shape were analyzed by scanning electron microscopy. A multivariate analysis (general linear model) identified a very strong influence of the material on all measured properties (p < 0.001; partial eta squared ηP2 > 0.943), whereby the most sensitive parameters when identifying differences within regions were the indentation modulus and the elastic indentation work. CAD/CAM RBC blocks show gradually varying properties that can increase or decrease from central to peripheral areas regardless of the chemical composition of the materials or the inorganic filler fraction. The degree of variation in the measured properties is material-specific and less than 8.7%. Clinical applications and in vitro study designs should consider slight inhomogeneity in CAD/CAM RBC blocks, while the location of the regions with best mechanical performance depends on the material.

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.

scholarly journals Efeito da fumaça de cigarro e escovação simulada na cêramica vítrea de dissilicato de lítio CAD/CAM

2021 ◽  
Vol 13 (4) ◽  
pp. e7296
Author(s):  
Magna Andréa Rabêlo Diógenes ◽  
Francisca Tauliane Lemos de Castro ◽  
Samara Kelly da Silva Cavalcante ◽  
Ana Carolina Matias Dinelly Pinto ◽  
Pedro Henrique Chaves Isaias ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Lithium Disilicate ◽  
Computer Aided Manufacturing ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design

Objetivo: Revisar acerca do efeito da fumaça do cigarro, associada ou não à escovação, na rugosidade superficial e na microdureza de uma cerâmica vítrea de dissilicato de lítio “Computer-Aided Design/Computer-Aided Manufacturing” (CAD/CAM). Métodos: Pesquisaram-se os descritores cadastrados no MeSH “lithium disilicate”, “smoking”, “CAD CAM”, “brushing”, “rough”, “hardness”, combinados entre si pelo operador booleano “AND”, na base de dados PubMed nos últimos 5 anos. Resultados: De acordo com a pesquisa, foram encontrados 625 artigos e selecionados 12 estudos in vitro. 5 estudos concluíram que as restaurações cerâmicas CAD/CAM apresentaram estabilidade de cor e de rugosidade da superfície, após escovação simulada e termociclagem.  4 estudos observaram que a escovação simulada e algumas bebidas aumentaram significativamente a rugosidade superficial da cerâmica de dissilicato de lítio. 3 estudos inferiram que a rugosidade superficial e a microdureza podem ser influenciadas pelos tratamentos de superfícies. Considerações finais: As cerâmicas de dissilicato de lítio CAD/CAM possuem propriedades satisfatórias em relação a sua resistência e estética, após exposição à fumaça do cigarro, associada ou não com a escovação.

Structural Integrity Evaluation of Large MOD Restorations Fabricated With a Bulk-Fill and a CAD/CAM Resin Composite Material

2019 ◽  
Vol 44 (3) ◽  
pp. 312-321 ◽  
Author(s):  
C Papadopoulos ◽  
D Dionysopoulos ◽  
K Tolidis ◽  
P Kouros ◽  
E Koliniotou-Koumpia ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fracture Resistance ◽  
Structural Integrity ◽  
Resin Composite ◽  
Testing Machine ◽  
Fracture Load ◽  
Chi Square ◽  
Significance Level ◽  
Computer Aided ◽  
Cad Cam

SUMMARY Aims: To evaluate the effect of two composite restorative techniques (direct bulk fill vs indirect CAD/CAM) on the fracture resistance and mode of fracture of extended mesio-occlusal-distal (MOD) cavity preparations. Methods: Fifty-one sound human mandibular third molars were divided into three groups (n=17). Extended bucco-lingual MOD cavities were prepared. Teeth in group 1 were restored with a bulk-fill resin composite (Filtek Bulk-Fill Posterior Restorative), teeth in group 2 were restored with composite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays (Lava Ultimate), and teeth in group 3 served as control and remained intact. All specimens were submitted to thermocycling, and a fracture resistance test was performed using a Universal testing machine (0.5 mm/min). Mode of fracture was classified into five types. One-way analysis of variance and the Duncan test were used to analyze the fracture load data at a significance level of α = 0.05. A chi-square test was used for the analysis of fracture mode between the restorative groups. Results: Statistical analysis showed significant differences in fracture resistance among the experimental groups. The teeth restored with the bulk-fill composite exhibited lower fracture resistance (1285.3±655.0 N) when compared to the teeth restored with the composite CAD/CAM inlays (1869.8±529.4 N) (p&lt;0.05). Mode of fracture showed the same distribution between the restorative groups. Conclusions: Although both types of restorations failed at loads larger than those found in the oral cavity, the CAD/CAM composite inlays increased the fracture resistance of teeth with large MOD cavities when compared to direct bulk-fill composite restorations. The majority of fracture types were intraorally repairable for both restorative techniques.

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