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

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.

Author(s):  
Abdulrahman Alhaddad ◽  
Samar Abuzinadah ◽  
Abdullah Al-Otaibi ◽  
Abrar Alotaibi ◽  
Mohsen Alfkih ◽  
...  

Background: Zirconia-based restorations have become more popular in dentistry during the last two decades. Patients choose metal-free restorations, preferring materials with similar attributes to natural teeth and similar light scattering characteristics, resulting in a nice esthetic appearance. Restoring a root canal treated teeth is one of the hot topics today. endo crown materials can be either; feldspathic, glass-ceramic, monolithic hybrid ceramic or composite material. Considering the marginal gap of endocrown, an important cause of failure of treatment, the current study evaluated the marginal gap of CAD‐CAM concocted endo-crowns. Materials and Methods: This research is an analysis systemic review study was conducted between January 2020 and October 2021. We followed the PRISMA principles and recorded this systematic review using the PROSPERO database to find and identify published literature related to the marginal adaptation of CAD-CAM-fabricated endocrown. The search will include all relevant articles through the end of 2021. Finally, 24 papers on marginal clearance and fracture resistance in coronary arteries were reviewed. Results: The electronic database search yielded 98 studies that were relevant. After cross-referencing, further seven studies were added. After a full-text analysis and duplicate reduction, 74 of the 98 articles were eliminated. 5 clinical (prospective) studies, 19 in vitro studies were found. Conclusion: This analysis of the recent literature on the marginal seating integrity and fracture resistance of CAD/CAM made-up endo-crowns showed that the endo-crown had superior marginal seating integrity than classical full crown. CAM/CAM showed statistically significant higher mean fracture resistance than MAD/MAM.


2019 ◽  
Vol 18 (4) ◽  
pp. 764-772
Author(s):  
Asa Yazdani Fard ◽  
Zuryati Ab Ghani ◽  
Zaihan Ariffin ◽  
Dasmawati Mohamad

Background: Studies on microleakage of Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) crowns are abundant. However many of them are inconclusive, especially those using self adhesive cements. Aims: To compare the microleakage between CAD/CAM crowns milled out of feldspathic ceramic and resin nano ceramics, cemented with three resin cements. Materials and Methods: Crown preparation was made on 54 extracted human premolars. Impressions were captured optically using CEREC 3D machine intraoral camera, and crowns were milled from feldspathic ceramic (CEREC® Blocs PC, VITA) and resin nano ceramic (Lava™ Ultimate CAD/CAM Restorative, 3M ESPE) blocks. The crowns were then cemented with three cements (n = 9); RelyX™ U200 Self-Adhesive Resin Cement (3M ESPE); NX3 Nexus ® cement with two-step etch-and-rinse adhesive (Kerr Corporation) or three/multistep etch-and-rinse resin cement, Variolink® II/Syntac Classic (Ivoclar Vivadent). The specimens were kept in water for 24 hours, thermocycled, and then soaked in methylene blue dye for 24 hours, before being sectioned mesiodistally. Microleakage was assessed using a fivepoint scale using stereomicroscope. Statistical analysis of the data was carried out using ONEWay ANOVA. Results: CEREC® Blocs PC crowns showed significantly less microleakage (p< 0.001) compared to Lava™ Ultimate. RelyX™ U200 showed significantly lower microleakage (p< 0.001) compared to other cements. Combination of Lava™ Ultimate crown cemented with RelyX™ U200 showed the least microleakage (p< 0.001). Conclusions: The microleakage scores were affected by the types of crown and cements. Bangladesh Journal of Medical Science Vol.18(4) 2019 p.764-772


2018 ◽  
Vol 43 (4) ◽  
pp. 437-446 ◽  
Author(s):  
NG Fischer ◽  
A Tsujimoto ◽  
AG Baruth

SUMMARY Objective: Limited information is available on how to polish and finish zirconia surfaces following computer-aided design/computer-aided manufacturing (CAD/CAM), specifically, how differing application forces and reuse of zirconia polishing systems affect zirconia topography. Purpose: To determine the effect of differing, clinically relevant, polishing application forces and multiple usages of polishing burs on the surface topography of CAD/CAM zirconia. Methods: One hundred twenty 220-grit carbide finished zirconia disks were sintered according to manufacturer's directions and divided into two groups for the study of two coarse polishing bur types. Each group was divided into subgroups for polishing (15,000 rpm) at 15 seconds for 1.0 N, 4.5 N, or 11 N of force using a purpose-built fixture. Subgroups were further divided to study the effects of polishing for the first, fifth, 15th, and 30th bur use, simulating clinical procedures. Unpolished surfaces served as a control group. Surfaces were imaged with noncontact optical profilometry (OP) and atomic force microscopy (AFM) to measure average roughness values (Ra). Polishing burs were optically examined for wear. Scanning electron microscopy (SEM) was performed on burs and zirconia surfaces. One-way ANOVA with post hoc Tukey HSD (honest significant difference) tests (α=0.05) were used for statistical analyses. Results: AFM and OP Ra values of all polished surfaces were significantly lower than those of the unpolished control. Different polishing forces and bur reuse showed no significant differences in AFM Ra. However, significant differences in OP Ra were found due to differing application forces and bur reuse between the first and subsequent uses. SEM and optical micrographs revealed notable bur wear, increasing with increasing reuse. SEM and AFM micrographs clearly showed polished, periodic zirconia surfaces. Nanoscale topography, as analyzed with kurtosis and average groove depth, was found dependent on the specific polishing bur type. Conclusions: These in vitro results suggest changes in OP Ra due to bur reuse and polishing application force. Within the parameters of this study, the resultant topography of zirconia polishing is force-dependent and the reuse of coarse polishing burs is possible without statistically significant differences in Ra values after initial use. Nanoscale and microscale topography were shown to depend on specific polishing bur type.


2021 ◽  
Vol 9 (D) ◽  
pp. 37-42
Author(s):  
Abd El Azeem Mostafa ◽  
Cherif A. Mohsen

BACKGROUND: Ceramic laminate veneer restoring is considered a challenging modality in solving various esthetic dental problems. AIM: The purpose of this study was to investigate the effect of digital internal relief space on the color of ceramic laminate veneer. MATERIALS AND METHODS: An acrylic central incisor model was prepared for ceramic laminate veneer with standard measures. The prepared acrylic resin dentotype model was scanned with intraoral computer-aided design/computer-aided manufacturing (CAD/CAM) optical scanner (CEREC Omnicam|Dentsply Sirona). The laminate veneer design was planned on the optically scanned preparation on CAD/CAM system software (CEREC software|Dentsply Sirona). Thirty ceramic laminate veneer specimens were machined from zirconia-reinforced lithium silicate (Celtra Duo blocks, Dentsply/Sirona) according to standard design by CAD/CAM system with the change of the digital internal relief space settings. The specimens were divided into three groups according to their digital internal relief settings (IRS) (20, 60, and 100 μm) (n = 10). Thirty epoxy dies were duplicated from the prepared acrylic model. The ceramic laminate veneer specimens were cemented to epoxy dies with total etch resin cement system according to the manufacture instructions. The color change (ΔE) of the cemented ceramic laminate veneer specimens was measured by spectrophotometer (Vita Easy shade, Ivoclar Vivadent AG, Schaan, Liechtenstein) using the CIELAB scale and L*, a*, b*. Each specimen was measured two times (before and after cementation). The value of color difference (ΔE) was calculated according to the formula: ΔE = [(L*2 - L*1)2 + (a*2 - a*1)2 + (b*2- b*1) 2]½. RESULTS: The highest mean value of ΔE was recorded in G100 group (1.91 ± 0.33), followed by G60 group (1.83 ± 0.09), with the least value recorded in G20 group (1.49 ± 0.49). Analysis of variance test revealed a statistically significant difference between groups (p = 0.024). CONCLUSION: The change of the digital IRS affects the color of ceramic laminate veneers.


2019 ◽  
Vol 8 (11) ◽  
pp. 1932 ◽  
Author(s):  
Amesti-Garaizabal ◽  
Agustín-Panadero ◽  
Verdejo-Solá ◽  
Fons-Font ◽  
Fernández-Estevan ◽  
...  

Background: The aim of this systematic review and meta-analysis was to determine the fracture resistance and survival rate of partial indirect restorations inlays, onlays, and overlays fabricated using computer-aided design and computer-aided manufacturing (CAD-CAM) technology from ceramics, composite resin, resin nanoceramic, or hybrid ceramic and to analyze the influence of proximal box elevation on fracture resistance. Materials and methods: This systematic review was based on guidelines proposed by the preferred reporting items for systematic reviews and meta-analyses (PRISMA). An electronic search was conducted in databases US National Library of Medicine National Institutes of Health (PubMed), Scopus, Web of Science (WOS), and Embase. In vitro trials published during the last 10 years were included in the review. Results: Applying inclusion criteria based on the review’s population, intervention, comparison, outcome (PICO) question, 13 articles were selected. Meta-analysis by restoration type estimated the fracture resistance of inlays to be 1923.45 Newtons (N); of onlays 1644 N and of overlays 1383.6 N. Meta-analysis by restoration material obtained an estimated fracture resistance for ceramic of 1529.5 N, for composite resin of 1600 Ne, for resin nanoceramic 2478.7 N, and hybrid ceramic 2108 N. Conclusions: Resin nanoceramic inlays present significantly higher fracture resistance values. Proximal box elevation does not exert any influence on the fracture resistance of indirect restorations.


2019 ◽  
Vol 17 (1) ◽  
pp. 228080001880710 ◽  
Author(s):  
İbrahim Duran ◽  
Necati Kaleli ◽  
Çağrı Ural ◽  
İdris Kavut

Background: This in vitro study aimed to evaluate the amount of polymerizing light passing through hybrid ceramic specimens in different shades and thicknesses. Methods: Rectangular-shaped feldspathic ceramic computer aided design and computer aided manufacturing (CAD-CAM) blocks and translucent and high translucent polymer infiltrated hybrid ceramic CAD-CAM blocks in four different shades (1M1, 1M2, 2M2, and 3M2) were sectioned in four different thicknesses (0.8, 1.5, 2, and 3 mm), and a total of 48 groups ( n = 10) were obtained. Feldspathic ceramic specimens served as the control group. The light transmission of each ceramic specimen was measured three times by using a light-emitting diode and a radiometer. Data were statistically analyzed by using univariate analysis of variance (ANOVA) followed by one-way ANOVA, Tukey honest significant difference, and Tamhane T2 tests (α = 0.05). Results: Translucent polymer infiltrated hybrid ceramic specimens exhibited significantly ( p < 0.001) lower light transmission values than high translucent polymer infiltrated hybrid ceramic and feldspathic ceramic specimens, whereas feldspathic ceramic specimens exhibited significantly ( p < 0.001) higher light transmission than translucent and high translucent polymer infiltrated hybrid ceramic specimens. The amount of light transmission significantly ( p < 0.05) decreased when the shade value decreased and the thickness increased. Conclusions: Polymer infiltrated hybrid ceramic specimens showed lower light transmission values than feldspathic ceramic specimens, and the amount of light transmission was affected by the ceramic shade and thickness.


2020 ◽  
pp. 232020682097597
Author(s):  
Ece Irem Oguz ◽  
Mehmet Ali Kılıçarslan ◽  
Merve Erdog˘ Özgür ◽  
Kaan Orhan ◽  
Sohaib Shujaat

Aim: To compare the marginal adaptation of crowns fabricated by using three different resin-ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials. Materials and Methods: Crowns fabricated from three different resin-ceramic CAD/CAM blocks, applied on a typodont premolar (#14), were tested with regard to marginal adaptation, in this in vitro study. The typodont maxillary first premolar was prepared to serve as the master die and digitized with an intraoral scanner. The same virtual crown design was used to fabricate all specimens. Forty-eight crowns were fabricated from the same virtual crown design using three different CAD/CAM resin-ceramic blocks as follows ( n = 16): Lava Ultimate (LU), GC Cerasmart (GC), Vita Enamic (VE). Master die and crowns were scanned with a laboratory scanner and three-dimensional data were transferred into three-matic software. The software calculated the mean of the marginal discrepancy (MD) for each crown in negative and positive values, representing under and over estimation of the crown margin, respectively. A marginal discrepancy index (MDI) was obtained for each group using negative and positive MDs. All data were statistically analyzed using one-way analysis of variance and Tukey’s honest significance test ( α = 0.05). Results: The analysis of variance showed no statistical differences between materials regarding the negative and positive MDs ( P > .05). The MDI for LU was lower than GC and VE ( P < .05). Conclusion: The marginal adaptation of different resin-ceramic materials was different with regard to MDI values. Nevertheless, the MD values of all groups were within the clinically acceptable range.


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 ◽  
...  

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.


2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Nagy Abdulsamee

Background: Advanced computer-aided design and computer-aided manufacturing (CAD-CAM) technology led to the introduction of an increasing number of machinable materials suitable for dental prostheses. One of these materials is polyetheretherketone (PEEK), a high performance polymer recently used in dentistry with favorable physical, mechanical and chemical properties. Purpose: The aim of this study was to review the current published literature on the use of PEEK for the fabrication of dental prostheses with CAD-CAM techniques. Methods: Electronic database searches were performed using the terms “PEEK”, “CAD-CAM”, “dental”, “dentistry” to identify studies related to the use of PEEK for the fabrication of CAD-CAM prostheses. Results: A great number of in vitro studies are available in the current literature pointing out the noticeable properties of PEEK. The use of PEEK has been recommended for a wide range of CAD-CAM fabricated fixed and removable dental prostheses, occlusal splints, intra-radicular posts, implant abutments, customized healing abutments, space maintainers for pediatric dentistry, orthodontic appliances and provisional restorations. However, only a few clinical studies were identified. Conclusions: PEEK could be considered as a viable alternative for CAD-CAM dental appliances to well-established dental materials. Due to the scarcity of clinical data, clinical trials are needed to assess the longterm performance of PEEK prostheses.


2019 ◽  
Vol 44 (3) ◽  
pp. 312-321 ◽  
Author(s):  
C Papadopoulos ◽  
D Dionysopoulos ◽  
K Tolidis ◽  
P Kouros ◽  
E Koliniotou-Koumpia ◽  
...  

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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