Novel CAD-CAM zirconia coping design to enhance the aesthetics and strength for anterior PLZ crowns

2021 ◽  
pp. 1-11
Author(s):  
Ebrahim Fihaid Alsubaiy ◽  
Saurabh Chaturvedi ◽  
Osama A. Qutub ◽  
Hisham Abdullah Mously ◽  
Mohammad Abdullah Zarbah ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Fracture Resistance ◽  
Fracture Load ◽  
Test Results ◽  
Significant Difference ◽  
Cad Cam ◽  
The Aesthetic ◽  
One Way Anova

BACKGROUND: The aesthetics and strength of anterior porcelain layered zirconia (PLZ) crowns are mainly affected by the zirconia (Zr) coping design. There is a need for a modified design to enhance aesthetics with strength. OBJECTIVES: The purpose of this study was to compare the fracture resistance of anterior PLZ crowns having modified CAD-CAM Zr coping designs (in terms of thickness and marginal collar designs) with standard Zr copings. METHODS: Fifty PLZ crowns were fabricated and divided into two groups: Gr 1: Standard Zr Coping (SZC) (control gr) with 0.5 mm thickness (Facial-F, Mesial-M, Distal-D, incisal-I, and Palatal-P) without a collar; Gr 2: Collar Zr Coping (CZC) (test gr) with 2.5 mm collar height on M, D, P and 0.2 mm F and variable facial wall thickness. Subgroups: Gr 2a: (CZC-0.5 mm) facial wall thickness 0.5 mm; Gr 2b: (CZC-0.4 mm) facial wall thickness 0.4 mm; Gr 2c: (CZC-0.3 mm) facial wall thickness 0.3 mm; Gr 2d: (CZC-0.2 mm) facial wall thickness 0.2 mm. The fracture load was determined and analysed using One-way ANOVA and Dunnet test. RESULTS: The minimum fracture load was 927.36 ± 127.80 N observed for Gr 2c (CZC at 0.3 mm) while the maximum fracture load was 1373.61 ± 146.54 N observed for Gr 2a (CZC at 0.5 mm). A highly significant difference in mean fracture load among various Zr coping groups (p< 0.001) was determined. CONCLUSIONS: Novel Zr coping design for anterior PLZ crowns can provide better aesthetics with strength. Reducing the thickness of Zr coping in the aesthetic zone to 0.2 mm and providing a modified collar design (2.5 mm collar height on M, D, P, and 0.2 mm F) would provide strength without jeopardizing aesthetics.

scholarly journals PENGARUH VARIASI KONSENTRASI EKSTRAK DAUN BELIMBING WULUH (Averrhoa bilimbi L) TERHADAP KARAKTERISTIK SEDIAAN SALEP DENGAN MENGGUNAKAN BASIS PEG 4000 dan PEG 400

2021 ◽  
Vol 2 (02) ◽  
pp. 7
Author(s):  
Tri Puji Lestari
Keyword(s):  
Leaf Extract ◽  
Homogeneity Test ◽  
Test Results ◽  
Peg 400 ◽  
Cell Tissue ◽  
Peg 4000 ◽  
Significant Difference ◽  
Ointment Formulation ◽  
The Difference ◽  
One Way Anova

ABSTRAK Daun Belimbing Wuluh (Averrhoa bilimbi L) memiliki kandungan tanin dan flavonoid. Kandungan Flavonoid dan Tanin yang terdapat dalam belimbing wuluh mampu memberikan efek untuk menyembuhkan kulit yang mengalami kerusakan jaringan sel akibat luka bakar. Ada beberapa cara untuk pemanfaatan Daun Belimbing Wuluh antara lain dengan dibuat dalam sediaan salep. Pada penelitian ini salep dibuat dengan variasi konsentrasi ekstrak daun belimbing wuluh sebesar 10%, 15%, dan 20%  mengguankan basis PEG 4000 dan PEG 400. Ekstrak daun belimbing wuluh diperoleh menggunakan metode maserasi dengan menggunakan etanol 70% sebagai pelarutnya. Salep yang sudah dibuat kemudian dilakukan uji karakteristik meliputi uji organoleptis, homogenitas, daya lekat dan uji daya sebar. Hasil uji organoleptis dan homogenitas di analisa secara deskrisptif kemudian hasil uji daya lekat dan uji daya sebar di analisa dengan menggunakan analisa statistik one-way ANOVA.  Hasil penelitian menunjukan bahwa salep berbentuk semipadat dengan warna hijau muda sampai hijau kehitaman. Hasil uji homogenitas di dapatkan untuk ketiga formula adalah homogen. Nilai daya sebar pada ketiga formula menunjukan perbedaan yang signifikan, pada hasil uji daya lekat dan pH didapatkan tidak ada perbedaan yang signifikan terhadap ketiga formulasi. Dengan demikian perbedaan konsentrasi zat aktif yang digunakan berpengaruh terhadap daya sebar sediaan salep ekstrak daun belimbing wuluh. Kata kunci: Averrhoa bilimbi L; Salep; PEG   ABSTRACT Carambola leaf Wuluh (Averrhoa bilimbi L) contains tannins and flavonoids. The content of flavonoids and tannins contained in starfruit able to give effect to heal skin damaged cell tissue from burns. There were several ways for  utilization  of  Averrhoa  bilimbi  L.  among  others,  made  some  preparations, especially ointment formulation. This study aims to formulate leaf extract ointment preparation starfruit (Averrhoa bilimbi L) with various concentrations of 10%, 15%, and 20% using the PEG 4000 and PEG 400 as a base. Leaf extract obtained from meserasi leaf Averrhoa bilimbi  L  with  70%  ethanol. The ointment that has been made is then subjected to characteristic tests including organoleptic tests, homogeneity, adhesion and spreadability tests. The results of the organoleptic test and homogeneity were analyzed descriptively, then the results of the adhesion test and the spreadability test were analyzed using one-way ANOVA statistical analysis. The results showed that the ointment was semisolid, light green to blackish green. The homogeneity test results obtained for the three formulas are homogeneous. The value of the spreadability of the three formulas showed a significant difference, the results of the adhesion and pH test showed no significant difference between the three formulations. Thus the difference in the concentration of the active substance used affects the spreadability of the starfruit leaf extract ointment. Keywords: Averrhoa bilimbi L; ointment; PEG

scholarly journals Effect of Incisal Porcelain Veneering Thickness on the Fracture Resistance of CAD/CAM Zirconia All-Ceramic Anterior Crowns

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Noha Badran ◽  
Sanaa Abdel Kader ◽  
Fayza Alabbassy
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Mode Iii ◽  
Nickel Chromium ◽  
Significant Difference ◽  
All Ceramic ◽  
Metal Ceramic ◽  
Cad Cam ◽  
Ceramic Crown

Statement of Problem. In some clinical situations, the vertical length of either a prepared tooth or an implant abutment is short, while the occlusal clearance to be restored by a porcelain crown is large. Incisal thickness of the veneering porcelain should be considered to prevent mechanical failure of the crown. Purpose. The aim of this study is to evaluate the effect of two different incisal veneering porcelain thickness on the fracture resistance of the anterior all-ceramic CAD/CAM zirconia crown system as compared with the conventionally used metal ceramic crown system. Method. CAD/CAM zirconia all-ceramic and metal ceramic crowns were fabricated on the prepared dies with standardized dimensions and designs using standardized methods according to the manufacturer’s instructions. All crowns were then adhesively luted with resin-based cement (Multilink cement system), subjected to thermal cycling and cyclic loading, and were loaded until fracture using the universal testing machine to indicate the fracture resistance for each crown material in each veneering thickness. Results. Statistical analysis was carried out, and the results showed that the fracture resistance of the nickel-chromium metal ceramic group was significantly higher than that of the CAD/CAM zirconia all-ceramic group. Also, the fracture resistance of crowns with 1.5 mm incisal veneering thickness was significantly higher than those with 3 mm incisal veneering thickness in both groups. Furthermore, there was no significant difference in the fracture mode of the two groups where 50% of the total specimens demonstrated Mode II (veneer chipping), while 35% demonstrated Mode I (visible crack) and only 15% demonstrated Mode III (bulk fracture). Conclusion. High failure load values were demonstrated by the specimens in this study, which suggest sufficient strength of both incisal veneering thickness in both crown systems to withstand clinical applications; however, the fracture patterns still underline the requirement of a core design that support a consistent thickness of the veneering ceramic, and it is recommended to conduct long-term prospective clinical studies to confirm findings reported in the present study.

scholarly journals Effect of Reduced Occlusal Thickness with Two Margin Designs on Fracture Resistance of Monolithic Zirconia Crowns

2020 ◽  
Vol 14 (02) ◽  
pp. 245-249
Author(s):  
Haider Hasan Jasim ◽  
Meelad Basil Findakly ◽  
Nada Ali Mahdi ◽  
Mustafa Tariq Mutar
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Three Dimensional ◽  
Fracture Load ◽  
Anova Test ◽  
Optical Scanner ◽  
Nickel Chromium ◽  
Significant Difference ◽  
Zirconia Crowns ◽  
Monolithic Zirconia

Abstract Objectives The aim of this study was to compare the effects of two margin designs (shoulderless and slight chamfer) with two occlusal thicknesses on fracture resistance and failure mode of the monolithic zirconia crowns. Materials and Methods Forty nickel–chromium dies were duplicated from the previous two prepared teeth using a three-dimensional optical scanner. Nickel–chromium supporting dies were divided into two main groups (n = 20) according to the type of margin design: group A, slight chamfer margin design and group B, shoulderless margin design. These groups were further divided into two subgroups according to the occlusal thicknesses (0.5 and 1 mm). The digital imaging of each die was done using a three-dimensional optical scanner, then zirconia blocks were milled by 5-axis machine. The crowns were cleaned by alcohol, air dried, and cemented by resin cement. Next, the crowns were subjected to 500 hot and cold cycles (30 seconds for each cycle). The samples were subjected to a static load until failure using an electronic universal testing machine and fracture resistance was recorded in Newton (N). Statistical Analysis Data were analyzed using the test of normality (Shapiro–Wilk test) and two-way analysis of variance (ANOVA) test. Results  The highest mean fracture load was recorded by the shoulderless (1 mm occlusal thickness) subgroup (3,992.5 N), followed by shoulderless (0.5 mm occlusal thickness) subgroup (3,244.4 N), and the slight chamfer (1 mm occlusal thickness) subgroup (2,811 N). The lowest mean of fracture load was recorded by slight chamfer (0.5 mm occlusal thickness) subgroup (1,632.9 N). The two-way ANOVA test revealed a significant difference between the four subgroups. Regarding the fracture mode, the slight chamfer subgroups showed a severe fracture of the restoration while the shoulderless subgroups showed a fracture through the midline of the restoration. Conclusion Within the limitation of the comparative study, shoulderless margin design has a more favorable outcome than a slight chamfer design in all thicknesses. Although the restoration with reduced occlusal thickness has lower fracture resistance than 1 mm occlusal thickness, the 0.5 mm restorations still can tolerate occlusal forces.

scholarly journals Influence of Sealing of the Screw Access Hole on the Fracture Resistance of Implant-Supported Restorations

2016 ◽  
Vol 27 (2) ◽  
pp. 148-152 ◽  
Author(s):  
Rodrigo de Paula Pereira ◽  
Cibele Oliveira de Melo Rocha ◽  
José Maurício dos Santos Nunes Reis ◽  
João Neudenir Arioli-Filho
Keyword(s):  
Fracture Resistance ◽  
Resin Composite ◽  
Filling Material ◽  
Ceramic Surface ◽  
Access Hole ◽  
Mandibular Molar ◽  
Significant Difference ◽  
Metal Ceramic ◽  
One Way Anova ◽  
Ceramic Implant

Abstract The purpose of this study was to assess the influence of sealing of the screw access hole (SAH) on the fracture resistance of metal-ceramic implant-supported restorations. UCLA abutments were used to make 30 implant-retained mandibular molar restorations and divide equally into three groups: Group SRS: screw-retained restorations with SAH sealed; Group SRNS: screw-retained restorations with SAH not sealed; Group CR: cement-retained restorations. The following protocol was adopted to restore the SAH: the ceramic surface of the SAH was air-abraded with aluminum oxide; etched with 10% hydrofluoric acid; a silane coupling agent and a bonding agent were applied; cotton pellets were used as filling material and P-60 resin composite as restoring material. The cement-retained restorations were cemented with Rely-X U100. A metal rod with a spherical tip of 6.0 mm diameter was used to apply a vertical static load, simultaneously on the buccal and lingual incline cusps, at a crosshead speed of 0.5 mm/min until the fracture of the specimens. Data were analyzed using one-way ANOVA and Dunnet test (p<0.05) for multiples comparisons. The mode of failure was evaluated by a scanning electron microscopy (SEM). No significant difference between screw-retained restorations was found. The highest mean fracture resistance values were observed with CR group. Therefore, it was shown that SAH sealing did not influence the fracture resistance of the screw-retained restorations.

scholarly journals In vitro study of marginal, internal and proximal adaptation of implant-supported single-crown CAD/CAM restorations

2020 ◽  
Vol 19 ◽  
pp. e207286
Author(s):  
Kamila Aguiar Figueiredo Alves ◽  
Janaina Emanuela Damasceno ◽  
Viviane Maia Barreto de Oliveira ◽  
Luiz Gustavo Cavalcanti Bastos ◽  
Andrea Nóbrega Cavalcanti
Keyword(s):  
Repeated Measures ◽  
T Test ◽  
Digital Impression ◽  
Single Crown ◽  
Significant Difference ◽  
Cad Cam ◽  
Student’S T ◽  
One Way Anova ◽  
Student’S T Test

Aim: This study evaluated the precision of a CAD/CAM system by measuring marginal, internal and proximal fits in implantsupported single-crown restorations. Methods: Ten models of the upper arch were made in which implants replaced the upper left premolars. For fabrication of the zirconia infrastructures, titanium bases (TiBase) were coded and scanned using a scan body. A second digital impression was made for the fabrication of prostheses. Silicone impression material was used to determine the internal clearance between the TiBase and infrastructure and between the infrastructure and crown, whose thickness was measured at three points [P1 (cervical), P2 (middle) and P3 (occlusal)] with a stereoscopic microscope at 70x and 100x magnification. One-way ANOVA for repeated measures and the Student t-test were used for the analysis of internal and marginal adaptation. Proximal contacts were analyzed qualitatively. Results: There was no significant difference between the teeth evaluated (Student’s t-test; p>0.05) or between the corresponding points evaluated in either tooth (one-way ANOVA; p>0.05). Analysis of the internal clearance between the infrastructure and crown demonstrated that all points were significantly different compared to the reference standardized at 100 μm (Student’s t-test p<0.0001). There was no significant difference between P1 and P2, with the thickness at these two points being lower than that obtained at P3 (one-way ANOVA, p<0.05). The proximal contacts did not coincide with the quality defined by the device. Conclusion: The system tested was unable to produce implantsupported single-crown ceramic restorations with marginal, internal and proximal fits matching the digital workflow, with the inferior fits requiring adjustment prior to cementation.

scholarly journals THE SCIENTIFIC LITERACY PERFORMANCE OF GIFTED YOUNG SCIENTIST CANDIDATES IN THE DIGITAL AGE

2021 ◽  
Vol 40 (2) ◽  
pp. 467-498
Author(s):  
Muhammad Mifta Fausan ◽  
Herawati Susilo ◽  
Abdul Gofur ◽  
Sueb Sueb ◽  
Farrah Dina Yusop
Keyword(s):  
Scientific Literacy ◽  
Grade Level ◽  
Young Scientist ◽  
Test Results ◽  
Essential Question ◽  
Significant Difference ◽  
Technological Developments ◽  
Literacy Performance ◽  
The One ◽  
One Way Anova

Scientific Literacy (SL) is an important competency to deal with and keep up with the increasingly sophisticated technological developments. However, information about the SL of prospective gifted young scientists over 15 years old has not been widely revealed holistically. Therefore, this survey research aimed to investigate the SL performance of prospective gifted young scientists holistically and compare the SL performance based on the grade level. A total of 278 students from a public senior high school in Jombang Regency, East Java Province, Indonesia, participated in this research. They were asked to take the SL test with 18 essential question items. As a result, the participants still showed low SL performance (total success rate = 40). The one-way ANOVA test results indicated no significant difference in the participants' SL performance based on the grade level. Therefore, three recommendations were provided: teachers should use various learning models, SL should be an explicit focus in science and non-science classrooms, and schools need to be equipped with supporting facilities to accommodate student readiness to practice SL.

scholarly journals Different fabrication techniques of implant-supported prostheses

2019 ◽  
Vol 18 ◽  
pp. e191573
Author(s):  
Silas Monteiro Borges ◽  
Stephanie Francoi Poole ◽  
Izabela Cristina Maurício Moris ◽  
Aloísio Oro Spazzin ◽  
Adriana Cláudia Lapria Faria ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Computer Aided Design ◽  
Fracture Load ◽  
Fracture Pattern ◽  
Thermomechanical Cycling ◽  
Significant Difference ◽  
Computer Aided ◽  
Before And After ◽  
Cad Cam ◽  
Manufacturing Techniques

Aim: This study evaluated the mechanical behavior of implant-supported crowns obtained by different fabrication technique after thermomechanical cycling. Methods: Thirty-two external hexagon dental implants were divided into four groups (n=10): CC – conventional casting with torch; EI – electromagnetic induction casting; PL – plasma casting; and CAD-CAM – milling through computer-aided design and computer-aided manufacturing. Vickers microhardness of the specimens were made before and after the thermomechanical cycling, and then subjected to fracture load. Fracture pattern was evaluated. Results: No significant difference was observed comparing the microhardness before and after thermomechanical cycling. CAD-CAM group presented significant lower microhardness than the other groups. No significant statistical difference was showed on fracture load between the groups. The CAD-CAM and PL presented lower number of failure by plastic deformation. Conclusion: The manufacturing techniques affected the mechanical behavior and the failure pattern of implant-supported crowns tested.

scholarly journals Fracture Resistance of a Bulk-Fill and a Conventional Composite and a Combination of Both for Coronal Restoration of Severely Damaged Primary Anterior Teeth

2019 ◽  
Author(s):  
Shahram Mosharrafian ◽  
Maryam Shafizadeh ◽  
Zeinab Sharifi
Keyword(s):  
Fracture Resistance ◽  
Treatment Time ◽  
Testing Machine ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
One Way Anova

Objectives: This study aimed to compare the fracture resistance of a bulk-fill and a conventional composite and a combination of both for coronal restoration of severely damaged primary anterior teeth. Materials and Methods: In this in vitro experimental study, 45 primary anterior teeth were randomly divided into three groups. After root canal preparation, the canals were filled with Metapex paste such that after the application of 1 mm of light-cure liner, 3 mm of the coronal third of the canal remained empty for composite post fabrication. Filtek Z250 conventional composite was used in group 1, Sonic-Fill bulk-fill composite was used in group 2 and Sonic-Fill with one layer of Filtek Z250 as the veneering were used in group 3. Adper Single Bond 2 was used in all groups. The teeth were thermocycled, and fracture resistance was measured by a universal testing machine. The mode of fracture was categorized as repairable or irreparable. Data were analyzed using one-way ANOVA. Results: The mean fracture resistance was 307.00±74.72, 323.31±84.28 and 333.30±63.96 N in groups 1 to 3, respectively (P=0.55). The mean fracture strength was 14.53±2.98, 15.08±2.82 and 15.26±3.02 MPa in groups 1 to 3, respectively (P=0.77). The frequency of repairable mode of failure was 80% for the conventional, 73.6% for the bulk-fill and 80% for the bulk-fill plus conventional group, with no significant difference (P>0.05). Conclusions: Bulk-fill composites can be used for coronal reconstruction of severely damaged primary anterior teeth similar to conventional composites to decrease the treatment time in pediatric patients.

Material Thickness Influence on Fracture Load of Polymer Infiltrated Ceramic Network CAD/CAM Restorations

2021 ◽  
Vol 58 (2) ◽  
pp. 8-17
Author(s):  
Liane Avram ◽  
Luciana Goguta ◽  
Sergiu-Valentin Galatanu ◽  
carmen Opris ◽  
Codruta Ille ◽  
...  
Keyword(s):  
Load Capacity ◽  
Compressive Force ◽  
Fracture Load ◽  
Milling Machine ◽  
Wet Milling ◽  
Significant Difference ◽  
Cad Cam ◽  
Adhesive Cement ◽  
Posterior Area ◽  
Scanning Electron

Polymer infiltrated ceramics are hybrid materials that combine the strength of ceramics and the flexibility of polymers. The aim of this study was to compare the fracture load capacity of monolithic CAD/CAM crowns with different occlusal thicknesses, made from polymer infiltrated ceramic network. Fifteen full contour CAD/CAM crowns made of Vita Enamic with occlusal thicknesses of 0.5 mm, 1.0 mm and 1.5 mm were fabricated with a wet milling machine. Restorations were cemented on human molars with adhesive cement. Samples were loaded along the long axis until fracture, with a single static compressive force. A scanning electron microscope (SEM) was used to examine the fracture surface of specimens after the fracture. The results of this study reveals that the fracture load of the samples increased progressively with the occlusal thickness. The highest fracture value was recorded for1.5 mm occlusal thickness of the crown. No statistically significant difference was reported between the three experimental groups. It can be concluded that hybrid monolithic CAD-CAM crowns showed sufficient fracture strength to be used for single restorations in the posterior area, even with a reduced occlusal thickness.

scholarly journals Fracture Resistance of New Metal-Free Materials Used for CAD-CAM Fabrication of Partial Posterior Restorations

Medicina ◽  
2020 ◽  
Vol 56 (3) ◽  
pp. 132
Author(s):  
Georgina García-Engra ◽  
Lucia Fernandez-Estevan ◽  
Javier Casas-Terrón ◽  
Antonio Fons-Font ◽  
Pablo Castelo-Baz ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Fracture Resistance ◽  
Lithium Disilicate ◽  
Lithium Silicate ◽  
Control Group ◽  
Test Machine ◽  
Occlusal Wear ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam

Background and Objectives: To evaluate in vitro the fracture resistance and fracture type of computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Discs were fabricated (10 × 1.5 mm) from four test groups (N = 80; N = 20 per group): lithium disilicate (LDS) group (control group): IPS e.max CAD®; zirconium-reinforced lithium silicate (ZRLS) group: VITA SUPRINITY®; polymer-infiltrated ceramic networks (PICN) group: VITA ENAMIC®; resin nanoceramics (RNC) group: LAVA™ ULTIMATE. Each disc was cemented (following the manufacturers’ instructions) onto previously prepared molar dentin. Samples underwent until fracture using a Shimadzu® test machine. The stress suffered by each material was calculated with the Hertzian model, and its behavior was analyzed using the Weibull modulus. Data were analyzed with ANOVA parametric statistical tests. Results: The LDS group obtained higher fracture resistance (4588.6 MPa), followed by the ZRLS group (4476.3 MPa) and PICN group (4014.2 MPa) without statistically significant differences (p < 0.05). Hybrid materials presented lower strength than ceramic materials, the RNC group obtaining the lowest values (3110 MPa) with significant difference (p < 0.001). Groups PICN and RNC showed greater occlusal wear on the restoration surface prior to star-shaped fracture on the surface, while other materials presented radial fracture patterns. Conclusion: The strength of CAD-CAM materials depended on their composition, lithium disilicate being stronger than hybrid materials.

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