scholarly journals Dimensional Changes of 3-Unit Implant-Supported Zirconia Frameworks of Two CAD/CAM Systems from Scanning to Sintering

2019 ◽  
Author(s):  
Marzieh Alikhasi ◽  
Narges Ameri ◽  
Hakimeh Siadat ◽  
Ahmad Reza Shamshiri ◽  
Mohammadreza Nejati
Keyword(s):  
Repeated Measures ◽  
Computer Aided Design ◽  
Calculated Data ◽  
T Test ◽  
Dimensional Changes ◽  
Computer Aided ◽  
Cad Cam ◽  
Master Model ◽  
Cam Systems

Objectives: Internal fit of implant frameworks is an important factor determining the long-term success of dental implant restorations. This in-vitro study aimed to evaluate dimensional changes of implant-supported zirconia frameworks fabricated by two computer-aided design/computer-aided manufacturing (CAD/CAM) systems from scanning to sintering. Materials and Methods: A master model of a three-unit fixed partial denture was fabricated with two implant abutments. In each CAD/CAM system (AmannGirrbach and Zirkonzahn), the master model was scanned 12 times, and data were saved as Standard Transformation Language files (scanning groups). Using semi-sintered zirconia, 12 real-size frameworks (milling groups) and 12 enlarged frameworks, were sintered (sintering groups) and made by each system. Dimensions of the master model and frameworks in each phase were measured. Dimensional changes (compared to the master model) were calculated. Data were analyzed using repeated measures analysis of variance, independent t-test, and paired sample t-test (α=0.05). Results: Comparison of the two systems revealed that although dimensional changes were greater in the milling phase of Zirkonzahn, they were larger in the sintering phase of the AmannGirrbach system. Evaluation of fabrication phases revealed greater dimensional changes in the milling phase compared to the other phases in the Zirkonzahn system (P<0.05). However, in the AmannGirrbach system, the values were not significantly different between milling and sintering phases (P>0.05). Conclusion: Within the limitations of this study, the results showed that fabrication phases, CAD/CAM system type and abutment size had significant effects on dimensional changes.

scholarly journals (In-Vitro Comparison between Closed Versus Open CAD/CAM Systems) Comparison between Closed and Open CAD/CAM Systems by Evaluating the Marginal Fit of Zirconia-Reinforced Lithium Silicate Ceramic Crowns

2021 ◽  
Vol 11 (10) ◽  
pp. 4534
Author(s):  
Gil Ben-Izhack ◽  
Asaf Shely ◽  
Omer Koton ◽  
Avi Meirowitz ◽  
Shifra Levartovsky ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Open Systems ◽  
Lithium Silicate ◽  
Marginal Gap ◽  
Computer Aided ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Aided Design ◽  
Cam Systems

Background: This study compared the marginal gap (MG) and absolute marginal discrepancy (AMD) of computer-aided design and computer-aided manufacturing (CAD–CAM) used in open systems (OSs) and closed systems (CSs) for producing monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns. Methods: 60 ZLS ceramic crowns were cemented to abutment acrylic teeth; thirty crowns were designed and milled by an OS, and thirty by a CS. All crowns were sectioned for evaluating the marginal gap by scanning electronic microscopy (SEM). To compare the marginal gap between CS and OS techniques, data were analyzed using the independent-samples Mann–Whitney U Test (α = 0.05). Results: AMD was found to be significantly better for the closed system (p < 0.05). Mean AMD values for the CS were 148 µm, and for the OS it was 196 µm. MG was found to be significantly better for the OS (p < 0.05). Mean MG values for the CS were 55 µm, and for the OS they were 38 µm. Conclusions: The marginal gap in relation to AMD was significantly better for CS. However, the marginal gap in relation to MG was significantly better for OS. Both techniques showed clinically acceptable MG values (<120 µm).

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.

Effect of In-office Bleaching on Color, Translucency, and Whiteness Variations in CAD-CAM Monolithic Materials

2021 ◽  
Author(s):  
RG Fonseca ◽  
RC Peńa ◽  
R Simóes ◽  
AC Ramos ◽  
LN Dovigo
Keyword(s):  
Optical Properties ◽  
Computer Aided Design ◽  
Calculated Data ◽  
Color Difference ◽  
Deionized Water ◽  
Stain Removal ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
The Impact

SUMMARY Little is known about the impact of bleaching on the optical properties of computer-aided design and computer-aided manufactured (CAD-CAM) monolithic materials. The aim of the present study was to evaluate the effect of one session of in-office bleaching on stain removal, staining susceptibility, translucency, and whiteness variations of CADCAM monolithic materials. Disks were fabricated from Lava Ultimate (LU), Vita Enamic (VE), Vita Suprinity (VS), and IPS e.max CAD (IPS). A spectrophotometer was used to register Commission Internationale de l’Eclairage L*a*b* coordinates. For stain removal, 80 specimens from each material were assessed at baseline (R0) and after immersion in deionized water or coffee for 365 days followed or not by bleaching with 40% hydrogen peroxide (R1). For staining susceptibility, 80 specimens from each material were analyzed at baseline (R0’), and after having been bleached or not and immersed in deionized water or coffee (R1’). Both analyses were calculated as the color difference (ΔE00) between R1-R0 and R1’-R0’, respectively. Differences in translucency (ΔTP00) and whiteness (ΔWID) between R1-R0 and R1’-R0’ were also calculated. Data were analyzed by three-way ANOVA and the Games-Howell post hoc test (α=0.05). Clinical significance was based on 50%:50% perceptibility and acceptability thresholds for ΔE00, ΔTP00 and ΔWID, respectively. Surfaces were analyzed by scanning electron microscopy. Coffee increased ΔE00 in LU, VE, and VS, and decreased their translucency and whiteness, whereas the IPS had only its whiteness affected. Bleaching after immersion in coffee decreased ΔE00 in LU and VE, and increased translucency and whiteness of LU, VE, and VS. No effect was observed on IPS. Bleaching before immersion in coffee decreased translucency of LU, but within the acceptable interval, while VE exhibited lower ΔE00, and became more translucent and less dark. Both VS and IPS were not affected. One session of in-office bleaching benefited optical properties of the previously stained LU, VE, and VS, without increasing their susceptibility to staining or adversely providing clinically unacceptable variations in their translucency and whiteness. All variations exhibited by the IPS were below the perceptible threshold.

Review of Marginal Adaptation and Fracture Resistance of Computer Aided Design/Computer Aided Manufacturer (CAD‐CAM) Fabricated Endo-crowns

2021 ◽  
pp. 196-208
Author(s):  
Abdulrahman Alhaddad ◽  
Samar Abuzinadah ◽  
Abdullah Al-Otaibi ◽  
Abrar Alotaibi ◽  
Mohsen Alfkih ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fracture Resistance ◽  
Systemic Review ◽  
Marginal Adaptation ◽  
Marginal Gap ◽  
Computer Aided ◽  
Cad Cam ◽  
Electronic Database Search ◽  
Cause Of Failure

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.

scholarly journals Single blinded in-vitro study comparing microleakage between CAD/CAM crowns milled out of feldspathic ceramic and resin nano ceramic, cemented with three resin cements

2019 ◽  
Vol 18 (4) ◽  
pp. 764-772
Author(s):  
Asa Yazdani Fard ◽  
Zuryati Ab Ghani ◽  
Zaihan Ariffin ◽  
Dasmawati Mohamad
Keyword(s):  
Computer Aided Design ◽  
Medical Science ◽  
In Vitro Study ◽  
Resin Cement ◽  
Blue Dye ◽  
Resin Cements ◽  
Etch And Rinse ◽  
Computer Aided ◽  
Cad Cam

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

Biomechanical In Vitro Study on the Stability of Patient-Specific CAD/CAM Mandibular Reconstruction Plates: A Comparison Between Selective Laser Melted, Milled, and Hand-Bent Plates

2020 ◽  
pp. 194338752095268
Author(s):  
Robin Kasper ◽  
Karsten Winter ◽  
Sebastian Pietzka ◽  
Alexander Schramm ◽  
Frank Wilde
Keyword(s):  
In Vitro Study ◽  
Mandibular Reconstruction ◽  
Patient Specific ◽  
Plate Fracture ◽  
Computer Aided ◽  
Cad Cam ◽  
Number Of Cycles ◽  
Bent Plates ◽  
Cam Systems

Study Design: An experimental in vitro study. Objective: Plate fractures are a recurrent problem in alloplastic mandibular reconstruction. Hypothetically it can be assumed that computer-aided design (CAD)/computer-aided manufacturing (CAM) reconstruction plates have a higher stability than conventional hand-bent plates. The aim of the study was to compare additive and subtractive fabricated CAD/CAM mandibular reconstruction plates as well as conventional plates with regard to their biomechanical properties. Methods: In a chewing simulator, plates of 2 conventional locking plate systems and 2 CAD/CAM-fabricated plate systems were compared. The plates were loaded in a fatigue test. The maximum number of cycles until plate fracture and the plate stiffness were compared. Results: While all conventional plates fractured at a maximum load between 150 and 210 N (Newton) after a number of cycles between 40 000 and 643 000, none of the CAD/CAM plates broke despite a nearly doubled load of 330 N and 2 million cycles. Both CAD/CAM systems proved to be significantly superior to the hand-bent plates. There was no difference between the 2 CAD/CAM systems. Conclusions: Concerning the risk of plate fracture, patient-specific CAD/CAM reconstruction plates appear to have a significant advantage over conventional hand-bent plates in alloplastic mandibular reconstruction.

scholarly journals Monitoring Alveolar Ridge Remodelling Post-Extraction Using Sequential Intraoral Scanning over a Period of Four Months

2020 ◽  
Vol 17 (18) ◽  
pp. 6638
Author(s):  
Khaled E. Ahmed
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Dimensional Changes ◽  
Intraoral Scanning ◽  
Computer Aided ◽  
Potential Applications ◽  
Cad Cam ◽  
Aided Design ◽  
2D And 3D

The potential applications of computer-aided design/computer-aided manufacturing (CAD/CAM) and intraoral scanning exceed the delivery of standard prosthodontic interventions. The aim of this study was to clinically present a developed assessment technique, that relies on the use of sequential intraoral scanning, three-dimensional superimposition, and 2D and 3D deviation analyses based on a standardised protocol, as an auxiliary tool in monitoring dimensional changes of residual ridge post-extraction with a follow-up period of four months.

The current status on 3D scanning and CAD/CAM applications in textile research

2019 ◽  
Vol 32 (6) ◽  
pp. 891-907
Author(s):  
Ivana Špelic
Keyword(s):  
Computer Aided Design ◽  
Textile Industry ◽  
Future Trend ◽  
Current Status ◽  
New Production ◽  
Initial Development ◽  
Content Type ◽  
Computer Aided ◽  
Cad Cam ◽  
Cam Systems

Purpose In order to present a significant usage of the computer-aided design (CAD)/computer-aided manufacturing (CAM) systems in the apparel and textile industry, the current literature has been observed. Although the CAD/CAM systems have also been increasingly applied to all fields apparel and textile manufacturing for the last few decades, improving the precision, productivity and the organization of the information flow, they have not been fully utilized in these industrial fields. The paper aims to discuss these issues. Design/methodology/approach The paper is structured in three main sections showing the vast applicability of the CAD/CAM systems, the benefits provided by them and the future trend in their development. Findings Although the initial development of the CAD/CAM systems strived to completely eliminate manual and time-consuming operations, they have not been accepted in practice due to their inflexibility at making changes and the time needed for regenerating a complex parametric model. The textile and apparel industries show slow progress in acquiring the CAD/CAM systems. Originality/value This CAD/CAM technology enabled the customization in the design process according to individual needs and directed the textile and the apparel industry to moving into new directions such as the mass customization to personalization. The paper makes clear that although this technological concept is rather old, the use of the CAD/CAM systems will inevitably broaden in terms of applicability to new production stages.

Effects of Polishing Bur Application Force and Reuse on Sintered Zirconia Surface Topography

2018 ◽  
Vol 43 (4) ◽  
pp. 437-446 ◽  
Author(s):  
NG Fischer ◽  
A Tsujimoto ◽  
AG Baruth
Keyword(s):  
Surface Topography ◽  
Computer Aided Design ◽  
Groove Depth ◽  
Control Group ◽  
Limited Information ◽  
Average Roughness ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam

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.

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.

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