scholarly journals Marginal and internal fit of CAD/CAM fabricated all-ceramic restorations: a literature review.

2017 ◽  
Vol 74 (3) ◽  
pp. 229
Author(s):  
Brenda Gonçalves de Carvalho ◽  
Mariana Silva Thiel Ribeiro ◽  
Leonardo Rocha Brasil ◽  
Maria José Santos de Alencar
Keyword(s):  
Software Design ◽  
Computer Aided Design ◽  
Dental Restoration ◽  
Review Of Literature ◽  
All Ceramic ◽  
Cad Cam ◽  
Tooth Preparation ◽  
Aided Design ◽  
Internal Fit ◽  
Ceramic Restorations

Objective: the aim of this article was to review the literature about the marginal and internal fit of CAD/CAM fabricated all-ceramic restorations. Material and Methods: a review of literature using Pubmed and Bireme database was executed and 37 articles in English and Portuguese were selected. The keywords were “Computer-Aided Design,” “Dental marginal adaptation,” “Dental restoration, permanent.” Results: the results proved that this system can generate restorations with clinically acceptable marginal fit (?100 µm). However, other parameters must be considered to achieve these results such as milling machine, bur diameter, software, design preparation, smooth preparation margins and incorporation of rounded line angles on the tooth preparation, learning curve of the operator and type of impression method. Conclusion: therefore, although some clinicians present concerns related to the internal fit of CAD/CAM system fabricated restorations, studies corroborate the success on the fit of these restorations, which justifies clinical use and indication of CAD/CAM system.

scholarly journals Dual-scan technique for the customization of zirconia computer-aided design/computer-aided manufacturing frameworks

2013 ◽  
Vol 07 (S 01) ◽  
pp. S115-S118 ◽  
Author(s):  
Rafael Ferrone Andreiuolo ◽  
Carlos Eduardo Sabrosa ◽  
Katia Regina H. Cervantes Dias
Keyword(s):  
Computer Aided Design ◽  
Uniform Thickness ◽  
Simple Manner ◽  
Computer Aided Manufacturing ◽  
All Ceramic ◽  
Computer Aided ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Tooth Preparation ◽  
Aided Design

ABSTRACTThe use of bi-layered all-ceramic crowns has continuously grown since the introduction of computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia cores. Unfortunately, despite the outstanding mechanical properties of zirconia, problems related to porcelain cracking or chipping remain. One of the reasons for this is that ceramic copings are usually milled to uniform thicknesses of 0.3-0.6 mm around the whole tooth preparation. This may not provide uniform thickness or appropriate support for the veneering porcelain. To prevent these problems, the dual-scan technique demonstrates an alternative that allows the restorative team to customize zirconia CAD/CAM frameworks with adequate porcelain thickness and support in a simple manner.

scholarly journals Evaluation of the Feasibility of NaCaPO4-Blended Zirconia as a New CAD/CAM Material for Dental Restoration

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou
Keyword(s):  
Computer Aided Design ◽  
Optical Microscope ◽  
Dental Restoration ◽  
Numerical Control ◽  
Test Results ◽  
Cnc Machine ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
Better Than

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.

scholarly journals Viability of the Digitalization of Dental Laboratory in Bacolod City

2020 ◽  
Vol 3 (2) ◽  
pp. 31-32
Author(s):  
Paul Brian S. Mendez ◽  
Rizalie N.E. Mibato
Keyword(s):  
Computer Aided Design ◽  
Data File ◽  
Dental Restoration ◽  
Design Data ◽  
Dental Patients ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
Improved Accuracy ◽  
The City

Dentistry has evolved from its origin to the present day, becoming almost entirely digitized and supervised. The digitalized dental laboratory saves time due to computer-aided design and computer-aided manufacture (CAD/CAM) technology, which will capture and display clients' tooth or teeth and gums on a 3D image on a computer screen sent to the lab.  It enables a dental lab technician to work faster and get the perfect design of the digital dental restoration. The main advantage of digitalization includes faster and improved efficiency on the turn-around time of devices, like crowns and bridges, and improved accuracy of procedures and manufactured gadgets. Digitalization Dental Laboratory (DDL) is the first to offer a digital dental lab in the city of Bacolod. The service allows laboratories to design the prosthesis digitally from in-house CAD software and email the design data provider or download the data file into a proprietary web host or server. The lab will cater to the digital needs of dental patients of the Multi-Specialty Dental Center (a sister company of DDL) and other dental clients.

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.

scholarly journals Effects of Computer-Aided Manufacturing Technology on Precision of Clinical Metal-Free Restorations

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ki-Hong Lee ◽  
In-Sung Yeo ◽  
Benjamin M. Wu ◽  
Jae-Ho Yang ◽  
Jung-Suk Han ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Computer Aided Manufacturing ◽  
Marginal Fit ◽  
Significance Level ◽  
Metal Free ◽  
All Ceramic ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
Cam Systems

Purpose. The purpose of this study was to investigate the marginal fit of metal-free crowns made by three different computer-aided design/computer-aided manufacturing (CAD/CAM) systems.Materials and Methods. The maxillary left first premolar of a dentiform was prepared for all-ceramic crown restoration. Thirty all-ceramic premolar crowns were made, ten each manufactured by the Lava system, Cercon, and Cerec. Ten metal ceramic gold (MCG) crowns served as control. The marginal gap of each sample was measured under a stereoscopic microscope at 75x magnification after cementation. One-way ANOVA and the Duncan’s post hoc test were used for data analysis at the significance level of 0.05.Results. The mean (standard deviation) marginal gaps were 70.5 (34.4) μm for the MCG crowns, 87.2 (22.8) μm for Lava, 58.5 (17.6) μm for Cercon, and 72.3 (30.8) μm for Cerec. There were no significant differences in the marginal fit among the groups except that the Cercon crowns had significantly smaller marginal gaps than the Lava crowns(P<0.001).  Conclusions. Within the limitation of this study, all the metal-free restorations made by the digital CAD/CAM systems had clinically acceptable marginal accuracy.

scholarly journals Chairside Fabrication of an All-Ceramic Partial Crown Using a Zirconia-Reinforced Lithium Silicate Ceramic

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Sven Rinke ◽  
Anne-Kathrin Pabel ◽  
Matthias Rödiger ◽  
Dirk Ziebolz
Keyword(s):  
Computer Aided Design ◽  
Lithium Silicate ◽  
Computer Assisted ◽  
Model Free ◽  
All Ceramic ◽  
Alternative Material ◽  
Cad Cam ◽  
Aided Design ◽  
Partial Crown ◽  
Silicate Ceramic

The chairside fabrication of a monolithic partial crown using a zirconia-reinforced lithium silicate (ZLS) ceramic is described. The fully digitized model-free workflow in a dental practice is possible due to the use of a powder-free intraoral scanner and the computer-aided design/computer-assisted manufacturing (CAD/CAM) of the restorations. The innovative ZLS material offers a singular combination of fracture strength (>370 Mpa), optimum polishing characteristics, and excellent optical properties. Therefore, this ceramic is an interesting alternative material for monolithic restorations produced in a digital workflow.

scholarly journals Effect of the Crystallization Process on the Marginal and Internal Gaps of Lithium Disilicate CAD/CAM Crowns

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Hong Kim ◽  
Seunghan Oh ◽  
Soo-Hyuk Uhm
Keyword(s):  
Computer Aided Design ◽  
Crystallization Process ◽  
Lithium Disilicate ◽  
Mean Values ◽  
Computer Aided ◽  
Before And After ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Aided Design ◽  
Internal Fit

The aim of this study is to quantify the effect of the crystallization process on lithium disilicate ceramic crowns fabricated using a computer-aided design/computer-aided manufacturing (CAD/CAM) system and to determine whether the effect of crystallization is clinically acceptable by comparing values of fit before and after the crystallization process. The mandibular right first molar was selected as the abutment for the experiments. Fifteen working models were prepared. Lithium disilicate crowns appropriate for each abutment were prepared using a commercial CAD/CAM system. Gaps in the marginal area and 4 internal areas of each crown were measured twice—before and after crystallization—using the silicone replica technique. The mean values of fit before and after crystallization were analyzed using a pairedt-test to examine whether the conversion that occurred during crystallization affected marginal and internal gaps (α=0.05). Gaps increased in the marginal area and decreased in the internal areas after crystallization. There were statistically significant differences in all of the investigated areas (P<0.05). None of the values for marginal and internal fit of lithium disilicate CAD/CAM crowns after crystallization exceeded 120μm, which is the clinically acceptable threshold.

Structural Analysis of Product and Computer-Aided Assembly Planning in AssemBL Software Package

2018 ◽  
pp. 11-33
Author(s):  
A. N. Bozhko
Keyword(s):  
Computer Aided Design ◽  
State Of The Art ◽  
Graph Model ◽  
Design System ◽  
Assembly Planning ◽  
Complex Products ◽  
Assembly Sequences ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design

Computer-aided design of assembly processes (Computer aided assembly planning, CAAP) of complex products is an important and urgent problem of state-of-the-art information technologies. Intensive research on CAAP has been underway since the 1980s. Meanwhile, specialized design systems were created to provide synthesis of assembly plans and product decompositions into assembly units. Such systems as ASPE, RAPID, XAP / 1, FLAPS, Archimedes, PRELEIDES, HAP, etc. can be given, as an example. These experimental developments did not get widespread use in industry, since they are based on the models of products with limited adequacy and require an expert’s active involvement in preparing initial information. The design tools for the state-of-the-art full-featured CAD/CAM systems (Siemens NX, Dassault CATIA and PTC Creo Elements / Pro), which are designed to provide CAAP, mainly take into account the geometric constraints that the design imposes on design solutions. These systems often synthesize technologically incorrect assembly sequences in which known technological heuristics are violated, for example orderliness in accuracy, consistency with the system of dimension chains, etc.An AssemBL software application package has been developed for a structured analysis of products and a synthesis of assembly plans and decompositions. The AssemBL uses a hyper-graph model of a product that correctly describes coherent and sequential assembly operations and processes. In terms of the hyper-graph model, an assembly operation is described as shrinkage of edge, an assembly plan is a sequence of shrinkages that converts a hyper-graph into the point, and a decomposition of product into assembly units is a hyper-graph partition into sub-graphs.The AssemBL solves the problem of minimizing the number of direct checks for geometric solvability when assembling complex products. This task is posed as a plus-sum two-person game of bicoloured brushing of an ordered set. In the paradigm of this model, the brushing operation is to check a certain structured fragment for solvability by collision detection methods. A rational brushing strategy minimizes the number of such checks.The package is integrated into the Siemens NX 10.0 computer-aided design system. This solution allowed us to combine specialized AssemBL tools with a developed toolkit of one of the most powerful and popular integrated CAD/CAM /CAE systems.

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.

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