Marginal Integrity, Internal Adaptation and Compressive Strength of 3D Printed, Computer Aided Design and Computer Aided Manufacture and Conventional Interim Fixed Partial Dentures

2019 ◽  
Vol 9 (12) ◽  
pp. 1745-1750
Author(s):  
Laila Al Deeb ◽  
Khold Al Ahdal ◽  
Ghaith Alotaibi ◽  
Abdullah Alshehri ◽  
Bader Alotaibi ◽  
...  

The aim was to investigate the marginal fit, internal adaptation and compressive strength of SLA provisionals (SLA) in comparison to CAD-CAM and conventional (CONV) interim fixed partial dentures (FPDs). Thirty interim FPDs were fabricated using CAD-CAM technology (CAD-CAM blocks Ceramill TEMP, PMMA), conventional molding technique (CONV) (TrimPlus, PMMA) and Stereolithography (SLA) method (Form 2, Formlabs, PMMA) (n = 10). Internal adaptation (occlusal, coronal, middle and cervical) and marginal integrity (inner and outer edge) was assessed using micro-computerized tomography (Micro-CT). The failure and compressive strength was assessed by application of a static load at a crosshead speed of 1 mm/min until fracture. Data was analysed using ANOVA and multiple comparisons test. The maximum and minimum marginal mis-fit was for CONV (283.3± 98.6 nm) and CAD-CAM (68.2± 18.1 m) groups. CAD-CAM (68.2± 18.1 m) and SLA (84.7± 27.5 m) provisionals showed comparable marginal mis-fit (p > 0.05). The mean failure load was significantly higher (p < 0.05) in CAD-CAM (687.86± 46.72 N), compared to SLA (534.8± 46.1 N) and CONV (492.7± 61.8 N) samples. Compressive strength for CAD-CAM (2.44± 0.27 MPa) samples was significantly higher (p < 0.05) than SLA (1.80± 0.15 MPa) and CONV (1.65± 0.20 MPa) groups. Marginal fit and internal adaptation of SLA printed FPDs was comparable to CAD-CAM interims. Compressive strength of the SLA interims FPDs can withstand intra-oral loads.

2020 ◽  
Vol 18 ◽  
pp. 228080002092451
Author(s):  
Khulud A Al-Aali ◽  
Mohammed S. Bin-Shuwaish ◽  
Aasem M Alhenaki ◽  
Khold Al Ahdal ◽  
Laila Al Deeb ◽  
...  

Objective: The aim of this study was to evaluate marginal fit of yttrium tetragonal zirconia polycrystals (Y-TZP)’ copings with different finish line designs fabricated with various digital scanners and milling systems. Methods: Three model plastic teeth were prepared with three finish line designs: Design-1, continuous chamfer; Design-2, chamfer with shallow depression; Design-3, chamfer with deep depression. The “master models” were replicated using elastomeric polyvinyl siloxane impression material and poured in type IV stone generating 90 dies, 30 dies for each design. Dies were scanned and copings were milled utilizing three digital scanners and computer-aided design/computer-aided manufacturing (CAD/CAM) systems: System-1, InEos Red Scan (Sirona Dental Systems, Germany), Vitablocks® Mark II (VITA, Germany) copings milled by Cerec® inLab (Sirona Dental Systems, Germany); System-2, Cerec® AC Connect with BlueCam (Sirona Dental Systems, Germany), Vitablocks® Mark II (VITA, Germany) copings milled by Cerec® inLab (Sirona Dental Systems, Germany); and System-3, NobleProcera™ Optical Scanner (NobleBiocare™), procera zirconia coping milled by a Noble Procera™ milling machine (NobleBiocare™). Copings were seated on their respective “master models” and secured with uniform force. Eight measurements per coping were performed at pre-established points, with a metallurgical microscope (Zeiss, Germany) connected to a high precision digital video-micrometer (Javelin JV6000, California, USA) at 200 × magnification. Results: The tested systems demonstrated marginal gaps ranging from 12.4 to 26.6 µm. Results for marginal fit of milled copings fabricated using three systems with different finish line designs differed significantly ( p < 0.05). Procera zirconia copings scanned and milled with NobleProcera™ exhibited significantly lower marginal gaps compared to other specimen groups. However, InEos Red Scan/Vitablocks® Mark II/Cerec® inLab showed maximum marginal gaps among the study specimens. Conclusions: CAD-CAM manufactured Y-TZP’ copings exhibited marginal gaps ranging from 12.49 to 26.6 µm. The CAD-CAM fabrication system was a significant factor influencing the marginal misfit of Y-TZP’ copings. Margin design exhibited system dependent influence on the marginal misfit. Marginal misfit observed for all systems were within clinically acceptable parameters.


Prosthesis ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 325-332
Author(s):  
Kelly M. Suralik ◽  
Jie Sun ◽  
Chia-Yu Chen ◽  
Sang J. Lee

There has been an increase in utilizing 3D printers in dental restorations. The purpose of the study is to compare mechanical properties of 3D-printed prostheses to those of self-cured and/or computer-aided design-computer-aided manufacturing (CAD-CAM) restorations. A metal master typodont was prepared for the mandibular left sextant with implant analogs embedded at the first premolar and first molar positions with a missing second premolar. Three-unit provisional fixed dental prosthesis (FDP) was designed utilizing the 3Shape tooth library and forty-five uniform specimens were fabricated with different materials: self-cured poly(methyl methacrylate) (PMMA) (N = 15), milled PMMA CAD-CAM blocks (N = 15) and 3D-printed resin (N = 15). All specimens were tested using an Instron machine at a crosshead speed of 0.5 mm/min by an axial load on the occlusal surface of the second premolar pontic site. Statistical analysis was completed with Shapiro-Wilk, ANOVA and Tukey post-hoc tests. Mean fracture force was 300.61 N, 294.64 N and 408.49 N for self-cured PMMA, milled PMMA and 3D-printed resin, respectively. Mean force at FDP fracture of 3D-printed resin was significantly greater than the mean fracture force of either self-cured (p = 0.016, 95% CI [17.86, 197.91]) or milled (p = 0.010, 95% CI [23.83, 203.88]) PMMA.


Prosthesis ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 46-52 ◽  
Author(s):  
Leonardo Cavallo ◽  
Antonia Marcianò ◽  
Marco Cicciù ◽  
Giacomo Oteri

(1) Background: To mitigate the shortage of respiratory devices during the Covid-19 epidemic, dental professional volunteers can contribute to create printed plastic valves, adapting the dental digital workflow and converting snorkeling masks in emergency CPAP (continuous positive airways pressure) devices. The objective of this report was to provide the specific settings to optimize printing with the 3D printers of the dental industry. (2) Methods: In order to provide comprehensive technical notes to volunteer dental professionals interested in printing Charlotte and Dave connectors to breathing devices, the entire digital workflow is reported. (3) Results: The present paper introduces an alternative use of the dental Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) machinery, and reports on the fabrication of a 3D printed connection prototypes suitable for connection to face masks, thereby demonstrating the feasibility of this application. (4) Conclusions: This call for action was addressed to dentists and dental laboratories who are willing to making available their experience, facilities and machinery for the benefit of patients, even way beyond dentistry.


2016 ◽  
Vol 41 (6) ◽  
pp. 607-616 ◽  
Author(s):  
MD Gaintantzopoulou ◽  
HM El-Damanhoury

SUMMARY The aim of the study was to evaluate the effect of preparation depth and intraradicular extension on the marginal and internal adaptation of computer-aided design/computer-assisted manufacture (CAD/CAM) endocrown restorations. Standardized preparations were made in resin endodontic tooth models (Nissin Dental), with an intracoronal preparation depth of 2 mm (group H2), with extra 1- (group H3) or 2-mm (group H4) intraradicular extensions in the root canals (n=12). Vita Enamic polymer-infiltrated ceramic-network material endocrowns were fabricated using the CEREC AC CAD/CAM system and were seated on the prepared teeth. Specimens were evaluated by microtomography. Horizontal and vertical tomographic sections were recorded and reconstructed by using the CTSkan software (TView v1.1, Skyscan).The surface/void volume (S/V) in the region of interest was calculated. Marginal gap (MG), absolute marginal discrepancy (MD), and internal marginal gap were measured at various measuring locations and calculated in microscale (μm). Marginal and internal discrepancy data (μm) were analyzed with nonparametric Kruskal-Wallis analysis of variance by ranks with Dunn's post hoc, whereas S/V data were analyzed by one-way analysis of variance and Bonferroni multiple comparisons (α=0.05). Significant differences were found in MG, MD, and internal gap width values between the groups, with H2 showing the lowest values from all groups. S/V calculations presented significant differences between H2 and the other two groups (H3 and H4) tested, with H2 again showing the lowest values. Increasing the intraradicular extension of endocrown restorations increased the marginal and internal gap of endocrown restorations.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ki-Hong Lee ◽  
In-Sung Yeo ◽  
Benjamin M. Wu ◽  
Jae-Ho Yang ◽  
Jung-Suk Han ◽  
...  

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.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
D G E Thiem ◽  
B Al-Nawas ◽  
P W Kämmerer

Abstract In recent years, alloplastic temporomandibular joint (TMJ) replacement has become a permissible procedure for the reconstruction of severely destroyed TMJs. The use of computer-aided design/computer-aided manufacturing (CAD/CAM) has extended the range of applications to complex anatomical situations. The aim of the treatment is to improve the usually restricted mouth opening and thus oral hygiene and nutrition, which leads to a regular improvement in the general quality of life. The following case report describes the bilateral replacement of ankylotically destroyed TMJs using patient-specific endoprostheses with simultaneous displacement of the maxilla. Innovative in the case described is the impression-free CAD/CAM planning, whereby the upper and lower prostheses were produced on the basis of 3D printed patient models.


Author(s):  
A. N. Bozhko

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.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou

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.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1986
Author(s):  
Andreas Koenig ◽  
Julius Schmidtke ◽  
Leonie Schmohl ◽  
Sibylle Schneider-Feyrer ◽  
Martin Rosentritt ◽  
...  

The performance of dental resin-based composites (RBCs) heavily depends on the characteristic properties of the individual filler fraction. As specific information regarding the properties of the filler fraction is often missing, the current study aims to characterize the filler fractions of several contemporary computer-aided design/computer-aided manufacturing (CAD/CAM) RBCs from a material science point of view. The filler fractions of seven commercially available CAD/CAM RBCs featuring different translucency variants were analysed using Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), Micro-X-ray Computed Tomography (µXCT), Thermogravimetric Analysis (TG) and X-ray Diffractometry (XRD). All CAD/CAM RBCs investigated included midifill hybrid type filler fractions, and the size of the individual particles was clearly larger than the individual specifications of the manufacturer. The fillers in Shofu Block HC featured a sphericity of ≈0.8, while it was <0.7 in all other RBCs. All RBCs featured only X-ray amorphous phases. However, in Lava Ultimate, zircon crystals with low crystallinity were detected. In some CAD/CAM RBCs, inhomogeneities (X-ray opaque fillers or pores) with a size <80 µm were identified, but the effects were minor in relation to the total volume (<0.01 vol.%). The characteristic parameters of the filler fraction in RBCs are essential for the interpretation of the individual material’s mechanical and optical properties.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1401
Author(s):  
Doo-Bin Song ◽  
Man-So Han ◽  
Si-Chul Kim ◽  
Junyong Ahn ◽  
Yong-Woon Im ◽  
...  

This study investigated the fitting accuracy of titanium alloy fixed dental prostheses (FDP) after sequential CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) fabrication. A three-unit FDP model connecting mandibular second premolars and molars was prepared and scanned to fabricate titanium FDPs by CAD/CAM milling. A total of six FDPs were sequentially milled in one titanium alloy disk using a new set of burs every time (n = 4). The fitting accuracy of FDPs was mesiodistally evaluated by a silicone replica technique and the measurement was triplicated at four different locations: MO (marginal opening), MG (marginal gap), AG (axial gap), and OG (occlusal gap). Data were statistically analyzed using ANOVA and Tukey’s HSD test. The fitting accuracy of PMMA (polymethyl methacrylate) FDPs milled using the worn or new bur were evaluated by the same procedure (n = 6). The mean dimensions of titanium FDP for all measuring positions, except for AG, were significantly increased from the third milling. However, no difference was noted between the first FDP and the second FDP milled with the same set of burs. Severe edge chippings were observed in all milling burs. Detrimental effects of the worn burs on the fitting accuracy were demonstrated in the CAD/CAM-milled PMMA FDP. The results recommend proper changing frequency of cutting burs to achieve the quality of fit and predictable outcomes for dental CAD/CAM prostheses.


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