scholarly journals Flexural Strength of 3D-Printing Resin Materials for Provisional Fixed Dental Prostheses

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3970
Author(s):  
Sang-Mo Park ◽  
Ji-Man Park ◽  
Seong-Kyun Kim ◽  
Seong-Joo Heo ◽  
Jai-Young Koak
Keyword(s):  
3D Printing ◽  
Flexural Strength ◽  
Computer Aided Design ◽  
Testing Machine ◽  
Fused Deposition ◽  
Fixed Dental Prosthesis ◽  
Dental Prostheses ◽  
Significant Difference ◽  
Fixed Dental Prostheses ◽  
3D Printed

The clinical application of 3D-printed provisional restorations is increasing due to expansion of intraoral scanners, easy dental computer-aided design (CAD) software, and improved 3D printing speed. This study compared flexural strength of 3D-printed three-unit fixed dental prostheses with that of conventionally fabricated and milled restorations. A metal jig of two abutments and pontic space and an indenter for flexural strength measurement were fabricated. A three-unit fixed dental prosthesis was designed and manufactured using three additive manufacturing technologies, with subtractive manufacturing and a conventional method as controls. Digital light processing (DLP) group specimens were prepared from a polymethyl methacrylate (PMMA)-based resin and printed with a DLP printer. Stereolithography (SLA) group specimens were prepared from PMMA-based resin and printed with an SLA printer, and fused deposition modeling (FDM) group specimens were from a polylactic acid-based resin and printed with an FDM printer. Flexural strength was investigated using a universal testing machine, and the results were statistically analyzed. DLP and SLA groups had significantly higher flexural strength than the conventional group (p < 0.001). No significant difference was observed in flexural strength between DLP and SLA groups. The FDM group showed only dents but no fracture. The results of this study suggest that provisional restorations fabricated by DLP and SLA technologies provide adequate flexural strength for dental use.

scholarly journals Influence of the Postcuring Process on Dimensional Accuracy and Seating of 3D-Printed Polymeric Fixed Prostheses

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Jaewon Kim ◽  
Du-Hyeong Lee
Keyword(s):  
3D Printing ◽  
Dimensional Accuracy ◽  
3 Dimensional ◽  
Fixed Dental Prosthesis ◽  
Dental Prostheses ◽  
Significant Difference ◽  
Implant Abutments ◽  
Prosthetic Implant ◽  
3D Printed ◽  
Internal Gap

The postcuring process is essential for 3-dimensional (3D) printing of photopolymer-based dental prostheses. However, the deformation of prostheses resulting from the postcuring process has not been fully investigated. The purpose of this study was to evaluate the effects of different postcuring methods on the fit and dimensional accuracy of 3D-printed full-arch polymeric fixed prostheses. A study stone model with four prosthetic implant abutments was prepared. A full-arch fixed dental prosthesis was designed, and the design was transferred to dental computer-aided manufacturing (CAM) software in which supports were designed to the surface of the prosthesis design for 3D printing. Using a biocompatible photopolymer and a stereolithography apparatus 3D printer, polymeric prostheses were produced ( N = 21 ). In postcuring, the printed prostheses were polymerized in three different ways: the prosthesis alone, the prosthesis with supports, or the prosthesis on a stone model. Geometric accuracy of 3D-printed prostheses, marginal gap, internal gap, and intermolar distance was evaluated using microscopy and digital techniques. Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction were used for the comparison of results among groups ( α = 0.05 ). In general, the mean marginal and internal gaps of cured prostheses were the smallest when the printed prostheses were cured with seating on the stone model ( P < 0.05 ). With regard to the adaptation accuracy, the presence of supports during the postcuring process did not make a significant difference. Error in the intermolar distance was significantly smaller in the model seating condition than in the other conditions ( P < 0.001 ). Seating 3D-printed prosthesis on the stone model reduces adverse deformation in the postcuring process, thereby enabling the fabrication of prostheses with favorable adaptation.

Evaluation of Mechanical Properties of Dental Feldsphatic Porcelains for Metal and Zirconia Core

2012 ◽  
Vol 727-728 ◽  
pp. 1104-1107
Author(s):  
Antonio Alves de Almeida-Junior ◽  
Gelson Luis Adabo ◽  
Beatriz Regalado Galvão ◽  
Diogo Longhini ◽  
Claudinei dos Santos
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
High Hardness ◽  
Hardness Test ◽  
Dental Prostheses ◽  
Significant Incidence ◽  
Significant Difference ◽  
Fixed Dental Prostheses ◽  
Intermediate Value

Studies has been reported a significant incidence of chipping of the feldspathic porcelain veneer in zirconia-based restorations. The purpose of this study was to compare the three-point flexural strength (MPa), Weibull parameters, Vickers hardness (VHN) and Vickers indentation fracture toughness (MPa/mm1/2) in feldspatic porcelains for metal and for zirconia frameworks. Bar specimens were made with the porcelains e.MaxCeram (EM) and VitaVM9 (V9) for zirconia core, and Duceragold (DG) and VitaVMK95 (VK) for metal core (n= 15). Kruskal-Wallis and Dun test were used for statistical analysis. There was no significant difference (p=0.31) among the porcelains in the flexural strength (Median= 73.2; 74.6; 74.5; 74.4). Weibull calculation presented highest reliability for VK (10.8) followed by EM (7.1), V9 (5.7) and DG (5.6). Vickers hardness test showed that EM (536.3), V9 (579.9) and VK (522.1) had no difference and DG (489.6) had the lowest value (p.001). The highest fracture toughness was to VK (1.77), DG (1.58) had an intermediate value while V9 (1.33) and EM (1.18) had the lowest values (p.001). Despite of the suitable flexural strength, reliability and high hardness, the porcelains used to zirconia-based fixed dental prostheses showed lower fracture toughness values.

scholarly journals 3D-Printable PP/SEBS Thermoplastic Elastomeric Blends: Preparation and Properties

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 347 ◽  
Author(s):  
Shib Banerjee ◽  
Stephen Burbine ◽  
Nischay Kodihalli Shivaprakash ◽  
Joey Mead
Keyword(s):  
3D Printing ◽  
Carbon Black ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Polymeric Materials ◽  
Fused Deposition ◽  
3D Printed ◽  
Injection Molded ◽  
Preferential Location

Currently, material extrusion 3D printing (ME3DP) based on fused deposition modeling (FDM) is considered a highly adaptable and efficient additive manufacturing technique to develop components with complex geometries using computer-aided design. While the 3D printing process for a number of thermoplastic materials using FDM technology has been well demonstrated, there still exists a significant challenge to develop new polymeric materials compatible with ME3DP. The present work reports the development of ME3DP compatible thermoplastic elastomeric (TPE) materials from polypropylene (PP) and styrene-(ethylene-butylene)-styrene (SEBS) block copolymers using a straightforward blending approach, which enables the creation of tailorable materials. Properties of the 3D printed TPEs were compared with traditional injection molded samples. The tensile strength and Young’s modulus of the 3D printed sample were lower than the injection molded samples. However, no significant differences could be found in the melt rheological properties at higher frequency ranges or in the dynamic mechanical behavior. The phase morphologies of the 3D printed and injection molded TPEs were correlated with their respective properties. Reinforcing carbon black was used to increase the mechanical performance of the 3D printed TPE, and the balancing of thermoplastic elastomeric and mechanical properties were achieved at a lower carbon black loading. The preferential location of carbon black in the blend phases was theoretically predicted from wetting parameters. This study was made in order to get an insight to the relationship between morphology and properties of the ME3DP compatible PP/SEBS blends.

scholarly journals 3D Printing Custom Bioactive and Absorbable Surgical Screws, Pins, and Bone Plates for Localized Drug Delivery

2019 ◽  
Vol 10 (2) ◽  
pp. 17 ◽  
Author(s):  
Karthik Tappa ◽  
Udayabhanu Jammalamadaka ◽  
Jeffery Weisman ◽  
David Ballard ◽  
Dallas Wolford ◽  
...  
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Flexural Strength ◽  
Bone Plates ◽  
Patient Specific ◽  
Fixation Devices ◽  
Significant Difference ◽  
3D Printed ◽  
Localized Drug Delivery ◽  
Orthopedic Applications

Additive manufacturing has great potential for personalized medicine in osseous fixation surgery, including maxillofacial and orthopedic applications. The purpose of this study was to demonstrate 3D printing methods for the fabrication of patient-specific fixation implants that allow for localized drug delivery. 3D printing was used to fabricate gentamicin (GS) and methotrexate (MTX)-loaded fixation devices, including screws, pins, and bone plates. Scaffolds with different infill ratios of polylactic acid (PLA), both without drugs and impregnated with GS and MTX, were printed into cylindrical and rectangular-shaped constructs for compressive and flexural strength mechanical testing, respectively. Bland PLA constructs showed significantly higher flexural strength when printed in a Y axis at 100% infill compared to other axes and infill ratios; however, there was no significant difference in flexural strength between other axes and infill ratios. GS and MTX-impregnated constructs had significantly lower flexural and compressive strength as compared to the bland PLA constructs. GS-impregnated implants demonstrated bacterial inhibition in plate cultures. Similarly, MTX-impregnated implants demonstrated a cytotoxic effect in osteosarcoma assays. This proof of concept work shows the potential of developing 3D printed screws and plating materials with the requisite mechanical properties and orientations. Drug-impregnated implants were technically successful and had an anti-bacterial and chemotherapeutic effect, but drug addition significantly decreased the flexural and compressive strengths of the custom implants.

scholarly journals Development of a 3D Printed Double-Acting Linear Pneumatic Actuator for the Tendon Gripping

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2528
Author(s):  
Ivan Grgić ◽  
Vjekoslav Wertheimer ◽  
Mirko Karakašić ◽  
Željko Ivandić
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Testing Machine ◽  
Pneumatic Actuator ◽  
Tensile Testing Machine ◽  
Laboratory Equipment ◽  
Testing Procedures ◽  
Fused Deposition ◽  
Custom Made ◽  
3D Printed

The lack of standardization in tissue testing procedures results in a variety of custom-made devices. In the case of the determination of the mechanical properties of tendons, it is sometimes necessary to adapt the existing laboratory equipment for conducting experiments when specific commercial equipment is not applicable to solve issues such as proper gripping to prevent tendon slipping and rupturing, gripping control and manoeuvrability in case of tendon submerging and without contamination of the testing liquid. This paper presents the systematic development, design, and fabrication using 3D printing technology and the application of the double-acting linear pneumatic actuator to overcome such issues. It is designed to do its work submerged in the Ringers’ solution while gripping the tendon along with the clamps. The pneumatic foot valve unit of the Shimadzu AGS-X tensile testing machine controls the actuator thus preventing Ringers’ solution to be contaminated by the machine operator during specimen set-up. The actuator has a length of 60 mm, a bore of 50 mm, and a stroke length of 20 mm. It is designed to operate with an inlet pressure of up to 0.8 MPa. It comprises the cylinder body with the integrated thread, the piston, the piston head, and the gripper jaw. Fused deposition modeling (FDM) has been used as the 3D printing technique, along with polylactic acid (PLA) as the material for 3D printing. The 3D printed double-acting linear pneumatic actuator was developed into an operating prototype. This study could open new frontiers in the field of tissue testing and the development of similar specialized devices for medical purposes.

scholarly journals Effect of Fabrication Method on Fracture Strength of Provisional Implant-Supported Fixed Dental Prostheses

Prosthesis ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 325-332
Author(s):  
Kelly M. Suralik ◽  
Jie Sun ◽  
Chia-Yu Chen ◽  
Sang J. Lee
Keyword(s):  
Computer Aided Design ◽  
Fracture Force ◽  
Fixed Dental Prosthesis ◽  
Computer Aided ◽  
Cad Cam ◽  
3D Printers ◽  
Fixed Dental Prostheses ◽  
3D Printed ◽  
Aided Design ◽  
Post Hoc

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.

scholarly journals Comparative Evaluation of Flexural Strength of Nano-zirconia-integrated Pressable Feldspathic and Lithium Disilicate Ceramics

2018 ◽  
Vol 19 (3) ◽  
pp. 339-344
Author(s):  
Chengalvarayan Sasikala ◽  
N Gopi Chander
Keyword(s):  
Flexural Strength ◽  
Computer Aided Design ◽  
Comparative Evaluation ◽  
Testing Machine ◽  
Lithium Disilicate ◽  
Control Group ◽  
Significant Difference ◽  
Computer Aided ◽  
Feldspathic Porcelain ◽  
Zirconia Nanoparticles

ABSTRACT Aim The purpose of the study was to evaluate and compare the flexural strength of nano-reinforced zirconia feldspathic porcelain, lithium disilicate ceramics, and zirconia. Materials and methods Ten bar-shaped specimens of computer-aided design (CAD)/computer-aided manufacturing (CAM) zirconia, reinforced feldspathic porcelain, and reinforced lithium disilicate were fabricated in accordance to International Organization for Standardization (ISO 6872; n = 10). Feldspathic porcelain and lithium disilicate ceramic specimens were reinforced with 5, 10, 15, and 20% of zirconia nanoparticles through a customized technique. The specimens were subjected to three-point flexural strength test using universal testing machine (UTM) and examined for crack propagation using a scanning electron microscope (SEM). One­way analysis of variance (ANOVA) and Tukey test were used to analyze the data (p < 0.05). Results The flexural strength of feldsphatic porcelain increased with the increase in the concentration of zirconia particles. The mean flexural strength of 5, 10, 15, and 20% nano-zirconia-incorporated lithium disilicate was 93.8, 97.1, 100.6, and 100.8 MPa respectively, and was lower than the control group (221.7 MPa). A significant difference in the flexural strength was found with the incorporation of nano-zirconia particles. Conclusion The flexural strength of zirconia-integrated feldspathic porcelain increased and lithium disilicate ceramics decreased with the nano-zirconia reinforcement. Clinical significance The simplified approach of reinforcing feldspathic porcelain with zirconia nanoparticles can be adapted in clinical situations of higher masticatory forces. How to cite this article Sasikala C, Chander NG. Comparative Evaluation of Flexural Strength of Nano-zirconia-integrated Pressable Feldspathic and Lithium Disilicate Ceramics. J Contemp Dent Pract 2018;19(3):339-344.

scholarly journals Dimensional Stability of 3D Printed Parts: Effects of Process Parameters

2019 ◽  
Vol 119 (2) ◽  
pp. 9 ◽  
Author(s):  
Elizabeth Azhikannickal ◽  
Aaron Uhrin
Keyword(s):  
3D Printing ◽  
Process Parameters ◽  
Dimensional Stability ◽  
Computer Aided Design ◽  
3D Model ◽  
Dimensional Error ◽  
Layer Height ◽  
Fused Deposition ◽  
3D Printed ◽  
Rms Error

The three-dimensional (3D) printing manufacturing process begins with the creation of a 3D model—using computer aided design (CAD) software—of the part to be printed. Using a type of 3D printing known as fused deposition modeling (FDM®), the 3D printer extrudes molten plastic to scan lines to create individual layers (i.e., the infill): one on top of the other. (Note that "scan" in this context refers to the movement of the extruder head, along an x,y coordinate path, while depositing molten plastic.) This process is repeated until the overall geometry, specified by the 3D model, is built. This process is attractive for producing proof of concept or prototype parts in various fields including automotive, aerospace, and medical. However, FDM subjects the material to rapid heating and cooling; therefore, some degree of undesirable warpage of the part occurs post fabrication. The primary objective of this study was to determine the effect of 4 process parameters (i.e., infill shape, infill density, number of perimeters created per layer, and layer height) on the total dimensional error of a representative 3D-printed part. This part (the "simple part"), used in Trials 1 through 3 of this study, was a square acrylonitrile butadiene styrene (ABS) plate having a nominal measurement of 50 mm × 50 mm × 5 mm thick. A residual error (the difference between the measured post-printing dimension and the theoretical CAD file dimension) was calculated along each given direction and for each test print. Finally, a root mean square (RMS) error (i.e., the square root of the average of the squared residual errors along the length, width, and thickness directions) was calculated for each printed part. Three repeat test prints were carried out for each parameter. The number of perimeters played a key role in the dimensional stability of the part. As the number of perimeters increased up to 5, the RMS error decreased. Beyond 5 perimeters, however, the RMS error increased due to excessive warpage/curvature at the corners of the part. Ultimately, when examined individually, a grid infill shape at 100% density, a 0.4 mm layer height, and 5 perimeters each produced the lowest warpage. In combination, these same 4 parameters also produced the lowest RMS error (based on dimensional analysis of 3 test prints) when used to print a more complicated part (the "stacked part") in Trial 4.

Biodegradable 3D Printed Polymer Microneedles for Transdermal Drug Delivery

2018 ◽  
Author(s):  
Michael A. Luzuriaga ◽  
Danielle R. Berry ◽  
John C. Reagan ◽  
Ronald A. Smaldone ◽  
Jeremiah J. Gassensmith
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Transdermal Drug Delivery ◽  
Fused Deposition Modeling ◽  
Fused Deposition ◽  
Modeling Software ◽  
Deposition Modeling ◽  
3D Printed ◽  
Microfabrication Technique ◽  
Mechanical Strengths

Biodegradable polymer microneedle (MN) arrays are an emerging class of transdermal drug delivery devices that promise a painless and sanitary alternative to syringes; however, prototyping bespoke needle architectures is expensive and requires production of new master templates. Here, we present a new microfabrication technique for MNs using fused deposition modeling (FDM) 3D printing using polylactic acid, an FDA approved, renewable, biodegradable, thermoplastic material. We show how this natural degradability can be exploited to overcome a key challenge of FDM 3D printing, in particular the low resolution of these printers. We improved the feature size of the printed parts significantly by developing a post fabrication chemical etching protocol, which allowed us to access tip sizes as small as 1 μm. With 3D modeling software, various MN shapes were designed and printed rapidly with custom needle density, length, and shape. Scanning electron microscopy confirmed that our method resulted in needle tip sizes in the range of 1 – 55 µm, which could successfully penetrate and break off into porcine skin. We have also shown that these MNs have comparable mechanical strengths to currently fabricated MNs and we further demonstrated how the swellability of PLA can be exploited to load small molecule drugs and how its degradability in skin can release those small molecules over time.

scholarly journals Design of a 3D-printed hand prosthesis featuring articulated bio-inspired fingers

2020 ◽  
pp. 095441192098088
Author(s):  
Juan Sebastian Cuellar ◽  
Dick Plettenburg ◽  
Amir A Zadpoor ◽  
Paul Breedveld ◽  
Gerwin Smit
Keyword(s):  
3D Printing ◽  
Design Principles ◽  
Prosthetic Hand ◽  
Hand Prosthesis ◽  
Fused Deposition ◽  
Pinch Force ◽  
Actuation System ◽  
3D Printed ◽  
Energy Dissipated ◽  
Dual Material

Various upper-limb prostheses have been designed for 3D printing but only a few of them are based on bio-inspired design principles and many anatomical details are not typically incorporated even though 3D printing offers advantages that facilitate the application of such design principles. We therefore aimed to apply a bio-inspired approach to the design and fabrication of articulated fingers for a new type of 3D printed hand prosthesis that is body-powered and complies with basic user requirements. We first studied the biological structure of human fingers and their movement control mechanisms in order to devise the transmission and actuation system. A number of working principles were established and various simplifications were made to fabricate the hand prosthesis using a fused deposition modelling (FDM) 3D printer with dual material extrusion. We then evaluated the mechanical performance of the prosthetic device by measuring its ability to exert pinch forces and the energy dissipated during each operational cycle. We fabricated our prototypes using three polymeric materials including PLA, TPU, and Nylon. The total weight of the prosthesis was 92 g with a total material cost of 12 US dollars. The energy dissipated during each cycle was 0.380 Nm with a pinch force of ≈16 N corresponding to an input force of 100 N. The hand is actuated by a conventional pulling cable used in BP prostheses. It is connected to a shoulder strap at one end and to the coupling of the whiffle tree mechanism at the other end. The whiffle tree mechanism distributes the force to the four tendons, which bend all fingers simultaneously when pulled. The design described in this manuscript demonstrates several bio-inspired design features and is capable of performing different grasping patterns due to the adaptive grasping provided by the articulated fingers. The pinch force obtained is superior to other fully 3D printed body-powered hand prostheses, but still below that of conventional body powered hand prostheses. We present a 3D printed bio-inspired prosthetic hand that is body-powered and includes all of the following characteristics: adaptive grasping, articulated fingers, and minimized post-printing assembly. Additionally, the low cost and low weight make this prosthetic hand a worthy option mainly in locations where state-of-the-art prosthetic workshops are absent.

Sign in / Sign up

Export Citation Format

Share Document