Effect of Washing Condition on the Fracture Strength, and the Degree of Conversion of 3D Printing Resin

This study compared the surface roughness, contact angle, surface energy, residual monomers, degree of conversion, and flexural strength of 3D-printed dental resin under various washing conditions. The specimens were printed with a digital light processing (DLP) printer and were divided into four groups: the group dipped in IPA for 5 s (IPA-D), the group washed in IPA for 1 min (IPA-1), the group washed in IPA for 10 min (IPA-10), and the group washed with TPM for 10 min (TPM-10). Following, the groups were redivided into two groups: a cured group and an uncured group. All experimental data were statistically analyzed using one-way analysis of variance and Tukey’s test. In all groups, the surface roughness showed a value of 1.2–1.8 μm, with no significant difference (p > 0.05). Contact angle showed a significant difference between the three groups using IPA and the TPM group, whereby the TPM-washed specimen showed a low contact angle (p < 0.05). The degree of conversion (DOC) increased in the following order: IPA-D group, IPA-1 group, IPA-10 group, and TPM-10 group, exhibiting a significant difference between all groups (p < 0.05). Flexural strength was measured at 110–130 MPa in all groups, with no significant difference between groups (p > 0.05). The washing time and washing solution type of the 3D printing material had no significant effect on surface roughness and flexural strength.

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Influence of surface treatments in flexural strength and superficial topography of a lithium disilicate ceramic

Brazilian Dental Science ◽

10.14295/bds.2019.v22i3.1678 ◽

2019 ◽

Vol 22 (3) ◽

pp. 305-312

Author(s):

Natalia Rivoli Rossi ◽

Tabata Do Prado Sato ◽

Caroline Cotes Marinho ◽

Vanessa Cruz Macedo ◽

Tarcisio José de Arruda Paes Junior ◽

...

Keyword(s):

Surface Roughness ◽

Contact Angle ◽

Flexural Strength ◽

Lithium Disilicate ◽

Surface Treatments ◽

P Value ◽

Sem Images ◽

Ultrasonic Bath ◽

Significant Difference ◽

Ceramic Blocks

The aim of the study was to evaluate the influence of different surface post-etching treatments in flexural strength, contact angle and surface roughness of a lithium disilicate ceramic. 60 bars (16x2x4mm) were divided in six groups (n=10): C, no treatment; HF, hydrofluoric acid for 20s (HF) + washing (60s), drying (30s); HFL, HF + washing (60s), drying (30s) and luting; HFNL, HF + washing (60s) + neutralization with sodium bicarbonate (SB) for 40s + washing (5s), drying (30s) and luting; HFUL, HF + washing (60s) + ultrasonic bath (UB) for 4 min, drying (30s) and luting; HFNUL, HF + washing (60s) + SB (40s) + UB (4 min) and luting. The bars were submitted to three-points flexural strength test. To analyze roughness and contact angle 25 ceramic blocks (12x7x7 mm) were divided into five groups (n=5): C - no treatment; HF - HF ; HFU - HF and UB for 5 min ; HFN - HF and SB; HFNU - HF, UB and SB. A scanning electron microscope (SEM) analysed the surface of the samples. ANOVA one-way statistical analysis was done for comparison of results. There was no statistical difference for flexural strength (p-value=0.15) and for surface roughness (p-valor=0.15). However, it was obtained statistically significant difference for contact angle (p-valor=0.00). SEM images showed precipitates after the acid etching, which were removed by post-etching treatments. It can be concluded that the different post-etching surface treatments did not increase the flexural strength, surface roughness and ceramic wetting, but it influenced the SEM images.

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Dimensional Accuracy of Dental Models for Three-Unit Prostheses Fabricated by Various 3D Printing Technologies

Materials ◽

10.3390/ma14061550 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1550

Author(s):

Soo-Yeon Yoo ◽

Seong-Kyun Kim ◽

Seong-Joo Heo ◽

Jai-Young Koak ◽

Joung-Gyu Kim

Keyword(s):

Surface Roughness ◽

Three Dimensional ◽

Dimensional Accuracy ◽

3D Analysis ◽

Digital Light Processing ◽

Test Models ◽

Reference File ◽

Significant Difference ◽

Jet Printing ◽

3D Printed

Previous studies on accuracy of three-dimensional (3D) printed model focused on full arch measurements at few points. The aim of this study was to examine the dimensional accuracy of 3D-printed models which were teeth-prepped for three-unit fixed prostheses, especially at margin and proximal contact areas. The prepped dental model was scanned with a desktop scanner. Using this reference file, test models were fabricated by digital light processing (DLP), Multi-Jet printing (MJP), and stereo-lithography apparatus (SLA) techniques. We calculated the accuracy (trueness and precision) of 3D-printed models on 3D planes, and deviations of each measured points at buccolingual and mesiodistal planes. We also analyzed the surface roughness of resin printed models. For overall 3D analysis, MJP showed significantly higher accuracy (trueness) than DLP and SLA techniques; however, there was not any statistically significant difference on precision. For deviations on margins of molar tooth and distance to proximal contact, MJP showed significantly accurate results; however, for a premolar tooth, there was no significant difference between the groups. 3D color maps of printed models showed contraction buccolingually, and surface roughness of the models fabricated by MJP technique was observed as the lowest. The accuracy of the 3D-printed resin models by DLP, MJP, and SLA techniques showed a clinically acceptable range to use as a working model for manufacturing dental prostheses

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IMMERSION OF HEAT POLYMERIZED ACRYLIC RESIN DENTAL BASE IN ARAK BALI AGAINST SURFACE ROUGHNESS

Interdental Jurnal Kedokteran Gigi (IJKG) ◽

10.46862/interdental.v17i1.2140 ◽

2021 ◽

Vol 17 (1) ◽

pp. 22-26

Author(s):

Kadek Ayu Wirayuni ◽

◽

I Made Hendri Dwi Saputra ◽

Keyword(s):

Surface Roughness ◽

Acrylic Resin ◽

Control Group ◽

Surface Strength ◽

Denture Base ◽

A Value ◽

Removable Denture ◽

Significant Difference ◽

Post Test ◽

Oral Tissue

Introduction: The denture base is the part of the removable denture that is supported by good adaptation to the underlying oral tissue. Most of the denture bases are made of acrylic or polymethyl methacrylate resin, better known as PMMA. However, the acrylic resin also has disadvantages such as easily broken and absorbs liquids both water and chemicals. The chemical absorption like alcohol, ethanol, and some drinks that contain acidic materials will chemically be induced with acrylic resin and settle in the pores of the acrylic resin. The chemical damage or defect creates roughness on the surface of the acrylic resin which can cause cracking or crazing and a decrease in surface strength and hardness. Materials and Methods: The method used in this research was a laboratory experimental design with a post-test-only control group using 12 samples consisting of 2 different types of samples by measuring the surface roughness of the acrylic resin after immersing the sample with a predetermined time. Results and Discussions: One-way ANOVA test results showed a significant difference in surface roughness after the samples immersion with a value of p = 0.006 (p <0.05). Conclusions: Based on this research, can be concluded that there is an increase in the surface roughness of the heated polymerized acrylic resin for 3 hours and 4 hours of immersion. The longer the heated polymerized acrylic resin is soaked in arak hence the level of surface roughness increases.

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Color Stability, Surface Roughness and Flexural Strength of an Acrylic Resin Submitted to Simulated Overnight Immersion in Denture Cleansers

Brazilian Dental Journal ◽

10.1590/0103-6440201302151 ◽

2013 ◽

Vol 24 (2) ◽

pp. 152-156 ◽

Cited By ~ 39

Author(s):

Helena de Freitas Oliveira Paranhos ◽

Amanda Peracini ◽

Marina Xavier Pisani ◽

Viviane de Cássia Oliveira ◽

Raphael Freitas de Souza ◽

...

Keyword(s):

Surface Roughness ◽

Flexural Strength ◽

Color Stability ◽

Acrylic Resin ◽

National Bureau ◽

Alkaline Peroxide ◽

Significant Difference ◽

Color Data ◽

Effervescent Tablet ◽

Denture Cleansers

This study evaluated color stability, surface roughness and flexural strength of acrylic resin specimens after immersion in alkaline peroxide and alkaline hypochlorite, simulating a period of one and a half year of use of overnight immersion. Sixty disc-shaped (16X4 mm) and 80 rectangular specimens (65X10X3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and distributed into 4 groups (n=20): C1: without immersion, C2: 8 h immersion in distilled water; AP: 8 h immersion in alkaline peroxide effervescent tablet; SH: 8 h immersion in 0.5% NaOCl solution. Properties were evaluated at baseline and after the immersion. Color data were also calculated according the National Bureau of Standards (NBS). Results were analyzed statistically by ANOVA and Tukey's HSD test (α=0.05). AP (2.34 ± 0.41) caused color alteration significantly higher than C2 (0.39 ± 0.30) and SH (1.73 ± 0.52). The mean ΔE values were classified as indicial for C2 (0.36 ± 0.29) and noticeable for AP (2.12 ± 0.39) and SH (1.59 ± 0.48). SH (0.0195 ± 0.0150) caused significantly higher ΔRa (p=0.000) than the C2 (0.0005 ± 0.0115) and PA (0.0005 ± 0.0157) groups. There was no statistically significant difference (p=0.063) among the solutions for flexural strength (C1: 105.43 ± 14.93, C2: 100.30 ± 12.43, PA: 97.61 ± 11.09, SH: 95.23 ± 10.18). In conclusion, overnight immersion in denture cleansing solutions simulating a year and a half of use did not alter the flexural strength of acrylic resin but caused noticeable color alterations, higher for alkaline peroxide. The 0.5% NaOCl solution caused increase in surface roughness.

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Effects of Denture Cleansers on Heat-Polymerized Acrylic Resin: A Five-Year-Simulated Period of Use

Brazilian Dental Journal ◽

10.1590/0103-6440201300120 ◽

2015 ◽

Vol 26 (4) ◽

pp. 404-408 ◽

Cited By ~ 11

Author(s):

Carolina Noronha Ferraz Arruda ◽

Danilo Balero Sorgini ◽

Viviane de Cássia Oliveira ◽

Ana Paula Macedo ◽

Cláudia Helena Silva Lovato ◽

...

Keyword(s):

Surface Roughness ◽

Flexural Strength ◽

Testing Machine ◽

Color Stability ◽

Acrylic Resin ◽

National Bureau ◽

Alkaline Peroxide ◽

Significant Difference ◽

Bonferroni Test ◽

Clinically Significant

<p>This study evaluated color stability, surface roughness and flexural strength of acrylic resin after immersion in alkaline peroxide and alkaline hypochlorite solutions, simulating a five-year-period of use. Sixty disc-shaped (16x4 mm) and 60 rectangular specimens (65x10x3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and assigned to 3 groups (n=20) of immersion (20 min): C1: distilled water; AP: warm water and one alkaline peroxide tablet; SH: 0.5% NaOCl solution. Color data (∆E) were determined by a colorimeter and also quantified according to the National Bureau of Standards units. A rugosimeter was used to measure roughness (μm) and the flexural strength (MPa) was measured using a universal testing machine. Data were evaluated by Kruskal-Wallis followed by Dunn tests (color stability and surface roughness) and by one-way ANOVA and Bonferroni test (flexural strength). For all tests was considered α=0.05. AP {0.79 (0.66;1.42)} caused color alteration significantly higher than C1 {0.45 (0.37;0.57)} and SH {0.34 (0.25;0.42)}. The mean ∆Ε values quantified by NBS were classified as "trace" for C1 (0.43) and SH (0.31) and "slight" for AP (0.96). SH {-0.015 (-0.023;0.003)} caused significantly higher ΔRa than the C1 {0.000 (-0.004;0.010)} and AP {0.000 (-0.009;0.008)} groups. There was no statistically significant difference among the solutions for flexural strength (C1: 84.62±16.00, AP: 85.63±12.99, SH: 84.22±14.72). It was concluded that immersion in alkaline peroxide and NaOCl solutions simulating a five-year of 20 min daily soaking did not cause clinically significant adverse effects on the heat-polymerized acrylic resin.</p>

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Effect of Modification of Aluminum Borate Whiskers with Three Methods on Flexural Properties of Dental Resin Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.364.687 ◽

2013 ◽

Vol 364 ◽

pp. 687-691

Author(s):

Yan Bo Yuan ◽

Xing Xing Li ◽

Wen Yun Zhang ◽

Qing Hua Chen ◽

Yu Hong Xiao ◽

...

Keyword(s):

Flexural Strength ◽

Sol Gel ◽

Flexural Properties ◽

Resin Composites ◽

Dental Resin ◽

Dental Resin Composites ◽

Aluminium Borate ◽

Significant Difference ◽

Group A ◽

Group B

This study aimed to compare three different methods for the modification of aluminium borate whiskers and investigate the effect of aluminium borate whiskers composites on flexural properties of dental resin composites. Method A was to mix aluminium borate whiskers and silicon dioxide (SiO2) nanoparticles directly. Method B was to modify the mixture of aluminium borate whiskers and SiO2nanoparticles with sol-gel process of tetraethoxysilane (TEOS). Method C was to modify the aluminium borate whiskers with SiO2nanoparticles which were repaired by sol-gel method of TEOS. The effects of the three methods were characterized by the TEM and SEM. There was a significant difference (p<0.05) in the flexural strength among three methods. Group C had a flexural strength of 149.59 ± 12.86 MPa (mean ± SD; n = 5), which is significantly higher than 95.28 ± 4.53 MPa for Group A and 123.14 ± 17.37 MPa for Group B. It is concluded that ceramic whisker reinforcement significantly improves the flexural properties of resin composites; different methods produce different effects.

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Comparison of Intaglio Surface Trueness of Interim Dental Crowns Fabricated with SLA 3D Printing, DLP 3D Printing, and Milling Technologies

Healthcare ◽

10.3390/healthcare9080983 ◽

2021 ◽

Vol 9 (8) ◽

pp. 983

Author(s):

Keunbada Son ◽

Jung-Ho Lee ◽

Kyu-Bok Lee

Keyword(s):

3D Printing ◽

Computer Aided Design ◽

Reference Model ◽

Digital Light Processing ◽

3 Dimensional ◽

Dental Crowns ◽

Test Models ◽

Significant Difference ◽

Manufacturing Accuracy ◽

Aided Design

This study aimed to evaluate the intaglio surface trueness of interim dental crowns fabricated with three 3-dimensional (3D) printing and milling technologies. Dental crown was designated and assigned as a computer-aided design (CAD) reference model (CRM). Interim dental crowns were fabricated based on CRM using two types of 3D printer technologies (stereolithography apparatus and digital light processing) and one type of milling machine (n = 15 per technology). The fabricated interim dental crowns were obtained via 3D modeling of the intaglio surface using a laboratory scanner and designated as CAD test models (CTMs). The alignment and 3D comparison of CRM and CTM were performed based on the intaglio surface using a 3D inspection software program (Geomagic Control X). Statistical analysis was validated using one-way analysis of variance and Tukey HSD test (α = 0.05). There were significant differences in intaglio surface trueness between the three different fabrication technologies, and high trueness values were observed in the milling group (p < 0.05). In the milling group, there was a significant difference in trueness according to the location of the intaglio surface (p < 0.001). In the manufacturing process of interim dental crowns, 3D printing technologies showed superior and uniform manufacturing accuracy than milling technology.

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

Journal of Functional Biomaterials ◽

10.3390/jfb10020017 ◽

2019 ◽

Vol 10 (2) ◽

pp. 17 ◽

Cited By ~ 15

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.

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Dimensional Accuracy Evaluation of Temporary Dental Restorations with Different 3D Printing Systems

Materials ◽

10.3390/ma14061487 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1487 ◽

Cited By ~ 1

Author(s):

Wonjoon Moon ◽

Seihwan Kim ◽

Bum-Soon Lim ◽

Young-Seok Park ◽

Ryan Jin-Young Kim ◽

...

Keyword(s):

3D Printing ◽

Liquid Crystal Display ◽

Dimensional Accuracy ◽

Accuracy Evaluation ◽

Digital Light Processing ◽

Color Mapping ◽

Stl File ◽

Deviation Analysis ◽

Dental Restorations ◽

Significant Difference

With the advent of 3D printing technologies in dentistry, the optimization of printing conditions has been of great interest, so this study analyzed the accuracy of 3D-printed temporary restorations of different sizes produced by digital light processing (DLP) and liquid crystal display (LCD) printers. Temporary restorations of 2-unit, 3-unit, 5-unit, 6-unit, and full-arch cases were designed and printed from a DLP printer using NextDent C&B or an LCD printer using Mazic D Temp (n = 10 each). The restorations were scanned, and each restoration standard tessellation language (STL) file was superimposed on the reference STL file, by the alignment functions, to evaluate the trueness through whole/point deviation. In the whole-deviation analysis, the root-mean-square (RMS) values were significantly higher in the 6-unit and full-arch cases for the DLP printer and in the 5-unit, 6-unit, and full-arch cases for the LCD printer. The significant difference between DLP and LCD printers was found in the 5-unit and full-arch cases, where the DLP printer exhibited lower RMS values. Color mapping demonstrated less shrinkage in the DLP printer. In the point deviation analysis, a significant difference in direction was exhibited in all the restorations from the DLP printer but only in some cases from the LCD printer. Within the limitations of this study, 3D printing was most accurate with less deviation and shrinkage when a DLP printer was used for short-unit restorations.

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The effect of radiation exposure and storage time on the degree of conversion and flexural strength of different resin composites

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00605-y ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Ragia M. Taher ◽

Lamiaa M. Moharam ◽

Amin E. Amin ◽

Mohamed H. Zaazou ◽

Farid S. El-Askary ◽

...

Keyword(s):

Flexural Strength ◽

Radiation Exposure ◽

Storage Time ◽

Resin Composite ◽

Degree Of Conversion ◽

Bending Test ◽

Resin Composites ◽

Significant Difference ◽

Infrared Spectrometer ◽

And Storage

Abstract Background This study was conducted to evaluate the effect of radiation exposure and storage time on the degree of conversion (DC%) and flexural strength (FS) of three different resin composites. In total, 90 disk-shaped, and 360 rod-shaped composite specimens were prepared to evaluate the DC% and FS, respectively. Specimens were divided into 18 groups (DC%: n = 5 and FS: n = 20) according to the three experimental factors of the study: 1—Radiation (no-exposure and exposure), 2—Resin composite material (Herculite XRV Ultra, Z250 XT and Grandio), and 3—Storage time (24 h in distilled water, 3-m and 6-m in 70% ethanol). Fourier transform infrared spectrometer (FTIR) was used to determine the DC%. For FS, the specimens were subjected to a three-point bending test at 1 mm/min crosshead speed. Data were analyzed using three-way ANOVA/Tukey HSD test. Significant level was set at P = 0.05. Results For DC%, there was no significant difference between no-radiation exposure and radiation exposure (P > 0.05). Herculite XRV Ultra revealed the highest statistically significant DC% (P < 0.05). The 24-h storage time revealed the least significant DC% (P < 0.05). For FS, radiation exposure showed a statistically significant higher value compared to no-radiation exposure (P < 0.05). Herculite XRV Ultra showed the least FS value (P < 0.05). The 24-h storage time showed the highest significant value (P < 0.05). Conclusions Radiation exposure has no significant impact on the DC% of the different resin composites, but it has a significant positive effect on the FS. Storage time had a significant effect on both DC% and FS.

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