scholarly journals Glass Fiber Reinforced Composite Orthodontic Retainer: In Vitro Effect of Tooth Brushing on the Surface Wear and Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1028 ◽  
Author(s):  
Maria Francesca Sfondrini ◽  
Pekka Kalevi Vallittu ◽  
Lippo Veli Juhana Lassila ◽  
Annalisa Viola ◽  
Paola Gandini ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Resin Composite ◽  
Maximum Load ◽  
Tooth Brushing ◽  
Bending Test ◽  
Bending Stress ◽  
Fiber Reinforced ◽  
Sem Images ◽  
Surface Cover

Fiber reinforced composites (FRCs) are metal free materials that have many applications in dentistry. In clinical orthodontics, they are used as retainers after active treatment in order to avoid relapse. However, although the modulus of the elasticity of FRCs is low, the rigidity of the material in the form of a relatively thick retainer with a surface cover of a flowable resin composite is known to have higher structural rigidity than stainless steel splints. The aim of the present study is to measure load and bending stress of stainless steel wires, as well as flowable resin composite covered and spot-bonded FRC retainer materials after tooth brushing. These materials were tested with a three point bending test for three different conditions: no brushing, 26 min of brushing, and 60 min of brushing. SEM images were taken before and after different times of tooth brushing. Results showed that stainless steel was not significantly affected by tooth brushing. On the other hand, a significant reduction of values at maximum load at fracture was reported for both FRC groups, and uncovered FRCs were most affected. Concerning maximum bending stress, no significant reduction by pretreatment conditions was reported for the materials tested. SEM images showed no evident wear for stainless steel. Flowable resin composite covered FRCs showed some signs of composite wear, whereas spot-bonded FRCs, i.e., without the surface cover of a flowable resin composite, showed signs of wear on the FRC and exposed glass fibers from the FRC’s polymer matrix. Because of the significant changes of the reduction of maximum load values and the wear for spot-bonded FRCs, this technique needs further in vitro and in vivo tests before it can be performed routinely in clinical practice.

scholarly journals Effect of Long-Term Brushing on Deflection, Maximum Load, and Wear of Stainless Steel Wires and Conventional and Spot Bonded Fiber-Reinforced Composites

2019 ◽  
Vol 20 (23) ◽  
pp. 6043 ◽  
Author(s):  
Andrea Scribante ◽  
Pekka Vallittu ◽  
Lippo V. J. Lassila ◽  
Annalisa Viola ◽  
Paola Tessera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Maximum Load ◽  
Tooth Brushing ◽  
Clinical Use ◽  
Surface Wear ◽  
Fiber Reinforced ◽  
Sem Images ◽  
Similar Reduction ◽  
Bonding Technique

Fiber-reinforced composite (FRC) retainers are an aesthetic alternative to conventional Stainless Steel splints. They are generally used with a full bonded technique, but some studies demonstrated that they could be managed with a spot bonding technique to significantly decrease their rigidity. In order to propose this FRC spot bonding technique for clinical use, the aim of this study was to evaluate mechanical properties and surface wear of fibers left uncovered. Tests were made by simulating tooth brushing, comparing FRC spot bonding technique splints with stainless steel and FRC traditional technique splints. Specimens were tested both at 0.1 mm of deflection and at maximum load, showing higher values of rigidity for the FRC full bonded technique. After tooth brushing, no significant reduction in values at 0.1 mm deflection was reported, while we found a similar reduction in these values for the Stainless Steel and FRC spot bonding technique at maximum load, and no significant variation for the FRC full bonded technique. SEM images after tooth brushing showed wear for FRC fibers left uncovered, while no relevant wear signs in metal and conventional FRC fibers were noticed. Results showed that FRC spot bonding technique has advantages in mechanical properties when compared to the FRC traditional full bonding technique, also after tooth brushing. However, the surface wear after tooth brushing in the FRC spot bonding technique is considerable and other tests must be performed before promoting this technique for routine clinical use.

scholarly journals Scanning Accuracy of Bracket Features and Slot Base Angle in Different Bracket Materials by Four Intraoral Scanners: An In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 365
Author(s):  
Seon-Hee Shin ◽  
Hyung-Seog Yu ◽  
Jung-Yul Cha ◽  
Jae-Sung Kwon ◽  
Chung-Ju Hwang
Keyword(s):  
Stainless Steel ◽  
In Vitro Study ◽  
Sem Images ◽  
Polycrystalline Alumina ◽  
Base Angle ◽  
Accurate Expression ◽  
Dental Model ◽  
Alumina Composite ◽  
The Difference

The accurate expression of bracket prescription is important for successful orthodontic treatment. The aim of this study was to evaluate the accuracy of digital scan images of brackets produced by four intraoral scanners (IOSs) when scanning the surface of the dental model attached with different bracket materials. Brackets made from stainless steel, polycrystalline alumina, composite, and composite/stainless steel slot were considered, which have been scanned from four different IOSs (Primescan, Trios, CS3600, and i500). SEM images were used as references. Each bracket axis was set in the reference scan image, and the axis was set identically by superimposing with the IOS image, and then only the brackets were divided and analyzed. One-way analysis of variance (ANOVA) was used to compare the differences. The difference between the manufacturer’s nominal torque and bracket slot base angle was 0.39 in SEM, 1.96 in Primescan, 2.04 in Trios, and 5.21 in CS3600 (p < 0.001). The parallelism, which is the difference between the upper and lower angles of the slot wall, was 0.48 in SEM, 7.00 in Primescan, 5.52 in Trios, 6.34 in CS3600, and 23.74 in i500 (p < 0.001). This study evaluated the accuracy of the bracket only, and it must be admitted that there is some error in recognizing slots through scanning in general.

scholarly journals Long-Term Stability of a RAFT-Modified Bulk-Fill Resin-Composite under Clinically Relevant versus ISO-Curing Conditions

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5350
Author(s):  
Niklas Graf ◽  
Nicoleta Ilie
Keyword(s):  
Fracture Mechanism ◽  
Resin Composite ◽  
Bending Test ◽  
Depth Sensing ◽  
Matrix Formulation ◽  
Curing Conditions ◽  
Term Stability ◽  
Long Term Stability

The addition of RAFT (reversible addition-fragmentation chain transfer) agents to the matrix formulation of a bulk-fill resin composite can significantly decrease the required curing time down to a minimum of 3 s. Evaluating the long term-stability of this resin composite in relation to varied curing conditions in an in-vitro environment was this study’s goal. Specimens were produced according to either an ISO or one of two clinical curing protocols and underwent a maximum of three successive aging procedures. After each one of the aging procedures, 30 specimens for each curing condition were extracted for a three-point bending test. Fragments were then stereo-microscopically characterized according to their fracture mechanism. Weibull analysis was used to quantify the reliability of each aging and curing combination. Selected fragments (n = 12) underwent further testing via depth-sensing indentation. Mechanical values for either standardized or clinical curing were mostly comparable. However, changes in fracture mechanism and Weibull modulus were observed after each aging procedure. The final procedure exposed significant differences in the mechanical values due to curing conditions. Curing conditions with increased radiant exposure seemingly result in a higher crosslink in the polymer-matrix, thus increasing resistance to aging. Yet, the clinical curing conditions still resulted in acceptable mechanical values, proving the effectiveness of RAFT-polymerization.

Study on the Performance of Orthodontic Self-Drilling Correction Screw of Ti6Al4V and Stainless 316L

2016 ◽  
Vol 872 ◽  
pp. 276-280
Author(s):  
The Vinh Do ◽  
Quang Cherng Hsu ◽  
Po Hung Chen ◽  
Yu Liang Chen
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Torsion Test ◽  
Maximum Load ◽  
3D Models ◽  
Bending Test ◽  
Geometrical Parameters ◽  
Initial Stability ◽  
Stainless Steel Screws ◽  
Titanium Alloy Ti6al4v

In this research, the performance of orthodontic self-drilling correction screw of Titanium alloy (Ti6Al4V) and stainless steel (Stainless 316L) was analyzed by using the finite element method. SolidWorks software was employed to design the 3D models. The dimensions and geometrical parameters of the mini-screw according to ASTM F543-07. The analysis was conducted by using Ansys software. The biomechanical test is carried out that includes the static bending test and the torsion test. Based on the analysis of the results of the tests, the initial stability of the stainless steel screw is slightly higher than the titanium alloy screw. However, in prolonged stress results, attention to interactions with biological organisms from the medical perspective, the titanium bone screw have more advantages. In terms of the maximum load, the titanium alloy screws are better than the stainless steel screws. In terms of stiffness, the stainless steel screws proved superior to the type of titanium alloy. The orthodontic self-drilling correction screw saving of about 30% of the torque and more stable compared to the nonself-drilling type.

scholarly journals ANALISA HASIL UJI KEKUATAN TARIK, TEKAN & STRUKTUR MAKRO SAMPAH PLASTIK JENIS PET, HDPE, DAN CAMPURAN (PET+HDPE)

JTAM ROTARY ◽  
2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Holy Ramagisandy ◽  
Rudi Siswanto
Keyword(s):  
Tensile Strength ◽  
Bending Strength ◽  
Maximum Load ◽  
Bending Test ◽  
Stress And Strain ◽  
Bending Stress ◽  
Test Results ◽  
Recycled Pet ◽  
Tensile Strength Test ◽  
Used Oil

Plastik is a material which has difficult to decompose. Therefore, the utilization of waste into useful material is important to do. This study aims to identify the tensile strength, bending, and macro structure of recycled PET, HDPE, and PET + HDPE plastik waste mixtures and recommendations for plastik products that fit the characteristics of these plastik types. PET and HDPE plastik waste is melted with oil and reprinted into tensile and bending test samples in accordance with predetermined variations, and then the results of the fracture are analyzed in a macro structure. Based on tensile testing, the tensile strength test results have the highest stress and strain values obtained in the mixture of 40% + HDPE 60% (B2) used oil specimens of 10.58 MPa and strain values of 11.98%. The results of bending strength testing which has the highest bending stress value and maximum load value are obtained in plastik mixture specimens with 30% used oil mixture + 70% HDPE (B1) of 11.58 MPa and for maximum load values of 43.33 KN. Testing the tensile strength and bending strength of the type of plastik mixture Oil and HDPE + PET (50%: 50%), the results obtained can still not be recommended to be used as a paving block product because the value of stress, strain, bending stress, and the maximum load is still relatively low, namely for the tensile test the highest variation of stress value is 5.21 MPa, the highest variation of strain value is 5.23%, the maximum load value is 10 KN, and the highest variation of bending stress value is 40% + 60% by 4.01 MPa.

In vitro Mechanical Testing of Glass Fiber-reinforced Composite Used as Dental Implants

2008 ◽  
Vol 9 (2) ◽  
pp. 41-48 ◽  
Author(s):  
Lippo Lassila ◽  
Pekka Vallittu ◽  
Ahmed Ballo ◽  
Timo Nărhi
Keyword(s):  
Glass Fiber ◽  
Mechanical Testing ◽  
Dental Implants ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Polymerization Conditions

Abstract Aim The aim of this study was to evaluate the design of fiber-reinforced composite (FRC) on some mechanical properties of a dental implant. Methods and Materials FRC implants were fabricated using different polymerization conditions and designs of the glass-fiber structure. Specimens were tested with a cantilever bending test and a torsional test. The degree of monomer conversion (DC%) was measured using a Fourier transform infrared spectroscopy (FTIR). Results Statistical analysis showed significant differences between groups revealing mean fracture load values from 437 N to 1461 N. The mean torsional force in fracture varied from 0.01 to 1.66 Nm. The DC% varied from 50% to 90%. Conclusion This study suggests by modifying the polymerization conditions and fiber orientation of FRC implants, the biomechanical properties of an FRC can be tailored to the needs of dental implants. Citation Ballo AM, Lassila LV, Närhi TO, Vallittu PK. In vitro Mechanical Testing of Glass Fiber-reinforced Composite Used as Dental Implants. J Contemp Dent Pract 2008 February;(9)2:041-048.

scholarly journals Improvement of the Shock Absorption Ability of a Face Guard by Incorporating a Glass-Fiber-Reinforced Thermoplastic and Buffering Space

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Takahiro Wada ◽  
Hiroshi Churei ◽  
Haruka Takayanagi ◽  
Naohiko Iwasaki ◽  
Toshiaki Ueno ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Maximum Stress ◽  
Flexural Modulus ◽  
Maximum Load ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Shock Absorption ◽  
Glass Fiber Reinforced ◽  
Test Shock ◽  
Materials Used

This study aimed to evaluate the shock absorption ability of trial face guards (FGs) incorporating a glass-fiber-reinforced thermoplastic (GF) and buffering space. The mechanical properties of 3.2 mm and 1.6 mm thick commercial medical splint materials (Aquaplast, AP) and experimental GF prepared from 1.6 mm thick AP and fiberglass cloth were determined by a three-point bending test. Shock absorption tests were conducted on APs with two different thicknesses and two types of experimental materials, both with a bottom material of 1.6 mm thick AP and a buffering space of 30 mm in diameter (APS) and with either (i) 1.6 mm thick AP (AP-APS) or (ii)  1.6 mm thick GF (GF-APS) covering the APS. The GF exhibited significantly higher flexural strength (64.4 MPa) and flexural modulus (7.53 GPa) than the commercial specimens. The maximum load of GF-APS was 75% that of 3.2 mm AP, which is widely used clinically. The maximum stress of the GF-APS only could not be determined as its maximum stress is below the limits of the analysis materials used (<0.5 MPa). Incorporating a GF and buffering space would enhance the shock absorption ability; thus, the shock absorption ability increased while the total thickness and weight decreased.

scholarly journals Retentive Force of Three Fiber-reinforced Resin Composite Posts and a Zirconia Post Cemented with Two Adhesive Luting Agents: In Vitro Study

2007 ◽  
Vol 26 (5) ◽  
pp. 672-676 ◽  
Author(s):  
Zelal SEYFIOGLU POLAT ◽  
Ibrahim Halil TACIR ◽  
Sebnem ESKIMEZ ◽  
M. Yusuf ÇELIK
Keyword(s):  
Resin Composite ◽  
In Vitro Study ◽  
Vitro Study ◽  
Fiber Reinforced ◽  
Retentive Force ◽  
Luting Agents ◽  
Adhesive Luting

scholarly journals Flexural Characteristics of Functionally Graded Fiber-Reinforced Cementitious Composite with Polyvinyl Alcohol Fiber

2021 ◽  
Vol 5 (4) ◽  
pp. 94
Author(s):  
Toshiyuki Kanakubo ◽  
Takumi Koba ◽  
Kohei Yamada
Keyword(s):  
Polyvinyl Alcohol ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Maximum Load ◽  
Functionally Graded ◽  
Bending Test ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Four Point Bending

The objective of this study is to investigate the flexural characteristics of functionally graded fiber-reinforced cementitious composite (FG-FRCC) concerning the fiber volume fraction (Vf) varying in layers and the layered effect in bending specimens. The FG-FRCC specimens, in which Vf increases from 0% in the compression zone to 2% in the tensile zone, are three-layered specimens using polyvinyl alcohol (PVA) FRCC that are fabricated and tested by a four-point bending test. The maximum load of the FG-FRCC specimens exhibits almost twice that of homogeneous specimens, even when the average of the fiber volume fraction in the whole specimen is 1%. The result of the section analysis, in which the stress–strain models based on the bridging law (tensile stress–crack width relationship owned by the fibers) consider the fiber orientation effect, shows a good adaptability with the experiment result.

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