scholarly journals Comparison of Mechanical Resistance to Maximal Torsion Stress in Original and Nonoriginal or Compatible Prosthetic Implant Screws: An In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
António Sérgio Silva ◽  
José Manuel Mendes ◽  
Tiago Araújo ◽  
Carlos Aroso ◽  
Pedro Barreiros
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Fracture Site ◽  
Mechanical Resistance ◽  
Mean Values ◽  
Maximal Torsion ◽  
Significant Difference ◽  
Bone Preservation ◽  
Prosthetic Implant

Micromovements of the implant-abutment connection influence peri-implant bone preservation. The maximal torque after a cycle of implant prosthetic screw tightening using original components of different manufacturers and replicas produced by other companies is evaluated and quantified in this study. A total of 30 Mis Seven® standard platform implants and 30 interfaces were used, and 30 standard platform screws were tested, 10 Mis®, 10 Iconekt®, and 10 Exaktus®. The screws were tightened with an MIS® torquemeter until their respective fracture, and the fracture point was measured through the equipment’s load cell, CS-Dental Testing Machine®. The screws were analyzed under an Olympus® SZ61 microscope. The fracture points were recorded and compared among all samples. To compare the mean values of the fracture torques, t-tests were performed using the reference values associated with each brand and the sample results. The variable “Place of Fracture” between the original Mis® brand and the Exaktus® replica compared to the Iconekt® replica presented a statistically significant difference (p < 0.001). When analyzing the variable “Fracture Torque,” although it was verified that the replica screws (Iconekt® and Exaktus®) had a lower maximum torque, 65.11 Nm and 62.89 Nm, respectively, compared to the original Mis® brand (70 Nm and 69 Nm), there were no statistically significant differences p > 0.05. Nonoriginal screws did not present different fracture resistances compared to the original Mis® brand screws. The fracture site of Iconekt® screws showed a different pattern compared to the other brands.

scholarly journals Incorporation of Arginine to Commercial Orthodontic Light-Cured Resin Cements—Physical, Adhesive, and Antibacterial Properties

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4391
Author(s):  
Saulo Geraldeli ◽  
Lucas de Almeida Maia Carvalho ◽  
Isaac Jordão de Souza Araújo ◽  
Maurício Bottene Guarda ◽  
Marcelle M. Nascimento ◽  
...  
Keyword(s):  
Shear Bond Strength ◽  
Testing Machine ◽  
Antibacterial Properties ◽  
In Vitro Study ◽  
Resin Cement ◽  
Preventive Strategy ◽  
Resin Cements ◽  
Mean Values ◽  
Significant Difference

(1) Background: The amino acid arginine is now receiving great attention due to its potential anti-caries benefits. The purpose of this in vitro study was to evaluate the shear bond strength (SBS), ultimate tensile strength (UTS), and antimicrobial potential (CFU) of two arginine-containing orthodontic resin cements. (2) Methods: Forty bovine incisors were separated into four groups (n = 10): Orthocem, Orthocem + arginine (2.5 wt%), Transbond XT, and Transbond XT + arginine (2.5 wt%). The brackets were fixed to the flat surface of the enamel, and after 24 h the SBS was evaluated using the universal testing machine (Instron). For the UTS test, hourglass samples (n = 10) were made and tested in a mini-testing machine (OM-100, Odeme). For the antibacterial test (colony forming unit-CFU), six cement discs from each group were made and exposed to Streptococcus mutans UA159 biofilm for 7 days. The microbiological experiment was performed by serial and triplicate dilutions. The data from each test were statistically analyzed using a two-way ANOVA, followed by Tukey’s test (α = 0.05). (3) Results: The enamel SBS mean values of Transbond XT were statistically higher than those of Orthocem, both with and without arginine (p = 0.02033). There was no significant difference in the SBS mean values between the orthodontic resin cements, either with or without arginine (p = 0.29869). The UTS of the Transbond XT was statistically higher than the Orthocem, but the addition of arginine at 2.5 wt% did not influence the UTS for either resin cement. The Orthocem + arginine orthodontic resin cement was able to significantly reduce S. mutans growth, but no difference was observed for the Transbond XT (p = 0.03439). (4) Conclusion: The incorporation of arginine to commercial orthodontic resin cements may be an efficient preventive strategy to reduce bacterial growth without compromising their adhesive and mechanical properties.

scholarly journals Comparison in Four Different Implant Systems of Mechanical Resistance to Maximal Stress in Prosthetic Screws—An In Vitro Study

2020 ◽  
Vol 8 (4) ◽  
pp. 116
Author(s):  
Pedro Barreiros ◽  
Luís Neves ◽  
Carlos Aroso ◽  
José M. Mendes ◽  
António Sérgio Silva
Keyword(s):  
In Vitro Study ◽  
Mechanical Resistance ◽  
Fracture Force ◽  
Mean Values ◽  
Multiple Comparison Test ◽  
Implant Abutment ◽  
Maximal Stress ◽  
Bone Preservation ◽  
Level Of Significance

Micromovements of the implant–abutment connection influence peri-implant bone preservation. This study evaluates and quantifies the maximal torque after a cycle of implant prosthetic screws tightening using original components. A total of 40 samples were tested: Megagen®—Daegu, South Korea; Dentium®—Gangnam-Gu, Seoul, Korea; BIOMET 3i®—West Palm Beach, FL, USA and BTI®—Álava, Spain. Screws from each manufacturer were subjected to maximal stress force until they fractured. The fracture points were recorded and compared among all samples. To compare the mean values of fracture torques, the reference values associated with each brand and the sample results were used in t-tests. ANOVA (analysis of variance) was used to compare the maximal resistance limit between brands, complemented with Tukey’s multiple-comparison test. The maximal considered level of significance was 5%. The average fracture force for the brands was 40.07 Ncm for Megagen®, 53.39 Ncm for Dentium®, 39.74 Ncm for Biomet 3i®, and 68.84 Ncm for BTI®. BTI® screws showed the most resistance to fracture. According to the protocol that was applied, the implant–abutment connection demonstrated good resistance and a precise fit between these interfaces; therefore, in some cases, the presented values showed a lack of quality control and low fracture resistance.

scholarly journals “Ormocer an innovative technology”: A replacement for conventional cements and veneer? A comparative in vitro analysis

2017 ◽  
Vol 11 (01) ◽  
pp. 058-063 ◽  
Author(s):  
Vini Rajeev ◽  
Rajeev Arunachalam ◽  
Sanjna Nayar ◽  
P. R. Arunima ◽  
Sivadas Ganapathy ◽  
...  
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Sem Analysis ◽  
Innovative Technology ◽  
Group I ◽  
Luting Cement ◽  
Significant Difference ◽  
Vitro Analysis

ABSTRACT Objective: This in vitro study was designed to assess shear bond strength (SBS) of ormocer flowable (OF) resin as a luting agent, ormocer as an indirect veneer material with portrayal of modes of failures using scanning electron microscope (SEM). Materials and Methods: Sixty maxillary central incisors were divided into Group I, II, and III with 20 samples each based on luting cement used. They were OF, self-adhesive (SA) cement, and total etch (TE) cement. These groups were subdivided into “a” and “b” of ten each based on the type of veneering materials used. Veneer discs were fabricated using Ormocer restorative (O) and pressable ceramic (C). Specimens were thermocycled and loaded under universal testing machine for SBS. The statistical analysis was done using one-way ANOVA post hoc Tukey honest significant difference method. Results: A significant difference was observed between the Groups I and II (P < 0.05). The highest mean bond strength when using ormocer veneer was obtained with the Group Ia (19.11 ± 1.92 Mpa) and lowest by Group IIa (8.1 ± 1.04 Mpa), whereas the highest mean bond strength while using ceramic veneer was of similar range for Group Ib (18.04 ± 4.08 Mpa) and Group IIIb (18.07 ± 1.40 Mpa). SEM analysis revealed OF and TE presented mixed type of failure when compared with SA where failure mode was totally adhesive. Conclusion: OF was found equally efficient like TE. Bond strength of ormocer as a veneer was not inferior to ceramic making it one of the promising additions in the field of dentistry.

Evaluating Dentin Surface Treatments for Resin-Modified Glass Ionomer Restorative Materials

2013 ◽  
Vol 38 (4) ◽  
pp. 429-438 ◽  
Author(s):  
TA Imbery ◽  
A Namboodiri ◽  
A Duncan ◽  
R Amos ◽  
AM Best ◽  
...  
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Positive Control ◽  
Negative Control ◽  
Surface Treatments ◽  
Band Matrices ◽  
Dentin Surface ◽  
Occlusal Surfaces ◽  
Significant Difference

SUMMARY This in vitro study evaluated the effect of six surface treatments on the shear bond strength of three resin-modified glass ionomers (RMGIs) to dentin. Occlusal surfaces of caries-free third molars were reduced to expose only dentin. Surface treatments were smear layer intact (negative control), Cavity Conditioner, EDTA, Ketac Primer, Self Conditioner, and etching with 35% phosphoric acid followed by the application of Optibond Solo Plus. Filtek Z250 composite resin bonded with Optibond Solo Plus served as a positive control. Conditioning agents were used according to the manufacturers' instructions. After surface treatments, Fuji II LC, Riva LC, Ketac Nano, and Filtek Z250 were placed in copper-band matrices 5 mm in diameter and 2 mm in height and were light-cured for 20 seconds. Specimens were stored in 100% humidity for 24 hours, after which they were placed in deionized water for 24 hours at 37°C. They were then tested under shear forces in an Instron Universal Testing Machine at a crosshead speed of 0.5 mm/min. A two-way analysis of variance and Tukey honestly significant difference statistical analyses (p&lt;0.05) indicated significant interaction between RMGIs and conditioning agents. Acid etching followed by Optibond Solo Plus provided highest bond strengths for all three RMGIs, which were not statistically different from the positive control.

scholarly journals Fracture Resistance of Zirconia-Reinforced Lithium Silicate Ceramic Crowns Cemented with Conventional or Adhesive Systems: An In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2012
Author(s):  
Gianmaria D’Addazio ◽  
Manlio Santilli ◽  
Marco Lorenzo Rollo ◽  
Paolo Cardelli ◽  
Imena Rexhepi ◽  
...  
Keyword(s):  
Mechanical Test ◽  
Testing Machine ◽  
In Vitro Study ◽  
Resin Cement ◽  
Human Tooth ◽  
Lithium Silicate ◽  
Significant Difference ◽  
Aesthetic Characteristics ◽  
Silicate Ceramic

In recent years, Zirconia-reinforced Lithium Silicate ceramic (ZLS), combining lithium-silicate and zirconia features, has shown to have excellent mechanical and aesthetic characteristics. Thus, the aim of this study was to compare the fracture strength of ZLS single crowns cemented with two different cementation techniques. Twenty crowns were realised and cemented on teeth replicas achieved from an extracted premolar human tooth. The samples were divided into two groups of 10 specimens each, Glass-ionomeric cement (GIC) group and Self-Adhesive Resin Cement (ARC) group. The mechanical test was performed using a universal testing machine. The specimens were then evaluated with a scanning electron microscope (SEM) to identify for all crowns and related abutments the pattern of fracture after the breaking point. The data obtained were statistically analysed. The mean fracture toughness values and standard deviations (±SD) were 2227 ± 382 N and 3712 ± 319 N respectively for GIC and ARC groups. In fact, t-test showed a statistically significant difference between the two groups (p < 0.001). Moreover, the SEM results demonstrated portions of abutments still attached to the crown fragments in the ARC group, whilst these were not present in the GIC group. Within the limitations of this study, these results suggest the use of adhesive cementation for ZLS crowns, which significantly increase the compressive strength of ZLS restorations compared to GIC.

A Comparative in vitro Study of the Load at Fracture of All-ceramic Crowns with Various Thicknesses of In-Ceram Core

2008 ◽  
Vol 9 (4) ◽  
pp. 17-25 ◽  
Author(s):  
Ilser Turkyilmaz ◽  
Suat Gokce ◽  
Emine Celik-Bagci
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Chromium Alloy ◽  
Dental Practitioners ◽  
Significant Difference ◽  
All Ceramic ◽  
Feasible Option ◽  
Ceramic Crowns

Abstract Aim The aim of this study was to investigate the influence of three different thicknesses of In-Ceram core on the load at fracture of all-ceramic crowns. Methods and Materials Thirty standardized crown-shaped nickel-chromium alloy dies were fabricated using a milling machine. Twenty dies were prepared with a 1 mm shoulder for Groups A and B. The only difference in the ten dies used for Group C was a smaller 0.5 mm lingual shoulder. The thicknesses of In-Ceram were 0.5 mm, 1.5 mm, and 0.75 mm for Groups A, B, and C. All all-ceramic crowns were fabricated in accordance with the manufacturer's instructions. After cementation of the crowns, their fracture resistance was tested with a universal testing machine. The load was directed to a point located 3 mm from the lingual aspect of the incisal edge at 30 degrees to the long axis of each specimen until catastrophic failure occurred. Results The mean loads at fracture for Groups A, B, and C were 1117±388 N, 2083±385 N, and 1439±368 N, respectively. No statistically significant difference in load at fracture between Groups A and C was found (p>0.05). However, the differences were statistically significant between Groups A and B (p<0.001) and Groups B and C (p<0.001). Conclusion Under the guidelines of this study, increasing the thickness of the In-Ceram core increased the fracture resistance of the all-ceramic crowns. Clinical Significance The sufficient thickness of the In-Ceram core of all-ceramic crowns is an important factor in fracture resistance. Therefore, dental practitioners should be careful in patient selection; if the horizontal overlap of a tooth to be restored is too limited, then all-ceramic crowns may not be a feasible option. Citation Gokce S, Celik-Bagci E, Turkyilmaz I. A Comparative in vitro Study of the Load at Fracture of Allceramic Crowns with Various Thicknesses of In-Ceram Core. J Contemp Dent Pract 2008 May; (9)4:017-025.

scholarly journals INFLUÊNCIA DA MODIFICAÇÃO DA BASE DE COLAGEM E DA CONTAMINAÇÃO SALIVAR NA RESISTÊNCIA DE UNIÃO DE TUBOS ORTODÔNTICOS COLADOS AO ESMALTE HUMANO

2021 ◽  
Vol 58 (1) ◽  
pp. eUJ3657
Author(s):  
Germano Brandão ◽  
◽  
Liliana Ávila Maltagliati ◽  
Ana Carla Raphaelli Nahás-Scocate ◽  
Murilo Matias ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Statistical Significance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Metal Mesh ◽  
Human Teeth ◽  
Significance Level ◽  
Significant Difference

The objective of this in vitro study was to assess and compare the shear bond strength of conventional and modified orthodontic tubes bonded to the surface of dry and saliva-contaminated enamel. The sample consisted of 40 human teeth, which were randomly divided into four groups according to attachment base and presence or absence of saliva contamination as follows: Group CB, conventional orthodontic tubes without salivary contamination; Group CB-S, conventional orthodontic tubes with salivary contamination; Groups BM, orthodontic tubes modified by welding a metal mesh to their base without salivary contamination; and Group BM-S, modified orthodontic tubes with salivary contamination. Shear bond strength test was performed in a universal testing machine and analysis of the adhesive remnant index (ARI) by optical microscopy. Two-way ANOVA was used, followed by Tukey’s test at a statistical significance level of 5%. The ARI results were analysed descriptively. There was statistically significant difference between the groups regarding the shear bond strength values, with conventional tubes presenting significantly higher values (P < 0.05). In addition, the presence of salivary contamination interfered negatively with the behaviour of conventional tubes only (P < 0.05). Shear bond strength was not improved by increasing the area of the orthodontic tubes. Moreover, salivary contamination influenced negatively the SBS values, but only when conventional tubes were used.

scholarly journals Time-dependent Variation in Compressive Strengths of Three Posterior Esthetic Restorative Materials: An in vitro Study

2016 ◽  
Vol 6 (3) ◽  
pp. 63-65
Author(s):  
Anjna Sharma ◽  
Pankaj Mishra
Keyword(s):  
Testing Machine ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Composite Resins ◽  
Time Dependent ◽  
Glass Ionomer ◽  
Significant Difference ◽  
Resin Modified Glass Ionomer ◽  
Restorative Materials

ABSTRACT Aim To compare the compressive strengths of composite resins and resin-modified glass ionomer cements (RMGICs) at different times. Materials and methods A total of 36 samples were prepared, 12 samples of each group, composite resins Filtek Z 250, Filtek Z 350, and resin-modified glass ionomer cement. Compressive strengths of specimens were measured after 1, 24 hours, and 7 days. Test was carried out on a “Universal Testing Machine” with cross-head speed of 5 mm/min. Results There was a significant difference between all the three restorative materials. Analysis of variance showed that mean compressive strengths of Z 250 after 1, 24 hours were higher than Z 350 and RMGIC (p < 0.05). The mean compressive strengths were reduced after 7 days in all the three groups, but after 7 days, the values of Z 250 when compared with the Z 350 and RMGIC were higher. Conclusion The study demonstrated that compressive strengths of hybrid composite resins (Z 250) were significantly higher than that of nanocomposites (Z 350) and RMGIC. How to cite this article Sharma A, Mishra P, Mishra SK. Time-dependent Variation in Compressive Strengths of Three Posterior Esthetic Restorative Materials: An in vitro Study. Int J Prosthodont Restor Dent 2016;6(3):63-65.

scholarly journals Effects of a bleaching agent with calcium on bovine enamel

2014 ◽  
Vol 08 (03) ◽  
pp. 320-325 ◽  
Author(s):  
Larissa Alexandrino ◽  
Yasmin Gomes ◽  
Eliane Alves ◽  
Hilton Costi ◽  
Hervé Rogez ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Negative Control ◽  
Double Blind ◽  
Tristimulus Colorimetry ◽  
Mean Values ◽  
Significant Difference ◽  
Bovine Enamel ◽  
Bleaching Treatment

ABSTRACT Objective: This in vitro study analyzed the effects of a bleaching treatment containing 35% hydrogen peroxide (HP) with or without calcium on bovine enamel, using the Knoop hardness number (KHN), tristimulus colorimetry (TC), and scanning electron microscopy. Materials and Methods: Forty-five specimens were randomly divided into groups (n = 5), which included artificial saliva (negative control [NC]), 35% HP (positive control [PC]), and 35% HP Blue Calcium (HP Blue). The specimens were subjected to three bleaching sessions. During the sessions, the specimens were immersed in artificial saliva at 37°C. Before and after bleaching, KHN tests were conducted using a force of 25 gf for 5 s. TC was performed using the CIE-L*a*b* system and readouts were obtained at the following 4 time points: Before the bleaching treatment; after the first session, the second session, and the third session. The specimens were dehydrated and coated with gold, and the photomicrographs were analyzed in a double-blind manner with a LEO microscope. Results: Using one-way analysis of variance and Tukey's test (P < 0.05), a statistically significant difference was identified between the initial and final mean KHNs of the NC and PC groups, while the initial and final mean KHNs were not significantly different in the HP Blue group. The final mean values of ⋄E, ⋄L, and ⋄b of the PC and HP Blue groups were significantly higher than the initial values (P < 0.01 for both). The photomicrographs revealed no differences among the groups. Conclusions: Therefore, treatment with HP Blue prevented changes in the KHN without reducing the efficacy of bleaching.

Suction force rather than aspiration flow correlates with recanalization in hard clots: an in vitro study model

2021 ◽  
pp. neurintsurg-2020-017242
Author(s):  
David Fernandez-Sanchez ◽  
Daniel Garcia-Sabido ◽  
Tudor G Jovin ◽  
Helena Villanova ◽  
Tommy Andersson ◽  
...  
Keyword(s):  
Testing Machine ◽  
Physical Property ◽  
In Vitro Study ◽  
Suction Force ◽  
Mean Values ◽  
Distal Surface ◽  
Stent Retrievers ◽  
Rate Sensor

BackgroundANA Advanced Neurovascular Access provides a novel funnel component designed to reduce clot fragmentation and facilitate retrieval in combination with stent-retrievers (SRs) in stroke patients by restricting flow and limiting clot shaving. In previous publications ANA presented excellent in vitro/in vivo efficacy data, especially with fibrin-rich hard clots. We aimed to determine the main physical property responsible for these results, namely suction force versus aspiration flow.MethodsWe evaluated in a bench model the suction force and flow generated by ANA and compared them to other neurovascular catheters combined with a SR (Solitaire). Aspiration flow was evaluated with a flow rate sensor while applying vacuum pressure with a pump. Suction force was determined using a tensile strength testing machine and a purposely designed tool that completely seals the device tip simulating complete occlusion by a hard clot. Suction force was defined as the force needed to separate the device from the clot under aspiration. All experiments were repeated five times, and mean values used for comparisons.ResultsAspiration flow increased with the inner diameter of the device: ANA 1.85±0.04 mL/s, ACE68 3.74±0.05 mL/s, and 8F-Flowgate2 5.96±0.30 mL/s (P<0.001). After introducing the SR, the flow was reduced by an average of 0.57±0.12 mL/s. Due to its larger distal surface, ANA suction force (1.69±0.40 N) was significantly higher than ACE68 (0.26±0.04 N) and 8F-Flowgate2 (0.42±0.06 N) (P<0.001). After introducing the SR, suction force variation was not relevant except for ANA that increased to 2.64±0.41 N.ConclusionDespite lower in vitro aspiration flow, the ANA design showed a substantially higher suction force than other thrombectomy devices.

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