scholarly journals Experimental Evaluation of Strength Degradation of Orthodontic Chain Elastics Immersed in Hot Beverages

2019 ◽  
Vol 53 (4) ◽  
pp. 244-248 ◽  
Author(s):  
Emanuel Braga ◽  
Gabriella Souza ◽  
Paula Barretto ◽  
Caio Ferraz ◽  
Matheus Pithon
Keyword(s):  
Tensile Strength ◽  
Green Tea ◽  
Artificial Saliva ◽  
Testing Machine ◽  
Strength Degradation ◽  
Hot Water ◽  
Group 4 ◽  
Group 2 ◽  
Force Reduction ◽  
Elastomeric Chains

Introduction: Elastomeric chains are relevant in orthodontic mechanics due to the form memory property; however, elastomers present high force reduction in some circumstances. The objective was to evaluate the effect of hot beverages on tensile strength degradation of orthodontic elastomeric chains. Material and Methods: Four groups were tested according to different immersion liquids: artificial saliva (group 1), hot water (group 2), green tea (group 3), and coffee (group 4). The elastomeric chains of groups 2, 3, and 4 were immersed in the respective liquids, with temperature of 70 ± 1°C twice daily for 30 seconds for a period of 7, 14, or 21 days. All samples were kept in artificial saliva and stored in an incubator at controlled temperature of 37 ± 1°C. The elastomeric chains were then examined in the testing machine (AME-2kN; Filizola, São Paulo, Brazil) to measure the tensile strength degradation. Results: It was observed through intragroup comparisons that the control showed a progressive reduction of tensile strength in a statistically significant manner throughout the study period. In turn, the hot water, green tea, and coffee samples showed a statistically significant reduction from 7 to 14 days. From 14 to 21 days, the tension remained stable. When the test groups were compared with the control, it was observed that all groups presented tension reduction in a statistically significant manner at all periods, except for the coffee group at 21 days ( P < .001). Conclusions: Experimental immersion in hot water, green tea, and coffee at 70 ± 1°C contributed in a statistically significant manner to the strength degradation of orthodontic elastomeric chains in the period of 7 and 14 days.

scholarly journals Differences in the tensile strength of direct nanohybrid composite veneers between the V and VIII generation dentin bonding agent after extracoronal bleaching

2018 ◽  
Vol 30 (1) ◽  
pp. 28
Author(s):  
Erlin Zuke Rizkia ◽  
Setiadi Warata Logamarta ◽  
Irfan Dwiandhono
Keyword(s):  
Tensile Strength ◽  
Artificial Saliva ◽  
Testing Machine ◽  
Bonding Agent ◽  
Tooth Surface ◽  
Dental Bonding ◽  
Dentin Bonding ◽  
Dentin Bonding Agent ◽  
Nanohybrid Composite ◽  
Group 2

Introduction: Tooth discolouration is the most common esthetic problems in dentistry. Direct composite veneer is an adjunctive therapy for severe teeth discolouration by attaching to the tooth surface using an acid etching and dental bonding agent. In several cases of severe discolouration, it is required to have certain preliminary treatments such as bleaching prior to the placement of the composite veneer. However, bleaching agents are able to lead the enamels morphology and microstructure alteration by inhibiting the polymerisation bonding thus affecting the veneer adhesion. This study was aimed to determine the tensile bond strength of direct composite veneers between the V and VII generation dentin bonding agent after extracoronal bleaching. Methods: This study was an experimental laboratory of as much as 32 human permanent maxillary central incisors were divided into 4 groups. Group 1 was treated with extracoronal bleaching and bonded with the V generation bonding nanohybrid composite. Group 2 was treated with extracoronal bleaching and bonded with the VIII generation bonding nanohybrid composite. Group 3 was only bonded with the V generation bonding nanohybrid composite. Group 4 was only bonded with the VIII generation bonding nanohybrid composite. All samples were immersed in artificial saliva then incubated at the room temperature for 24 hours. Results: The tensile strength value was determined using the Universal Testing Machine. The ANOVA test results showed significant differences in all four groups (p < 0.05). Conclusion: The VIII generation bonding agent had a higher tensile strength than the V generation.

scholarly journals An in vitro comparison of the force decay generated by different commercially available elastomeric chains and NiTi closed coil springs

2007 ◽  
Vol 21 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Ana Cristina Soares Santos ◽  
André Tortamano ◽  
Sandra Regina Frazatto Naccarato ◽  
Gladys Cristina Dominguez-Rodriguez ◽  
Julio Wilson Vigorito
Keyword(s):  
Artificial Saliva ◽  
Testing Machine ◽  
In Vitro Study ◽  
Original Length ◽  
Force Decay ◽  
Decay Pattern ◽  
The Mean ◽  
Initial Force ◽  
Elastomeric Chains

This in vitro study was designed to compare the forces generated by commercially available elastomeric chains and NiTi closed coil springs, and to determine their force decay pattern. Forty elastomeric chains and forty NiTi closed coil springs were divided into 4 groups according to the following manufacturers: (1) Morelli®, (2) Abzil®, (3) TP Orthodontics® and (4) American Orthodontics®. The specimens were extended to twice their original length and stored in artificial saliva at 37°C. Initial force was measured by means of an Instron universal testing machine and then at 1, 4, 7, 14, 21, and 28 days. The results revealed that the elastomeric chains delivered a mean initial force of 347 g for Morelli®, 351 g for American Orthodontics®, 402 g for Abzil®, and 404 g for TP Orthodontics®. The NiTi closed coil springs generated a mean initial force of 196 g for American Orthodontics®, 208 g for TP Orthodontics®, 216 g for Abzil®, and 223 g for Morelli®. The mean percentage of force decay observed after 28 days for the elastomeric chains was 37.4% for TP Orthodontics®, 48.1% for American Orthodontics®, 65.4% for Morelli®, and 71.6% for Abzil®. After 28 days, the NiTi closed coil springs presented a mean percentage of force decay of 22.6% for American Orthodontics®, 29.8% for Abzil®, 30.6% for Morelli®, and 45.8% for TP Orthodontics®. At the end of the study, significant differences were observed between the elastomeric chains and the NiTi closed coil springs. The results indicated that the studied NiTi closed coil springs are more adequate for dental movement than the elastomeric chains.

Effect of Bidirectional Insertion of External Skeletal Fixation Pins on Axial Pullout Strength in Canine Cadaveric Bone

2021 ◽  
Author(s):  
Jane Park ◽  
Danielle Dugat ◽  
Mark Rochat ◽  
Hall Griffin ◽  
Mark E. Payton
Keyword(s):  
Testing Machine ◽  
Fluoroscopic Guidance ◽  
Pullout Strength ◽  
Group 4 ◽  
Group 12 ◽  
Group 3 ◽  
Group 2 ◽  
Depth Gauge ◽  
Position Group ◽  
Group 1

Abstract Objective The aim of this study was to evaluate the effect of bidirectional insertion on axial pullout strength of tapered run out (TRO), traditional negative profile (TNP) and positive profile (PP) pins. Study Design Cadaveric adult canine tibiae were harvested. Tapered run out pins (Group 1) were inserted unidirectionally to the desired position; bidirectionally past the desired position, then withdrawn to the desired position (Group 2); and bidirectionally as described for Group 2, repeated twice (Group 3). Traditional negative profile pins (Group 4–6) and PP pins (Group 9–11) were placed in the same manner. Tapered run out (Group 7), TNP (Group 8) and PP pins (Group 12) were driven unidirectionally such that the shaft of the pin violated the cis-cortex. A servohydraulic testing machine extracted the pins and measured axial peak pullout strength. Results Positive profile pins had significantly greater pullout strength than TRO and TNP pins placed unidirectionally to the desired position. Method of insertion had no effect on peak pullout strength of TNP pins. TRO and PP pins inserted unidirectionally to the desired position had significantly greater peak pullout strengths than insertion bidirectionally or if the shaft of the pin violated the cis-cortex. Conclusion The authors recommend that pins used for external skeletal fixation should be placed unidirectionally to the desired position with fluoroscopic guidance, intra-operative depth gauge measurements or measurements from preoperative radiographs. Repositioning pins results in loss of peak pullout strength with TRO and PP pins.

Bond Integrity of Titanium Surface to Resin Cement After Conditioning with Different Photobiomodulataion Therapy (PBT)

2021 ◽  
Vol 11 (5) ◽  
pp. 970-975
Author(s):  
Khold Al Ahdal ◽  
Laila Al Deeb ◽  
Mohammed S. Bin-Shuwaish ◽  
Rana S. Al-Hamdan ◽  
Modhi Al Deeb ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Testing Machine ◽  
Resin Cement ◽  
Control Group ◽  
Sem Images ◽  
Group 4 ◽  
Modes Of Failure ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.

scholarly journals AN INVITRO COMPARATIVE EVALUATION OF FRACTURE RESISTANCE OF ENDODONTICALLY TREATED TEETH OBTURATED WITH RESILON AND GUTTA-PERCHA

2014 ◽  
Vol 04 (03) ◽  
pp. 075-079
Author(s):  
Kiran Halkai ◽  
Rahul Halkai ◽  
Mithra N. Hegde ◽  
Vijay Kumar ◽  
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Control Group ◽  
Endodontically Treated Teeth ◽  
Group 4 ◽  
Anterior Teeth ◽  
Ah Plus ◽  
Group 3 ◽  
Group 2

Abstract Aim: To compare and evaluate in-vitro the fracture resistance of endodontically treated teeth obturated with resilon & epiphany sealer and guttapercha using different sealers. Epoxy resin based sealer AH-plus and zinc oxide eugenol based sealer-TubliSeal (EWT). Methodology: sixty four human single rooted maxillary anterior teeth, cleaned stored in 0.9% saline. All the teeth were decoronated to root length 14mm and bucco-lingual diameter of 5-7mm, After access openings teeth were instrumented using K3.06 up to final apical size 30/.06 and randomly allocated into 4 experimental groups (n=16 per group). Group 1(Control group): teeth were instrumented but not obturated, Group 2: Resilon cones and epiphany SE-sealer. Group 3: guttapercha cones and epoxy based sealer AH plus. Group 4: guttapercha and Tubli seal EWT. Coronal seal was done using IRM cement. Each of the specimens were tested for fracture resistance by instron universal testing machine. Results: Higher fracture resistance values were observed for group 2 (Resilon & Epiphany SE sealer) followed by group 3(Guttapercha & AH Plus sealer) and group 4(Guttapercha & TubliSeal EWT) when compared to group1 (control-instrumented but not obturated). Conclusion: filling the root canals with contemporary polymer based root canal obturating system- Resilon increased the in vitro fracture resistance of endodontically treated teeth.

Dentin Bond Strength of Composites with Self-etching Adhesives Using LED Curing Lights

2007 ◽  
Vol 8 (5) ◽  
pp. 34-42 ◽  
Author(s):  
Yonca Korkmaz ◽  
Nuray Attar
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Significance Level ◽  
Group 4 ◽  
Group 6 ◽  
Group 3 ◽  
Curing Light ◽  
Group 5 ◽  
Group 2 ◽  
Self Etch

Abstract Aim The purpose of this study was to investigate the effect of light-emitting diode (LED) light curing units (LCUs) compared with halogen LCUs on the shear bond strength (SBS) of one nanofill composite (Filtek Supreme) and one microhibrid composite (Artemis) with self-etch adhesives. Methods and Materials The buccal surfaces of 60 non-carious extracted human molars were flattened to expose dentin and, subsequently, polished for 60 seconds with 600-grit wet silicon carbide abrasive paper. Specimens were assigned into six groups (n=10) according to composite material, self-etch adhesive, and curing light used as follows: Group 1: Adper Prompt L-Pop (AP) and Filtek Supreme (FS) using an Elipar Free Light (EFL); Group 2: AP and FS using an Elipar Free Light 2 (EFL2); Group 3: AP and FS using a Hilux Expert (HE) light, Group 4: AdheSE (AS)+Artemis (AR) using an EFL; Group 5: AS+AR using an EFL2; and Group 6: AS+AR using a HE light. The specimens were thermocycled for 500 cycles (5°C–55°C) and then loaded to failure in a Zwick universal testing machine at a crosshead speed of 5 mm/minute. SBS values were calculated as megapascals (MPa) and statistically analyzed using the one-way analysis of variance (ANOVA) test at a significance level of 0.05. Results Mean SBS (± standard deviations) values were as follows: Group1: 15.99±5.18; Group 2: 18.76±6.71; Group 3: 17.70±5.04; Group 4: 16.93±3.99; Group 5: 18.01±5.19, and Group 6: 17.46±5.40. There were no statistically significant differences for SBS to dentin among the groups tested. Conclusion The LED curing lights used in the study seem to be comparable with the halogen curing light for nanofill and microhybrid composites used in conjunction with self-etching systems in dentin. The EFL2 reduces curing time, which can be considered as an advantage. Citation Korkmaz Y, Attar N. Dentin Bond Strength of Composites with Self-etching Adhesives Using LED Curing Lights. J Contemp Dent Pract 2007 July;(8)5:034-042.

scholarly journals Comparison of the Fluoride Release of Silver Diamine Fluoride, Fluoride Varnish, Acidulated Phosphate Fluoride Gel on Extracted Teeth over Various Time Intervals in Artificial Saliva

2021 ◽  
pp. 55-63
Author(s):  
Taniya Thakur ◽  
Pratik Kumar Lahiri ◽  
Madhumanti Karmakar ◽  
Bhumi Sarvaiya ◽  
Piyali Datta ◽  
...  
Keyword(s):  
Tap Water ◽  
Artificial Saliva ◽  
Fluoride Concentration ◽  
Maximum Amount ◽  
Fluoride Varnish ◽  
Fluoride Ion ◽  
Fluoride Release ◽  
Silver Diamine Fluoride ◽  
Group 4 ◽  
Group 2

Silver Diamine Fluoride (SDF) has been documented to effectively arrest dental caries and reduce dental hypersensitivity. SDF promotes remineralization and harden the carious lesion. SDF increases fluoride concentration in saliva and increase the bioavailability of fluoride in saliva. After SDF application, fluoride ion promotes remineralization and silver ion is available for antimicrobial action. Aim: The study aims to determine and compare the amount of fluoride released from various fluoride releasing materials in artificial saliva after 24 hours, 7th day and 14th day of the study. Materials and Methods: 96 premolars free of any caries, fractures, or any other defects were sterilized in 10% formalin for 2 weeks. Then they were rinsed in tap water to remove any fixative from its surface and then stored in deionised distilled water for a period of 30 days prior to testing. Tooth samples were divided into four groups- Group 1: 38% SDF, Group 2: 1.23% APF gel, Group 3: Fluoride varnish and Group 4: Control. All the teeth specimens were blot dried and subjected to their respective material. Fluoride release was analysed using a Fluoride ion-selective electrode after 24 hours, 7days and 14 days of suspension in artificial saliva. Results: Mann-Whitney U Test for inter-group comparison was used for statistical evaluation. 24 Hours fluoride release: The maximum amount of fluoride was released from Fluoride Varnish followed by SDF then APF Gel and least by artificial saliva alone (control) (p<0.001). 7th Day fluoride release: The maximum amount of fluoride was released from SDF followed by Fluoride Varnish then APF Gel and least by artificial saliva alone (control) (p<0.001). 14th Day fluoride release: The maximum amount of fluoride was released from Fluoride Varnish followed by SDF then APF Gel and least by artificial saliva alone (control) (p<0.001).

scholarly journals In situ evaluation of orthodontic elastomeric chains

2012 ◽  
Vol 23 (4) ◽  
pp. 394-398 ◽  
Author(s):  
Carolina Baratieri ◽  
Cláudia Trindade Mattos ◽  
Matheus Alves Jr ◽  
Thiago Chon Leon Lau ◽  
Lincoln Issamu Nojima ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Testing Machine ◽  
Time Factors ◽  
Time Interval ◽  
Significance Level ◽  
Universal Testing ◽  
Initial Force ◽  
Post Hoc ◽  
Elastomeric Chains

The hypothesis tested in this study was that intraoral exposure of elastomeric chains alters their tensile strength. For such purpose, it was evaluated the in situ behavior of different elastomeric chains stretched for 3 weeks. Three kinds of elastomeric chains, Plastic chain (PC), Memory chain (MC) and Super slick chain (SSC), were randomly placed in 3 quadrants of 13 patient in a fixed distance of 16 mm and mean initial force of 180 g. Tensile testing was performed in an universal testing machine at different intervals: initial, 1 h, 24 h, 1 week, 2 weeks and 3 weeks. A two-way ANOVA test was performed to identify the influence of both material and time on the force decrease. A subsequent one-way ANOVAtest with the Tukey's post hoc test was used to identify statistically significant intragroup and intergroup remaining force (g and %) differences at 5% significance level. The effect of both the material and the time factors were significant. All groups showed significant force decrease after the 1-h period (23% for PC and 14% for MC and SSC). At the end of the 3-week period, the remaining force was 57% (96 g), 67% (129 g) and 71% (125 g) for PC, MC and SSC, respectively. In conclusion, intraoral exposure of elastomeric chains altered their tensile strength. In general, the greater force decrease occurred within the first hour. The remaining force of the enhanced chains measured at each time interval was greater than the conventional one (PC). After 3 weeks, only the enhanced chains maintained the force applied over 100 g.

scholarly journals Exposure of Biomimetic Composite Materials to Acidic Challenges: Influence on Flexural Resistance and Elastic Modulus

Biomimetics ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 56
Author(s):  
Andrea Scribante ◽  
Simone Gallo ◽  
Stefano Scarantino ◽  
Alberto Dagna ◽  
Claudio Poggio ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Composite Materials ◽  
Flexural Strength ◽  
Testing Machine ◽  
Distilled Water ◽  
Group 4 ◽  
Significant Difference ◽  
Group 5 ◽  
Group 2 ◽  
Flexural Resistance

Acidic conditions of the oral cavity, including soft drinks and cariogenic bacteria, represent a damage for restorative biomimetic composite materials. The aim of this study is to assess the influence of two different acidic challenges on the flexural strength and elastic modulus of five composites: x-tra fil (Group 1, XTF), GrandioSO x-tra (Group 2, GXT), Admira Fusion x-tra (Group 3, AFX), VisCalor bulk (Group 4, VCB), and Enamel Plus HRi (Group 5, EPH). Thirty samples for each group were randomly divided and assigned to three different treatments: storage in distilled water as the controls (subgroups 1a–5a), 3 weeks distilled water + 1 week Coca-Cola (subgroups 1b-5b), and 4 weeks Coca-Cola (subgroups 1c–5c). For each subgroup, the flexural strength and elastic modulus were measured using an Instron universal testing machine, and data were submitted to statistical analysis. Considering subgroups B, no material showed a significant difference in the flexural strength with the controls (p > 0.05), whereas for subgroups C, only GXT and VCB showed significantly lower values (p < 0.05). AFX reported the lowest flexural strength among the materials tested. As regards the elastic modulus, no material showed a significant variation after acidic storages when compared with the respective control (p > 0.05). AFX and EPH reported the lowest elastic modulus compared to the other materials. All composites tested showed adequate flexural properties according to the standards, except for AFX. This biomimetic material, along with EPH, might be indicated for V class (cervical) restorations considering the lowest values of elasticity reported.

scholarly journals Evaluation of the efect of EDTA, EGTA and CDTA on dentin adhesiveness and microleakage with different root canal sealers

2002 ◽  
Vol 13 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Manoel D. Sousa-Neto ◽  
Jarbas Gonçalves Passarinho-Neto ◽  
Jacy Ribeiro Carvalho-Júnior ◽  
Antonio M. Cruz-Filho ◽  
Jesus D. Pécora ◽  
...  
Keyword(s):  
Root Canal ◽  
Testing Machine ◽  
Apical Region ◽  
Group 4 ◽  
India Ink ◽  
Mathematical Correlation ◽  
Human Dentin ◽  
Group 3 ◽  
Group 2

The effect of chelating solutions EDTA, EGTA and CDTA on human dentin adhesiveness and microleakage with 4 sealers (Sealer 26, Sealapex, N-Rickert and Endofill) was evaluated in vitro. Whether or not there was a mathematical correlation between the tests of adhesiveness and microleakage was also evaluated. A total of eighty maxillary and mandibular molars were used to test adhesiveness. After wearing of the occlusal surface to obtain a flat surface, the sealer was placed with an aluminum cylinder (10 mm x 6 mm). Adhesiveness was evaluated with a 4444 Instron universal testing machine. Microleakage was evaluated in 160 maxillary canines after root canal instrumentation, obturation and clearing. The penetration of India ink in the apical region was measured with a measurescope. The teeth were divided into 4 groups: group 1, distilled water; group 2, EDTA; group 3, EGTA; group 4, CDTA. Sealer 26 and EDTA had the best results (p<0.01) for adhesiveness and microleakage. There was no correlation between the test for adhesiveness and microleakage.

Sign in / Sign up

Export Citation Format

Share Document