scholarly journals Comparison of friction produced by two types of orthodontic bracket protectors

2014 ◽  
Vol 19 (1) ◽  
pp. 86-91 ◽  
Author(s):  
Steyner de Lima Mendonça ◽  
Otávio José Praxedes Neto ◽  
Patricia Teixeira de Oliveira ◽  
Patricia Bittencourt Dutra dos Santos ◽  
Fábio Henrique de Sá Leitão Pinheiro
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Causative Factor ◽  
Control Group ◽  
Orthodontic Appliances ◽  
Orthodontic Bracket ◽  
Fixed Orthodontic Appliances ◽  
Intergroup Comparison ◽  
Level Of Significance

INTRODUCTION: Fixed orthodontic appliances have been regarded as a common causative factor of oral lesions. To manage soft tissue discomfort, most orthodontists recommend using a small amount of utility wax over the brackets in order to alleviate trauma. This in vitro study aimed at evaluating friction generated by two types of bracket protectors (customized acetate protector [CAP] and temporary resin protector [TRP]) during the initial stages of orthodontic treatment. METHODS: An experimental model (test unit) was used to assess friction. In order to measure the friction produced in each test, the model was attached to a mechanical testing machine which simulated maxillary canines alignment. Intergroup comparison was carried out by one-way ANOVA with level of significance set at 5%. RESULTS: The friction presented by the TRP group was statistically higher than that of the control group at 6 mm. It was also higher than in the control and CAP groups in terms of maximum friction. CONCLUSION: The customized acetate protector (CAP) demonstrated not to interfere in friction between the wire and the orthodontic bracket slot.

Evaluation of physical and adhesive properties of enamel after a therapeutic dose of radiation and bonding of orthodontic metal brackets: an in vitro study

2020 ◽  
pp. 1-5
Author(s):  
A. Anushree ◽  
Ashutosh Shetty ◽  
Crystal Runa Soans ◽  
M. N. Kuttappa ◽  
Akhil Shetty ◽  
...  
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Tooth Surface ◽  
Control Group ◽  
Adhesive Properties ◽  
Adhesive Resin ◽  
Adhesive Remnant Index ◽  
Group 3 ◽  
Group 2

Abstract Aim: The study aimed to evaluate the shear bond strength (SBS) of metal brackets and adhesive properties of bonded irradiated and non-irradiated teeth. Methods: Sixty-six extracted premolar samples were randomly divided into three groups—(a) Control group consisting of 22 non-irradiated, non-aged teeth (Group 1), (b) 22 non-irradiated, aged samples (Group 2) and (c) 22 irradiated, aged samples (Group 3). Irradiation was done using gamma irradiation with a fractionated dose of 60 Gy for 5 consecutive days per week over 6 weeks. Metal brackets were bonded on all samples with light cure adhesive and subjected to SBS test using universal testing machine. The samples were assessed under the scanning electron microscope to check for the adhesive remnant index (ARI) and tag depth. Results: There was a statistically significant decrease in the mean SBS of the irradiated samples compared to the non-irradiated teeth. The non-irradiated, aged samples showed a majority of ARI scoring 1 and 2. Whereas, the irradiated samples showed ARI scoring 2 and 3. Approximately, 77·3% of the non-irradiated samples showed no adhesive present on the tooth surface, and 27·2% of the irradiated samples had more than 50% adhesive present on the enamel surface. Conclusion: There is a statistically significant decrease in SBS of irradiated enamel compared to that of non-irradiated teeth. However, the SBS observed in the three groups was well above the ideal SBS for orthodontic bonding, that is, 5·6–6·8 MPa. The adhesive remnant was found on all samples of the irradiated group. Deeper adhesive resin tags were found in the irradiated group in the resin–enamel interface.

scholarly journals Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Andreas Hellak ◽  
Jennifer Ebeling ◽  
Michael Schauseil ◽  
Steffen Stein ◽  
Matthias Roggendorf ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Control Group ◽  
Metal Composite ◽  
Universal Adhesive ◽  
Restorative Materials ◽  
Bonding Systems

Objective.The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond™and Scotchbond™) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™.Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces,n=30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120™testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P≤0.05).Results. Significant differences in SBS and ARI were found between the control group and experimental groups.Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.

scholarly journals Do dental bleaching sessions prior to orthodontic treatment change the bond strength of esthetic brackets?

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Samara Gasperoni PERCIANO ◽  
Diego Patrik Alves CARNEIRO ◽  
Patricia Rafaela dos SANTOS ◽  
Américo Bortolazzo CORRER ◽  
Silvia Amélia Scudeler VEDOVELLO ◽  
...  
Keyword(s):  
Bond Strength ◽  
Orthodontic Treatment ◽  
Mechanical Test ◽  
Testing Machine ◽  
In Vitro Study ◽  
Treatment Change ◽  
Dental Bleaching ◽  
Adhesive Remnant Index ◽  
Level Of Significance

ABSTRACT Objective: The aim of this experimental in vitro study was to evaluate whether dental bleaching performed before orthodontic treatment change the shear bond strength (SBS) of monocrystalline and polycrystalline esthetic brackets. Methods: Sixty (60) bovine incisors teeth were used and randomly divided into the following six groups (n=10): SCP (without bleaching/polycrystalline brackets); SCM (without bleaching/monocrystalline brackets); 1CP (one bleaching session/polycrystalline brackets); 1CM (one bleaching session/monocrystalline brackets); 3CP (three bleaching sessions/polycrystalline brackets); and 3CM (three bleaching sessions/monocrystalline brackets). The brackets were bonded seven days after the bleaching sessions. The samples were submitted to the SBS test in a universal testing machine (Instron model 4411) at 1 mm/min crosshead speed. The two-way analysis of variance (ANOVA) and the Tukey tests were performed at a 5% level of significance. After the mechanical test, samples were evaluated to determine the adhesive remnant index (ARI). Results: The SBS values were significantly higher for the monocrystalline brackets, when compared with the polycrystalline type (p< 0.0001), and significantly higher with three bleaching sessions than without bleaching (p< 0.0436). The ARI showed predominance of failures between the bracket and resin for all the groups (score 3). Conclusion: Three dental bleaching sessions increased the SBS values. Monocrystalline brackets showed higher SBS values than the polycrystalline type.

scholarly journals Influence of Exposing Root Canal Dentin to Calcium Hydroxide on Its Flexural Strength

2015 ◽  
Vol 1 (3) ◽  
pp. 143
Author(s):  
Diatri Nari Ratih
Keyword(s):  
Flexural Strength ◽  
Calcium Hydroxide ◽  
Root Canal ◽  
Artificial Saliva ◽  
Testing Machine ◽  
In Vitro Study ◽  
Control Group ◽  
Sterile Saline ◽  
Root Canal Dentin

Calcium hydroxide has been used extensively in endodontic treatments, for instance as an intra-canal dressing; however, the exposure of root canal dentin to calcium hydroxide may affect its flexural strength and could have important clinical implications for endodontic treatment. The purpose of this in vitro study was to investigate the influence of calcium hydroxide on the flexural strength of root canal dentin.Seventy-two extracted single-rooted human mandibular premolars were used in this study. Each tooth was instrumented using crown-down technique and was irrigated using sterile saline. The teeth were assigned into three groups of 24 each. The prepared root canal system of each tooth was filled with calcium hydroxide mixed with sterile saline (group 1), a calcium hydroxide commercially available product (UltraCal®) (group 2) or saline solution (group 3, as control). The apices and access opening were sealed using composite resin, and the teeth were immersed in artificial saliva. After 7, 14 and 30 days of immersion, the inner root canal dentin of 8 teeth respectively from each group were sectioned to create dentin bars (1 X 1 mm, with 7 mm in length). Each dentin bar then was subjected to a three-point bending flexural test using MTS (Universal Testing Machine). Data gathered were then analyzed using two-way ANOVA, followed by Tukey’s test with the level of significance of 95%. The results showed that exposure to calcium hydroxide either using calcium hydroxide mixed with sterile saline or UltraCal® for 14 and 30 days can reduce flexural strength of root canal dentin compared to control group (p<0.05). In contrast, after 7 days exposure, there was no significantly different of flexural strength between three groups (p>0.05).   It can be concluded that calcium hydroxide reduced the flexural strength of root canal dentin. The longer the exposure to calcium hydroxide would produce a greater effect on flexural strength of root canal dentin.   

scholarly journals Effect of Incorporation of Disinfectants on Surface Hardness and Dimensional Accuracy of Die Stone: An in vitro Study

2017 ◽  
Vol 7 (3) ◽  
pp. 86-91
Author(s):  
Anubhuti Bakshi ◽  
Rajat Dang
Keyword(s):  
Sodium Hypochlorite ◽  
Testing Machine ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Control Group ◽  
Time Interval ◽  
Type Iv ◽  
Post Hoc

ABSTRACT Aim To evaluate surface hardness and dimensional accuracy of type IV dental stone after incorporation of disinfectants. Materials and methods A total of 100 specimens, 50 (40 mm⨯ 10 mm) disk shaped and 50 frustum cone shaped, were fab- ricated from type IV dental stone after incorporation of various disinfectants, namely glutaraldehyde (2%), iodophor (1.76%), chlorhexidine (2%), and sodium hypochlorite (1%), for evaluation of surface hardness and dimensional accuracy. Surface hardness was tested after 1- and 24-hour time interval using Rockwell hard- ness testing machine. Dimensional accuracy was measured using traveling microscope. Data obtained were compiled and analyzed statistically by using analysis of variance and post hoc test. Results Results showed significant decrease in surface hard- ness of samples incorporated with disinfectants at 1 hour as compared with control (distilled water). Surface hardness of all the samples increased with time and was almost equal to control group at 24-hour interval, with iodophor showing the maximum value in comparison with the other disinfectants used. When dimensional accuracy of all the groups was compared, iodophor and sodium hypochlorite were found to cause negative alterations. Conclusion Within the limitations of this in vitro study, it was concluded that incorporation of disinfectants in die stone during mixing did not affect the hardness value at 24-hour interval. Dimensional accuracy was altered by iodophor and sodium hypochlorite, but remained unaffected by chlorhexidine and glutaraldehyde. How to cite this article Bakshi A, Dang R. Effect of Incorpo- ration of Disinfectants on Surface Hardness and Dimensional Accuracy of Die Stone An in vitro Study. Int J Prosthodont Restor Dent 2017;7(3):86-91.

scholarly journals Effects of a newly designed apparatus on orthodontic skeletal anchorage

2013 ◽  
Vol 07 (S 01) ◽  
pp. S083-S088 ◽  
Author(s):  
Murat Tozlu ◽  
Didem Nalbantgil ◽  
Fulya Ozdemir
Keyword(s):  
Cortical Bone ◽  
Lateral Displacement ◽  
Tangential Force ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Favorable Effect ◽  
Control Group ◽  
Insertion Torque

ABSTRACT Objective: An appliance was designed to increase the cortical bone surface contact area of miniscrew implants (MSIs). The purpose of this in vitro study was to evaluate the effects of this appliance on the anchorage force resistance and the stability of orthodontic MSIs. Materials and Methods: A total of 48 MSIs were placed into bone specimens prepared from the ilium of bovines. Half were placed with the newly designed apparatus and half were placed conventionally. All the specimens were subjected to tangential force loading perpendicular to the MSI with lateral displacement of 0.6 mm, using an Instron Universal Testing machine. The maximum removal torque of each tested specimen was also recorded. Both study and control groups were divided into two subgroups based on whether they had thin and thick cortical bone. Results: The test group had statistically higher force anchorage resistance and maximum insertion torque values than the control group (p < 0.001). The results were found to be more significant in cases in which the cortical bone was thin (p < 0.001). Conclusions: Within the limits of this in vitro study, the present findings suggest that the newly designed apparatus might have a favorable effect on MSI stability in patients presenting with thin cortical bone. Clinical studies are necessary to confirm the results that were observed in vitro.

Does Addition of Propolis to Glass Ionomer Cement Alter its Physicomechanical Properties? An in Vitro Study

2016 ◽  
Vol 40 (5) ◽  
pp. 400-403 ◽  
Author(s):  
P Subramaniam ◽  
KL Girish Babu ◽  
G Neeraja ◽  
S Pillai
Keyword(s):  
Compressive Strength ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Physicomechanical Properties ◽  
Control Group ◽  
Glass Ionomer ◽  
Experimental Group ◽  
Ionomer Cement

Propolis is a natural resinous substance produced by honey bees. The antimicrobial effects of glass ionomer cement have been shown to improve with the addition of propolis; however its effect on the physicomechanical properties of the cement is not known. Aim: The purpose of this study was to evaluate the compressive strength and solubility of conventional restorative glass ionomer cement following the addition of propolis. Study design: Twenty half cylindrical samples were prepared with conventional restorative glass ionomer cement formed the control group. Another twenty samples were prepared with propolis added to conventional restorative glass ionomer cement formed the experimental group. The compressive strength was assessed using universal testing machine. To assess solubility, the samples were immersed in deionised water at room temperature, for 7 days. The solubility was measured as a difference in the weight of the sample; prior to immersion and following immersion at the end of each day. Results: The control group had a significantly higher mean compressive strength of 146.26 Mpa as compared to the experimental group (135.06 Mpa). The solubility between the groups was significant. Conclusion: In comparison to the control group, incorporation of propolis to conventional restorative glass ionomer cement decreased the compressive strength significantly. The solubility of the cement in the experimental group increased significantly over 7day period as compared to the control group.

Comparative evaluation of shear bond strength of composite to dentin in presence of different dental liners: An in-vitro study

2021 ◽  
Author(s):  
Ladan Ranjbar Omrani ◽  
Saba Tohidkhah ◽  
Elham Ahmadi ◽  
Mahdi Abbasi ◽  
Reza Morvaridi Farimani
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Control Group ◽  
The One ◽  
Post Hoc

Abstract Background: The aim of the current study was to evaluate and compare the influence of Dycal, Lime-lite, Theracal LC, Biodentine, Resin-modified glass ionomer cement (RMGIC), and Activa Bioactive as the pulp capping material on the shear bond strength of resin composite to dentin.Methods: A total of 70 extracted caries-free molars were randomly assigned to seven groups. Six test groups were covered with various protective liners: Dycal (GD), Theracal LC (GT), lime-lite (GL), Activa Bioactive (GA), Biodentine (GB), RMGIC (GR). The control group (GC)received no liner pretreatment. Each sample was bonded to resin composite using the total-etch tetric N bond adhesive. The samples were then tested for shear bond strength using the universal testing machine at a cross-head speed of 1 mm/min until bond failure occurred. The data were analyzed using the one-way ANOVA test followed by the Tamhane post-hoc test for pairwise comparisons of the groupsResults: Independent of the type of the applied liner, all groups exhibited inferior SBS to dentine compared to the control group. GT and GR showed significantly higher shear bond strength than GB and GD, which showed the lowest shear bond strength. GL and GA also had significantly lower SBS results than GT. The mode of fracture was predominantly cohesive in GD, GB, and GT and adhesive in GA.Conclusion: This present study concludes that the bond strength of resin-composite to dentine can be affected differently using various types of liners.

scholarly journals The influence of distal-end heat treatment on deflection of nickel-titanium archwire

2016 ◽  
Vol 21 (1) ◽  
pp. 83-88
Author(s):  
Marcelo Faria da Silva ◽  
Célia Regina Maia Pinzan-Vercelino ◽  
Júlio de Araújo Gurgel
Keyword(s):  
Heat Treatment ◽  
Statistical Significance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Distal Portion ◽  
Nickel Titanium ◽  
Control Group ◽  
Orthodontic Wires ◽  
Niti Wires

Objective: The aim of this in vitro study was to evaluate the deflection-force behavior of nickel-titanium (NiTi) orthodontic wires adjacent to the portion submitted to heat treatment. Material and Methods: A total of 106 segments of NiTi wires (0.019 x 0.025-in) and heat-activated NiTi wires (0.016 x 0.022-in) from four commercial brands were tested. The segments were obtained from 80 archwires. For the experimental group, the distal portion of each segmented archwire was subjected to heat treatment (n = 40), while the other distal portion of the same archwire was used as a heating-free control group (n = 40). Deflection tests were performed in a temperature-controlled universal testing machine. Unpaired Student's t-tests were applied to determine if there were differences between the experimental and control groups for each commercial brand and size of wire. Statistical significance was set at p < 0.05. Results: There were no statistically significant differences between the tested groups with the same size and brand of wire. Conclusions: Heat treatment applied to the distal ends of rectangular NiTi archwires does not permanently change the elastic properties of the adjacent portions.

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