scholarly journals Evaluation of the Friction of Self-Ligating and Conventional Bracket Systems

2011 ◽  
Vol 05 (03) ◽  
pp. 310-317 ◽  
Author(s):  
Simona Tecco ◽  
Donato Di Iorio ◽  
Riccardo Nucera ◽  
Beatrice Di Bisceglie ◽  
Giancarlo Cordasco ◽  
...  
Keyword(s):  
In Vitro Study ◽  
P Value ◽  
Low Friction ◽  
Experimental Conditions ◽  
Beta Titanium ◽  
Conventional Brackets ◽  
Orthodontic Archwires ◽  
Post Hoc ◽  
Conventional Bracket

ABSTRACTObjectives: This in vitro study evaluated the friction (F) generated by aligned stainless steel (SS) conventional brackets, self-ligating Damon MX© brackets (SDS Ormco, Glendora, California, USA), Time3© brackets (American Orthodontics, Sheboygan, Wisconsin, USA), Vision LP© brackets (American Orthodontics), and low-friction Slide© ligatures (Leone, Firenze, Italy) coupled with various SS, nickel-titanium (NiTi), and beta-titanium (TMA) archwires. Methods: All brackets had a 0.022-inch slot, and the orthodontic archwires were 0.014-inch, 0.016-inch, 0.014×0.025-inch, 0.018×0.025-inch, and 0.019×0.025-inch NiTi; 0.017×0.025-inch TMA; and 0.019×0.025-inch SS. Each bracket-archwire combination was tested 10 times. In the test, 10 brackets of the same group were mounted in alignment on a metal bar. The archwires moved through all the 10 brackets at a crosshead speed of 0.5 mm/min (each run lasted approximately 5 min). The differences among 5 groups of brackets were analyzed through the Kruskal-Wallis test, and a Mann-Whitney test was calculated as post hoc analysis. The P value was set at 0.05. Results: Coupled with 0.014-inch NiTi and 0.016-inch NiTi, Victory Series© brackets generated the greatest F, while Damon MX© and Vision LP© brackets generated the lowest (P<.05); no significant differences were observed between Time3© brackets and Slide© ligatures. Coupled with all the rectangular archwires, Victory Series© brackets, Slide© ligatures, and Vision LP© self-ligating brackets generated significantly lower F than did Time3© and Damon MX© self-ligating brackets (P<.05). Conclusions: These findings suggest that self-ligating brackets are a family of brackets that, in vitro, can generate different levels of F when coupled with thin or thick, rectangular, or round archwires. Clinical conclusions based on our results are not possible due to the limitations of the experimental conditions. (Eur J Dent 2011;5:310-317)

scholarly journals Friction Forces during Sliding of Various Brackets for Malaligned Teeth: An In Vitro Study

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Vito Crincoli ◽  
Letizia Perillo ◽  
Maria Beatrice Di Bisceglie ◽  
Antonio Balsamo ◽  
Vitaliano Serpico ◽  
...  
Keyword(s):  
Friction Force ◽  
In Vitro Study ◽  
Friction Forces ◽  
Orthodontic Wire ◽  
Conventional Brackets ◽  
Frictional Forces ◽  
The Right ◽  
Post Hoc ◽  
Sliding Mechanics

Aims. To measure the friction force generated during sliding mechanics with conventional, self-ligating (Damon 3 mx, Smart Clip, and Time 3) and low-friction (Synergy) brackets using different archwire diameters and ligating systems in the presence of apical and buccal malalignments of the canine.Methods. An experimental setup reproducing the right buccal segment of the maxillary arch was designed to measure the friction force generated at the bracket/wire and wire/ligature interfaces of different brackets. A complete factorial plan was drawn up and a three-way analysis of variance (ANOVA) was carried out to investigate whether the following factors affect the values of friction force: (i) degree of malalignment, (ii) diameter of the orthodontic wire, and (iii) bracket/ligature combination. Tukey post hoc test was also conducted to evaluate any statistically significant differences between the bracket/ligature combinations analyzed.Results. ANOVA showed that all the above factors affect the friction force values. The friction force released during sliding mechanics with conventional brackets is about 5-6times higher than that released with the other investigated brackets. A quasilinear increase of the frictional forces was observed for increasing amounts of apical and buccal malalignments.Conclusion. The Synergy bracket with silicone ligature placed around the inner tie-wings appears to yield the best performance.

scholarly journals Antimicrobial Efficacy of Calcium Hydroxide and Triple Antibiotic Paste Combination on E. faecalis Biofilm- an In vitro Study

2020 ◽  
pp. 120-126
Author(s):  
Azima Hanin S. M. ◽  
Anjaneyulu K. ◽  
Muralidharan N. P.
Keyword(s):  
Calcium Hydroxide ◽  
In Vitro Study ◽  
Antimicrobial Efficacy ◽  
Diffusion Method ◽  
P Value ◽  
Tryptone Soya Agar ◽  
Triple Antibiotic Paste ◽  
High Alkalinity ◽  
Post Hoc

Calcium hydroxide (CH) is an intracanal medicament that has been widely used in endodontics, which can eliminate bacteria because of its high alkalinity. However, E. faecalis is resistant to CH. Triple antibiotic paste (TAP) is a mixture of ciprofloxacin, minocycline, and metronidazole, and is highly effective against E. faecalis. Hence the main aim of this study was to find the antimicrobial efficacy of CH and TAP combination against E. faecalis. The study was done by agar diffusion method, three wells were punched in Tryptone soya agar and filled with CH, TAP, and the combination of both. The zone of inhibition values was recorded and subjected to statistical analysis using SPSS. One way ANOVA and Post Hoc tests were used to compare the means. The combination of CH with TAP was found to be significantly better than CH and TAP used alone (p-value <0.05).Within the limits of this study, it can be concluded that TAP is more efficient when compared with CH,The combination of CH and TAP proved to be more effective when compared to the two when used alone.

scholarly journals Impact of Simulated Gastric Acid on Surface Roughness and Frictional Resistance of Orthodontic Archwires: An In vitro Study

2020 ◽  
Author(s):  
Laila Baidas ◽  
Huda Alkawari ◽  
Nada Alshihah ◽  
Ghaida Almashaan ◽  
Haya Alwaalan
Keyword(s):  
Surface Roughness ◽  
Reflux Disease ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Vitro Study ◽  
Distilled Water ◽  
Orthodontic Wires ◽  
Beta Titanium ◽  
Orthodontic Archwires

Introduction: Acid regurgitation caused by gastro-oesophageal reflux disease can lead to decreases in intraoral pH below the critical pH for orthodontic appliances. Exposure of brackets and archwires to such acidic environments causes changes in the surface properties that affect the frictional forces generated during orthodontic sliding mechanics and reduce the clinical efficacy of the wires. Aim: This in vitro study aimed to determine the effects of simulated gastric acid with pH 1.2 and pH 4 on the surface topography, surface roughness, and frictional resistance properties of different types of orthodontic archwires. Materials and Methods: A comparative in vitro study evaluated a total of 135 samples of three commercially available archwires: Stainless Steel (SS), nickel titanium, and beta-titanium (n=45/group). Each archwire was divided into three subgroups (n=15) according to different pH solutions: distilled water (control; pH 6.7), pH 4, and pH 1.2. The samples in the two acidic pH subgroups were immersed in the respective solution for two minutes, rinsed with distilled water, and stored in distilled water at 37°C. The procedure was repeated 6 times a day for nine days with 24-hours interval in between each cycle. The surface topography of the wires was examined by scanning electron microscopy, while the surface roughness was inspected by noncontact surface profilometry. Finally, the frictional resistance was measured by a universal testing machine. One-way ANOVA and a Tukey’s post-hoc test were used for analysis, with values of p≤0.05 considered significant. Results: The results showed an increase in surface roughness of the SS (p<0.001) and beta-titanium (p=0.003) wires as the acidity of the solution increased. The SS wires showed the lowest frictional resistance in pH 1.2 solution among the wires used (p=0.005). No correlation was found between surface roughness and frictional resistance in this study. Conclusion: Increased acidity condition significantly affects the surface roughness of beta-titanium and SS wires, and has no effect on the frictional behaviour of the orthodontic wires expects in the SS wires. Thus, because the surface properties of the archwires can be affected by acidity in the oral cavity, it is recommended to change the orthodontic wires regularly throughout orthodontic treatment, especially in patients with gastro-oesophageal reflux disease.

scholarly journals Comparative evaluation of anti-bacterial efficacy of silver nanoparticle, nanoparticle calcium hydroxide and calcium hydroxide against enterococcus faecalis biofilm- An In vitro study

2018 ◽  
Vol 6 (2) ◽  
pp. 57
Author(s):  
Dr.Abirami V. ◽  
Dr.A.Shafie Ahamed ◽  
Dr.Bhavani S. ◽  
Dr.Rajaraman G.
Keyword(s):  
Silver Nanoparticles ◽  
Calcium Hydroxide ◽  
Enterococcus Faecalis ◽  
Silver Nanoparticle ◽  
In Vitro Study ◽  
P Value ◽  
Antibacterial Efficacy ◽  
Significant Difference ◽  
Post Hoc

The purpose of this study was to evaluate the antibacterial efficacy of silver Nanoparticles, Nanoparticle calcium hydroxide and calcium hydroxide as intracanal medicament against Enterococcus faecalis bio film formed on root dentinThe Minimal inhibitory concentration test and Anti microbial test were conducted for silver nanoparticle, Nanoparticle calcium hydroxide. Teeth were inoculated with E.faecalis strains for 1month to establish a standard mono species bio film model. Biofilm formation is confirmed using SEM. The intracanal medicaments were placed inside the canal and colony forming units (CFU) were counted before and 7 days later the placement of the medicament.MIC for AGNP is 25µg/200µl and for NCH is 12.5µg/200µl. The Antimicrobial test conducted shows zone of inhibition about 11mm and 14mm for AGNP and NCH respectively at 500µg. The calcium hydroxides do not show any antibacterial activity at this concentration. In antibacterial efficacy test using CFU count, the AGNP and NCH shows 75% and 61% of antibacterial efficacy respectively whereas calcium hydroxide has exhibited just 11% of antibacterial efficacy. Silver Nanoparticles and nanoparticle calcium hydroxide had statistically significant difference in the reduction in the number of colonies when compared to calcium hydroxide by post hoc turkey test and p-value of <0.01 was considered as significant in this study.

scholarly journals Streptococcus mutans adherence to conventional and self-ligating brackets: an in vitro study

2021 ◽  
Vol 26 (6) ◽  
Author(s):  
Murilo Fernando Neuppmann FERES ◽  
Fernanda VICIONI-MARQUES ◽  
Fábio Lourenço ROMANO ◽  
Marina Guimarães ROSCOE ◽  
Vinícius Matsuzaki de SOUZA ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Bacterial Adhesion ◽  
In Vitro Study ◽  
Vitro Study ◽  
Bacterial Suspension ◽  
Colony Forming Units ◽  
Conventional Brackets ◽  
Adhesion Rate ◽  
Post Hoc

ABSTRACT Introduction: Although self-ligating brackets presumably provide better hygiene conditions, no consensus has been reached so far. Objective: Therefore, the objective of this study was to evaluate, in an in vitro experimental design, the adherence of Streptococcus mutans (SM) in self-ligating and conventional brackets of different manufacturers and ligature types. Methods: Four commercial brands of maxillary premolar metal brackets were tested (Abzil®; Morelli®; 3M Unitek®; and GAC®). Each one was subdivided into three groups, which varied according to the type of ligature and bracket model (metallic, elastic, and self-ligating), totalizing twelve groups, composed of six brackets each. Previously sterilized brackets were initially immersed in saliva for one hour, and subsequently washed and added in a bacterial suspension, maintained in aerobiosis for 72 hours. The adhered bacteria were then separated and quantified by colony forming units (CFU/mL) counting after 48 hours of growth. The groups were compared by Kruskal-Wallis and Dunn post-hoc tests (p< 0.05). Results: Regardless of the commercial brand, self-ligating brackets had significantly less CFU/mL. However, according to comparisons performed within each commercial brand, only Abzil® self-ligating brackets had significantly lower biofilm adhesion. Among all of the self-ligating models, GAC® brackets presented the highest bacterial adhesion rate. Conclusions: Self-ligating brackets are likely to present lower rates of biofilm adhesion. Particularly, Abzil® and GAC® self-ligating brackets are less likely to accumulate biofilm. Although such results are derived from an in vitro study, practitioners might acknowledge findings concerning bacterial adhesion as one of the relevant features to be considered during bracket selection.

scholarly journals Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

2021 ◽  
Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
In Vitro Study ◽  
Color Difference ◽  
Blood Contamination ◽  
Tooth Color ◽  
Color Changes ◽  
Gutta Percha ◽  
Tooth Discoloration ◽  
Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

scholarly journals Potential of different fluoride gels to prevent erosive tooth wear caused by gastroesophageal reflux

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Philipp Körner ◽  
Luca Georgis ◽  
Daniel B. Wiedemeier ◽  
Thomas Attin ◽  
Florian J. Wegehaupt
Keyword(s):  
Gastroesophageal Reflux ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Wear ◽  
Control Group ◽  
Erosive Tooth Wear ◽  
Custom Made ◽  
Post Hoc ◽  
Bovine Enamel

Abstract Background This in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear. Methods Surface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1–5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2–5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test. Results The overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047). Conclusions After 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.

scholarly journals In Vitro Frictional Forces Generated by Three Different Ligation Methods

2008 ◽  
Vol 78 (5) ◽  
pp. 917-921 ◽  
Author(s):  
Paola Gandini ◽  
Linda Orsi ◽  
Chiara Bertoncini ◽  
Sarah Massironi ◽  
Lorenzo Franchi
Keyword(s):  
Steel Wire ◽  
Testing Machine ◽  
Low Friction ◽  
Instron Testing Machine ◽  
Resistance To Sliding ◽  
Titanium Wire ◽  
Frictional Forces ◽  
Conventional Bracket ◽  
Wire Resistance

Abstract Objective: To test the hypothesis that there is no difference between the frictional forces produced by a passive self-ligating bracket (SLB) in vitro and a conventional bracket (CB) used with two types of elastomeric ligatures. Materials and Method: The brackets, wires and ligation methods used in vitro were a passive SLB and a CB used with two types of elastomeric ligatures (conventional elastomeric ligature [CEL] and unconventional elastomeric ligatures [UEL]). The bracket ligation systems were tested with two types of wires (0.014″ super elastic nickel titanium wire and 0.019″ × 0.025″ stainless steel wire). Resistance to sliding of the bracket/wire/ligature systems was measured with an experimental model mounted on the crosshead of an Instron testing machine with a 10 N load cell. Each sample was tested 10 consecutive times under a dry state. Results: Frictional forces close to 0 g were recorded in all tests with SLB and in all tests with UEL on CB with both wire types. Resistance to sliding increased significantly (87–177 g) (P &lt; .05) when CEL on CB was used with both wires. Conclusion: UELs may represent a valid alternative to passive SLBs for low-friction biomechanics.

scholarly journals Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

2009 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Fernando Henrique Ruppel Osternack ◽  
Danilo Biazzetto de Menezes Caldas ◽  
Rodrigo Nunes Rached ◽  
Sérgio Vieira ◽  
Jeffrey A. Platt ◽  
...  
Keyword(s):  
Room Temperature ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Bottom Surface ◽  
Steel Mold ◽  
Polymerization Condition ◽  
Post Hoc

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

Comparison of bivalirudin, enoxaparin, and unfractionated heparin in preventing cardiac catheter thrombosis

2008 ◽  
Vol 100 (10) ◽  
pp. 693-698 ◽  
Author(s):  
Michael Buerke ◽  
Sebastian Schubert ◽  
Iris Reindl ◽  
Thomas Michel ◽  
Baerbel Hauroeder ◽  
...  
Keyword(s):  
Unfractionated Heparin ◽  
Continuous Infusion ◽  
Treatment Strategies ◽  
In Vitro Study ◽  
Coronary Intervention ◽  
Thrombin Inhibitor ◽  
P Value ◽  
Cardiac Catheter ◽  
Before And After

SummaryBivalirudin, a direct thrombin inhibitor binds specifically and reversibly to both fibrin-bound and unbound thrombin. Bivalirudin is approved for use as an anticoagulant in patients undergoing percutaneous coronary intervention. The OASIS-5 trial presented a significant increase in cardiac catheter thrombosis for the pentasaccharid fondaparinux compared to enoxaparin. Catheter thrombosis has never been reported in any trial using bivalirudin. Our study compared the development of catheter thrombosis for bivalirudin, enoxaparin, and unfractionated heparin in a controlled in-vitro environment. Ten healthy male volunteers were pretreated with aspirin 500 mg 2 hours before venesection of 50 ml of blood. The seven groups of anticoagulant combinations tested were:UFH, UFH + eptifibatide, enoxaparin, enoxaparin + eptifibatide, bivalirudin bolus, bivalirudin + eptifibatide, bivalirudin bolus + continuous infusion. The blood/anticoagulant mix continuously circulated through a cardiac guiding catheter for 60 minutes or until the catheter became blocked with thrombus. Thrombus development was assessed by weighing each catheter before and after the procedure. Electron microscopy was used to quantify the degree of erythrocyte, platelet and fibrin deposition. Following anticoagulation with bolus dose bivalirudin, the catheter was invariably occluded with thrombus after 33 minutes of circulation. However, a continuous infusion of Bivalirudin prevented the development of occlusive catheter thrombosis. In the bolus bivalirudin group the mean thrombus weight was significantly greater than in all other groups (p-value < 0.01 in all analyses). Bivalirudin given as a bolus was not sufficient to prevent cardiac catheter thrombosis in our in-vitro study. However, a continuous infusion of bivalirudin had similar anti-thrombotic efficacy compared to other treatment strategies.

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