scholarly journals Comparative study of frictional forces generated by NiTi archwire deformation in different orthodontic brackets: In vitro evaluation

2012 ◽  
Vol 17 (4) ◽  
pp. 45-50 ◽  
Author(s):  
Gilberto Vilanova Queiroz ◽  
Rafael Yagüe Ballester ◽  
João Batista De Paiva ◽  
José Rino Neto ◽  
Giselle Mara Galon

INTRODUCTION: The purpose of this study was to compare the frictional forces between 0.014-in NiTi wires (Aditek) with 4 mm horizontal deflection and brackets with different archwire ligation systems. METHODS: Four types of self-ligating brackets (Damon MX, Easy Clip, Smart Clip and In-Ovation), a triple bracket (Synergy) and a twin bracket with 8-shaped ligature (Tecnident) were tested. Twin brackets with conventional elastomeric ligatures (Morelli) were used as control group. Tests were repeated 10 times for each bracket/archwire combination. Frictional forces were measured in an Instron universal tensile machine at 3 mm/minute speed and a total displacement of 6 mm. Statistical analysis comprised ANOVA and Dunnett's multiple comparison post hoc test. RESULTS: Deflection-induced frictional (DIF) forces increased in the following order: Synergy, Damon, 8-shaped Ligature, Easy Clip, In-Ovation, Smart-Clip and conventional ligatures. The differences among groups were significant, with the exception of the 8-shaped ligature groups which was equal to the Damon and Easy Clip groups. CONCLUSIONS: Compared to conventional ligatures, all ligation systems tested reduced frictional forces. However, such reduction varied according to the ligation system employed.

2014 ◽  
Vol 893 ◽  
pp. 467-471
Author(s):  
Sroisiri Thaweboon ◽  
Yadana Aung ◽  
Suwannee Luppanapornlarp ◽  
Supatchai Boonpratham ◽  
Boonyanit Thaweboon

Objective: The aim of this study was to evaluate the adhesion ofStreptococcus mutans (S. mutans)on different types of orthodontic brackets commonly used in Thailand. Materials and Methods: The adhesion ofS. mutanson 7 types of orthodontic brackets (Clarity, Spirit MB, Inspire Ice, 3M, Tomy, Ormco and W&H) was investigatedin vitro. The saliva-coated brackets were immersed in a flat-bottomed 96-well plate containingS. mutanssuspension (108CFU/ml) and incubated at 37 ̇C in 10% CO2and 100 rpm for 2 hours. The adhered bacterial cells were fixed by 99% methanol and stained with 0.5% crystal violet. The quantity of adhesion was determined by measuring optical density (OD) at 590 nm. The data were analyzed with Kolmogorov-Smirnov test, Levene test, one way ANOVA and Games-Howell post hoc test. Results: Significantly higher bacteria adhesion was found on Clarity, Spirit MB, Tomy, Ormco and W&H compared to Inspire Ice and 3M Gemini. However, there were no significant differences among the different types of bracket materials (ceramic, plastics and metal). Conclusion: The amount of bacteria adhesion was independent of the type of bracket materials. The size and shape of brackets also played an important role in the amount of adhesion of microorganism.


Author(s):  
Natália Almeida BASTOS ◽  
Sandro Basso BITENCOURT ◽  
Juliana Fraga Soares BOMBONATTI ◽  
Ana Paula Camatta DO NASCIMENTO ◽  
Claudia Machado de Almeida MATTOS ◽  
...  

ABSTRACT Objective The bleaching agents may interact with restorative materials, such as dental amalgam, providing an increase mercury ions (Hg) release, whose toxic effect is known. Whereas many patients have amalgam restorations (AR) and seek bleaching treatments, the present study aimed to evaluate in vitro the amount of Hg released from AR made with spherical alloy, after being subjected to different concentrations of carbamide peroxide (CP) for home bleaching. Methods 40 class I AR were prepared in bovine teeth. Afterthe restoration, the samples were randomly allocated into 4 groups (n = 10): C (control group), CP10 (CP 10%) CP15 (CP 15%) CP20 (CP 20%) and its treatments were simulated for 14 days for 6 hours daily. The Hg ions released was measured by energy dispersive X-ray spectroscopy (EDS) and surface changes were assessed in the Scanning Electron Microscope (SEM). Hg levels (percent mass) were recorded and the differences were statistically analyzed using the Kruskal-Wallis test and Dunn’s “Post hoc” test. Results Statisticalanalysis showed the bleaching treatment resulted in a higher Hg release (p <0.05), although no visible changes were identified in micrographs when comparing the control group with the other groups (CP10, CP15, CP20). Conclusion Increased Hg release may be observed during simulated home bleaching.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Philipp Körner ◽  
Luca Georgis ◽  
Daniel B. Wiedemeier ◽  
Thomas Attin ◽  
Florian J. Wegehaupt

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.


2020 ◽  
Vol 11 (2) ◽  
pp. 160-166
Author(s):  
Mohammad Javad Moghaddas ◽  
Horieh Moosavi ◽  
Sara Yaghoubirad ◽  
Nasim Chiniforush

Introduction: The purpose of this study was to compare the effect of the bioactive glass, the glass ionomer, and the Erbium YAG laser as liners on the remineralization of the affected dentin. Methods: The present study was conducted on 64 healthy extracted human molars divided into 4 groups, 1 control group and 3 experimental groups. After artificially inducing dentinal caries lesions, each of the experimental groups was applied to the cavity floor and then restored with a composite. The samples were stored after thermocycling in an incubator for two months. Finally, the hardness of the cavity floor was measured at 3 depths of 20, 50 and 100 μm by the Vickers microhardness tester. The dentin conditions underneath the liners were also evaluated with FESEM. Statistical analysis was performed by two-way ANOVA and the post-hoc Games-Howell test (P<0.05). Results: Among the groups, the lowest microhardness value was in the control group (P<0.05) except at a depth of 100 μm; therefore, there was no significant difference between the control group and the bioactive glass (P>0.05). The laser group had the highest microhardness value, which was significantly different from the control group (P<0.05). There was a significant difference between the laser and bioactive glass (P<0.05), except at a depth of 20 μm. The laser and glass ionomer had only a significant difference at a depth of 100 μm (P<0.05). The microhardness value induced by glass ionomer was higher than bioactive glass, which in no depth was significant (P>0.05). Partial dentinal tubule occlusion was observed with FESEM in each of the experimental groups as compared to the control group. Conclusion: The microhardness values were higher in all groups than in the control group. The laser might be more successful in remineralization than the other ones.


2019 ◽  
Vol 11 (1) ◽  
pp. 23-32
Author(s):  
Cut Soraya ◽  
Sunnati ◽  
Fenny Wulandari

Perawatan saluran akar adalah perawatan yang dilakukan untuk mempertahankan gigi agar dapatberfungsi di lengkung gigi selama mungkin. Penyebab dominan dari kegagalan perawatan endodontikadalah adanya bakteri di dalam saluran akar. Bakteri yang paling sering ditemukan pada isolasi darigigi yang mengalami kegagalan perawatan saluran akar adalah Enterococcus faecalis (E.faecalis).Salah satu jenis tanaman herbal yang memiliki sifat antibakteri yang tinggi adalah tanaman mimba(A.indica). Tujuan penelitian ini untuk menganalisis efek antibakteri ekstrak daun mimba (A.indica)terhadap pertumbuhan E. faecalis. Penelitian ini merupakan penelitian eksperimental laboratorisdengan desain penelitian true experimental posttest only control group. Penelitian dilalukan denganmenguji ekstrak daun mimba (A.indica) pada konsentrasi 10%, 20%, 40%, 60%, 80% dan 100%terhadap pertumbuhan E. faecalis yang dilakukan di Laboratorium Mikrobiologi Fakultas KedokteranHewan (FKH) Universitas Syiah Kuala Banda Aceh. Hasil uji fitokimia yang dilakukan menunjukkanbahwa ekstrak daun mimba (A. indica) positif mengandung triterpenoid, phenolic compound, tanin,steroid dan saponin yang berperan sebagai antibakteri. Hasil uji efek antibakteri ekstrak daun mimba(A. indica) menunjukkan adanya pembentukan zona hambat di sekitar kertas cakram pada setiapkonsentrasi. Hal ini membuktikan bahwa ekstrak daun mimba memiliki efek antibakteri yangmemiliki kemampuan dalam menghambat pertumbuhan E. faecalis. Uji statistik digunakanmenggunakan one way ANOVA. Kemudian dilakukan uji lanjut (Post hoc test) menggunakan LeastSignificant Difference untuk menganalisis perbedaan efek antibakteri ekstrak daun mimba (A. indica)dalam konsentrasi 10%, 20%, 40%, 60%, 80% dan 100% terhadap pertumbuhan E.faecalis.Kesimpulan penelitian ini ekstrak daun mimba (A. indica) berpotensi menghambatpertumbuhan E. faecalis.Kata Kunci: Azadirachta indica, Enterococcus faecalis, perawatan saluran akar.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Francesca Cattoni ◽  
Giulia Teté ◽  
Alessandro Mauro Calloni ◽  
Fabio Manazza ◽  
Giorgio Gastaldi ◽  
...  

Abstract Background Aesthetic porcelain veneers proved to be a long-term reliable prosthetic solution, ensuring minimal invasiveness. The use of veneers requires an adhesive cementation technique, so maintaining as much enamel as possible is to ensure lasting success. A diagnostic mock-up is a key tool that allows a preview of the outcome of the aesthetic restoration: it is obtainable both in an analog and digital way. With the recent developments in impression technology and the ever so fast growing use of CAD-CAM technologies it is useful to understand the pros and cons of either one of these techniques (analog and digital) in order to identify the easier and more convenient workflow in aesthetic dentistry. Methods After taking pictures and impressions of the dental arcs of a patient in need of aesthetic rehabilitation, 52 resin models were produced and a digital drawing of the smile was outlined. Both an analog and a digital wax-up were obtained from two of the 52 models: the latter was obtained using digital impressions and a dedicated software. The analog wax-up was then used to produce 25 matrices that have later been used to mould 25 resin mock-ups using a traditional moulding protocol (Control Group - CG). The digital wax-up was used to mill 25 PMMA mock-ups. Each mock-up, both milled and moulded (total 50), was then laid on the other 50 resin models as a digital impression of it was taken. The STL. files of the milled mock-ups were compared with the 3D CAD wax-up made using a specific software. The STL. files of the analog printed mock-ups were compared with the traditional wax-up design. A statistical analysis was carried out to evaluate the difference between the groups. Results The statistical analysis showed a significant difference (P > 0.01) between the mean value of the distance between the points of the overlapping STL. meshes in GC (0.0468 mm) and in TG (Test Group - TG) (0,0109 mm). Conclusions The study showed a difference in accuracy between traditional moulded and milled mock-ups compared to their original wax-up. The data analysis reports that the digital method allows for greater accuracy. Within the limitations of this study, a fully digital workflow is to considered more reliable when it come to creating an esthetic mockup: the digital procedure has been shown to be more accurate than the one made manually which is much more operator dependent and it brings an increase to the chance of error, and that could ultimately affect the final result.


2019 ◽  
Author(s):  
Sakti Charlia Maharani ◽  
Indah Julianto ◽  
Suci Widhiati

Beluntas (Pluchea indica Less.) is a herbal plant which contains variety of benefits. Quercetin, one of flavonoid, is the most bioactive agent in beluntas leaf. Collagen inhibition by quercetin may modulate extracellular matrix deposition and inhibit the formation of hypertrophic scar. This was an in vitro study with senescent fibroblasts to determine the role of beluntas leaf extract in preventing the occurence of fibroblasts hyperproliferations. There were 4 groups were stained by anti-collagen I antibodies and secondary antibody. Flowcytometry analysis was done to measure the fibroblasts density. Anova test was performed with a value of p=0.000 (p<0.05). A post hoc analysis showed significant differences in the average decrease of fibroblasts that absorbs staining anti-collagen I antibody treatment group compared with the control group. There were significant effects of beluntas leaf extract in preventing the occurrence of fibroblasts hyperproliferations. Beluntas leaf extract with a concentration of 80 mol/L had the most significant effect on the fibroblasts density. Thus beluntas leaf extract has the ability in preventing the occurrence of fibroblasts hyperproliferation.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Vito Crincoli ◽  
Letizia Perillo ◽  
Maria Beatrice Di Bisceglie ◽  
Antonio Balsamo ◽  
Vitaliano Serpico ◽  
...  

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.


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