Degree of Conversion of Three Light-Cured Orthodontic Adhesives

2018 ◽  
Vol 777 ◽  
pp. 577-581
Author(s):  
Wassana Wichai ◽  
Kanin Nimcharoensuk ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn ◽  
Pitchaya Roongrujimek
Keyword(s):  
Stainless Steel ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
In Vitro Study ◽  
Degree Of Conversion ◽  
Friedman Test ◽  
Orthodontic Adhesives ◽  
Time Periods

Introduction: The aim of this in-vitro study was to analyze the polymerization ability of 3 light-cured orthodontic adhesives by determining the degree of conversion (DC). Materials and Methods: Fourier transform infrared spectroscopy (FTIR) was used to evaluate the DC after polymerization immediately, 1 day, 7 days, and 30 days. The adhesives investigated were Transbond XT (3M Unitek, USA), Grengloo (Ormco Corp., USA), and Green Glue (Hangzhou Biomaterials, China). Twelve stainless steel brackets (n=4) were used and the adhesives were cured with Bluephase G2 (Ivoclar Vivadent, Liechtenstein). The data were analyzed by Kruskal-Wallis test for comparing materials and Friedman test for comparing the time periods. Results: The DC values were significantly different among the materials and among the time periods. The highest DC in each period was obtained for Grengloo and the lowest DC was observed for Transbond XT. Thus, there were significant differences between the DC values of Grengloo and Transbond XT in each period. Among the time periods, DC% at T1 (Immediately) and T3 of the material were significantly different. The DC values of all adhesives increased extremely from immediately following curing to 1 day and then slightly increased from 1 day to 7 days. Conclusions: Grengloo showed the highest levels of DC at all tested periods. The percentage values of DC largely increased from immediately following curing to 1 day. This concluded that monomers in orthodontic adhesives kept converting even after completion of photoactivation.

scholarly journals Cytotoxicity and degree of conversion of methacrylate and silorane

2020 ◽  
Vol 19 ◽  
pp. e200656
Author(s):  
Virgínia Angélica Silva ◽  
Sávio Morato de Lacerda Gontijo ◽  
Alexandre Gatti ◽  
Luiz Thadeu de Abreu Poletto ◽  
Hugo Henriques Alvim
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Cell Viability ◽  
Fourier Transform Infrared Spectroscopy ◽  
Mtt Assay ◽  
Composite Resin ◽  
Fourier Transform Infrared ◽  
Degree Of Conversion ◽  
Similar Degree ◽  
Bonferroni Correction

Composites have been proven to have a cytotoxiceffect on a variety of tissues and cells. Aim: The aim of thisstudy was to analyse the degree of conversion of resinsand its correlation with the cell viability in primary gingivalfibroblasts. Methods: Resin-based silorane (Filtek P90)and conventional methacrylate resins (Filtek Z100, FiltekZ250 and Filtek Z350XT) were used to evaluate cell viabilityand the degree of conversion. The resins were light-cured bya LED for 20 and 40 seconds. The degree of conversion wasanalysed by Fourier transform infrared spectroscopy. Cellularmetabolism was evaluated after 24 hours by the MTT assay(n = 6) using the storage solution of composite resin foreither 24 hours or 12 days. Variance analysis (ANOVA) witha Bonferroni correction (p < 0.05) was performed to comparethe groups. Results: The composite Filtek P90 showed ahigher degree of conversion when polymerised for 40 or20 seconds, while the composites Filtek Z100, Filtek Z250 andFiltek Z350XT showed similar degree of conversion. Only theFiltek Z100 resin was cytotoxic. Conclusion: We found nostatistically significant correlation between cell viability andthe degree of conversion.

Degree of Conversion of Experimental Light-Cured Orthodontic Adhesives

2019 ◽  
Vol 801 ◽  
pp. 27-32
Author(s):  
Kanin Nimcharoensuk ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn ◽  
Vanthana Sattabanasuk ◽  
Panya Sunintaboon ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Statistical Analysis ◽  
Fourier Transform Infrared ◽  
Degree Of Conversion ◽  
Monomer Ratio ◽  
Orthodontic Adhesives ◽  
Group 3 ◽  
Ftir Spectrometer ◽  
Time Periods ◽  
Group 1

The objectives of this study were to compare the polymerization of three experimental light-cured orthodontic adhesives by determining their degree of conversion (DOC) and to compare the results with a control (Transbond XT; 3M Unitek, USA). Three formulas of an in-house orthodontic adhesive were divided according to monomer ratio (BisGMA:TEGDMA) into group 1 (8:2), 2 (7:3), and 3 (6:4), respectively, with 60-70 weight % of filler amount and 0.5 % of photoinitiator (TPO). All specimen (n=5 per group) were cured with a LED curing unit. The DOC was estimated using Fourier transform infrared (FTIR) spectrometer (Nicolet 6700, Madison, Michigan, USA) immediately following polymerization and on Day 1, Day 7, and Day 30. For statistical analysis, Kruskal-Wallis and Friedman tests were used to compare the materials and the periods, respectively, with p=0.05. The result showed that the DOC was significantly different among the groups and time periods. The highest and lowest DOC at each of the periods were obtained from group 3 and group 1, respectively. Among the time periods, the DOC values of all groups increased considerably on Day 1 following curing as compared to when it was measured immediately, and the DOC gradually increased until Day 30. In conclusion, the experimental orthodontic adhesive in group 3 with a monomer ratio of 6:4 provided the highest DOC among all the adhesives and was superior to Transbond XT at all periods of examination.

scholarly journals A Comparative Evaluation of Static Frictional Resistance Using Various Methods of Ligation at Different Time Intervals: An In Vitro Study

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Amanpreet Singh Natt ◽  
Amandeep Kaur Sekhon ◽  
Sudhir Munjal ◽  
Rohit Duggal ◽  
Anup Holla ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Static Friction ◽  
Significant Difference ◽  
Dry Conditions ◽  
The Mean ◽  
Time Periods

Aim. To compare and evaluate the static frictional resistance offered by the four different types of ligation methods in both dry and wet conditions and at different durations when immersed in artificial saliva.Material and Methods. Alastik Easy to Tie modules, Super Slick Mini Stix elastomeric modules, Power “O” modules, and 0.009″Stainless Steel ligatures were used to compare the static friction using maxillary canine and premolar Preadjusted Edgewise brackets with 0.022″× 0.028″slot and 0.019″× 0.025″stainless steel wires.Results. The mean frictional resistance for Alastik modules was the lowest and that of Stainless Steel ligatures was found to be highest among the four groups compared and the difference among the four groups was statistically significant (P<0.005). The mean static frictional resistance in all groups under dry conditions was lower than that under wet conditions. No statistical significant differences were found when the groups were compared at different time periods of immersion in artificial saliva.Conclusion. This study concludes that the Alastik modules showed the lowest mean static frictional forces compared to any other ligation method, though no significant difference was found for different time periods of immersion in the artificial saliva.

scholarly journals A Facile Method to Prepare a Hydrophilic/Hydrophobic Metal Surface by Peptide

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1289
Author(s):  
Chunying Ma ◽  
Chengqing Yuan ◽  
Pan Cao
Keyword(s):  
Stainless Steel ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Surface Morphology ◽  
Fourier Transform Infrared Spectroscopy ◽  
Metal Surface ◽  
Metal Binding ◽  
Steel Surface ◽  
Stainless Steel Surface ◽  
Binding Peptide

A facile method to prepare a hydrophilic/hydrophobic metal surface by metal-binding peptide was proposed in this article. Metal-binding peptide sequenced NLNPNTASAMHV was taken as the target peptide to interact with stainless steel. The surface morphology, roughness and Fourier-Transform Infrared spectroscopy (FTIR) showed that some changes occurred on the modified stainless steel surface. Not only were the surfaces coarser but also some organic groups appeared on the modified sample surfaces. By comparing the CAs of all the samples, the most suitable concentration of peptide and treating time were determined. A new and facile way to endow some metals surfaces with hydrophobicity or hydrophilicity has been developed, which is useful especially for antibiofouling.

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