Thomas Manoukakis, Alexandros K Nikolaidis, Elisabeth A Koulaouzidou
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引用次数: 0
Abstract
Background: The purpose of the study was to measure the degree of conversion (DC) of direct-printed aligners (DPA) that were post-cured under ambient and nitrogen atmosphere at specific time intervals and investigate the kinetics of polymerization reaction of this material.
Methods: A total of 48 aligners were produced in 4 printing series by a 3D printer with TC-85DAC resin (Graphy Inc). From each series of printing, 12 aligners were included. The aligners were divided into two groups according to their post-curing conditions. One group was post-cured under ambient air with the presence of oxygen and the other under a nitrogen atmosphere, both using the same UV post-curing unit recommended by the company. The aligners were post-cured at six different time intervals: 1, 2, 3, 5, 10, and 20 min. Each time interval included 8 aligners, with 2 aligners from each series. The DC of the cured aligners was measured by means of attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) through acquisition of the respective spectra for each UV-curing condition. Statistical analysis was performed to compare the results and differences within each atmosphere post-curing protocol, as well as between the different selected atmosphere conditions. Statistical significance level was set at p-value ≤ 0.05.
Results: Pairwise analysis between post-curing protocols showed statistically significant differences only at the first minute of polymerization. Post-curing with nitrogen did not yield statistically significant results across different time intervals. Post-curing in ambient air showed some significant differences on the 1st and 2nd minute of the post-curing process.
Conclusions: Almost complete double bond conversion was observed. Significant differences were observed only during the first minute of polymerization under the nitrogen atmosphere.
期刊介绍:
Progress in Orthodontics is a fully open access, international journal owned by the Italian Society of Orthodontics and published under the brand SpringerOpen. The Society is currently covering all publication costs so there are no article processing charges for authors.
It is a premier journal of international scope that fosters orthodontic research, including both basic research and development of innovative clinical techniques, with an emphasis on the following areas:
• Mechanisms to improve orthodontics
• Clinical studies and control animal studies
• Orthodontics and genetics, genomics
• Temporomandibular joint (TMJ) control clinical trials
• Efficacy of orthodontic appliances and animal models
• Systematic reviews and meta analyses
• Mechanisms to speed orthodontic treatment
Progress in Orthodontics will consider for publication only meritorious and original contributions. These may be:
• Original articles reporting the findings of clinical trials, clinically relevant basic scientific investigations, or novel therapeutic or diagnostic systems
• Review articles on current topics
• Articles on novel techniques and clinical tools
• Articles of contemporary interest