Abstract
Background. This in vitro study aimed to evaluate biofilm accumulation on and deactivation force of orthodontic nickeltitanium (NiTi) archwires before and after exposure to an oral medium. Methods. Four commercial brands of orthodontic NiTi 0.016" archwires were examined before and after exposure to the oral medium for 4 weeks. Six archwire segments, 30 mm in length, from each manufacturer were tested in a device with four selfligating brackets, channel 0.022", adapted to a universal test machine to evaluate the deactivation force between 0.5 and 3 mm of deflection. The presence of biofilm on the archwire surfaces was evaluated by scanning electron microscopy, before and after exposure to the oral medium. The Wilcoxon and kappa tests were applied to the biofilm scores, three-way ANOVA for repeated measures (Bonferroni post-test), and linear regression between biofilm and deactivation force. Results. The exposure to the oral medium promoted moderate to severe presence of debris on the archwire surfaces and caused a reduction in deactivation force for the Ormco and GAC brands, while maintaining them with adequate force levels. The MORELLI and ORTHOMETRIC archwires underwent no significant reduction in deactivation force; moreover, these maintained elevated levels of force after exposure to the oral medium. The Spearman test indicated a low correlation between biofilm accumulation and deflection force for the Morelli (R2=0.132 and P=0.683) and Orthometric (R2=0.308 and P=0.330) brands. On the other hand, the GAC (R=0.767 and P=0.004) and ORMCO (R=0.725 and P=0.008) brands exhibited statistically significant correlation between these variables. Conclusion. Exposure to the oral medium for one month might give rise to significant changes in the dissipation of forces of orthodontic NiTi archwires, resulting from biofilm accumulation.
Highlights
The properties of NiTi wires are responsible for promoting low forces at physiological thresholds at the beginning of orthodontic treatment, improving in efficiency during the treatment.[1,2] Deactivation force and surface roughness are outstanding among these properties because they influence adequate sliding of the wire in the bracket channel, and its deflection throughout orthodontic movement.[3,4,5,6,7]Laboratory studies simulate orthodontic movements and reveal the different behaviors of archwires
The exposure to the oral medium promoted moderate to severe presence of debris on the archwire surfaces and caused a reduction in deactivation force for the Ormco and GAC brands, while maintaining them with adequate force levels
The MORELLI and ORTHOMETRIC archwires underwent no significant reduction in deactivation force; these maintained elevated levels of force after exposure to the oral medium
Summary
The properties of NiTi wires are responsible for promoting low forces at physiological thresholds at the beginning of orthodontic treatment, improving in efficiency during the treatment.[1,2] Deactivation force and surface roughness are outstanding among these properties because they influence adequate sliding of the wire in the bracket channel, and its deflection throughout orthodontic movement.[3,4,5,6,7]Laboratory studies simulate orthodontic movements and reveal the different behaviors of archwires. There has been little investigation into the influence of biofilm accumulation, which might compromise the deactivation force of archwires when in contact with brackets, as a result of the greater degree of friction, interfering with the effectiveness of movements.[8,9,10,11,12,13,14,15,16,17,18,19] In this sense, there are few trials about aging in the oral medium,[14,15] and they point out interference with friction and deflection of archwires. Up to now, little is known about the relationship between biofilm accumulation and the performance of NiTi archwires This in vitro study aimed to evaluate biofilm accumulation on and deactivation force of orthodontic nickeltitanium (NiTi) archwires before and after exposure to an oral medium
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Dental Research, Dental Clinics, Dental Prospects
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
