ABSTRACT
OBJECTIVE: The aim of this study was to examine the properties of fiber-reinforced composite and stainless steel twisted retainers for orthodontic retention. METHODS: Three different span lengths (5.0, 8.0, and 14.0 mm) of fiber-reinforced composite were investigated. The three fiber-reinforced composite retainer groups were subdivided according to the storage condition (dry and wet), resulting in a total of six groups. Each stainless steel and fiber-reinforced composite group was comprised of six specimens. The three-point bending flexural test was conducted using a universal testing machine. ANOVA was used to assess differences in the maximum load and maximum stress according to the span length, material, and storage condition. Post-hoc comparisons were performed if necessary. RESULTS: The maximum stress and maximum load were significantly (p < 0.001) associated with the span length, material, and storage condition. The significant interaction between the material and span length (p < 0.001) indicated the differential effects of the material for each span length on the maximum stress and maximum load, with the difference between materials being the highest for the maximum span length. CONCLUSIONS: Our findings suggest that fiber-reinforced composite retainers may be an effective alternative for orthodontic retention in patients with esthetic concerns or allergy to conventional stainless steel wires.
Subject(s)
Humans , Hypersensitivity , Orthodontic Retainers , Polymers , Stainless SteelABSTRACT
The aim of this study was to examine the antibacterial effect of several current orthodontic materials against a certain oral bacterium. The antibacterial activities of six orthodontic composite resins (Transbond LR, Light Cure Retainer (LCR), Light Bond, System 1+, Kurasper F, Transbond XT adhesive), two orthodontic bonding materials (Transbond XT primer and System 1+ activator) and two glass ionomer cements (GIC) [Multicure Glass Ionomer and Ketac Cem GIC] were evaluated against Streptococcus mutans. The hard materials were put into the Teflon mould. The liquid materials were put on a paper disc. All materials were handled under aseptic conditions and placed on agar culture plates. All plates were incubated at 5% CO2 and 37 ºC for 48 hours. The bacterial growth inhibition zones including the diameter of the sample were measured in millimetres. As a result of this study, the multicure GIC showed the highest antibacterial effectiveness, but no inhibition zones were noted for ketac cem GIC. The light bond adhesive of the Reliance orthodontic bonding system produced high antibacterial effect against S mutans, while the Reliance composite (LCR) did not show any antibacterial effect (p < 0.05). Both composite and primer of the transbond XT system demonstrated significant antibacterial effect against the test bacterium when compared to transbond LR (p < 0.05). Among the materials tested, kurasper F, Ormco system 1+ and system 1+ activator showed slight or no inhibitory effect against the test bacterium in this study. In patients who have relatively high salivary levels of Streptococci mutans before treatment, the multicure GIC, the Reliance light bond adhesive, and transbond XT system which had high level antibacterial properties could be applied.
El objetivo de este estudio fue examinar el efecto antibacteriano de varios materiales ortodóncicos actuales sobre cierta bacteria oral. Se evaluaron las actividades antibacterianas frente al Streptococcus mutans, de seis resinas compuestas (composites) ortodóncicas (Transbond LR, Light Cure Retainer (LCR), Light Bond, System 1+, Kurasper F, Transbond XT), dos adhesivos ortodóncicos (Transbond XT y Sistema 1+ activador) y dos cementos de ionómeros de vidrio (GIC) [ionómero de vidrio Multi-cure y Ketac Cem GIC]. Los materiales duros fueron puestos en el molde de Teflón. Los materiales líquidos fueron puestos en un disco del papel. De todos los materiales fueron manipulados bajo condiciones asépticas y pusieron en el agar cultive los platos. Todos las placas fueron manipuladas en condiciones asépticas, y colocados en placas de cultivo agar. Todas las placas fueron incubadas a 5% CO2 y 37 ºC durante 48 horas. Las zonas de inhibición del crecimiento bacteriano, incluido el diámetro de la muestra, fueron medidas en milímetros. Un aspecto del resultado de este estudio, fue que el Multi-Cure GIC mostró la efectividad antibacteriana más alta, en cambio no se observó ninguna zona de inhibición para el ketac cem GIC. El adhesivo Light Bond del sistema Reliance para la adhesión ortodóncica, produjo altos efectos antibacterianos frente al S mutans, mientras que el composite de Reliance (LCR) no mostró efecto antibacteriano alguno (p < 0.05). Tanto el composite como el iniciador (primer) del sistema XY transbond probaron poseer un efecto antibacteriano significativo frente a la bacteria de la prueba, cuando se les comparó con el transbond LR (p < 0.05). Entre los materiales probados, kurasper F, Ormco Sistema 1+ y sistema 1+ activador no mostraron efecto inhibitorio alguno, o sólo ligeramente, frente a las bacterias de la prueba en este estudio. En pacientes con niveles salivales relativamente altos de Streptococci mutans antes del tratamiento, podrían aplicarse el Multi-Cure GIC, el adhesivo Reliance Light Bond, y el sistema transbond XT - los cuales tuvieron un alto nivel de propiedades antibacterianas.
Subject(s)
Dental Cements/pharmacology , Glass Ionomer Cements/pharmacology , Resins, Synthetic/pharmacology , Streptococcus mutans/drug effects , Microbial Sensitivity Tests , Streptococcus mutans/growth & developmentABSTRACT
O objetivo deste trabalho é apresentar uma revisão sobre os conceitos relacionados à biocompatibilidade dos materiais empregados em Ortodontia. Fatos relacionados às reações de hipersensibilidade aos diversos materiais ortodônticos são discutidos, sendo apresentadas as condutas recomendáveis nestas situações.
The aim of this paper is to present a review on the biocompatibility of orthodontic materials. Hypersensitivity reactions to these materials are discussed and the recommended conduct in this kind of situation are presented.