Six-month bracket failure rate with a flowable composite: A split-mouth randomized controlled trial

ABSTRACT INTRODUCTION: The use of flowable composites as an orthodontic bonding adhesive merits great attention because of their adequate bond strength, ease of clinical handling and reduced number of steps in bonding. OBJECTIVE: The aim of this Randomized Controlled Trial was to comparatively evaluate over a 6-month period the bond failure rate of a flowable composite (Heliosit Orthodontic, Ivoclar Vivadent AG, Schaan) and a conventional orthodontic bonding adhesive (Transbond XT, 3M Unitek). METHODS: 53 consecutive patients (23 males and 30 females) who fulfilled the inclusion and exclusion criteria were included in the study. A total of 891 brackets were analyzed, where 444 brackets were bonded using Heliosit Orthodontic and 447 brackets were bonded using Transbond XT. The survival rates of brackets were estimated with the Kaplan-Meier analysis. Bracket survival distributions for bonding adhesives, tooth location and dental arch were compared with the log-rank test. RESULTS: The failure rates of the Transbond XT and the Heliosit Orthodontic groups were 8.1% and 6% respectively. No significant differences in the survival rates were observed between them (p= 0.242). There was no statistically significant difference in the bond failure rates when the clinical performance of the maxillary versus the mandibular arches and the anterior versus the posterior segments were compared. CONCLUSIONS: Both systems had clinically acceptable bond failure rates and are adequate for orthodontic bonding needs.

RESUMO INTRODUÇÃO: o uso de resinas compostas fluidas como agentes de cimentação em Ortodontia tem merecido grande atenção, em função de sua adequada capacidade adesiva, facilidade de uso clínico e número reduzido de etapas de colagem. OBJETIVO: o objetivo deste estudo randomizado controlado foi avaliar o índice de falhas nos 6 meses após a colagem com uma resina composta fluida (Heliosit Orthodontic, Ivoclar Vivadent AG, Schaan), em comparação com um adesivo ortodôntico convencional (Transbond XT, 3M Unitek). MÉTODOS: 53 pacientes consecutivos (23 homens e 30 mulheres) que se enquadravam nos critérios de inclusão adotados foram incluídos no presente estudo. No total, 891 braquetes foram analisados, sendo 444 colados com o Heliosit Orthodontic e 447 colados com o Transbond XT. As taxas de sobrevivência dos braquetes foram estimadas por meio da análise de Kaplan-Meier. As distribuições das taxas de sobrevivência dos braquetes em função do adesivo usado, do dente e da arcada dentária em questão foram comparadas por meio do teste de log-rank. RESULTADOS: os índices de falhas para os grupos Transbond XT e Heliosit Orthodontic foram, respectivamente, de 8,1% e 6%. Não foram observadas diferenças significativas entre os grupos quanto às taxas de sobrevivência dos braquetes (p= 0,242). Também não foram observadas diferenças estatisticamente significativas quanto aos índices de falhas quando se comparou a performance clínica nas arcadas dentárias superior e inferior, e nos segmentos anterior e posterior da boca. CONCLUSÕES: ambos os sistemas apresentaram índices de falhas clinicamente aceitáveis, podendo ser considerados adequados para a colagem ortodôntica.

Light-emitting diode versus halogen light curing of orthodontic brackets: a clinical study of bond failure / Colagem de brackets ortodônticos: polimerização da resina por meio de diodos emissores de luz versus luz alógena: estudo clínico de falhas de adesão

OBJECTIVE: The purpose of this study was to evaluate the clinical performance of brackets cured with two light-curing units. MATERIALS AND METHODS: Forty female patients (between12-16 years old) who required fixed appliances were included in this study. Based on the characteristics of their lower arches, study participants were divided into two groups, A and B. In group A, the composites were cured on the right side by Ultralume LED2TM and on the left side by a conventional halogen unit. In group B, the sequence was reversed. A total of 160 brackets were bonded. After 12 months, bond failure rate was evaluated. RESULTS: We found that 18 brackets in the halogen group and 13 bracketsin the LED group were debonded. No statistically significant differences were found in total bond failure rate and no enamel damage was clinically detected for either technique. CONCLUSION: Theseresults suggest that LED dose curing does not result in more bond failure when compared with conventional halogen light curing.

OBJETIVO: O objetivo deste estudo foi avaliar o desempenho clínico de brackets colados utilizando-se de duas unidades de polimerização. MATERIAL E MÉTODO: quarenta pacientes adolescentes com indicação de tratamento ortodôntico fixo foram incluídos no trabalho, divididosem dois grupos, A e B. No grupo A, o compósito foi polimerizado no lado direito com Ultralume LED 2TM e no lado esquerdo com luz halógena convencional. No grupo B, a sequencia foi invertida. Um total de 160 brackets foram colados. Após 12 meses de tratamento, avaliou-se a taxa de falhas de colagem. RESULTADOS: 18 brackets no grupo halógeno e 13 no grupo LED sofreram descolamento. Não houve diferença estatisticamente significante na taxa total de falhas e nãoforam observados danos ao esmalte em ambas as técnicas. CONCLUSÃO: Estes resultados sugerem que a fotopolimerização com LED não resulta em maiores falhas de adesão quandocomparadas com a luz halógena convencional.

A study on bracket-adhesive combinations in aspect of shear bond strength and bond failure / 대한치과교정학회지

The purpose of the present study was to seek bracket-adhesive combinations which have adequate bond strength with no enamel and bracket fracture. The shear bond strengths were measured, the sites of failure and the enamel damage were investigated and the peripheral sealing and adaptation between enamel surface, bonding adhesive and bracket were evaluated 240 noncarious human premolars were divided into twenty four groups of ten teeth. Shear bond strengths of each group were determined in an universal testing machine after two days passed and the debonded specimens were inspected to determine the predominant bond failure sites. To evaluate peripheral sealing and adaption between enamel surface, adhesive and bracket, each specimen was cut longitudinally into two halves which included the midsection of the bracket, adhesive and enamel and exmined in scanning electron microscope. Six different types of brackets were bonded to the tooth with four different type of adhesives. Six different types of brackets were Image, Plastic, Crystaiine, Fascination, Transcend 2000 and metal bracket and four different adhesives were No-mix, Light-Bond, OrthoLC and Superbond C&B. From this study, it may be concluded that (1) The mean shear bond strength varied from a high of 36.58Kg (410.07 Kg/cm2) with the Fascination-Light Bond combination group to a low of 8.93 Kg (75.51 Kg/cm2) with the Image-OrthoLC combination group. When using OrthoLC as adhesive, the mean shear bond strength was significantly lower than that of other combination groups, (2) Regardless of adhesives, the mean shear bond strength of Fascination brackets was relatively high whereas Plastic and Image brackets had low shear bonding strength The shear bond strength of Crystaline bracket and Transcend 2000 was relatively equal to or lower than that-of metal bracket, (3) There was a correlation between bond strength, enamel damage and bracket fracture. As the shear bond strength was increased, the rate of enamel damage and bracket fracture were increased, (4) The combination groups that use OrthoLC as adhesive were debonded in shear stress without enamel fracture and bracket fracture, whereas the combination groups that use Superbond C&B as adhesive experienced a relative high enamel fracture rate and bracket fracture rate, (5) Peripheral sealing and adaptation between enamel-adhesive-bracket were relatively good when using Light-Bond or No-mix as adhesive. Regardless of adhesives, adaptation between bracket-adhesive were relatively good in Ceramic brackets, (6) The combination groups which had adequate bonding strength with no enamel and bracket fracture were Crystaline No mix, Crystaline-Light Bond, Crystaline-OrthoLC, metal-No mix, metal-Light Bond and metal-OrthoLC combination groups.