Improvement of the orthodontic bracket bond strength with pre-heated composite restoratives.
OBJECTIVE
This study aimed to evaluate the effect of pre-heated composite restoratives on the shear bond strength (SBS) of orthodontic brackets.


METHODS
The following materials were tested: a microhybrid composite restorative (Filtek Z250), two nanofilled composite restoratives (Filtek Z350 and NT Premium), a nanohybrid composite restorative (Brilliant) and a conventional orthodontic adhesive (Transbond XT). All materials were stored for 1 h in the incubator either at 25°C (room temperature simulation) or 60°C before bonding 100 orthodontic brackets on bovine lower incisors (n = 10). One Coat Bond SL and Transbond XT were used to bond the composite restoratives and the Transbond XT adhesive paste, respectively. After storage in distilled water for 24 h, the brackets were subjected to SBS test at a speed of 0.5 mm/min until bracket debonding. The Adhesive Remnant Index (ARI) was assigned to the fractured specimens. Data were analyzed using the one-way ANOVA and the Tukey post-hoc test (p < 0.05). The Kruskal-Wallis test was used to compare ARI scores between the groups (p < 0.05).


RESULTS
There was no statistically significant difference between the materials at room temperature. Samples bonded with pre-heated materials showed a statistically higher SBS than those bonded with room temperature materials. Samples bonded with the pre-heated orthodontic adhesive showed the highest SBS among all the pre-heated materials. All preheated composite restoratives produced an SBS mean higher than that of Transbond XT stored at room temperature.


CONCLUSIONS
The use of pre-heated composite restoratives and orthodontic adhesives might be an alternative approach to bond orthodontic brackets.
Department of Dentistry, School of Dentistry, Potiguar University (Laureate International Universities), Natal, Brazil. iek.castillo@gmail.com
Boniek Castillo Dutra
BC
Borges
Marcelo Viana
MV
Gurgel
Andre Felipe Alves
AF
Figueiroa
Ana Raquel Rocha Correia
AR
Vilela
Fabio Henrique de Sa Leitao
FH
Pinheiro
Rodivan
R
Braz
Marcos Antonio Japiassu Resende
MA
Montes
D000818:Animals; D002417:Cattle; D003188:Composite Resins; D008422:Materials Testing; D016910:Orthodontic Brackets
D003188:Composite Resins