Effect of curing lights and bleaching agents on physical properties of a hybrid composite resin.
J Esthet Restor Dent
; 20(4): 266-73; discussion 274-5, 2008.
Article
em En
| MEDLINE
| ID: mdl-18768000
UNLABELLED: The aim of this in vitro study was to evaluate the microhardness (MH) and diametral tensile strength (DTS) of a minifill hybrid composite (Filtek Z250, 3M ESPE), polymerized with halogen lamp or second generation light-emitting diode (LED), submitted to different bleaching agents. Composite resin specimens were randomly polymerized according to experimental groups (halogen, 550 mW/cm(2)/20 seconds; LED, 550 mW/cm(2)/25 seconds) and subdivided into three subgroups (N=8): A, without bleaching (control); H, 35% hydrogen peroxide; and C, 16% carbamide peroxide. After that, the MH test and DTS test were performed. Two-way analysis of variance (whitening x light) and Tukey's tests (alpha=5%) were performed. For DTS, there were no statistical differences among the bleaching agents and the control group; however, the halogen group presented statistically lower DTS (p<0.05) than the LED group. For the MH test, the carbamide peroxide group presented statistically lower MH means (p<0.05) than the control groups, and there were no statistical differences among the light-curing units. Sixteen percent carbamide peroxide reduced the MH of the hybrid composite tested. The second generation LED presented a performance similar to or better than the halogen lamp for hardness and DTS, respectively. CLINICAL SIGNIFICANCE: Repolishing of minifill hybrid composite is suggested, as the alteration caused after the contact with 16% carbamide peroxide was limited to the material surface. The second generation light-emitting diode is a good option for a curing light device when the polymerization initiator of composite resin is camphorquinone.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Clareamento Dental
/
Iluminação
/
Oxidantes
/
Resinas Compostas
/
Materiais Dentários
Tipo de estudo:
Clinical_trials
Limite:
Humans
Idioma:
En
Revista:
J Esthet Restor Dent
Assunto da revista:
ODONTOLOGIA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido