In vitro lingual bracket evaluation of indirect bonding with plasma arc, LED and halogen light.
OBJECTIVE
Evaluate the shear bond strength (SBS) and the adhesive remnant index (ARI) of indirect bonded lingual brackets using xenon plasma arc light, light-emitting diode (LED) and conventional quartz-tungsten-halogen light.


METHODS
Lingual brackets were bonded indirectly to 60 premolars divided to three groups according to the curing light used: Group 1, plasma arc for 6 s; Group 2, LED for 10 s; and Group 3, halogen light for 40 s. After bonding, the specimens were subjected to a shear force until debonding. The debonding pattern was assessed and classified according to the ARI scores. The mean shear bond strengths were accessed by anova followed by the Student-Newman-Keuls test for multiple comparisons. ARI scores were assessed using the chi-square test.


RESULTS
The three groups showed significant differences (p < 0.001), with the averages of group 1 < group 2 < group 3. Groups showed no differences regarding ARI scores.


CONCLUSIONS
Bonding lingual brackets indirectly with plasma arc, during 60% of the time used for the LED, produced lower SBS than obtained with the latter. Using LED during 25% of the time of the halogen light produced lower SBS than obtained with the latter. These differences did not influence the debonding pattern and are clinically acceptable according to the literature.
Magno
A F F
AF
Department of Pediatric Clinic, Faculty of Dentistry of Araraquara, UNESP, Araraquara, São Paulo, Brazil. mandamagno@yahoo.com.br
Martins
R P
RP
Vaz
L G
LG
Martins
L P
LP
D055117:Curing Lights, Dental; D003799:Dental Stress Analysis; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D016910:Orthodontic Brackets; D033081:Shear Strength