Nd:YAG laser effects on the microleakage of composite resin restorations.
OBJECTIVE
This study evaluated microleakage of composite restorations submitted to marginal treatment with Nd:YAG laser and surface sealant.


BACKGROUND
Previous studies have demonstrated that Nd:YAG-lased enamel melted and became recrystallized with a morphologic appearance similar to lava, and has been used clinically in the sealing of enamel pits and fissures.


METHODS
Class V cavities in enamel of human premolars were restored with composite resin (Z100, 3M) and randomly divided in six groups: G1, control; G2, surface sealant marginal treatment; G3 to G6, were treated with pulsed Nd:YAG laser (1.064 microm) marginal treatment, contact fiberoptic (300 microm), air cooling, for 30 seconds, powers of 1.2-2 W, repetition rates of 20-30 Hz, energies of 40-100 mJ. Teeth were impermeabilized, immersed in a rhodamine dye, sectioned, and evaluated under stereomicroscope microscopy with scores.


RESULTS
There were significant differences between marginal treatments; there were no differences between groups 1, 2, and 4, and 3,5, and 6; lower values of microleakage were at groups 3, 5, and 6 (Kruskal-Wallis,p = 0.05).


CONCLUSIONS
Nd:YAG laser showed improved marginal sealing and decreased microleakage of composite resins restorations.
Navarro
R S
RS
Department of Restorative Dentistry-School of Dentistry University of São Paulo, SP, Brazil. rnavarro@fo.usp.br
Esteves
G V
GV
Oliveira
W T
WT
Matos
A B
AB
Eduardo
C P
CP
Youssef
M N
MN
Matson
E
E
D000180:Acrylic Resins / Q000528:radiation effects*; D003188:Composite Resins / Q000528:radiation effects*; D003731:Dental Caries / Q000532:radiotherapy*; D003743:Dental Enamel / Q000528:radiation effects; D003763:Dental Leakage / Q000532:radiotherapy*; D003793:Dental Restoration, Permanent; D006801:Humans; D066298:In Vitro Techniques; D011140:Polyurethanes / Q000528:radiation effects*
D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011140:Polyurethanes