610 the journal of prosthetic dentistry volume 81 number 5

MATERIAL AND METHODS
Thirty noncarious human molars, which were stored
in a solution of 1% sodium hypochlorite for up to
4 months at room temperature, were test specimens.
After surface debridement with a hand-scaling instru-
ment and cleaning with a rubber cup and slurry of
pumice, a standardized Class V cavity preparation was
placed in the buccal and lingual surface at the cemen-
toenamel junction. Preparations were made with a
no. 329 carbide bur in a high-speed handpiece and a
template to a uniform kidney-shaped outline. Prepara-
tions measured 5 mm long, 3 mm wide, and 2 mm
deep with the occlusal margin in enamel and the gingi-
val margin in dentin or cementum.
Subsequently, teeth were randomly assigned to
3 experimental groups of 10 teeth each. Buccal and lin-
gual preparations of group 1 were restored with Fuji II
LC (GC Corp, Tokyo, Japan) resin-modified glass
ionomer cement; group 2 with Vitremer (3M, St Paul,
Minn.) resin-modified glass ionomer cement; and
group 3 with Dyract (De Trey Dentsply, Konstanz,
Germany) polyacid-modified resin composite.
In all cases, the manufacturers’ instructions for
dentin conditioning, powder/liquid proportioning and
mixing were strictly followed. For Fuji II LC glass
ionomer cement, the cavity wall was conditioned for
20 seconds with dentin conditioner (GC Dental Corp).
For Vitremer glass ionomer cement, Vitremer primer
(3M Dental Products) was applied on the cavity wall
for 20 seconds, gently air dried and light cured for
30 seconds. For Dyract composite restorations, the cav-
ity wall was treated with PAS primer/adhesive (DeTrey
Dentsply) for 30 seconds, excess was removed with a
blast from an air syringe and the adhesive was cured for
20 seconds. A second coat of the primer/adhesive was
applied and immediately light cured for 20 seconds.
Dyract composite was placed in 1 increment. The teeth
were prevented from dehydration by remaining in
deionized water storage at room temperature when not
being prepared for restoration.
Immediately after the restorative material was placed,
a clear cervical matrix (Clear Thru, Premier Dental
Products, Norristown, Pa.) was adapted over the resin-
modified GIC restorations and the materials cured with
a visible light source (Optilux 400, Demetron Research
Corp, Danbury, Conn.) in accordance with the manu-
facturers’ recommended time. The light was tested for
light output (>600 mW/cm
2
) before each use with a
Demetron radiometer (model 100, Demetron Research
Corp). When the matrix was removed, the unfinished
restorations were immediately coated with the respective
manufacturer’s sealer or varnish, and this was either
cured with a visible light source or allowed to dry before
returning the tooth to deionized water storage at room
temperature. After 24 hours, the teeth were finished to
contour and to the cavosurface margins with a no. 7901
carbide finishing bur (SS White, Lakewood, N.J.) with
air and water spray in a high-speed handpiece (Star Den-
tal, Lancaster, Pa.) and medium, fine, and super fine Sof-
Lex disks (3M Dental Products), which were first lubri-
cated with water and used in sequence with air-water
spray in a slow-speed handpiece (Star Dental). The
apical portions of all specimens were filled ad retrum
with a zinc oxide-eugenol paste.