A. Samadzadeh et al., FRACTURE STRENGTHS OF PROVISIONAL RESTORATIONS REINFORCED WITH PLASMA-TREATED WOVEN POLYETHYLENE FIBER, The Journal of prosthetic dentistry, 78(5), 1997, pp. 447-450
Statement of problem. Fracture strength of interim fixed partial prost
hesis is of great concern, especially in long-span restorations or are
as of heavy occlusal stress. Purpose. Effects of a plasma-treated wove
n polyethylene fiber (Ribbond) on the fracture strength of polymethyl
methacrylate (Coldpac) and a resin-based two-phase curing provisional
restorative material (Provipont DC) were evaluated. Material and metho
ds. A polpvinyl siloxane template was used to fabricate three-unit pos
terior provisional prostheses on a stainless steel die with two abutme
nts 22 mm apart. The reinforced groups were fabricated by affixing 3 m
m wide pieces of fiber treated with methyl methacrylate monomer or pol
yisocyanate (activator part of Provipont DC) on the occlusal surfaces
of abutments. The interim materials were mixed, according to the manuf
acturers' specifications, and placed in the template. The template was
pressed on the die and held secure until complete setting of the mate
rial occurred by light curing (Provipont DC) or autopolymerization (PM
MA). The specimens were divided into 4 groups of 10 each (A, reinforce
d Provipont DC; B, unreinforced Provipont DC; C, reinforced PMMA; and
D, unreinforced PMMA). A central compressive load force was exerted on
the specimen to determine the fracture load of the restorations. Resu
lts. The data revealed mean fracture loads of A, 65.59 +/- 11.27 kg; B
, 46.59 +/- 14.84 kg; C, 53.46 +/- 7.76 kg; and D, 49.86 +/- 14.44 kg.
Conclusion. Plasma-treated polyethylene reinforced PMMA restorations
showed no significant increase in fracture loads when compared with un
reinforced restorations (p > 0.10), whereas reinforced resin-based res
torations revealed significantly higher fracture loads (p < 0.01) than
the unreinforced resin-based and PMMA provisional restorations.