Adhesive restorative systems have expanded
the range of possibilities for direct pulp-capping
technique, with evidences of clinical success in
vital pulp therapy. However, quite few studies
have described the direct responses of pulp cells
following the application of resinous materials to
pulp exposure. To address this issue, effects of
exposure to an adhesive resin, 4-methacryloxyethyl
trimellitate anhydride/methyl methacrylate-
tri-n-butyl borane (4-META/MMA-TBB) resin
on cellular activity were investigated in an established
rat dental pulp cell line (RPC-C2A). RPC-C2A
cells were cultured on normal plastic plates or the
disks prepared from 4-META/MMA-TBB resin
(Super Bond
® C&B) in a-MEM containing 10%
FBS. After 3, 7 and 14 days, DNA content and alkaline
phosphatase (ALP) activity were measured.
Total RNA in each group was extracted and RT-PCR
analysis was performed. Moreover, the live cell
ratio was also evaluated by cytotoxicity assay
after treatment with various concentrations of 4-
META/MMA-TBB. At day 3, 7 and 14, amount of
DNA and ALP activity of the cells on normal plastic
plates and the one on the 4-META/MMA-TBB were
comparable. Cells of both groups expressed
mRNA of type I collagen (ColI), ALP, osteopontin
(OPN), osteocalcin (OC), and bone morphogenetic
protein (BMP-2). Furthermore, 4-META/MMA-TBB
(10
-1% or less) did not influence dead cell ratio in
the confluent state. According to the results of
these in vitro studies, exposure to this resinous
material would not induce cytotoxic response in the
pulp cells.
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