In vitro cytotoxicity of a remineralizing resin-based calcium phosphate cement.
Recently, a resin-based calcium phosphate cement (RCPC) has been reported as a remineralizing pulp-capping or lining cement. RCPC consists mainly of tetracalcium and dicalcium phosphates, ethoxylated bisphenol A dimethacrylate and pyromellitic glycerol dimethacrylate monomers and photo- and chemical initiators.


OBJECTIVE
Here, the cytotoxic effects of RCPC were evaluated. The hypothesis was that RCPC induced only minor cytotoxic response in immortalized murine odontoblast and pulp cells, comparable to that produced by similar dimethacrylates due to unpolymerized dimethacrylate monomer present after curing.


METHODS
Cytotoxicity was determined following the changes in cell succinate dehydrogenase activity after 24 h exposure to the cement components and after a 24 h recovery period. A fourfold range of concentrations was tested of the monomers, the eluate of cured RCPC leached in Dulbecco's modified Eagle's medium, and crushed cured cement in dimethyl sulfoxide.


RESULTS
The monomers themselves had cytotoxicities similar to those reported for other dimethacrylates, although they are significantly less toxic than Bis-GMA. Differential cell sensitivity was demonstrated, with the pulp cells having greater sensitivity to the unpolymerized monomer than the odontoblast-like cells. The leached components have cytotoxicity similar to that of the free monomers. The crushed material demonstrated no apparent cytotoxicity at the dilutions tested.


CONCLUSIONS
These data demonstrate that RCPC has an in vitro cytotoxicity that is comparable to other materials containing dimethacrylate monomers and suggest that the material may be suitable for use in dental restorations. The data also indicate that the pulp cells appear more sensitive to dimethacrylates than the odontoblasts.
Boland
Edward J
EJ
Department of Periodontics, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
MacDougall
Mary
M
Carnes
David L
DL
Dickens
Sabine H
SH
D000818:Animals; D001565:Benzoates / Q000633:toxicity; D017438:Bisphenol A-Glycidyl Methacrylate / Q000633:toxicity; D002130:Calcium Phosphates / Q000633:toxicity*; D002478:Cells, Cultured; D003764:Dental Materials / Q000633:toxicity; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects; D008422:Materials Testing; D008689:Methacrylates / Q000633:toxicity; D051379:Mice; D009804:Odontoblasts / Q000187:drug effects; D019279:Resin Cements / Q000633:toxicity*; D013385:Succinate Dehydrogenase / Q000187:drug effects; D013997:Time Factors; D014089:Tooth Remineralization
D001565:Benzoates; D002130:Calcium Phosphates; D003764:Dental Materials; D008689:Methacrylates; D019279:Resin Cements; C080129:pyromellitic dianhydride glycerol dimethacrylate adduct; C074277:ethoxylated bis-phenol A dimethacrylate; D017438:Bisphenol A-Glycidyl Methacrylate; C020243:calcium phosphate; D013385:Succinate Dehydrogenase