Cytotoxicity of four categories of dental cements.
OBJECTIVE
Assessment of dental material biocompatibility is gaining increasing importance for both patients and dentists. Dental cements may be in contact with oral soft tissues for prolonged periods of time and play an important role in prosthetic rehabilitation. The aim of the present study was to evaluate eight dental cements using a standardized L929-fibroblast cell culture test.


METHODS
For each material, fresh specimens (added to the cultures immediately after preparation) and specimens preincubated for 7 days in cell culture medium were prepared according to the manufacturers' recommendations. After exposure to test specimens, cell numbers were compared to glass controls. The main outcome was a two-sided 95% confidence interval for the mean value of the standardized cell number for each substance investigated.


RESULTS
Fresh specimens of all tested cements showed significant cytotoxicity, which diminished after 7 days preincubation. Cytotoxicity of fresh adhesive and self-adhesive resin cements was lower when specimens were dual-cured compared to self-cured. A rank order of cytotoxicity was established based on mean values: Nexus 2 (dual-cured) showed least cytotoxicity, followed by Variolink II (dual-cured), Nexus 2 (self-cured), Harvard, RelyxUnicem (dual-cured), Panavia 21, Fujicem, Durelon, Variolink II (self-cured), RelyxUnicem (self-cured), Maxcem (dual-cured) and Maxcem (self-cured). When bondings were added to Nexus 2 or Variolink II specimens, a slight increase in cytotoxicity was observed.


CONCLUSIONS
Adhesive resin cements showed less cytotoxicity than self-adhesive and chemically setting cements. Bonding only slightly influenced cytotoxicity of the adhesive resin cements. Dual-cured specimens of adhesive and self-adhesive resin cements showed significantly less toxicity than self-cured specimens.
Schmid-Schwap
Martina
M
Department of Prosthodontics, Bernhard Gottlieb University Clinic of Dentistry, Medical University of Vienna, Austria.
Franz
Alexander
A
König
Franz
F
Bristela
Margit
M
Lucas
Trevor
T
Piehslinger
Eva
E
Watts
David C
DC
Schedle
Andreas
A
D000179:Acrylates / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials / Q000633:toxicity; D002452:Cell Count; D018929:Cell Culture Techniques; D002460:Cell Line; D003470:Culture Media; D001840:Dental Bonding; D005347:Fibroblasts / Q000187:drug effects; D005899:Glass Ionomer Cements / Q000737:chemistry; D008422:Materials Testing; D051379:Mice; D010710:Phosphates / Q000737:chemistry; D011076:Polycarboxylate Cement / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry / Q000633:toxicity*; D012117:Resins, Synthetic / Q000737:chemistry; D013997:Time Factors; D015036:Zinc Phosphate Cement / Q000737:chemistry
D000179:Acrylates; D001672:Biocompatible Materials; D003470:Culture Media; C431351:Fuji II LC cement improved; D005899:Glass Ionomer Cements; C515955:Maxcem; C433206:Nexus; C451600:OptiBond Solo Plus; C093719:Panavia TPN-S; D010710:Phosphates; D011076:Polycarboxylate Cement; C483701:Rely X Unicem; D019279:Resin Cements; D012117:Resins, Synthetic; C078484:Syntac dentine adhesive; C103502:Variolink; C031374:zinc polyacrylate; D015036:Zinc Phosphate Cement; C074226:Harvard Cement; C040415:heliobond