IADR Abstract Archives

Cytotoxicity and Detoxification of Poly-methylmethacrylate Resin to Dental Pulp Cells

Dental tubules of the vital dentin are reportedly left open after tooth preparation until the mineral substances from saliva deposits. Poly-methylmethacrylate (PMMA) resin is the most frequently used material for temporary restorations and often fabricated directly on prepared abutments. Therefore, biocompatibility of the PMMA resin, particularly the response of the dental pulp cells to the material, is crucial.

Objective: This study examines cytotoxicity of PMMA resin to dental pulp cells and potential detoxification of the material with a newly found amino-acid (AA).

Methods: Self-cure poly-methylmethacrylate Resin (Unifast II, GC, Tokyo, Japan) was mixed with a powder/liquid ratio of 0.6g/0.4g and polymerized in the 12-well culture plate for 30 minutes at 37 degree C. Rat pulp cell extracted from the rat mandibular incisors were cultured on the resin in the osteoblastic media, as well as on the polystyrene as a control. For the detoxification study, the resin substrates added with AA with a variety of concentration (15mM, 25mM, 35mM) were prepared. The viability of the dental pulp cells was evaluated by annexin V-based flow cytometry at day 1 of culture, and the cell function by alkaline-phosphatase (ALP) stain at day 7.

Results: Ten % of the cell were viable on the PMMA resin, while the 70% or more cells were viable on the AA-added resin. Approximately 90% cells survived on the polystyrene dish. There is no area found to be ALP positive in the culture on the resin, while the extensive area was ALP positive on the AA-added resin in a dose-dependent manner.

Conclusion: Culturing the rat dental pulp cells on self-curing poly-methylmethacrylate resin resulted in a devastating cell death and complete suppression of the dentinogenic phenotype. An addition of a newly-found amino-acid into the resin significantly ameliorated the cytotoxicity to the virtually normal level.


IADR/AADR/CADR General Session
2007 IADR/AADR/CADR General Session (New Orleans, Louisiana)
New Orleans, Louisiana
2007
92
Prosthodontics Research
  • Yamada, Masahiro  ( University of California Los Angeles, Los Angeles, CA, USA )
  • Kojima, Norinaga  ( University of California Los Angeles, Los Angeles, CA, USA )
  • Paranjpe, Avina  ( University of California Los Angeles, Redmond, WA, USA )
  • Aita, Hideki  ( University of Hokkaido, Sapporo, N/A, Japan )
  • Att, Wael  ( University of California Los Angeles, Los Angeles, CA, USA )
  • Suzuki, Takeo  ( University of California Los Angeles, Los Angeles, CA, USA )
  • Jewett, Anahid  ( University of California Los Angeles, Los Angeles, CA, USA )
  • Ogawa, Takahiro  ( University of California Los Angeles, Los Angeles, CA, USA )
    • Oral Session
    Arthur R. Frechette Research Awards
    03/21/2007