Three-Dimensional Human Cell Cultures for Cytotoxicity Testing of Dental Filling Materials.
OBJECTIVE
So far, bovine immortalized pulp cells have been used as three dimensional cultures for cytotoxicity testing of filling materials in the dentin barrier test (DBT). In this study, the use of human pulp-derived cells was evaluated, which would better simulate the clinical situation, and a composite material with a new resin base was tested.


METHODS
SV40-transfected human pulp cells (tHPC) were cultured in hydrogels (fibrin, peptide, collagen) and mechanical properties and cell viability (MTT or WST-1) were determined. For cell cultures in collagen, a four week - proliferation assay was performed (WST-1). After 14 days of three-dimensional culture in collagen, tHPC were introduced into the DBT with 200 µm dentin disks. After a 24-hour incubation under perfusion (0.3 ml/h), the following materials were applied according to the manufacturers' instructions (1) President (Coltene): negative (non-toxic) control, (2) CaGPG14 (ISO 7405): positive (toxic) control, (3) Tetric EvoCeram (Ivoclar Vivadent) with Clearfil SEBond (Kuraray, reference material), (4) N´Durance (Sepodont, test material), (5) N´Durance with Clearfil SEBond. Cell viability was determined after 24-hour incubation (WST-1). The percentage of relative viability was calculated (negative control=100%) and statistically analyzed (Kruskal-Wallis-test, p<0.05).


RESULTS
Fibrin and peptide gels had insufficient mechanical properties for the DBT Collagen and appeared suitable for three-dimensional cell culture of tHPC for up to 21 days. The cultures could be transferred to the DBT device and results for controls were similar to previous tests with bovine cells. The DBT using tHPC in the collagen showed no statistically significant difference between the test material with and without the adhesive and the reference resin composite.


CONCLUSIONS
tHPC in collagen can replace bovine cells in the DBT. The tested filling material is not likely to cause pulp damage, if the pulp is covered by an intact dentin layer.
Department of Operative Dentistry and Periodontology, University of Regensburg, Germany; School of Dental Medicine (ZMK Bern), University of Bern, Switzerland.
Gottfried
G
Schmalz
Private Practice, Lechstr. 11b, 93026 Rosenheim, Germany.
Franziska
F
Gröppl
Department of Operative Dentistry and Periodontology, University of Regensburg, Germany.
Karl-Anton
KA
Hiller
Department of Operative Dentistry and Periodontology, University of Regensburg, Germany.
Kerstin M
KM
Galler
Cells; Dental Materials
Biomaterials. 2006 Jun;27(17):3238-48
16504285
Adv Wound Care (New Rochelle). 2012 Feb;1(1):3-9
24527271
Biopolymers. 2008 May;89(5):338-44
17941007
Eur J Oral Sci. 2006 Apr;114(2):138-46
16630306
Nat Biotechnol. 2003 Oct;21(10):1171-8
14520402
J Endod. 2005 May;31(5):396-9
15851937
Clin Oral Investig. 2013 Mar;17 (2):635-42
22552591
Tissue Eng Part B Rev. 2008 Jun;14(2):199-215
18544016
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Nov;108(5):e94-100
19836718
Dent Mater. 2008 Mar;24(3):362-71
17655923
J Endod. 2001 Apr;27(4):259-65
11485263
Adv Dent Res. 2011 Jul;23(3):333-9
21677088
Dent Mater. 2013 Apr;29(4):398-404
23414910
Tissue Eng Part A. 2009 May;15(5):1041-52
19119920
Clin Oral Investig. 2013 Jan;17(1):251-7
22411263
Clin Oral Investig. 2014;18(2):607-13
23712822
Clin Oral Investig. 2013 Jul;17 (6):1489-96
23011524
J Endod. 2002 Mar;28(3):188-92
12017178
J Endod. 1999 Jan;25(1):24-9
10196839