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Azerbaycan Saytlari

 »  Home  »  Endodontic Articles 11  »  Cytotoxicity of dentine-bonding agents on human pulp cells in vitro
Cytotoxicity of dentine-bonding agents on human pulp cells in vitro
Results - Discussion - References.



Results.
The results showed that dentine-bonding agents were cytotoxic to primary human pulp cells by MTT assay. The sensitivity of cytotoxicity to human pulp cells depended on the materials tested.
As shown in Fig. 1, eluates from five dentine-bonding agents were cytotoxic to primary human pulp cells (P < 0.05). SB was significantly more cytotoxic than the other dentine-bonding agents tested. Day 2 eluates from all materials tested significantly inhibited growth of cells (P < 0.05), but the leaching of toxic substances diminished at Day 5 (Fig.1). In addition, the Day 5 eluates of CB and HB on pulp cells were not significantly different from control values (P > 0.05).
In general, the rank orders with respect to cytotoxicity were found to be as follows: SB > PB > SC > HB > CB.

Figure 1. Effect of the eluates from five dentine-bonding agents on human pulp cells by MTT assay. Percentage of absorbance from each material, compared with that of control was calculated.

Effect of the eluates from five dentine-bonding agents on human pulp cells by MTT assay

Discussion.
In this study, cultured human pulp cells were used to evaluate the cytotoxicity of dentine-bonding agents. Primary pulp cells are more closely related to their original tissue and much easier to identify. In addition, pulp cells have a nearly unchanged metabolic state relative to their original tissue; the in vitro experiments thus approximate the in vivo situation. This is the reason why primary human pulp cells were chosen in this study.
Under normal conditions, few pulp cells proliferate in pulp tissue (Fitzgerald 1979). Pulp cells in the resting stage seem to reflect the in vivo condition more closely than do cells in the growing phase. Thus, in the present study, the cytotoxicity of dentine-bonding agents were examined on confluent cultures according to our recent studies (Chang & Chou 2001, Huang & Chang 2002b).
Several dentine-bonding agents have been evaluated for their cytotoxic effects (Hashieh et al. 1999, Schedle et al.1998, de SouzaCosta et al.1999, Kaga et al.2001, Szep et al. 2002, Huang & Chang 2002a). In accordance with this study, all dentine-bonding agents proved to be cytotoxic on different cell culture systems. Substances leached from dentine-bonding materials may be the reason why these materials exhibit cytotoxic effects. It has been demonstrated that unconverted monomers can be released from resin into an adjacent aqueous phase (Gerzina & Hume 1996) and can diffuse through dentine to the pulp space (Gerzina & Hume 1994). The toxic potential of components from dentine-bonding agents has been shown in vitro. Constituents of dentine- bonding agents, such as bisphenol-A-glycidyl methacrylate (Bis-GMA), triethyleneglycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA), were found to leach from dentine-bonding agents and may cause adverse effects (Geurtsen et al. 1998). It was found that hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA) or TEGDMA were cytotoxic but to a lesser grade than the more hydrophobic monomers Bis-GMA or UDMA (Ratanasthien et al. 1995). In addition, HEMA or TEGDMA may also have an influence on the immune system (Rakich et al.1999).
In addition, dentine-bonding agents were found to release photoinitiator camphoroquinone (CQ) (Geursten et al. 1999). CQ is one of the photosensitizers, a widely used aliphatic type, which has been found attributed to free radicals including reactive oxygen generation (Atsumi et al. 1998). It also has been documented not only as acytotoxic agent (Atsumi et al.1998, Geursten et al. 1999) but also as a mutagen (Heil et al. 1996). Thus, CQ leached from dentine-bonding agents may partly explain why dentine-bonding agents are toxic agents.
From the results observed in the present study, it is concluded that dentine-bonding agents are cytotoxic to human pulp cells. However, the dentine might be important in protecting the dental pulp from the effects of substances leached from dentine-bonding agents. It is difficult to determine how much leach able substances actually act on pulp cells after diffusing through the dentine. Furthermore, the pulp circulation in vivo will wash out and reduce the concentrations of cytotoxic agents on pulp cells. Because dentine-bonding agents come into close and prolonged contact with vital dentine, comprehensive studies should be undertaken to clarify the substances leached from dentine-bonding agents effects pulp tissue both in vitro and in vivo.

References.

Atsumi T , Murata J, Kamiyanagi I, Fujisawa S, Ueha T (1998) Cytotoxicity of photosensitizers camphorquinone and 9- fluoren one with visible light irradiation on a human submandibular- duct cell line in vitro. Archives of Oral Biology 43, 73-81.
Chang YC, Chou MY (2001) Cytotoxicity of fluoride on human pulp cell cultures in vitro. Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics   91, 230-4.
Chang YC, Huang FM, Cheng MH, Chou LSS, Chou MY(1998) In vitro evaluation   of the cytotoxicity and genotoxicity of root canal medicines on human pulp fibroblasts.   Journal of Endodontics 24, 604-6.
Chang YC, Tai KW, Huang FM, Huang MF (2000) Cytotoxic and nongenotoxic effects   of phenolic compounds in human pulp cell cultures. Journal of Endodontics   26, 440-3.
Feigal RJ,Yesilsoy C, Messer HH, Nelson J (1985) Differential sensitivity   of normal human pulp and transformed mouse fibroblasts to cytotoxic challenge.   Archives of Oral Biology 30, 609-13.
Fitzgerald M (1979) Cellular mechanics of dentinal bridge repair using 3H-thymidine.   Journal of Dental Research 58, 2198- 206.
Gerzina TM, Hume WR (1994) The effect of dentin on the release of TEGDMA   from resin composite in vitro. Journal of Oral Rehabilitation 21, 463-8.
Gerzina TM, Hume WR (1996) Diffusion of monomers from bonding resin-resin   composite combinations through dentine in vitro. Journal of Dentistry 24,   125-8.
Geurtsen W, Lehman F, Spahl W, Leyhausin G (1998) Cytotoxicity of 35 dental   resin composite monomers/additives in permanent 3T3 and three human primary   fibroblast cultures. Journal of Biomedical Materials Research 41, 474-80.
Geursten W, Spahl W, Muller K, Leyhausen G (1999) Variability of cytotoxicity   and leaching of substances from five dentin adhesives. Journal of Biomedical   Materials Research 48, 772-7.
HashiehI A, Cosset A, Franquin JC, Camps J (1999) In vitro cytotoxicity of   one-step dentin bonding system. Journal of Endodontics 25, 89-91.
Haustveit G, Torheim B, Fystro D, Eidem T, Sandvik M (1984) Toxicity testing   of medical device materials tested in human tissue cultures. Biomaterials   5, 75-80.
Heil J, Reifferscheid G, Waldmann P, Leyhansen G, Geurtsen W (1996) Genotoxicity   of dental materials. Mutation Research 28, 181-94.
Holley RW (1975) Control of growth of mammalian cells in cell culture.   Nature 258, 478-90.
Huang FM, Chang YC (2002b) Cytotoxicity of resin-based restorative materials   on human pulp cell cultures. Oral Surgery, Oral Medicine, Oral Pathology,   Oral Radiology Endodontics (in press).
Huang FM, Chou MY, Chang YC (2002a) Dentin bonding agents induce c-fos, c-jun   protooncogenes expression in human gingival fibroblasts. Biomaterials (in   press).
Kaga M, Noda M, Ferracane JL, Nakamura Q, Oguchi H, Sano H (2001) The in   vitro cytotoxicity of eluates from dentin bonding resins and their effect on   tyrosine phosphorylation of L929 cells. Dental Materials 17, 333-9.
Lechner JF, Kaighn ME (1979) Reduction of the calcium requirement of normal   human epithelial cells by EGF. Experimental Cell Research 121, 432-5.
Mjor IA (1978) Biologic assessment of restorative dental materials: interrelationship   of biologic and technologic properties. Operative Dentistry 3, 9-13.
Mosmann T (1983) Rapid colorimetric assay for cellular growth and survival:   application to proliferation and cytotoxicity assays. Journal of Immunologic   Methods 65, 55-63.
Rakich DR, Wataha JC, Lefebvre CA, Weller RN (1999) Effect of dentin bonding   agents on the secretion of inflammatory mediators from macrophages. Journal   of Endodontics 25, 114-7.
Ratanasthien S, Watnha JC, Hanks CT, Dennison JB (1995) Cytotoxic interactive   effects of dentin bonding components on mouse fibroblasts. Journal of Dental   Research 74, 1602-6.
Schedle A, Franz A, Rausch-Fan X, Spittler A, Lucas T, Samorapoompichit P, Sperr   W, Bolts-Nitulescu G (1998) Cytotoxic effects of dental composites, adhesive   substances, compomers and cements. Dental Materials 14, 429-40.
de Souza Costa CA, Vaeten MA, Edwards CA, Hanks T( 1999) Cytotoxic effects   of current dental adhesive systems on immortalized odontoblast cell line MDPC-23.   Dental Materials 15, 434-41.
Szep S, Kumkel A, Ronge K, Heidemann D (2002) Cytotoxicity of mordern dentin   adhesives: in vitro testing on gingival fibroblasts. Journal of Biomedical   Materials Research (Applied Biomaterials) 63, 53-60.
Yesilsoy C, Feigal RJ (1985) Effects of endodontic materials on cell viability across standard pore size filters. Journal of Endodontics 11, 401-7.