Effect Of 4-(n,n-dimethylamino) Phenethyl Alcohol On Degree Of Conversion And Cytotoxicity Of Photo - Polymerized Cq - Based Resin Composites

The aim of this study was to evaluate the degree of conversion (DC) and the cytotoxicity of photo-cured experimental resin composites containing 4-(N,N-dimethylamino) phenethyl alcohol (DMPOH) combined to the camphorquinone (CQ) compared with ethylamine benzoate (EDAB). The resin composites were mechanically blended using 35 wt% of an organic matrix and 65 wt% of filler loading. To this matrix was added 0.2 wt% of CQ and 0.2 wt% of one of the reducing agents tested. 5x1 mm samples (n=5) were previously submitted to DC measurement and then pre-immersed in complete culture medium without 10% (v/v) bovine serum for 1 h or 24 h at 37 °C in a humidifier incubator with 5% CO2and 95% humidity to evaluate the cytotoxic effects of experimental resin composites using the MTT assay on immortalized human keratinocytes cells. As a result of absence of normal distribution, the statistical analysis was performed using the nonparametric Kruskal-Wallis to evaluate the cytotoxicity and one-way analysis of variance to evaluate the DC. For multiple comparisons, cytotoxicity statistical analyses were submitted to Student-Newman-Keuls and DC analysis to Tukey’s HSD post-hoc test (α=0.05). No significant differences were found between the DC of DMPOH (49.9%) and EDAB (50.7%). 1 h outcomes showed no significant difference of the cell viability between EDAB (99.26%), DMPOH (94.85%) and the control group (100%). After 24 h no significant difference were found between EDAB (48.44%) and DMPOH (38.06%), but significant difference was found compared with the control group (p>0.05). DMPOH presented similar DC and cytotoxicity compared with EDAB when associated with CQ.256538542Furuse, A.Y., Mondelli, J., Watts, D.C., Network structures of Bis-GMA/ TEGDMA resins differ in DC, shrinkage-strain, hardness and optical properties as a function of reducing agent (2011) Dent Mat, 27, pp. 497-506Mundim, F., Pires-de-Souza, F., Garcia, L., Consani, S., Colour stability, opacity and cross-link density of composites submitted to accelerated artificial aging (2010) Eur J Prosthodont Rest Dent, 18, pp. 89-93Neumann, M.G., Miranda, W.G., Jr., Schmitt, C.C., Rueggeberg, F.A., Correa, I.C., Molar extinction coefficients and the photon absorption efficiency of dental photoinitiators and light curing units (2005) J Dent, 33, pp. 525-532Alvim, H.H., Alecio, A.C., Vasconcellos, W.A., Furlan, M., Oliveira, J.E., Saad, R.C., Analysis of camphorquinone in composite resins as a function of shade (2007) Dent Mat, 23, pp. 1245-1249Ruyter, I., Nilner, K., Moller, B., Color stability of dental resin materials for crown and bridge veneers (1987) Dent Mat, 3, pp. 246-251Heydecke, G., Zhang, F., Razzoog, M., In vitro color stability of double-layer veneers after accelerated aging (2001) J Prosthet Dent, 85, pp. 551-557Stansbury, J.W., Curing dental resins and composites by photopolymerization (2000) J Esthet Dent, 12, pp. 300-308Darvell, B., (2002) Materials science for dentistry, , 7th ed. Hong Kong: BW DarvelSilami, F.D.J., Mundim, F.M., Garcia, L.F.R., Sinhoreti, M.A.C., Pires-De-Souza, C.P., Colour stability of experimental composites containing different photoinitiators (2012) J Dent, 41, pp. e62-e66Albuquerque, P.P.A., Moreira, A.L., Moraes, R.R., Cavalcante, L.M., Schneider, F.J., Colour stability, conversion, water sorption and solubility of dental composites formulated with different photoinitiator systems (2012) J Dent, 41, pp. e67-e72Ely, C., Schneider, L.F.J., Ogliari, F.A., Schmitt, C.C., Correa, I.C., Lima, J.S., Polymerization kinetics and reactivity of alternative initiator systems for use in light-activated dental resins (2012) Dent Mat, 28, pp. 1199-1206Brandt, W.C., Tomaselli, L.O., Correr-Sobrinho, L., Sinhoreti, A.C., Can phenylpropanedione influence Knoop hardness, rate of polymerization and bond strength of resin composite restorations? (2011) J Dent, 39, pp. 438-447Schroeder, W.F., Vallo, C.I., Effect of different photoinitiator systems on conversion profiles of a model unfilled light-cured resin (2007) Dent Mat, 23, pp. 1313-1321Bowen, R.L., Argentar, H., Amine accelerators for methacrylate resin systems (1971) J Dent Res, 50, pp. 923-928Braden, M., Causton, B.E., Clarke, R.L., Diffusion in water in composite filling materials (1976) J Dent Res, 55, pp. 730-732Atai, M., Watts, D.C., A new kinetic model for the photopolymerization shrinkage-strain of dental composites and resin-monomers (2006) Dent Mat, 22, pp. 785-791Cook, W.D., Factors affecting the depth of cure of UV-polymerized composites (1980) J Dent Res, 59, pp. 800-808Lee, Y.K., Powers, J.M., Influence of background color on the color changes of resin composites after accelerated aging (2007) Am J Dent, 20, pp. 27-30Ota, M., Ando, S., Endo, H., Ogura, Y., Miyazaki, M., Hosoya, Y., Influence of refractive index on optical parameters of experimental resin composites (2012) Acta Odontol Scand, 70, pp. 362-367Fugita, K., Nishiyama, N., Nemoto, K., Okada, T., Ikemi, T., Effect of base monomer’s refractive index on curing depth and polymerization conversion of photo-cured resin composites (2005) Dent Mat J, 24, pp. 403-408Vargas, M.A., Cobb, D.S., Schmit, J.L., Polymerization of composite resins: Argon laser vs conventional light (1998) Oper Dent, 23, pp. 87-93Watts, D.C., Cash, A.J., Analysis of optical transmission by 400–500 nm visible light into aesthetic dental biomaterials (1994) J Dent, 22, pp. 112-117Porto, I.C.C.M., Andrade, A.K.M., Guenes, G.M.T., Ribeiro, A.I.A.M., Braz, R., Castro, M.B., In vitro potential cytotoxicity of an adhesive system to alveolar macrophages (2009) Braz Dent J, 20, pp. 195-200Ratanasathien, S., Wataha, J.C., Hanks, C.T., Dennison, J.B., Cytotoxic interactive effects of dentin bonding components on mouse fibroblasts (1995) J Dent Res, 74, pp. 1602-1606Ferracane, J.L., Elution of leachable components from composites (1994) J Oral Rehabil, 21, pp. 441-45