Comportamento celular na presença de materiais poliméricos em contato com dentina bovina hígida

Abstract

Polymeric materials are currently widely used in dentistry because they have several advantages over other restorative materials however the cytotoxicity of the leached compounds has been demonstrated after their polymerization. Thus the aim of this thesis was to first investigate the cellular viability of keratinocytes when in contact with different types of restorative polymeric materials in the presence of dentin. The degree of conversion of each of the materials was also evaluated. Clinically is probably that restorations using polymeric materials do not exert considerable aggression to gingival (HaCaT) cells due dentin acts like a protection factor. In order to simulate different clinical conditions, different direct and indirect restorations were performed on dentin bovine disks. Same restorative procedures were performed on glass plates to obtain a total of 14 experimental groups. The following materials were used according to the manufacturers’ instructions: OptiBond FL® (OB), Single Bond Universal® (SBU), Clearfil SE® (CSE), Dyad Flow® (DF), Filtek Z350XT® (Z350), Filtek Z350XT® Flow (FF), Dyad Flow® (DF), Variolink II® (VLII) and Rely U200® (U200). Three specimens for each polymeric restorative materials group were tested (n=84). Restoration extracts were obtained from 1 and 7 days incubation of specimens in cell culture at 37°C. HaCaT keratinocytes were exposed to the extracts for 24h and 7 days and viability was assessed using the MTT assay. Statistics for cell viability after day 1 showed that the factor material and the interaction between factors were both significant (p<0.001) and the presence of dentin was also a significant factor (p=0.023). At day 7, both factors and their interaction were significant (p<0.001). Statistical analyses by 95% confidence interval showed that there was not difference between CSE and OB, among DF, FF and U200, between SBU and Z350. Clinically is probably that restorations using polymeric materials do not exert considerable aggression to gingival (HaCaT) cells