Comparative study of different cytotoxicity of bonding systems with different dentin thickness on L929 cell line: An experimental study

Abstract

Background: Dentin‑bonding agents should have good biocompatibility as they come into close
and prolonged contact with vital dentin. The present study aimed to evaluate and compare the
cytotoxicity of total etch and self‑etch dentin bonding systems with two different dentin thickness
on L929 cell line.
Materials and Methods: In this in vitro study 80 Class I cavities were prepared on the occlusal
surfaces. The teeth were randomly divided to two groups of 40 each based on two RDT 0.5 mm
and 1.5 mm. Samples were further subdivided into four subgroups of 10. Group 1: Adper Scotch
bond Multi-Purpose (SBMP), Group 2: Adper Single Bond Plus (SBP), Group 3: Adper Scotch bond SE
(SSE) and Group 4: Adper Easy One (EO). Group 1 and 2 were total-etch and Group 3 and 4 were
self-etch. The cavities were sealed after applying of dentin bonding. Then crowns were immersed
in culture medium for 24 hours and the cytotoxicity of resultant toxic extraction was measured
with 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in 4 serial dilutions
(neat,1/2 ,1/10 ,1/100). Data were analyzed by Two-way ANOVA and t-test.
Results: For all the dilutions, cytotoxicity was significantly higher with 0.5 mm remaining dentin
thickness (RDT) relative to 1.5 mm RDT (P ≤ 0.05). In neat dilution for both RDTs, cytotoxicity
was different among all the four dentin bondings. Expression in decreasing order of cytotoxicity
was SBP > SBMP > SSE > EO for both RDTs in neat dilution (P < 0.05). For all the dilutions,
cytotoxicity was significantly lower for self‑etch bonding systems in comparison with total‑etch
bonding systems (P < 0.05).
Conclusion: In the present study, lower cytotoxicity was found with an increase in the dilution
of toxic extract and also cytotoxicity decreased with an increased dentin thickness. The adhesive
systems had degrees of cytotoxic effects on cultured L929 compared to the control, except for
the EO group.
Key Words: Cytotoxicity, Dentin adhesive system, L929 cell line, Dentin thickness