Physical and biological properties of experimental self-etching adhesive systems
cytotoxicity, experimental adhesive system and flexural strength
Objective: To evaluate the Residual Monomer Release (RMR), Flexural Strength (FS),
elastic modulus (EM) and cytotoxicity of GDMA-P-based experimental adhesives (EA). Methodology: EA
were divided into 9 groups according to the following parameters: a) monomeric %mass
of GDMA-P/HEMA/UDMA (10/30/30, 20/30/20 and 30/30/10); mol% of photoinitiators
CQ/BAPO/EDMAB/DH (1.0/0.0/1.0/0.2, 0.0/1.0/0.0/0.2; 0.5/0.5/1.0/0.2). For cytotoxicity, NIH-3T3
cells and the MTT Assay and Alamar Blue (n = 8) assays were used. For FS and EM, the method described
in ISO 4049 (n = 7) was followed. To assess RMR, 54 third molars were used to obtain a flat area of dentin
(n = 6), which received the adhesive systems and the MRL was read in a high performance liquid chromatography
apparatus after 24 hours. Statistical analysis was performed with two-way ANOVA and Tukey post-hoc test
(p<0.05). Results: for Alamar Blue, there was no difference among the 10%, 20% and 30% concentrations.
Among the photoinitiators, CQ and BAPO alone presented better values for 30% and CQ + BAPO for the 20%
concentration. For MTT Assay, there was no difference among photoinitiators and % of GDMA-P. For RMR, for
the same photoinitiators and different concentrations of GDMA-P, the 10% concentration released more HEMA.
For the different concentrations of GDMA-P and the same photoinitiators, the groups containing CQ released more
HEMA. For UDMA, among the groups of photoinitiators, only CQ presented differences, being the percentage of
10% of GDMA-P that most released UDMA monomers. For the three concentrations of GDMA-P, CQ released more
UDMA monomers. For the release of GDMA-P, among the same photoinitiators, the concentration of 10% provided
greater release of monomers to the groups containing CQ. Among the same concentrations and different
photoinitiators, CQ provided greater release of GDMA-P to 10% and 30%. For the 20% concentration, BAPO
allowed the highest release. For FS, 10% of GDMA-P presented differences between the photoinitiators, being the
BAPO group the highest FS. The BAPO + CQ mixture allowed a higher FS value for the 20% and 30%
concentrations. For EM, 30% GDMA-P was the only one to present significant difference, being the BAPO + CQ
group the highest value. Conclusions: 20% and 30% concentrations of GDMA-P associated with the BAPO + CQ
photoinitiator group may provide better results for the properties tested.