Influence of metacryloxydecyl dihydrogen phosphate and water on the degree of conversion of adhesives containing a three-component photoinitiator

• Published in: International journal of adhesion and adhesives Vol. 111; p. 102976
• Main Authors: Narimatsu, Mayara Hana, Fernandes Neto, Constantino, Da Costa, Reginaldo Mendonça, Wang, Linda, Bombonatti, Juliana Fraga Soares, Furuse, Adilson Yoshio
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2021; Elsevier BV
• Subjects: Adhesives; Compressed air; Conversion; Dental materials; Dentin; Evaporation; Infrared spectroscopy; Novel adhesives; Photoinitiators; Photopolymerization; Self-etch adhesive; Solvents; Substrates; Infrared spectroscopy; Photopolymerization; Novel adhesives; Self-etch adhesive
• ISSN: 0143-7496; 1879-0127
• DOI: 10.1016/j.ijadhadh.2021.102976

While self-etching dental adhesives are considered user friendly, their application is still technique-sensitive, especially considering the need of solvent evaporation during clinical used and the presence of water on the dentin substrate. The present study aimed to evaluate the influence of 10-metacryloxydecyl dihydrogen phosphate (10-MDP) concentration on the degree of conversion (DC) of adhesives containing a three-component photoinitiator under distinct manipulation protocols. Adhesives containing a three-component photoinitiator system (camphorquinone/1.2-diaminobenzene/iodonium salt) were prepared and different 10-MDP concentrations were added (0 wt%, 3 wt%, 6 wt%, 9 wt%, 12 wt%, and 15 wt%). Four protocols were evaluated: I) Control (without manipulation), II) 5 s of solvent evaporation with compressed air, III) 20 s of evaporation, and IV) addition of water to the adhesive to simulate the humidity of dentin in the oral environment. DC was evaluated by FTIR-ATR. Each adhesive (≈12 μL, n = 12) was dropped and tests were run before and after light-activation. Data were analysed with two-way ANOVA and Tukey's HSD (α = 0.05). Adhesives and protocols were statistically significant factors, as well as their interaction (p < 0.0001). The analysis of interaction indicates that 12% 10-MDP adhesive with water addition presented the highest DC with 92.79%, while the 10-MDP-free adhesive with 20 s evaporation had the lowest DC of 70.75%. The presence of water has increased DC for all groups, except for the MDP-free adhesive. These results suggest that 10-MDP can adjunctively increase the DC of three-component-photoinitiator adhesive and water did not seem to affect the DC in the presence of such monomer. •The polymerization of dental adhesives increases with the addition of 10-MDP.•The presence of water may not negatively influence the DC of adhesives containing 10-MDP and an iodonium salt.•The air-blowing may influence the DC of experimental adhesives evaluated.