Objective To evaluate the degree of conversion (DC%), salt yield and mechanical properties of self-adhesive luting agents (SAA) set under dual-cure (E) and self-cure (NE) modes. Methods Three SAA (GC LinkAce/GCLA, MaxCem Elite/MXEL, Rely-X Unicem 2/RXUN) and an adhesive resin luting agent (Rely-X Ultimate/RXUL-control) were used. The properties tested under E and NE modes were a) DC% and phosphate salt yield after 10 min, 1 h (h) and 3 weeks (w) storage, by infrared spectroscopy; and b) the mechanical properties of 3 w-stored specimens by instrumented indentation testing (Martens hardness/HM, Elastic modulus/EIT, Elastic index/ηIT) and microscopic Vickers hardness/VH. Statistical analysis was performed by 3-way ANOVA (DC%), 2-way ANOVA (salt yield) and 1-way ANOVA (mechanical properties) at an a = 0.05. Results Significantly higher DC% was found in E, except from the 3 w groups of GCLA and MXEL. Within E, no significant differences were found, but within NE, there were differences in the 3 w groups of GCLA (vs 10 min) and MXEL (vs 1 h). All materials demonstrated increased salt yield in NE, with the highest values found in RXUL and RXUN. GCLA, RXUL showed the lowest HM in E and MXEL the highest in NE. The rankings of the significant differences in EIT were MXEL > GCLA,RXUN,RXUL (E) and RXUL,MXEL > GCLA,RXUN (NE), whereas for ηIT RXUL,RXUN > GCLA,MXEL (E) and GCLA > RXUL > MXEL,RXUN (NE). The results of VH measurements showed an overestimation ranging from 13% up to 38% in comparison with HM. Significance There are significant differences in the properties tested, which may anticipate variations in the chemical, mechanical and biological performance of the products.
- FTIR, IIT
- Mechanical properties
- Self-adhesive resin luting agents
- Setting reaction