Methods: This is a laboratory experimental research. 30 resin composite specimens of 6 mm diameter and 3 mm depth were divided into 5 groups. The treatments are 24 hours immersion in water as control group, 24 hours immersion in isotonic drink, 24 hours immersion in isotonic drink then 72 hours immersion in artificial saliva, 48 hours immersion in isotonic drink, and 48 hours immersion in isotonic drink then 144 hours immersion in artificial saliva. The DTS (n=6) was determined using Universal Testing Machine with a crosshead speed 0.5 mm/min. Statistical analysis was performed by one-way ANOVA and post-hoc LSD test (α = 0.05).
Results: The DTS of resin composite immersed in water for 24 hours is 41,64 ± 1,53 MPa; in isotonic drink for 24 hours is 39,57 ± 1,42 MPa; in isotonic drink for 24 hours then artificial saliva for 72 hours is 44,67 ± 1,31 MPa; in isotonic drink for 48 hours is 40,57 ± 0,88 MPa; in isotonic drink for 48 hours then artificial saliva for 144 hours is 47,28 ± 3,67 MPa. There was statistically significant difference of DTS (p<0,05) between immersion only in isotonic drink compared with immersion in isotonic drink then artificial saliva.
Conclusion: Artificial saliva gives significant effect to the rising of DTS of resin composite previously immersed in isotonic drink. This is probably due to the post-polymerization period of resin composite.