Main Article Content
Composite resin is a caries filling material. Generally, dentists choose this type of resin as a restoration material because this material has a high compressive strength. There are several factors that influence the compressive strength of composite resins, including beverages consumed such as coffee. This study aims to determine the difference in the compressive strength of the composite resin with Sidikalang coffee immersion in 9 hours, 27 hours and 54 hours immersion time. This type of research is experimental laboratories with posttest only control group design. The research sample was composite resin measuring 8 mm in diameter and 4 mm in height. The sample size is determined by the Federer formula and a total sample of 24 was obtained for the four treatment groups. Measurement of compressive strength using a three-point bending tool on a universal testing machine. Data were analyzed by using the oneway Anova test. Based on the results of the study, the average compressive strength of composite resin in the group without immersion, 9 hours, 27 hours and 54 hours of immersion was 20.69 ± 0.84, 18.94 ± 0.41, 14.36 ± 0.66 and 6.70 ± 0.48. From the results of the study it can be concluded that the ads are a significant difference in the average compressive strength of composite resin after immersion in Sidikalang coffee for 9 hours, 27 hours and 54 hours.