Millions of people worldwide have cavities in teeth, thus ranking cavity issue important in global oral health. This study created the temporary dental composite filling material with zinc oxide, eugenol solvent, and polylactic acid (PLA) fibers. Zinc oxide and eugenol (IRM®) were blended with a weight ratio of 3:1, after which a variety of PLA fibers (2 wt%, 4 wt%, 6 wt%, 8 wt%, and 10 wt%) were then well mixed with the IRM® solution, completing the IRM®/PLA dental filling composite. The aim of this study was to determine the influence of different contents of PLA fiber on the prepared filling composite, by employing measurements of leakage property, compressive strength, solubility, leakage and setting timer. In particular, when the PLA fibers was 6 wt%, the IRM®/PLA dental filling composite did not have micro-leakage on Day 13.