Purpose To evaluate the effects of bioresorbable fixation screws (BFSs) on human gingival fibroblast (HGF) and mouse osteoblast (MC3T3-E1) cell viability. Materials and Methods The KLS Martin SonicPins Rx, Synthes RapidSorb Cortex Screws, and Inion CPS Bioabsorbable Fixation System each were incubated in Dulbecco's Modified Eagle Medium for 72 hours according to ISO 10993-5 standards. A real-time cell analyzer was used to evaluate cell survival. After seeding 200-μL cell suspensions in the wells of an E-plate View 96, HGF and MC3T3-E1 cells were treated with the bioactive components released by the bioresorbable materials and monitored every 15 minutes for 96 hours. Statistical significance was determined using 1-way analysis of variance and Tukey-Kramer tests. Results There were significant differences in the HGF responses to the untreated control conditions and the Synthes (P <.01), Inion (P <.05), and KLS Martin (P <.05) treatments over 48 hours. The Synthes (P <.01) and Inion (P <.01) treatments produced lower HGF cell index values than the untreated control at 72 hours, whereas the KLS Martin treatment did not. When left to elute for 96 hours, there were no significant differences in values among the control and study groups for HGFs (P >.05). All tested BFSs decreased cell survival rates of M3T3C1 cells for 48 hours (P <.01), 72 hours (P <.001), and 96 hours (P <.001). Conclusion Differences in the sensitivities of the 2 tested cell lines to the different BFSs might be the result of the different materials used to manufacture the screws. These results provide fundamental knowledge and new insights for the future design and development of new biocompatible BFSs for oral and maxillofacial surgery.