Objective: To investigate the effect of zirconia-based all-ceramic crown restoration in patients with dental defects after root canal therapy and its impact on periodontal health. Methods: A total of 88 patients who underwent dental implant restoration in the hospital from April 2023 to April 2025 were selected. According to the restoration method, they were divided into the cobalt-chromium alloy group (44 cases) and the zirconia group (44 cases). The restoration effects, biocompatibility, masticatory function, periodontal indicators, and occurrence of complications were compared between the two groups. Results: No statistically significant difference in the integrity of restoration was observed between the two groups (P>0.05). Compared to the cobalt-chromium alloy group, the zirconia group demonstrated better marginal fit of the restoration (P<0.05). There was statistically significant difference in masticatory function between the two groups (P>0.05). The zirconia group showed lower plaque index (PLI) and sulcus bleeding index (SBI) compared to the cobalt-chromium alloy group (P<0.05). The overall complication rates in the two groups were close (P>0.05). Conclusion: Zirconia-based all-ceramic crown restoration achieves similar restorative effects as cobalt-chromium alloy porcelain-fused-to-metal crown restoration. However, the former offers better marginal fit, better periodontal health, and good safety.