Objective To study the application of glass-based all-ceramic zirconia all-ceramic and fiber post-core zirconia crown restoration in posterior tooth defect. Methods A total of 64 patients with posterior tooth defect in our hospital from January 2020 to December 2022 were selected and divided into glass-based all-ceramic group (n=22), zirconia group (n=21) and fiber post-core group (n=21) according to the repair method. The glass-based all-ceramic group was repaired with glass-based all-ceramic onlay, the zirconia group was repaired with zirconia all-ceramic, and the fiber post-core group was repaired with fiber post-core zirconia crown. The inflammatory factors in gingival crevicular fluid [alkaline phosphatase (ALP), interleukin-1β (IL-1β), prostaglandin (PGE2)], periodontal health indicators [periodontal pocket depth (PD), gingival bleeding index (GBI)], masticatory efficiency and bite force were compared between the three groups. Results After the repair, the levels of ALP, IL-1β, and PGE2 in the glass-based all-ceramic group were lower than those in the zirconia group and the fiber post-core group, and the levels of ALP, IL-1β, and PGE2 in the zirconia group were lower than those in the fiber post-core group (P<0.05); after the repair, the PD and GBI in the glass-based all-ceramic group were lower than those in the zirconia group and the fiber post-core group, and the PD and GBI in the zirconia group were lower than those in the fiber post-core group (P<0.05); after the repair, the masticatory efficiency and bite force in the glass-based all-ceramic group were higher than those in the zirconia group and the fiber post-core group, and the masticatory efficiency and bite force in the zirconia group were higher than those in the fiber post-core group (P<0.05). Conclusion Compared with zirconia all-ceramic and fiber post-core zirconia crown restoration, the effect of glass-based all-ceramic onlay in repairing posterior tooth defect is better, which can improve the periodontal health status, increase the masticatory efficiency and bite force of patients, and reduce the inflammatory reaction of gingival crevicular fluid.