Comparison of Clinical, Radiographic, and Immunologic Inflammatory Parameters Around Dental Implants with Cement-Retained and Screw-Retained Restorations: A 5-Year Prospective Cohort Study in Men

Purpose: To compare bleeding on probing (BoP), probing depth (PD; ≥ 4 mm), radiographic (peri-implant crestal bone loss [CBL]), and immunologic inflammatory (interleukin-1beta [IL-1β] and matrix metalloproteinase-9 [MMP-9]) parameters around dental implants with cementretained (CR) and screw-retained (SR) implant-supported crowns. Materials and Methods: Based on the mode of retention of the restoration, 51 patients were divided into two groups: Group 1, consisting of 26 single implants restored with CR crowns, and Group 2, consisting of 25 single implants restored with SR crowns. Peri-implant BoP, PD, and CBL were scored, and levels of IL-1β and MMP-9 in the peri-implant crevicular fluid (PICF) in both groups were measured in duplicate using enzyme-linked immunosorbent assay. Full-mouth mechanical debridement was performed biannually in both groups. Statistical analysis was performed using Kruskal-Wallis test with the significance level set at P .05. Results: The mean CBL among implants in groups 1 and 2 was 1.7 ± 0.5 mm and 1.7 ± 0.4 mm, respectively. There was no statistically significant difference in mean BoP, PD, and CBL among implants in both groups (P > .05). There was no statistically significant difference between groups 1 and 2 in the PICF levels of IL-1β (7.3 ± 0.5 and 7.2 ± 0.5, respectively) and MMP-9 (165 ± 9.4 and 182 ± 10.6, respectively) (P > .05). Conclusion: The mode of retention of implant-supported crowns does not appear to affect their clinical correlations with BoP, PD, CBL, and levels of IL-1β and MMP-9 in the PICF when zinc oxide eugenol cement is used.