Combined Effect of Abutment Height and Restoration Emergence Angle on Peri‐Implant Bone Loss Progression: A Retrospective Analysis

ABSTRACT Introduction This study aimed to investigate the combined effect of trans‐mucosal abutment height (TmAH) and restorative emergence angle (REA) on marginal bone loss (MBL) around bone‐level implants. Methods Implant radiographs 12–18 months after crown placement (T0) and at least one year later (T1) were retrospectively analyzed. Sites were separated into four groups: Long/Narrow‐Angle (LN) with TmAH > 2 mm and REA < 30°, Long/Wide‐Angle (LW) with TmAH > 2 mm and REA ≥ 30°, Short/Narrow‐Angle (SN) with TmAH < 2 mm and REA < 30°, and Short/Wide‐Angle (SW) with TmAH < 2 mm and REA ≥ 30°. MBL was calculated, and multiple linear regression analysis was performed to control for patient‐level and implant/prosthesis‐level factors. Results 192 implants pertaining to 119 patients were included. Group significantly influenced MBL experience ( p < 0.001). Group SW experienced on average 0.48 mm (95% CI: 0.25–0.71, p < 0.001), 0.43 mm (95% CI: 0.18–0.68, p = 0.001), and 0.25 mm (95% CI: 0.00–0.45, p = 0.013) greater MBL compared to Groups LN, LW, and SN, respectively. Group was also a significant factor impacting the development of peri‐implantitis ( p = 0.041), with Group SW displaying a roughly 4× greater likelihood of having peri‐implantitis (PI) diagnosed compared to Groups LN (OR: 4.04; p = 0.091) and LW (OR: 4.19; p = 0.013). Every 1 mm increase in TmAH significantly decreased the likelihood of MBL > 0 mm (OR = 0.63; p = 0.003). Conclusions Abutment height > 2 mm may play a role in reducing PI and MBL related to ≥ 30° REA around bone‐level implants. REA was found to only be a significant factor when TmAH is less than 2 mm.