Using Different Low-Profile Abutments for Assisting Mandibular Implant Overdenture: A Split-Mouth Study.

Background: Using a pair of different low-profile abutments to assist mandibular implant overdenture (MIOD) in limited restorative space is questionable due to the different morphology. Objective: To investigate the marginal bone level (MBL) change and peri-implant-tissue health (PITH) around a pair of OT Equator® and Locator® suprastructures assisting MIOD. Methods: Seventeen edentulous patients received MIOD assisted by OT Equator® and Locator®. MBL change was investigated at the implant loading (T1), after six months (T2) and twelve months (T3) of implant loading. PITH was evaluated at T2 and T3. Results: There was within abutment significant difference in MBL change after T2 and T3 of loading for Locator (0.05 ± 0.02 and 0.32 ± 0.08, respectively) (P=0.01); and for Equator (0.11 ± 0.08 and 0.21 ± 0.09, respectively) (P=0.01). Also, there was a significant difference between Locator and Equator on the modified plaque index (MPI) after T3 (P=0.01). The significant results were recorded for the MPI at T2 and T3 for Locator (0.92 ± 0.26 and 1.5 ± 0.51, respectively) (P=0.01) and for Equator (0.82 ± 0.26 and 1.42 ± 0.51, respectively) (P=0.003). For modified bleeding index, there was significant difference at T2 and T3 for Locator (0.57 ± 0.19 and 1.14 ± 0.41, respectively) (P=0.03) and for Equator (0.46 ± 0.22 and 1.07 ± 0.41, respectively) (P=0.01). For gingival index, there was significant difference at T2 and T3 for Locator (0.57 ± 0.11 and 1.28 ± 0.35, respectively) (P=0.001) and for Equator (0.35 ± 0.21 and 1.1 ± 0.46, respectively) (P=0.001). Conclusions: Using different pairs of the low-profile OT Equator® and Locator® abutments to assist MIOD is clinically acceptable based on the MBL change and PITH outcomes.