Clinical and radiographic outcomes around 4 mandibular implant-retained overdentures in individuals with type 2 diabetes: A long-term retrospective study

Abstract

Objectives: To report the implant survival rates, clinical, and radiographic status after a period of more than 5 years in the function of 4 inter-foraminal implants retaining mandibular overdentures (OVDs) in individuals with T2DM.

Methods: 78 completely edentulous participants with type 2 diabetic mellitus (T2DM) who had worn mandibular OVDs retained by 4 inter-foraminal implants for long-term functional life were selected for this study. The participants were divided into 2 groups according to glycosylated haemoglobin A1c (HbA1c) levels before implant placement: group I with an HbA1c value > 6.5 % (inadequately controlled T2DM), and group II with an HbA1c value ≤6.5 % (well-controlled T2DM). The inadequately controlled T2DM was further subdivided into 2 groups: Group IA with an HbA1c value > 6.5 % and ≤8 % (moderately controlled), and Group IB has an HbA1c value > 8 % (poorly controlled). Implant survival rate, plaque index (PI), bleeding on probing (BOP), probing depth (PD), and radiographic crestal bone level (CBL) around implants were measured.

Results: Among 312 implants, 6 failed, 4 in well-controlled diabetics, and 2 in inadequately controlled diabetics. The overall survival rate was 98.07 %. The mean PI in group Ι was 36.4 (group IA =37.76, group IB = 34.27), and in group ΙΙ it was 19. The mean BOP in group Ι was 45.5 (group IA =47.84, group IB = 41.76), and in group ΙΙ it was 22. The mean PD in group Ι was 4.1 (group IA =4.3, group IB = 3.85) and in group ΙΙ was 2.2. The mean radiographic CBL in group Ι was 3.4 (group IA =3.7, group IB = 2.9), and in group ΙΙ was 1.5. Group IA exhibited a significantly greater level of PI, BOP, PD, and CBL compared to group IB and group IΙ (P1=0.017, P2=0.001).

Conclusions: Individuals with T2DM can benefit from 4 inter-foraminal implants retained mandibular OVDs, and their inability to maintain proper glucose control may not exclude implant success.

Clinical significance: This study is a significant step toward improving knowledge of options available for treatment and anticipated outcomes for T2DM completely edentulous populations undergoing implant therapy.

Keywords: Diabetes mellitus; Four implants; Implant overdentures.