Locators versus magnetic attachment effect on peri-implant tissue health of immediate loaded two implants retaining a mandibular overdenture: a 1-year randomised trial

This study aimed to evaluate peri-implant tissue health of immediate loaded two implants retaining a mandibular overdenture with either magnetic or locator attachment. Thirty two completely edentulous patients (20 males/12 females) were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible using flapless surgical technique. Mandibular overdentures were immediately connected to the implants with either magnetic (group I, GI) or locator (group II, GII) attachments. Peri-implant tissue health was evaluated clinically in terms of plaque scores (PI), bleeding scores (BI), probing depth (PD), implant stability (ISQ) and interleukin-1- (IL-1b) concentrations in peri-implant sulcular fluid. PI, BI and PD were measured at mesial, distal, buccal and lingual surfaces of each implant. Radiographic evaluation was performed in terms of vertical (VBL) and horizontal (HBLO) alveolar bone loss. Evaluations were performed 2 weeks (T0), 6 months (T1) and 12 months (T2) after overdenture insertion. Plague scores, PD, IL-1b, VBL and HBLO increased significantly with time. ISQ decreased significantly with time. BI showed no significant differences between observation times. GI recorded significant higher PI, ISQ and IL-1b at T2 compared to GII. GII recorded significant higher VBL than GI at T2 only. For HBLO, no significant differences between groups were noted. VBL and HBLO showed a significant positive correlation with PD. Locator attachments for immediate loaded implants retaining mandibular overdentures are associated with decreased plaque accumulation, decreased implant stability, decreased interleukin-1 concentration in peri-implant crevicular fluid and increased per-implant vertical bone loss compared to magnetic attachments after 1 year.