Changes of radiopacity around implants of different lengths: Five‐year follow‐up data of a randomized clinical trial

Abstract

Objective To follow‐up the radiographic changes in peri‐implant bone of short (6 mm, test group) and long (10 mm, control group) single‐unit implants five years after loading. Materials and methods Forty‐three implants of the test and 44 implants of the control group could be reassessed from 96 originally included implants. Standardized areas of interest (AOI) were defined in the peri‐implant bone at pre‐defined locations at mid‐length on both sides of the implants, and at the apex. An arbitrary mean grey scale value (GSV) was calculated for the AOI after brightness calibration of the radiographs. Changes for GSV were calculated and tested for possible inter‐ and intra‐group differences using the Mann–Whitney and Wilcoxon tests. Results The calculated intra‐group differences between baseline and 5 years in the test group accounted for 2.4 ± 19.6 (i.e. slight brightening) and −6.2 ± 20.2 for the control group (i.e. slight shading), which resulted in a statistically significant difference in GSV change (p < .05). Crown‐to‐implant ratio was the only parameter showing an effect on GSV change (p = .001). Conclusions Assessing conventional radiographs, longer implants showed a slightly stronger change of radiopacity of the peri‐implant bone (slight loss of density) than short ones (slightly enhanced density) after five years of loading.

Radiographic density changes may be associated with overloading and implant loss on short implants: A 5‐year analysis of a randomized controlled clinical trial

“…24,34 It has been found that the bone around short implants might F I G U R E 5 Median gray-scale values (GSV) of implants in the mandible that survived and the implants that failed at different time points become denser in response to the load. 25,29,35 This phenomenon was confirmed in the present study, where the radiographic density increased over time after implant loading in both groups.…”

“…Depending on the intensity and the direction of the load, the peri‐implant bone responds through up or downregulating bone metabolism 24,34 . It has been found that the bone around short implants might become denser in response to the load 25,29,35 . This phenomenon was confirmed in the present study, where the radiographic density increased over time after implant loading in both groups.…”

“…The calibration regions were then used to calibrate the results using the baseline image as a reference. The positioning of the ROI, superimposition on the follow‐up radiograph, calibration, and gray scale measurement were performed by the same calibrated operator (AG), trained by a senior faculty (Philipp Sahrmann) who developed this methodology of measurement 9,25,29 . Since GSV are non‐dimensional, the scales are indicated with “arbitrary units.” GSVs were calculated as well as the changes in GSV in between different time points.…”

Retracted: A 5‐year randomized controlled clinical trial comparing 4‐mm ultrashort to longer implants placed in regenerated bone in the posterior atrophic jaw

“…These findings are in agreement with a recent published RCT, reporting a difference of 0.41 mm even if at a follow-up of 1 year and with 5.5-mm short implants. 6 Furthermore, the better bone stability around short implants could be explained by a recent study 13 in which longer implants showed a slightly stronger change of radiopacity of the periimplant bone than short ones after five years of loading.…”

Autologous Materials in Regenerative Dentistry: Harvested Bone, Platelet Concentrates and Dentin Derivates

“…Due to the morbidity risks related to the surgical interventions, a parallel arm of research on short implants is currently on-going [13][14][15]. In their recent clinical report, Naenni et al highlighted how the use of implants of 6 mm length did not show significant differences in survival rate and peri-implant marginal bone loss compared to implants of 10 mm length [15].…”