Removable Partial Dentures with Polyetheretherketone Framework: The Influence on Residual Ridge Stability.

Abstract

To provide, in a clinicalcase-control study, 1-year data on edentulous residual ridge dimensional changes for patients wearing removable partial dentures (RPD)with Polyetheretherketone (PEEK) framework, fabricated with a digital workflow, and a control group of untreated patients. Tenpatients were treated withPEEK RPD, and six controls were studied.Intraoral scans at baseline (T0) and after a median period of 1 year (T1) weresuperimposed, trimmed, and reoriented (T0r and T1r),moved to a metrology software, and realigned. A curve (C0) was then traced on T0r, along the residual ridge crest; its projection (C1) on T1r was obtained. The mean distance C0-C1was the dependent variable of interest and represented the 1-year changes in the height of the edentulous ridge. In addition, mean 3D distance between T0 and T1 at each edentulous area was measured. Differences in these outcomes measured between RPD treated and control groups were statistically assessed. Twenty-six and 14 edentulous areas were investigated in the RPD treated and control groups, respectively. No significant differences were observed forpotentially confounding variables, such as median follow-up time (12.5 vs. 13 months, respectively), thealignment accuracy between T0r and T1r (0.01 mm vs. 0 mm, respectively), the median number of remaining teeth (6 vs. 8.5, respectively), and the median length of edentulous areas (25.5 mm vs. 22.8 mm, respectively). For the outcomes of interest, no statistically significant difference was seen in the mean distance between C0 and C1 (i.e., changes in residual ridge height: -0.39 ± 0.52 mm vs. -0.52 ± 0.54 mm, respectively) or in the mean 3D distance at corresponding points of the denture bearing areas (-0.3 ± 0.46 mm vs. -0.4 ± 0.35, respectively). Although 1 year is a relatively short observation period, this clinical study shows that there are no short-term differences in edentulous residual ridge height and overall dimensions between patients wearing PEEK RPD, fabricated with a digital workflow, and controls without an RPD.