Metal RPD frameworks are strong but cold, and allergy-prone patients reject them. PEEK offers a lighter, tissue-friendly frame.
Why PEEK frames
At ~1.3 g/cm³ vs cobalt-chrome's 8.3 g/cm³, a PEEK frame is a fifth of the weight, with enough flex to clasp undercuts without bending metal. It is also radiolucent, so the underlying bone stays visible.
Design rules
- Keep major connectors ≥6 mm wide; PEEK's lower modulus needs section.
- Support clasps on sound enamel, not gingiva.
- Polish to a closed surface — a rough PEEK frame stains.
Machine it from our PEEK discs on a standard 98 mm blank holder.
Designing a PEEK RPD
PEEK's low density (1.3 g/cm³) makes a framework a third the weight of cobalt-chrome, and patients notice. But PEEK is flexible, so the major connector needs thickness, not thinness.
| Element | Min thickness |
|---|---|
| Major connector | 2.0 mm |
| Clasp | 1.0 mm, half-round |
| Mesh | 0.8 mm |
Clasp detail
PEEK clasps engage undercuts of 0.25 mm; too deep and they over-flex and fatigue. A milled, not printed, clasp holds the tolerance better.