11/08/2026
From Data to RPD | Designing for Stability in Cases
For a Kennedy Class I mandibular case, the key challenge is not only retention — but also controlling movement and protecting the terminal abutments.
Three design decisions were considered in this framework:
1. Retention | Stress-releasing clasp design
Design
• 35 & 45: RPI clasp assemblies
Why
→ Based on abutment morphology, undercut distribution, and soft tissue conditions, RPI clasp assemblies were selected to provide retention while allowing controlled movement of the distal extension bases.
2. Stability | One indirect retainer is sufficient
Design
• 44 mesial occlusal rest as indirect retainer
Why
→ The mesial occlusal rests on 35 and 45 form the fulcrum line. The indirect retainer was positioned away from this axis to resist rotational movement of the distal extension bases.
→ In this type of design, a single properly positioned indirect retainer is often sufficient to provide effective control while avoiding unnecessary tooth preparation and additional components.
3. Major Connector | Lingual bar for hygiene and comfort
Design
• Lingual bar
Why
→ A lingual bar was selected to connect all framework components while maximizing gingival exposure, improving oral hygiene, and reducing unnecessary tissue coverage.
A predictable RPD design is not about adding more components — it is about selecting the right design for each clinical situation.
From digital design to 3D printed framework, we deliver the foundation for dental labs to complete the final restoration.
