Are Rests Damaging Teeth? A Closer Look at Their Impact

As someone who has spent decades working with dentures, I’ve had my fair share of experiences with rests. When designing partial dentures, my priority is always patient comfort, longevity, and the least invasive approach possible. While rests are commonly used in denture design, I’ve seen too many issues arise from them, which is why I rarely incorporate them.

The Role of Rests in Partial Dentures

Rests are designed to sit on the occlusal surface of a tooth, preventing the denture from being displaced downward. In theory, they provide stability. However, the reality is often different. To accommodate a rest, a dentist typically has to adjust the natural tooth by removing some of its structure. This process weakens the tooth, making it more susceptible to damage over time.

In my experience, rests create significant pressure points. I’ve seen many cases where they cause chipping, fractures, or even complete failure of the supporting tooth. The constant force applied to a single point of the tooth structure leads to excessive strain, something I prefer to avoid when designing dentures.

The Problem with Rests in Partial Dentures

One of the biggest issues with rests is their rigidity. When a partial denture is supported solely on natural teeth and doesn’t have any soft tissue support, there’s no flexibility in movement. This means all the occlusal force is concentrated on those teeth with rests, rather than distributing pressure evenly. Over time, this can lead to tooth loss, which completely defeats the purpose of a partial denture.

A Better Alternative: The Reciprocation Technique

Rather than relying on rests, I use what I call the reciprocation technique. This method eliminates the need to cut into teeth while still ensuring stability. Instead of resting on a single occlusal point, the denture framework sits slightly above the undercut of the tooth, distributing pressure more evenly.

With a properly designed chrome denture, the metal framework always sits above the undercut, with everything below it blocked out. This means the denture naturally rests on multiple contact points rather than a single rest seat, reducing strain on any one tooth. The reciprocation technique ensures that when force is applied, it is spread across all supporting teeth, preventing excessive pressure on any individual tooth.

Additionally, clasps play a crucial role in stabilising the denture. When used correctly, they prevent unwanted movement while still allowing a small degree of flexibility. This slight movement is important—it helps to absorb forces rather than transferring them directly to a single point on the tooth.

When Are Rests Necessary?

While I avoid rests whenever possible, there are some cases where they are unavoidable. If overcrowding prevents a clasp from seating properly, I may need to adjust the teeth to create room for the framework. However, this is always my last resort. In these situations, I ensure that the adjustment is minimal and carefully controlled to avoid unnecessary weakening of the tooth structure.

Final Thoughts

Over the years, I’ve refined my techniques to focus on preserving the patient’s natural teeth while providing a comfortable and secure denture fit. My approach prioritises long-term success rather than short-term fixes. The reciprocation technique offers a more balanced and less invasive alternative to rests, reducing the risk of tooth damage while maintaining denture stability.

While rests have their place in denture design, they are often overused or placed in ways that do more harm than good. By carefully considering each case, I ensure that my patients receive the best possible fit without unnecessary compromise to their natural teeth.