You may have hear both positive and negative things about all soft occlusal appliances. A common conversation is that they will aggravate muscle signs and symptoms. It is true that some patients will increase the amount of clenching they do in response to the squish of a soft appliance. For patients with muscle signs and symptoms and a healthy condyle disc assembly a soft appliance would not be my first choice. Another factor to consider is the amount of grinding and tooth wear a patient has. Soft appliances will protect the teeth from wear, where hard appliances do still have the ability to cause tooth wear, albeit at a much reduced rate than tooth against tooth. Two considerations for patients with significant wear, will they grind through a soft appliance quickly and will a hard appliance continue to wear their teeth. There is a balance between these two and I have some patients for whom it makes sense to replace a soft appliance annually versus continued tooth wear against hard acrylic.
The major use of soft appliances in my practice is for patients with disc displacements. One group of patients have a lateral pole disc displacement that does not reduce. These patients can suffer from pain of translation from retrodiscal tissues being pinched. Creating balancing side contacts will support the joint in translation and make the patient more comfortable. It can be very difficult if not impossible to create balancing side contacts on a hard appliance depending on the patient’s condylar guidance. On a full coverage soft it is simple to produce this supportive occlusion. Additionally patients who have medial pole disc displacement may also feel more comfortable in a full coverage soft as it creates a fully balanced occlusion and supports the joint.
Full coverage soft appliances can be made from one or two thicknesses of 3mm soft material. You can have them fabricated by a laboratory, or make them in your office on a Ministar. The material is easily trimmed with special scissors designed for this purpose. When delivering the appliance, soften the occlusal tables with a flame while on the model. Place over the teeth and have the patient bite into the softened material, than cool. Once cool, use a silicone polisher to smooth the edges of the material where the occlusion indented it. These appliances are best “polished” with chloroform on a gauze.