Appliances come in many different materials or material combinations. With all the different types out there it is hard for a dentist or patient to choose what to use.
Here are my thoughts about each material and what I prefer.
There are a few sleep appliances made 100% out of metal. These appliances are very good for someone that grinds so severe they wear everything down. The downside is these appliances can’t be adjusted much at all. If any change happens to the teeth such as restorations or crowns or lost teeth you can’t change the appliance. Also, if there is a metal allergy it can be an issue. The more metal contact with the teeth in an appliance the less likely I would use it.
All acrylic appliances (no linings). These are great appliances and I have used them for years. It can be a Herbst, dorsal or a few other styles. The impressions need to be perfect and little to no cosmetic work done to the teeth. Veneers are a problem with a tight fitting acrylic appliance because they can be pulled off or broken upon insertion and removal of the appliance. If no cosmetic or major work was done to the teeth the all acrylic appliance can outlast most others and can be relined and repaired if there are tooth changes such as loss of a tooth or crowns.
Polymer material like the Narval appliance is very strong and works well with people that grind. They are great for people with allergies to acrylic or monomers. They are expensive appliances and you can’t make much adjustment to them like adding material or relinings.
Acrylic appliances with a soft lining have a lining like a sports mouth guard and are easy to insert and remove. They feel the most comfortable to the patient and easy for an assistant to deliver the appliance. The soft lining is gentle on veneers and restorations. This is my favorite type of appliance to use because less potential for damage to the teeth. The downside is you can’t reline the material or add to it. The lining does not last as long as the acrylic. In most cases the lining lasts about 3 years. The only way to change the appliance if major work has been done to the teeth would be to remove the lining and put thermoplastic lining instead (only Dynaflex lab is doing that right now).
Acrylic appliance with thermoplastic lining is made by Dynaflex. It has to be warmed in hot water and placed in the mouth for a very short time and removed. If it is in too long after heating it is hard to remove and may cause damage. This is technique sensitive to deliver to the patient. It can be re-heated and refitted over and over making the appliance very good for times where major dental work has been done. If you live in a hot climate like the deserts of the southwest where temperatures get over 100 degrees this may not be the best choice because the lining can be destroyed by the heat. Also it must be explained to the patient to not try and heat the appliance and refit it at home.
So what appliance material do I prefer? I prefer an acrylic appliance with a soft lining. I know the soft lining won’t last as long as an all acrylic or all metal appliance, but I also know they won’t damage restorative work and are easier to deliver. Since I changed over to the soft linings my delivery time was reduced significantly and the patients have been happier. I have not had any dental restorations damaged as a result of an appliance with a soft liner. I have however had to glue the soft liner back in on several patients and had to drill out some parts of damaged liners.
The key is to try the different types of materials and see what work best for your office and your patients knowing the limits and potential problems.