Soft reline material

 Today I have my first experience with denture soft reline material and I thought I would jot down a few points that I learned. The clinical situation was actually one where I intended to do a lab reline but the patient came late for their appointment and we missed the boat. Being in the public system, the lab was booked out for same day relines for months so I had to think of an alternative option to reach our goals. The patient has had a an immediate upper partial denture for a very long time and the ridge has long since resorbed allowing a large A-P rock of the denture. This is causing severe fremitus on the upper lateral incisor which is the only anterior tooth left. My initial aim was to reline the denture to bring it back to the height where the clasps engage the abutment teeth and by adding the support, hopefully resolve the fremitus allowing us to retain the tooth and then create a new denture. 

Ideally, I would have done a hard reline, but the situation was against me as the only chairside reline materials that were available were soft reline materials. Before using it on the patient, I had a play around with the materials: Coe-soft from Dentsply-Sirona and GC tissue conditioner. Here is what I did/learned:

-The A-P rocking of the denture meant the denture moved between two points: Full occlusion with the intaglio surface against the tissues and when the mouth was open and the denture tipped down and the clasps engaged the undercuts. I intended to reline the denture to this position. Not trusting the soft reline material to not be compressed too far down on seating, I dried the denture and placed soft greenstick on the anterior saddle and seated the denture. I kept layering this greenstick on until the denture didn't over-seat. This was essentially my "vertical stop". I then relined the posterior saddle areas, removed the greenstick and relined the anterior saddle as the posterior saddles held the same vertical position.

-The material is actually quite soft. The consistency is initially runny like any acrylic mixture, it goes through sandy then stringy, then doughy then sets. The setting is quite slow, with the proper mixture ratios, it takes about 8 minutes from starting mixing to be set. Adding extra liquid slows the set and makes it more runny and a drier mixture makes it more stiff and sets faster.

-It is really sticky. If you get any on your glove or take the rest of the mixture in your hands in the stringy stage, it will stick to everything it touches and make a massive mess. Instead, if you need to feel the consistency, use a the plastic spatula to manipulate the mixture. Separator can be placed on the non fitting surfaces of the denture where you don't want it to stick which may come with the pack or vaseline can be used. They don't recommend vaseline on gloved fingers, instead suggesting wetting with water to avoid sticking. I found this didn't really work and instead, avoid touching the material at all with gloves or fingers as it will get super stretchy like melted stringy cheese and get everywhere.

-Even after fully set, it is the consistency of hard chewing gum so it does have the ability to deform over time and provide functional impressions over 48 hours. This means you have to be careful not to over handle the material early on as it will deform. As the patient wears it, it will harden some more but will never become fully firm. 

-The patient needs to keep immaculate hygiene as the soft reline material will pick up stain and smell, brushing it softly with a toothbrush and water only and leaving the denture out overnight in water is important. If it dries out it will tend to shrink and harden.

-Clean the denture surface with detergent and a brush to provide a good bonding surface. Use the acrylic liquid to wet the denture surface. Mix the material and place onto the denture fitting surface in the runny stage, seat it in the patient's mouth in the stringy/doughy stage and get the patient to bite together to make sure the occlusion is good. This is why I placed the greenstick initially as if the patient bit down, the denture would over seat. Leave in place until the setting time, remove the denture and trim the excess with a scalpel. You can put the denture in warm water in a pressure pot to set the acrylic harder and faster.

-Coat the whole denture surface with the material as even though the palate doesn't resorb and doesn't need to be relined, if only the alveolar ridge is covered, there will be a junction between the hard and soft acrylic which could peel away and allow food to get under.

-If there are any sore spots, grind them back or else these will still protrude through the reline material and stay as a sore spot.

Where I would utilise this material in the future would be:

- Post extraction in immediate dentures, over surgical sites.

-In an old, ill fitting denture causing trauma to the tissues before impressing for a new denture. It can be a functional impression for the new denture.

-As a functional impression material for a laboratory denture reline.

-Long term, soft reline materials e.g molloplast B can be used over sharp ridges or sensitive mucosa or in a window denture design over a natural tooth as per Findlay Sutton.