Placement of Temporary Resilient Liners (Tissue Conditioners)
Tissue conditioners provide one of the easiest means of improving the health of the denture foundation tissues. These materials are also one of the most abused in the dental office. It is often presumed that the mere presence of a temporary resilient liner will resolve any mucosal problem. This section outlines a technique that can be used to reduce soft liner adjustment time, while improving patient comfort and liner longevity. The technique described has been used with tissue conditioners such as Lynal (Dentsply International Inc., Milford, DE), Visco-gel (Dentsply Ltd, Detrey Division, Surrey, England), and Tru-Soft (Harry J. Bosworth Co., Skokey, IL), but it can be adapted to most other materials that are available in similar powder/liquid formulations.
1. Clean the denture prior to application of the soft liner. Use scalers, pumice on a wet ragwheel, and an ultrasonic cleaner to eliminate gross debris and calculus. Disinfect the denture by immersion in sodium hypochoride for at least 10 minutes prior to placement of the liner. This will help to minimize the presence of microbes, which might subsequently colonize the liner, thereby shortening liner lifespan. When relining opposing dentures, reline the least stable denture first so that the more stable denture can be used as reference for positioning the relined denture, using the occlusal contacts.
2. Determine if the denture base needs to be reduced prior to the placement of the liner. Flanges that are excessively long or areas that are causing severe inflammation or frank ulceration should be reduced. The entire denture bearing area should also be prepared to provide room for the liner. Most materials require a minimal thickness of approximately
2 mm in order to provide sufficient resiliency to minimize tissue trauma. If the existing occlusal vertical dimension is acceptable, and the thickness of the denture base will allow, provide uniform relief of internal surface of the denture using pilot grooves, acrylic burs and arbor bands. If there is insufficient occlusal vertical dimension (excessive interocclusal rest space or freeway space), there may be room to place the liner without reduction of the denture base. If the denture base is not reduced, the incisal display will probably be increased once the liner has been placed. The esthetic consequences of such a change should be evaluated and discussed with the patient.
3. Remove the glossy surface around the denture periphery where the conditioner will terminate on the denture (at least 6 mm past the edge of the flange). This helps ensure that the conditioner will adhere to the denture to minimize separation, leakage and microbial colonization.
4. Mix the tissue conditioner according to the manufacturer’s instructions. Mix with a stropping action against the mixing container. Do not use a vigorous stirring action which can lead to the incorporation of bubbles that are difficult to eliminate from the viscous mixture. In general, liners can be mixed slightly stiffer than recommended by adding additional powder to the liquid component. This can be done to decrease the flow
from underneath a denture during setting, when an increase in the occlusal vertical dimension is desired. Do not mix the liner thinner than suggested by the manufacturer, as this can have deleterious effects on the physical properties and longevity of the liner.
5. Apply a smooth even layer to the denture, usually starting at the posterior and teasing the material forward without incorporating air bubbles. Bring the tissue conditioner over peripheries about 6 mm, so that saliva cannot get between the denture and the conditioner in the area of the periphery. This will minimize the possibility of separation of the conditioner from the denture. Excess can be removed later.
6. Place the denture intraorally, having an assistant help retract the commissures of the mouth to avoid accidental removal of the liner during insertion. Insertion is easier if the patient relaxes the cheeks and lips rather than opening maximally. Avoid touching the material during initial placement.
7. Stabilize the denture and have the patient close lightly, until initial contact is felt or seen. If occlusal contacts are uneven, have the patient open, and tilt, tip or bodily move the denture into a position where stable even contacts can be obtained. Border mold the peripheries, when the material begins to gain viscosity (about 3 minutes for most tissue conditioners).
8. Use a cotton swab to remove any areas of gross excess prior to initial set. This will reduce the amount of trimming needed, and make for a neater, more comfortable external surface. Excess material most commonly requires removal in the area of the lingual vestibule and distobuccal flange of the mandibular denture, and the retrozygomal area and palate of the maxillary denture.
9. Remove after initial set (commonly 8-10 minutes) and trim with a hot scalpel blade. Heating the blade will allow the scalpel to cut through the liner without sticking, and leave a cleaner, smoother surface, which will enhance patient comfort. Do as little modification as possible at this time, as the material will be sticky and adjustment will often result in a rough or ragged surface that is uncomfortable and difficult to clean.
10. Clean the opposing denture and provide care instructions. Explain the temporary nature of the material to the patient. Have the patient rinse the denture with water, after eating, for the first 24-48 hours, and brush the liner with a soft tooth brush and a small amount of liquid dish detergent subsequently. Most commercial denture cleaners should be avoided as they contain sodium hypochloride which will reduce the lifespan and resiliency of the liner. The denture should be placed in a container with high humidity over night, but not immersed in liquid.
11. Have the patient return to the office twenty four to forty eight hours after placement, so that the conditioner can be trimmed with acrylic lab burs and polished with pumice on a damp rag wheel. Both the external surface and the peripheral roll should be polished, with care, to a fairly high shine. Polishing the liner will make it smoother, more comfortable and less prone to microbial colonization. In some instances polishing may improve liner longevity or hasten tissue resolution, since the liner will be easier to clean.
12. Change the soft liner as necessary. If there are no signs of tissue resolution, systemic conditions should be considered and appropriate investigations undertaken.