Soft denture reliners are materials that create a cushioned layer between the hard base of a denture and the oral mucosa (the tissues in the mouth). This material can be placed in either a new or existing denture to improve gum tissue health by reducing pressure on the gums and improving denture retention.
Generally, soft denture reliners play a crucial role in enhancing the fit, comfort, and function of dentures for patients.
These liners have several benefits and applications in denture patients:
Absorb impact to improve gum health
When you chew with your dentures, there is pressure applied to your gums. The soft liner helps absorb some of this pressure, acting as a cushioning material between the false teeth and your gums. By reducing the impact on your gums, soft liners help to improve their health and prevent irritation.
Improved force distribution
Soft liners help distribute the forces generated during chewing more evenly onto the underlying tissues. By absorbing some of the masticatory forces, they reduce the pressure on specific areas and provide a more balanced distribution of forces.
Enhanced denture retention
A soft liner is also necessary for enhancing denture retention. Soft liners are designed to adapt and conform to the contours of your gums and underlying bone. They have the ability to utilize undercuts in the bone and gum, which are recessed areas that hard liners may not be able to engage with without causing irritation. Soft liners can maneuver around these undercuts, creating a better fit and allowing for greater retention of the dentures. This means that your false teeth stay in place more securely when you wear them.
Enhanced comfort for specific conditions
Soft liners are particularly beneficial for patients with:
- Ridge atrophy (reduced bone support for dentures)
- Thin and non-resilient mucosa
- Bony undercuts (indentations in the bone)
- Bruxism (teeth grinding)
They also find utility in cases of irregular bone resorption, immediate prosthesis placement, healing after implant placement, and for patients with bruxism (teeth grinding) and xerostomia (dry mouth).
Different types of soft liners
There are two main types of soft liners: short-term liners (tissue conditioners) and long-term liners. Each type has its own composition and lifespan.
a. Short-term soft liners
Short-term liners, also known as tissue conditioners, are used immediately after surgery. They typically consist of poly ethyl methacrylate powder, aromatic esters, and alcohol. These materials do not contain methacrylate monomers, which can be irritating to the oral tissues.
Tissue conditioners are used for a short period, usually a few days to a week, but some can maintain their softness for up to 30 days, to help the healing process and provide temporary cushioning.
b. Long-term soft liners
On the other hand, long-term soft liners are designed to be used for a more extended period. They are typically made of either plasticized acrylic or silicone.
They can be made from silicone rubbers or plasticized acrylics and can be auto-heat or visible light polymerized.
- Plasticized acrylic resin
Plasticized acrylics have a composition similar to denture base polymers, with a high percentage of plasticizers. The plasticized acrylic resin consists of a powder containing acrylic polymers and copolymers, while the liquid component contains an acrylic monomer.
These plasticizers keep the material soft and flexible. However, over time, plasticized acrylic soft liners may harden and absorb water, resulting in a shorter service life. They can typically last up to 6 months.
- Silicone soft liners
Silicone soft liners, on the other hand, are intended for longer-term use, usually up to 1 year. They are made of dimethylsiloxane polymers and do not rely on leachable plasticizers. As a result, they tend to retain their elastic properties for longer periods.
Silicone soft liners face challenges in establishing a durable bond with the denture base. This issue can be resolved by using suitable solvent-based primers or employing mechanical methods to enhance the bonding between the liner and the denture base.
Applications of Soft Liners in Denture Dentistry
Soft liners have various indications in dentistry. Here are some common situations where soft liners are used:
- Diagnosing ill-fitting dentures: Soft liners can be used to see if the denture fits well and is comfortable. They help dentists make necessary adjustments to the denture’s size, shape, and appearance.
- Making impressions: Dentists use soft liners to make molds of the mouth, which help them create accurate dentures that fit securely and comfortably.
- Comfortable denture wear: Soft liners are used to improve the comfort of wearing dentures. They can help reduce discomfort, irritation, and ulcers caused by hard denture bases.
- Immediate dentures: Soft liners are sometimes used with immediate dentures, which are placed right after tooth extraction. They provide extra cushioning and help with the healing process.
- Difficult mouth shapes: Soft liners are useful for patients with irregular jawbone shapes or uneven gum surfaces. They can adapt to these contours and provide a better fit for the denture.
- Special cases: Soft liners are used for patients with specific conditions, such as cleft palate or oral defects, to improve denture retention and function.
- Post-surgery care: Soft liners are used temporarily after oral surgeries to aid in healing, reduce swelling, and provide comfort during the recovery process.
- Better retention: Soft liners can be used to enhance the grip and stability of removable partial dentures, especially in areas with limited support.
- Dry mouth relief: Patients with dry mouth (xerostomia) may find soft liners helpful. They can reduce soreness, discomfort, and improve denture retention in these cases.
- Compatibility with natural teeth: Soft liners can be used in overdentures that need to work well with remaining natural teeth, providing a comfortable fit and better chewing ability.
In all of these situations, soft liners offer specific benefits to make dentures more comfortable, functional, and customized to individual needs. Dentists evaluate each case and decide if using soft liners is appropriate and beneficial for the patient.
What makes a good soft denture reliner?
Soft liner materials should possess specific physical and mechanical properties.
Physically, they should:
- Provide cushioning to the oral mucosa
- Exhibit dimensional stability
- Permanent resilience
- Minimal fluid sorption and solubility
- Inhibit fungal growth
Mechanically, they should:
- Be easy to process, finish, and polish
- Adhere to denture resin without causing any adverse effects.
Are soft liners right for me?
Your dentist may recommend soft liners to address age-related changes in the tissues that support dentures. Soft liners can improve both masticatory efficiency (the ability to chew effectively) and oral comfort for patients with a reduced thickness of the oral mucoperiosteum (the lining of the mouth and underlying bone).
Which type of soft liner is best for me?
The choice of soft liner depends on the specific needs of the patient and the desired duration of use. As discussed above, short-term soft liners (tissue conditioners) are used immediately after surgery and provide temporary cushioning and healing support. Long-term soft liners can be made of plasticized acrylic or silicone, with plasticized acrylic soft liners lasting up to 6 months and silicone soft liners lasting up to 1 year.
What is the process of getting soft liners for dentures?
Generally, a dentist starts by placing temporary soft liners to assess whether they provide the desired enhanced retention for your false teeth. If they do, then the dentist may consider replacing them with a more permanent type of soft liner within a few months. But if they’re not effective, then your dentist may determine that a hard liner is the better option based on your specific needs. The objective is to find the best solution for your denture retention, ensuring that they fit comfortably and securely in your mouth while minimizing any irritation or discomfort.