Flexible Partial Denture: The Aesthetic & Comfortable Restoration by Chinese Dental Lab & WM Dental Lab

What is an invisible denture?

An invisible denture, also called a flexible denture, is a type of removable partial denture made from flexible resin base and artificial teeth.

Flexible resin was first introduced from the United States around 1995. Because the material has a certain degree of elasticity and flexibility, it can provide retention, so there is no need to make metal clasps. The color of the resin matches the color of the gingiva, making it difficult to detect when worn in the mouth. It is both aesthetic and comfortable, hence the name “invisible denture” or “flexible denture”.

Invisible dentures offer good adaptation, no metal clasps, easy insertion and removal, easy cleaning, no abrasion to healthy teeth, minimal foreign-body sensation, good comfort, good aesthetics in the mouth, and a relatively low cost, making them a popular removable restoration among patients. However, due to the special manufacturing process and material properties of invisible dentures, they are not repairable—if damaged during use, they cannot be mended. In addition, most flexible materials age relatively quickly and may discolor and lose elasticity after about two years in the mouth. Therefore, invisible dentures are classified as temporary restorations in many countries; in China, however, many clinicians still recommend them as long-term restorations.

Advantages of invisible dentures:

1. The greatest advantage is semi-transparency. The resulting base and clasps can show through the color of the gingiva and teeth, and under the effect of saliva, they look very natural, truly achieving an “invisible” effect.

2. The base resin of invisible dentures can withstand high temperatures up to 287°C and has extremely high toughness.

3. Good comfort.

4. Little or no tooth preparation is required.

5. Low cost.

Disadvantages of invisible dentures:

1. Masticatory efficiency is poor, and mucosal tenderness is common. When restoring missing molars with flexible dentures, the elastic nature can cause a “floating or sinking” sensation during occlusion.

2. The vertical occlusal force is entirely borne by the alveolar ridge mucosa in the edentulous area. Excessive local loading inevitably causes compressive damage to the periodontal tissues of the abutment teeth and leads to pathological resorption of the alveolar ridge.

3. The flexible clasp covers a large area of the abutment teeth and gingiva, which is not conducive to self-cleaning of the periodontal tissues. Plastic materials tend to accumulate plaque. Even with improved designs (e.g., adding occlusal rests) and good oral hygiene, there is still a potential risk of damage, which may lead to gingival recession and dental caries.

4. Short lifespan: Invisible dentures are prone to aging, discoloration, deformation, and loss of retention, resulting in continuous decline in function and aesthetics over a short period.

5. Damage cannot be repaired: There is no chemical bonding with traditional soft liner resins or artificial teeth.