Any temporary/removable dental prosthetic that rests on one or more dental implants or roots of natural teeth or remaining natural teeth is referred to as an overdenture. In the field of preventive dentistry, overdentures are considered to be among the most practical solutions. These dental prosthetics can be immediate or conventional, i.e., implant or tooth supported. It slows down the process of complete edentulism and the preservation of alveolar bone.
A denture that is held in place by attaching the base to implants, prepared roots, or one or more teeth is called an overdenture.
Unlike full dentures, an overdenture is a great option for seniors with few remaining teeth. In addition, this dental prosthetic is removable, as it is not permanently fixed in the mouth.
The roots left in the upper jaw (maxilla) aid in the prevention of bone resorption – which is one of the main advantages of overdentures compared to full dentures; This also helps improve the sensory aspect – considered to be another advantage. The sensation is significantly enhanced as the nerves are still present in the roots.
To keep overdentures from causing any additional problems, the gums around the teeth must be relatively healthy.
Depending on the nature/type of abutment used for support, overdentures can be divided into two main categories:
Overdentures Supported By Teeth
Natural tooth structures are used to support this type of overdenture. The teeth used for support are prepared through coronal modification and elective root canal treatment. As such, before contouring the tooth structure above the gum, the crowns and pulpal tissue of the natural teeth are removed. As a result, the distribution of occlusal stress over the support teeth and associated soft tissue is perfectly balanced. Furthermore, the process of resorption in the jaw is slowed down significantly through the retention of natural teeth in the jaw.
The following are some of the factors influencing the selection of support (abutment) teeth:
Every quadrant should have one support tooth – preferably a canine tooth – to ensure sufficient support.
Endodontic Treatment Feasibility
In order to facilitate the installation of the overdenture without affecting the bite, the crown of the support teeth must be removed in most cases; This makes removing the pulp a must. There is no need for endodontic treatment if the root canals of the support teeth are not destroyed. It’s improper to choose teeth with non-negotiable root canals as support teeth.
Overdentures Supported by Implants
Implant-supported overdentures are an excellent option for edentulous patients with enough bony ridges on their jaws. The intraoral tissues and dental implants provide the necessary support for this type of overdenture. In addition to reducing bone resorption, an implant-supported overdenture also ensures better prosthesis stability. On the other hand, a traditional complete denture is considered an alternative since less treatment time is required.
Overdentures have many benefits compared to the typical partial or full removable prosthesis. Both dental implants and natural roots left in place can be used to support overdentures. A great option even for patients with no teeth at all, implant-supported dentures can be either removable or fixed. This overdenture offers the same advantages as its root-supported counterparts.
Proprioceptive impulses are maintained, making it possible for patients to control occlusal forces the same way they did with natural teeth as they are aware of occlusal contacts, with the retention of roots for overdenture use and preservation of the periodontal membrane. It’s worth noting that patients tend to struggle with the loss of proprioception.
Jaw Bone Resorption
Bone resorption occurs when teeth roots are removed. This occurrence tends to be most significant in the mandible and can be mitigated through the retention of roots. Focusing on patients with immediate overdentures on two lower canines and on those with immediate complete dentures. In the interior part of the mandible, 5.2mm bone loss in the immediate complete dentures group and 0.6mm in the overdenture group were recorded over five years after installation. Patients gain functional and psychological benefits with reduced bone loss, which ensures improved retention and stability of the overdenture.
Patients can also enjoy an improved quality of life with the preservation of the alveolar ridge – especially in the lower prosthesis, which may enhance aesthetics, phonetics, chewing, and comfort. In addition, unlike with a prosthesis supported by tissue, a fixed implant retained denture is supported entirely by implants, thus preventing further resorption of the alveolar ridge; This can also improve the health of soft tissue.