Kreyer on Removables: Don't forget about overdentures

March 21, 2012

Root retained overdentures are a clinical and technical treatment option, which should be considered as part of removable prosthodontic treatment. All prosthodontic treatment is dictated by biology with a goal to maintain, not destroy, these biologic considerations. One major biologic consideration is the periodontal ligament that surrounds the roots of each tooth.

Root retained overdentures are a clinical and technical treatment option, which should be considered as part of removable prosthodontic treatment. All prosthodontic treatment is dictated by biology with a goal to maintain, not destroy, these biologic considerations. One major biologic consideration is the periodontal ligament that surrounds the roots of each tooth.

Periodontal ligaments have an array of proprioceptors, which receive mechanical stimulation and are very active during mastication and functional movements in the biologic condition of natural dentition. Proprioception provides patients with information on how much pressure and load they are applying during mastication and parafunctional movements. Proprioception also is linked to sense of mandibular position and movements of the body such as posture.

To maintain biology within the oral environment roots can be saved with endodontic therapy thereby saving periodontal ligaments as well and preserving a patient’s proprioception. The role of proprioception nerve endings in the periodontal ligament and this loss due to extraction of natural teeth has been documented in literature. The discussion regarding implants to replace teeth is: Does the presence of proprioceptive nerve endings in periosteum, muscles of mastication, oral mucosa and temporomandibular joint compensate for those lost from the missing periodontal ligament?

Simple solution

Refer to slideshow for figures.

In this article I will present a simple and effective stud attachment technique for root retained overdentures using the Preci-clix from Preat.

The roots have been endodontically treated then the titanium post is tried into the canal by the dentist before cementation (Fig. A).

After cementation of titanium posts the black impression tools are screwed into post before final impression (Fig. B). An impression of maxillary edentulous arch and impression tool is taken by the clinician and prepared for pouring cast. Impression tool and female analogue are screwed together and the black impression tool is placed into the impression with silver female analogue above intaglio surface ready to be embedded in master cast (Figs. C and D).

The master cast is poured and impression tools remain screwed into female cast analogues (Fig. E). The impression tools also provide a visual aide for parallelism of titanium posts in each root.

Black impression tools are removed from analogues and Preci-clix male balls are screwed in place (Fig. F). O-ring spacers are placed with metal housings and female retention caps over male Preci-clix balls.

An advantage of a ball attachment is its ability to rotate the female on ball, thus decreasing any divergency between abutments. The master casts are next blocked-out and prepared for fabrication of baseplate for records appointment (Figs. G, H, I, and J).
The ability to try-in a baseplate that contains attachments for a root retained overdenture enables the clinician to record accurate records with a stable and retentive base while maintaining the biologic condition of proprioception.

Summary

Root retained overdentures is a treatment option that should be considered before extraction of teeth and implant placement. Maintenance of roots and oral hygiene should always be a consideration as well during design and treatment options.
Root retained overdentures are still a viable treatment option for today’s complete denture prosthetics.