The Monoreductor - MultiSafe Lock (abridged version)

Where the reduction in dentition consists of more than one tooth, on one side of the jaw, the solution can be difficult, laborious or uncomfortable for the patient. Read, about the possibilities for the treatment of curtailed free end edentulous ridges by using the ‘Degudent multiSafe Lock’.

Description

A monoreductor is a one-sided prosthesis. This fills in free ends of free end edentulous ridges. The prosthesis is not supported by a tooth at its end; it rests on the jaw ridge on one half of the jaw. The construction principles of this type of prosthesis are based on a precision mechanical attachment element, the keyslide, which is attached to terminal crowns. The removable part of the prosthesis is fixed to this key-slide and prevents accidental removal
There is a small spring-loaded bolt in the removable secondary element, which ensures the firm attachment of the denture base. Pressed for prosthesis removal, this will spring back into the final position after insertion.

Applications

if a prosthesis or bridge mounted on an implant is not appropriate, then the two premolars are crowned and the molars are replaced by a monoreductor prosthesis. The premolar columnar teeth must be stable parodontally and fulfil the requirements of bridge abutments for fixed dental replacement.
The base should be made with as large an area as possible to facilitate a good distribution of pressure and torsion and also to avoid detrimental forces impinging on the abutment teeth and the slide-element.

Construction options

A solution of short posterior saddles using a precision mechanical element can be achieved in two ways:

RSS solution

Treatment of the terminally present teeth with blocked metal-ceramic faced crowns in which a horseshoe shaped groove is created in each crown permits the coupling to the removable part.
The leverage on the bridge abutment is not altered; the aesthetic and constructive advantages are a benefit for the whole denture.

Telescope solution

The second fundamental variation is based on the provision of telescopic crowns. These are also primarily blocked. Here, the attachment to the abutment teeth is achieved by the equally blocked secondary crowns, which are usually faced with composite.

Choosing a construct

Whether to use an RSS or telescopic attachment is a matter of choice and is dependent to a large degree on the existing clinical situation. The majority of monoreductors that we make are RSS variants.
The advantages are using tooth coloured anchor teeth with ceramic facings, and the retention provided by the abutments, when the denture is removed. The height of the bite is also ensured.
The telescope variant gives a slightly better fixing, with an easier handling on insertion. It does, however, require considerably more room due to the construction based on primary and secondary crowns. This requires a greater loss of original tooth material during preparation and there is a risk that the final monoreductor is too bulky. When the denture is removed, the primary crowns are visible as metal caps, especially in the lower jaw.

Advantages:

• The integrated attachment is very good at absorbing all the forces arising and simplifies insertion by the patient.
• Only high-quality materials (Degulor, HSL, etc.) are used
• Automatically fits into the primary component.
• Is released automatically by a short pressure on the slide axis
• Compact housing for difficult space conditions.
• Increased resorption of the alveolar ridge is avoided by regular relining.
• Longevity and a high degree of comfort for the patient if prepared according to their needs and checked on a six-monthly basis.

Disadvantages

• Demands a certain amount of dexterity and practice on insertion. Special consideration with older people!
• If one of the abutment teeth is lost, the denture cannot be rescued!
• Also: cannot be extended.
• Needs to be particularly well-serviced in the upper jaw, when the saddle is affected by gravity

Alternatives

• Removable cast denture with a sublingual arm or plate with cast clasps on the opposite side. A cost-effective solution with all the disadvantages of the clasp cast
• Acrylic denture with curved metal clasps – no comment!
• Implants, either as single implants or an implant bridge. Excellent and even more comfortable, but also the most expensive variant. Always associated with a clinical intervention.
• Combination of abutment teeth, implants and slides are common possible alternatives.
• Cantilever bridge fixed alternative for the replacement of one tooth only up to premolar width. A cantilever bridge is a fixed bridge that attaches to adjacent teeth on one end only.

Conclusion

The MultiSafe is, with correct construction, a good and long-lived functional dental replacement when relined at regular intervals.The MultiSafe is an effective solution for single free end saddle cases and intermediate in cost between dentures and implants.