Relining and Rebasing of Partial Dentures

Indicated when the fit has worsened resulting in an unstable denture or tissue trauma.

RELINES

Relining is the replacment of the fitting surface with a new material. Usually cold or heat cured acrylic or tissue conditioner. This can be carried out at directly (chariside) or indirectly (lab).

INDIRECT PARTIAL DENTURE RELINES

The procedure is described below.

Check the extensions of the saddles (reduce or add to if necessary). Grind out any undercuts in the acrylic of the fitting surface, this is because the reline impression material may flow in to undercuts of the natural teeth, which when replaced with acrylic would result in a denture that would not fit without extensive trimming. A zinc oxide wash impression is taken on the fitting surface of the denture, with the patient occluding gently. This prevents the occlusion being affected by the reline. In the laboratory the zinc oxide is replaced with heat cured acrylic to provide a better fitting denture that is well adapted to the patients oral tissues.

DIRECT RELINES

Materials used for this are cold cured acrylic or tissue conditioners (eg Viscogel or Fit). These are good short term solutions but their clinical life is limited and a more permanent material must eventually be used.

Cold cured acrylic reline using Total:

The flanges and some of the fitting surface a removed making sure there are no remaining undercuts. The fitting surface is then treated with Grab, an adhesive Total is then mixed and loaded on to the fitting surface and border moulding is carried out It is kept in the mouth until rubbery, which is about 5 minutes It is then cured in a hydro-flask for 10 minutes This will last for about 6 months. The method above is very similar to that of Viscogel.

REBASING

This is the replacement of the palate of the denture with a new one of orthodox thickness. The procedure for this the same as for complete dentures. The flanges are reduced and border moulding with cold cured acrylic is carried out. Holes are cut into the palate and an impression paste wash impression is taken on the fitting surface of the denture. The teeth should be gently in occlusion when the impression is being taken so as not to alter the occlusion.