some functional movement to prevent replacement root resorption (ankylosis). As a
general rule exarticulation (avulsion) injuries require 7-10 days and luxation injuries
2-3 weeks of functional splinting.
ROOT FRACTURES
These require 4 weeks of functional splinting. Individual cases may require longer
splinting. Excessive mobility leads to the fracture site becoming filled with
granulation tissue.
DENTOALVEOLAR FRACTURES
These require 3-4 weeks of rigid splinting.
Types and methods of constructing splints
COMPOSITE RESIN/ACRYLIC AND WIRE SPLINT
This method uses either a composite resin or a temporary crown material. The
composite resin is easier to place but the acrylic resin is easier to remove. Although
acrylic resin does not have the bond strength to enamel as the composite resin it is
suitable for all types of functional splinting (725HFig. 12.33).
Technique for a functional resin-wire splint:
- Bend a flexible orthodontic wire to fit the middle third of the labial surface of the
injured tooth and one abutment tooth either side. - Stabilize the injured tooth in the correct position with soft red wax palatally.
- Clean the labial surfaces. Isolate, dry, and etch middle of crown of teeth with 37%
phosphoric acid for 30 s, wash, and dry. - Apply 3-mm diameter circle either of unfilled then filled composite resin or of
acrylic resin, to the centre of the crowns. - Position the wire into the filling material then apply more composite or acrylic
resin. - Use a brush lubricated with unfilled composite resin to mould and smooth the
composite. Acrylic resin is more difficult to handle and smoothing and excess
removal can be done with a flat plastic instrument. - Cure the composite for 60 s. Wait for the acrylic resin to cure.
- Smooth any sharp edges with sandpaper discs.
726HFigure 12.33 shows an example of a functional splint. For a rigid splint use the same
technique but incorporate two abutment teeth on either side of the injured tooth. These
splints should not impinge on the gingiva and should allow assessment of colour
change and sensitivity testing.
ORTHODONTIC BRACKETS AND WIRE