Armamentarium
(1) rubber dam;
(2) zinc phosphate or IRM cement;
(3) 37% phosphoric acid;
(4) bleaching agent, for example, hydrogen peroxide, carbamide peroxide, or sodium
perborate;
(5) cotton wool;
(6) glass ionomer cement;
(7) white gutta percha temporary restorative;
(8) composite resin;
(9) non-setting calcium hydroxide.
Technique
- Take preoperative periapical radiographs; these are essential to check for an
adequate root filling (524HFig. 10.2 (a)). - Clean the teeth with pumice and make a note of the shade of the discoloured tooth.
- Place rubber dam, isolating the single tooth. Ensure adequate eye and clothing
protection for the patient, operator, and dental nurse. - Remove palatal restoration and pulp chamber restoration.
- Remove root filling to the level of the dentogingival junction⎯you may need to
use adult burs in a mini-head (525HFig. 10.2 (b) and (c)). - Place 1 mm of cement over the gutta percha.
- Freshen dentine with a round bur. Do not remove excessively.
- Etch the pulp chamber with 37% phosphoric acid for 30-60 s, wash, and dry⎯this
will facilitate the ingress of the hydrogen peroxide. - Place the bleaching agent, either alone or on a cotton wool pledget into the pulp
chamber. Place into the tooth, either alone with a flat plastic instrument or on a
cotton-wool pledget. - Place a dry piece of cotton wool over the mixture.
- Seal the cavity with glass ionomer cement.
- Repeat the process at weekly intervals until the tooth is slightly overbleached.
- Place non-setting calcium hydroxide into the pulp chamber for 2 weeks. Seal with
glass ionomer cement. - Finally, restore the tooth with white gutta percha (to facilitate reopening the pulp
chamber again, if necessary, at a later date) and composite resin.