Sir, a patient who sustained a facial burn during a routine bond-up procedure in which 37% phosphoric acid etch was used (Fig. 1) is a timely reminder of the potential hazard of acid burns to the skin during procedures using dental etching. A number of materials can be used for etching, but the most common approach is to use 30-40% phosphoric acid in the process of 'total etching'.

Figure 1
figure 1

Patient who sustained a facial burn during a routine bond-up procedure

Full size image

At present there are no formal guidelines on precautions, however, these can include using etch in the form of a coloured gel to allow for identification and prevent unwanted spreading of acid. Furthermore, etch should only be left in contact with the tooth for 30-40 seconds and then be removed using cotton wool followed by high speed aspiration. During the procedure, surrounding teeth can be protected using cotton wool rolls or a rubber dam and the patient should wear protective glasses and a bib. The application brush used to apply etch should not be overloaded and a direct application syringe can be used rather than transferring etch into a Dappens pot and then to the tooth.

Clinical features suggestive of a burn following the use of etch are the development of an area of erythema or an area of intense pain. If a burn is suspected then the most important intervention is to thoroughly irrigate the area using running water, taking care not to spread the acid from the affected area. Irrigation should be continued until such a point that the patient no longer feels pain in the affected area. If the acid contamination involves the eye then the eye should also be immediately irrigated very thoroughly.

Further treatment will depend upon the depth and extent of the burn but all patients sustaining facial burns should attend their local hospital, usually via Accident & Emergency.