Sir, we write to express support for the views of Dr Larah in his letter (BDJ 2012; 213: 49). He states that, as part of the consent process, he would like to be able to quote accurate success rates for the various restorative dental procedures that general dental practitioners carry out daily and suggested that prior to 2006, the Business Services Authority (BSA), previously the Dental Practice Board (DPB), held meaningful data. Such data are indeed available!

In 1991 a suitable dataset was established (of which we were fortunate enough to be part of the working group) at the DPB. A sample of the data was subjected, after ten years, to modified Kaplan Meier survival analysis,1 showing the survival of the 'humble' occlusal amalgam (57%)2 to the survival rates before re-intervention of crowns (68% for metal crowns, 62% for metal-ceramic and 48% for all-ceramic),3 veneers (53%),4 and most recently, bridges (similar survival to crowns).5

A previous publication summarises our work on directly placed restorations,6 in which several common themes emerged including that restoration age at re-intervention decreased with increasing age of the patient,7 and that in the GDS, patients with high frequency of attendance and higher mean gross spend on treatment per annum have restorations which survive less well.4,7 It therefore follows that, for this group of high treatment need (which could be considered a proxy for high caries activity) patients, the restorations represent poorer value for money, for patients who pay charges or for the taxpayer for patients whose charges are remitted. Further, common throughout the analyses was that patients who changed dentist received restorations which did not survive as long as those placed for patients who did not change dentist. This may be considered to occur, perhaps, because dentists tend to judge their own restorations more kindly than those of other dentists.

We agree that these data can be useful when obtaining consent, but we also consider that the data could inform Government on treatments which are appropriate use of taxpayers' money. In this regard, we are excited to advertise the establishment of a new database. The BSA has now deposited an anonymised large longitudinal sample of its data with the Economic and Social Data Service, soon to become part of the UK Data Service. This sample contains the dental treatment details of over a million patients tracked over the period October 1990-March 2006. This dataset is now freely available to all researchers, and indeed the first piece of work from this new dataset, Factors associated with patients changing dentist was seen at the Helsinki IADR PER meeting in September 2012.