What Happened Next? The Definitive General Dental Services Evidence Base

 Objectives:

1. to quantify the relative frequencies of different re-interventions on the same tooth following restoration, classified by type of restoration
2. to assess whether these frequencies differ between early and late re-intervention.

 Methods:

All records for patients who received restorations in the calendar year 1993 were extracted, and each restoration was associated with the time interval and type of next intervention, including extraction but ignoring maintenance treatments. Frequency matrices showed the types of intervention and corresponding re-intervention within 730 days (two years) and in 731 to 3652 days (2-10 years). The analysis was replicated for 1992 and 1994.

 Results:

1,075,218 restored teeth were tracked, of which 438,281 (41%) received re-intervention within ten years, and 182,587 (17%) within two. While the most common re-intervention is a repeat of the initial type, at around 65% for both amalgam (n=245,010) and resin composite (n=100,418), for glass-ionomer the proportion drops from 40% in two years (n=30,077) to 28% in 2-10 years (n=34,264), while for crowns the proportion of extractions rises from 26% (n=8,109) to 34% (n=17,241). Standard errors are all well below one percentage point and can be inferred from the sample size (n). 1992 and 1994 showed the same pattern.

Conclusion:

The newly released dataset provides robust evidence for outcomes in the General Dental Services. While the most likely early re-intervention is generally of the same type as the previous intervention, later re-interventions are more likely to be different for crowns and glass-ionomer restorations.