Objectives The aim was to investigate practice-level variation in common dental diagnostic, preventive, and care services provided for Danish adults who underwent a dental examination.

Methods This was a nationwide register-based study. Subsidized dental services delivered during the 13-week-period subsequent to the provision of one of three eligible dental examinations (extended, basic, or recall examination) during the first nine months of 2019 were investigated. Bayesian multilevel regression models were used to estimate the practice-level average predicted probability of supragingival care, subgingival care, individual prevention, bitewing radiographs, and endodontic treatment, and the average predicted count of extractions and direct restorations while adjusting for individual sociodemographics and dental treatments received during the previous 10 years.

Results The final sample included 445,516 examinations conducted in 1,593 dental practices. Supragingival care after basic or recall examinations showed the lowest practice-level variation, with around two-fold difference between top and bottom 2.5%. Individual preventive services after recall examinations showed the highest variation with over 30-fold difference between top and bottom 2.5%. All other outcomes showed around 3- to 8-fold differences between practices at top and bottom 2.5% across all examination types. The differences across practices were smaller—1.2- to 3.0-fold—when the top 25% and bottom 25% were compared instead.

Conclusions This study found considerable variation in diagnostic, preventive, and treatment services provided for Danish adults who underwent a dental examination. The findings highlight the need for research that can inform evidence-based practice through the development of quality clinical practice guidelines, continuing education programs, and closer surveillance of care delivery.

The authors have declared no competing interest.

We thank the Danish Rheumatism Association (Gigtforeningen, #R171-A5894) for the financial support.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Register-based studies do not require individual informed consent. The study was approved by the Danish Data Protection Agency (2015-57-0002) and Aarhus University (2016-051-000001-914).

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