Long-term clinical outcomes for single dental crowns versus extensive direct restorations: A register-based cohort study with up to 10 years of follow-up in a Swedish population
Year: 2025
Type: article
Study design: Observational Study
Abstract: OBJECTIVE: There is a lack of consensus regarding the optimal method for restoring teeth with extensive defects. In particular, it is not clear whether a direct restoration (tooth filling) can achieve comparable tooth survival rates to a dental crown (indirect restoration). This study compares the survival rates with up to 10 years post-intervention for large direct restorations (fillings involving three or more surfaces) with those of indirect restorations (single crowns), using a large dataset. METHODS: All patients (N = 189,195) who received either single crowns (indirect restorations) or direct restorations (involving three or more surfaces) between 2014 and 2019 in the public dental clinics of a Swedish region were followed retrospectively for a period of 5-10 years (N: 343,809 teeth). Outcome measures included tooth extraction, root canal treatment, and retreatment with either direct or indirect restorations. RESULTS: The 10-year cumulative survival rates were 92.77% for indirect restorations and 89.09% for direct restorations. Direct restorations were associated with a significantly greater need for retreatment over the 10-year period compared to indirect restorations. Specifically, the incidence rate ratio (IRR) for retreatment among direct restorations was 1.59 (95% CI 1.578-1.611) relative to indirect restorations. Previous root canal treatment or the presence of a post and core significantly increased the risk of extraction, with hazard ratios of 2.90 (95% CI 2.8389-2.9824) and 1.40 (95% CI 1.3269-1.4928), respectively. CONCLUSION: Teeth restored with large direct restorations tended to require more frequent retreatments and showed a higher risk of extraction over a period of up to 10 years compared with teeth restored with indirect restorations. This trend was particularly evident among non-vital teeth, especially those with a post and core or previous root canal treatment. However, due to the retrospective design and potential inclusion bias, these findings should be interpreted with caution. CLINICAL SIGNIFICANCE: Within the limitations of this retrospective, non-randomized study, teeth restored with large direct restorations appeared to have slightly lower long-term survival and a somewhat higher need for retreatment than teeth restored with crowns. Because treatment selection was based on clinical judgment and tooth condition rather than random allocation, the observed differences likely reflect both treatment choice and case complexity. Future studies using matched cohorts or randomized designs are needed to clarify the causal relationship between restoration type and long-term tooth survival.
Source: Journal of Dentistry
Authors: Julia Olander, Jan Kowar, Sargon Barkarmo
Institution: University of Gothenburg
Language: English
Subfield: Orthodontics
Field: Dentistry
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,160
OpenAlex ID: W4416703229