Marginal and internal fit accuracy of single-crown restorations: the impact of digital and conventional impression techniques


TOPDAĞI B., Guler C. C., Sultanoglu E. G.

BMC Oral Health, cilt.26, sa.1, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 26 Sayı: 1
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1186/s12903-025-07491-0
  • Dergi Adı: BMC Oral Health
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CINAHL, EMBASE, MEDLINE, Directory of Open Access Journals, Natural Science Collection (ProQuest), Biological Science Database (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
  • Anahtar Kelimeler: Digital impression, Conventional impression, Single-crown restoration, Marginal fit, Internal fit, Micro-computed tomography
  • Sağlık Bilimleri Üniversitesi Adresli: Evet

Özet

Background: In this study, we aimed to compare the marginal and internal fit of single-crown restorations fabricated using digital and conventional impression techniques, and to evaluate the potential advantages of digital impressions over conventional polyvinyl siloxane-based methods. Materials and methods: A total of 120 extracted maxillary first molars were randomly assigned to two groups (n = 60 each): the conventional impression group (polyvinyl siloxane) and the digital impression group (TRIOS 3 intraoral scanner, 3Shape A/S, Copenhagen, Denmark). Standardized tooth preparations and CAD/CAM fabrication (IPS e.max CAD, Ivoclar Vivadent AG, Schaan, Liechtenstein) were performed for all samples. Marginal and internal fit were assessed using both the silicone replica technique and micro-computed tomography (micro-CT). Measurements were analyzed using independent samples t-tests. Intraobserver and interobserver reliability were evaluated using intraclass correlation coefficients (ICC). Results: The digital impression group demonstrated significantly smaller marginal and internal gaps compared to the conventional group in both evaluation methods. In silicone replica analysis, marginal gaps were 45.8 ± 6.7 μm (digital) and 61.3 ± 7.5 μm (conventional) (p < 0.001); internal gaps were 84.5 ± 10.8 μm (digital) and 102.7 ± 12.1 μm (conventional) (p < 0.001). Micro-CT analysis confirmed these findings with marginal gaps of 43.2 ± 5.9 μm (digital) and 59.8 ± 6.4 μm (conventional) (p < 0.001), and internal gaps of 81.3 ± 9.6 μm (digital) and 98.4 ± 11.3 μm (conventional) (p < 0.001). Intraobserver and interobserver ICC values exceeded 0.95, indicating excellent measurement reliability. Conclusions: Digital impression techniques provided significantly superior marginal and internal adaptation compared to conventional polyvinyl siloxane-based impressions for single-crown restorations. The improved accuracy, combined with workflow efficiency and patient comfort, supports the clinical adoption of digital impression systems.