Influence of occlusal thickness and aging on the fracture load of additively manufactured definitive crowns in different resins
Journal of Prosthodontics, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1111/jopr.70174
- Dergi Adı: Journal of Prosthodontics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE, Natural Science Collection (ProQuest), Biological Science Database (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
- Anahtar Kelimeler: additively manufactured crowns, aging condition, fracture load, occlusal thickness, thermomechanical aging
- Ankara Üniversitesi Adresli: Hayır
Özet
Purpose: The purpose of this in vitro study was to assess the effects of occlusal thickness and thermomechanical aging on the fracture load of additively manufactured (AM) definitive crowns made from resins with different compositions, compared with crowns subtractively manufactured (SM) from a polymer-infiltrated ceramic network. Materials and Methods: Crowns were designed using scans of three mandibular first molar typodonts prepared with occlusal reductions of 1, 1.5, or 2 mm. These designs were used to fabricate crowns either additively (FREEPRINT Crown [AM-FC], Rodin Sculpture [AM-RS], and Rodin Sculpture 2.0 [AM-RS2]) or subtractively (Enamic [SM-VE]) (N = 14). The same typodont scans were used to additively manufacture resin abutments, and each crown was cemented onto its corresponding abutment using a dual-polymerizing resin cement. After cementation, crowns were randomly assigned to nonaged or aged groups (n = 7). Crowns in the aged groups were subjected to thermomechanical aging before load-to-fracture testing, whereas crowns in the nonaged groups were tested without having been aged. Fracture load data were analyzed with a generalized linear model and Bonferroni-corrected post hoc tests (α = 0.05). Results: All crowns survived thermomechanical aging. Fracture load values were significantly affected by material type, occlusal thickness, and aging, as well as by the two-way interactions involving aging (p ≤ 0.003). SM-VE crowns showed the lowest loads, regardless of the aging condition within each thickness (p ≤ 0.024). While aging did not reduce the fracture load of subtractively manufactured crowns, it reduced the fracture load of additively manufactured crowns and across all occlusal thicknesses (p < 0.001). Among all nonaged crowns, 2-mm crowns had the highest fracture load, whereas in the aged groups, 1.5-mm crowns demonstrated the lowest fracture loads (p < 0.001). Conclusions: Additively manufactured crowns exhibited higher fracture load than subtractively manufactured crowns made of polymer-infiltrated ceramic network despite their reduced strength following thermomechanical aging. The influence of occlusal thickness on fracture load depended on the aging condition, with all additively manufactured crowns showing a reduction in strength after aging.