Resistencia a la fractura y el modo de falla de coronas atornilladas incisivas de resina impresa en 3D y zirconio en bases de titanio largas y cortas en implantes de conexión cónica

Abstract

The fracture resistance of screw-retained implant-supported crowns is critical for the long-term success of dental restorations, and both abutment design and material cansignificantly influence their mechanical performance. This study, conducted during 2023–2024, aimed to evaluate the fracture resistance and failure modes of crowns made from 3D-printed resin and zirconia mounted on titanium abutments of two heights: 4 mm (short) and 6mm (long). Forty crowns were fabricated and divided into four groups: Group 1 (resin on 4 mmabutments), Group 2 (resin on 6 mm abutments), Group 3 (zirconia on 4 mm abutments), andGroup 4 (zirconia on 6 mm abutments). All specimens underwent fracture resistance testing,and results were analyzed using the Student’s t-test. Zirconia crowns showed significantlyhigher fracture resistance than 3D-printed resin crowns (p < 0.001), with Group 4 (zirconia +6 mm abutment) displaying the highest mean fracture strength (940.711 N ± 28.147), whileGroup 1 (resin + 4 mm abutment) had the lowest (282.912 N ± 41.351). F values of 1257.725and 2777.538 for the 4 mm and 6 mm abutments, respectively, confirmed the statisticalsignificance. Additionally, the Weibull analysis indicated greater reliability in zirconia crowns,particularly in Group 4, which showed the highest Weibull modulus (m = 30.812), reflectingsuperior structural stability. In conclusion, both zirconia and 3D-printed resin crowns exceededphysiological load thresholds, confirming their suitability for implant-supported anteriorrestorations. However, longer abutments are especially recommended for resin crowns tooptimize fracture resistance and overall performance.