Ceren Elif KENDIRLI, Hamiyet GÜNGÖR, Mehmet Ali KILIÇARSLAN, Lale KARAAĞAÇLIOĞLU
Meandros Medical and Dental Journal - 2026;27(2):210-218
Objective: This study aimed to evaluate how different Ti-base abutment heights (3.5 mm and 5.5 mm) affect the retention of monolithic zirconia crowns placed on straight (0 derece) and angled (15 derece) implants. Material and methods: Sixty monolithic zirconia crowns were fabricated and assigned to four groups according to implant angle and Ti-base height. After CAD/CAM fabrication and standardized cementation, all specimens underwent a pull-out test using a universal testing machine, and maximum force at cement failure (N) was recorded. Due to variance heterogeneity, Welch ANOVA and Tamhane T2 post-hoc tests were used for analysis. Results: Welch one-way ANOVA revealed a statistically significant difference in maximum load among the four experimental models (Welch F(3, 29.49) = 86.08, p < 0.0001). Tamhane T2 post-hoc analysis showed significant differences between all group pairs (p < 0.05), except between Model 1 (0 derece, 3.5 mm) and Model 3 (15 derece, 3.5 mm) (p = 0.862). The highest mean maximum load was observed in Model 4 (15 derece, 5.5 mm) (969.66 N), followed by Model 2 (0 derece, 5.5 mm) (736.24 N), while the lowest value was recorded in Model 3 (15 derece, 3.5 mm) (267.10 N). Overall, specimens restored with 5.5-mm Ti-bases demonstrated approximately a three-fold higher maximum load compared with those restored with 3.5-mm Ti-bases. Conclusions: Implant angulation did not affect maximum load capacity in groups with 3.5-mm Ti-base abutments but produced a significant difference between groups with 5.5-mm Ti-base abutments. Overall, increasing Ti-base height significantly enhanced the maximum load capacity for crown retention. Clinically, using the longest appropriate Ti-base height may reduce the risk of crown detachment, especially in angled implant cases.
