Mechanical properties of an implant titanium base abutment with a new biologically inspired design.

OBJECTIVES

Abutment design in the esthetic zone must support peri‑implant soft tissues while maintaining sufficient mechanical strength. This in vitro study evaluated the fracture resistance of two commercial titanium-base (Ti-base) abutments and two customized Ti‑bases featuring biologically inspired, soft‑tissue-oriented geometries.

METHODS

Four groups were tested: A: commercial Ti‑base (transmucosal height 2.0 mm; bonding-base height 4.0 mm); B: commercial Ti‑base with increased bonding-base height (8.0 mm); C: customized Ti‑base with an anatomically contoured margin (mesial and distal areas 1.5 mm, and palatal area 1.0 mm more coronal than the vestibular margin; transmucosal height 2.5 mm; bonding‑base height 4.0 mm); D: customized Ti‑base with contoured margin and channel for angled screw (transmucosal height 2.5 mm; bonding‑base height 4.0 mm). Abutments were tightened onto implant analogs and subjected to static load-to-fracture testing using a universal testing machine (Instron). One‑way ANOVA and Tukey post‑hoc tests were applied (α = .05).

RESULTS

Statistically significant differences were detected among groups (p < 0.0001), however no statistically significant difference was found between group B and D (p = 0.0685). Mean fracture resistance values (N ± SD) were: Group A, 873.2 ± 18.2; Group B, 570.2 ± 34.3; Group C, 1068.5 ± 75.5; Group D, 631.6 ± 66.0. Yield point values were: Group A, 755 ± 17.6; Group B, 468.8 ± 31.8; Group C, 885.2 ± 28.1; Group D, 608.4 ± 85.9.

CONCLUSIONS

Within the limitations of this in vitro mechanical evaluation, the anatomically contoured customized Ti‑base demonstrated the highest fracture resistance.

CLINICAL SIGNIFICANCE: The use of a Ti-base with anatomically scalloped shoulders (1.5 mm interproximal elevation, 1.0 mm palatal elevation) demonstrated superior mechanical properties (1068.5 N fracture load) compared to conventional designs (873.2 N), suggesting potential clinical advantages for managing esthetic cases with scalloped-thin gingival phenotypes, while maintaining fracture resistance above physiological loads (90-390 N). However, clinical validation and fatigue testing are required before widespread adoption.