Evaluating effect of Implant Inclination and type of Abutment on Biomechanics of Implant prosthesis

Abstract

Background: Implant-supported prostheses are a reliable treatment for edentulous and partially
edentulous patients. However, biomechanical complications such as marginal bone loss and screw
Loosening may arise due to improper implant angulation and abutment selection. Implant inclination
alters the direction of occlusal force transmission, while abutment type influences the load distribution
pattern. Understanding these factors is critical to optimising long-term success and prosthetic stability.
Materials and Methods: This in vitro study was conducted to evaluate the biomechanical effect of varying
implant inclinations (0°, 15°, and 25°) and two types of abutments (straight and angulated) on stress
distribution in implant-supported prostheses. A total of 12 polyurethane mandibular models were used.
with implants placed in the second premolar region at different inclinations. Strain gauges were bonded
to record microstrains under static vertical load (100 N). A finite element analysis (FEA) was also
conducted to validate stress patterns. The main outcomes included strain levels around implants and
stress distribution in abutments and crowns.
Results: Implants with 0° inclination and straight abutments showed the lowest strain values
(245.3 ± 21.7 με), while 25° inclined implants with angulated abutments recorded the highest strain
(487.6 ± 30.4 με). The FEA results corroborated the experimental findings, indicating increased stress
concentration around the cervical region of inclined implants. A statistically significant difference was
observed between groups (p < 0.01). Angulated abutments partially compensated for inclined implant
placement, but did not eliminate unfavorable stress patterns entirely.
Conclusion: Implant inclination significantly influences the biomechanical behavior of implant-supported
prostheses. While angulated abutments can reduce stress concentrations, optimal outcomes are achieved
when implants are placed with minimal inclination. Proper implant alignment during placement should
Be prioritised to ensure longevity and stability of the prosthesis.
Keywords: Implant inc