Materials & Methods: This study was conducted in the department of Prosthodontics. It included 25 dental implants. Data regarding name, age, gender, diameter of implant and bone quality were considered and evaluated.

Results: A total of 25 patients were included in the present study which underwent prosthetic rehabilitation for missing mandibular first molar by dental implants. Out of 25 dental implants, failure of dental implants occurred in 3 cases.

Conclusion: Dental implant failure is one of the challenges for dentist. Factors such as implant diameter, quality of bone play important role in survival rate of dental implants. Dental implant with diameter < 3.75mm and in type II bone showed maximum failures.