Jeong-Kui Ku, Academic Committee – Oral Surgery Division (Long-Term Clinical Outcomes of Single Short Implants in the Mandibular Molar Region)

http://www.jdir.org/journal/view.html?doi=10.54527/jdir.2023.42.1.1

1. Purpose
To retrospectively evaluate the long-term outcomes (survival, success, marginal bone loss) of 7 mm and 8 mm single short implants placed in mandibular molar regions.

2. Methods Study Period
November 2005 – February 2014 Subjects: 81 patients with 7 mm or 8 mm mandibular molar implants Evaluation Parameters: Survival (Kaplan–Meier analysis) Success (Albrektsson criteria) Marginal bone loss (digital panoramic radiographs) Additional: Crown/implant ratio, initial/secondary stability (ISQ), healing time

3. Results
Mean follow-up: 7.0 ± 2.8 years Overall survival: 96.3% Success rate: 93.3% Marginal bone loss: 0.5 ± 0.8 mm (mean) No significant differences between 7 mm and 8 mm implants Survival: 93.8% vs 98.0% Success: 90.6% vs 95.9% Main complications: peri-implantitis, screw loosening, osseointegration failure Average crown/implant ratio: 1.6 (all prostheses designed with ≤3 mm cantilever)

4. Discussion
Only 6.2% of implants showed annual bone loss ≥1.5 mm or ≥0.2 mm. Mean marginal bone loss was just 0.5 mm. After 7 years of loading, survival remained high (96.3%), comparable to standard-length implants. Wide-diameter short implants increase contact surface but may elevate biomechanical stress. This study showed favorable results even with 5.3 mm–wide implants, suggesting wide diameters are not always necessary. All implants featured internal connection and platform switching, advantageous for stress distribution. Short implants can serve as minimally invasive, cost-effective alternatives without bone grafting.

5. Conclusion
Single 7 mm and 8 mm mandibular molar short implants, with modern surface treatment and internal connection, demonstrate high survival and success rates, confirming their reliability as a treatment option.