Clinical Performance of Narrow Versus Standard Diameter Dental Implants: A Comparative Retrospective Split-Mouth Study.

Aim: To compare the clinical performance of narrow diameter implants (NDIs) to standard diameter implants (SDIs) over a minimum three-year follow-up period, focusing on different anatomical locations and prosthetic designs.

Materials and methods: This retrospective study analyzed 100 MIS LANCE and SEVEN dental implants with an internal hex connection (50 NDIs, 3.3mm; 50 SDIs, 3.75-4.2mm) placed in 43 patients (mean age 52 years). Implants were evaluated in three configurations: homologous split-mouth design, different arches, and same arch/segment. Marginal bone loss (MBL) was measured using periapical radiographs. Technical complications were recorded and survival rates were calculated.

Results: There was no failure of either implant type during a mean follow-up of 4.2 ± 0.8 years. There were no statistically significant differences in MBL between the implant types, with mean values of 0.83 mm for NDIs and 0.87 mm for SDIs. Similarly, there were no significant differences in MBL between jaws, locations or between splinted and non-splinted restorations. However technical complications including one abutment screw fracture (2%) and two cases of abutment screw loosening (4%) were only noted with NDIs.

Conclusions: The clinical outcomes of NDIs with an internal connection were comparable to SDIs in terms of survival rates and marginal bone loss over a three-year period. While technical complications were only seen in NDIs, the overall performance supports their use as a viable alternative to SDIs, particularly in cases with limited bone width or restricted interdental spaces. The outcomes of single and splinted restorations were similarly favorable in the anterior or posterior regions of both jaws.