Influence of X-ray beam angulation on the radiographic detection of implant-abutment interface misfits: A...

This study evaluated the effect of periapical X-ray angulation on the diagnostic accuracy of detecting vertical misfits at the implant-abutment interface using Medentika Microcone dental implants (4.0 mm diameter, 11 mm length; internal conical connection).

Standardized abutment-implant assemblies were tested using four polyvinyl chloride (PVC) spacer thicknesses (50, 100, 150, and 200 µm) and 0 thickness as a control group. For each thickness group, 13 digital radiographs were taken at angles ranging from 0° to ±30° in 5° increments. Vertical discrepancies were measured using calibrated CS Imaging Software. Each image was measured seven times for consistency by the same experienced radiology resident. Data were analyzed using the Shapiro-Wilk test for normality, followed by Kruskal-Wallis and Wilcoxon signed-rank tests.

Measurements across all PVC thickness groups demonstrated statistically significant differences (p < 0.05). In the 0-µm group, minimal variability was observed across angulations except at +20° to +25° and -20° to -25°. The 50-µm and 100-µm groups showed significant reductions in vertical misfit between +15° to +20° and -15° to -20°. The 150-µm and 200-µm groups exhibited increased detectability, with significant differences in both positive and negative directions as the projection angle increased, specifically between +20° and +25° for the 150-µm group and between +25° to +30° for the 200-µm group.

Within the limitations of this in vitro study, diagnostic performance varied with projection angulation and misfit magnitude. For the tested configurations, certain angulations (approximately 15°-25°) showed higher diagnostic performance metrics; however, these findings should not be interpreted as a clinical recommendation and require validation under clinical conditions.