Resumen:
Background/Objectives: Perforation of the maxillary sinus floor by dental implants is a complication that can occur during treatment in posterior sectors; however, its clinical and radiological consequences remain controversial. Therefore, this study aimed to use the diagnostic value of CBCT to determine the possible association between sinus floor-perforating implants and their clinical and/or radiological impact. Methods: A retrospective observational study was conducted on CBCT scans from 21 patients with implants protruding into the maxillary sinus. Morphometric analysis was performed to assess sinus membrane thickening (SMT) patterns, height, surface area and density and the presence of sinonasal symptoms. Statistical analysis was used to explore potential associations between SMT and variables such as implant protrusion length, number of perforating implants, age and gender. Results: SMT was observed in all patients, with a mean area of 11.1 ± 6.4 mm2 in panoramic sections. Most cases (85.7%) exhibited a circumferential SMT pattern. No statistically significant correlation was found between SMT and implant protrusion length, age or sex. Additionally, none of the patients reported sinonasal symptoms, and no clinical signs of sinusitis were detected during follow-up. Conclusions: Although sinus floor-perforating implants commonly induce SMT detectable on CBCT, this thickening appears largely asymptomatic and may not compromise patient well-being in the short term. Nevertheless, clinicians should monitor these cases radiographically to detect possible long-term complications.