Objectives:: Maxillary sinus augmentation is a well-documented procedure with long-term success in implant dentistry. Assessing graft volume changes over time is crucial, since resorption remains a major concern. CBCT is commonly employed to assess the quantity and quality of the available bone at the implant receptor site. However, its applicability in following graft volume changes is yet to be determined. The study aimed to assess CBCT accuracy in following simulated graft resorption ex vivo.
Methods:: 4 differently sized autogenous bone blocks harvested from the zygomatic buttress were bilaterally placed in the maxillary sinus of 12 human cadavers. The Accuitomo (J Morita, Kyoto, Japan) CBCT system was employed to scan each one of the 4 grafts in each of the 12 cadavers using identical settings. Gold standard graft measurements were obtained using micro-CT. One independent observer assessed the volume of each graft on CBCT images twice. Intraobserver reliability was assessed using Cohen's kappa and one-sample t-test was used to compare CBCT with micro-CT volumetric measurements.
Results:: The mean micro-CT graft volumes were 97.12 ± 1.4, 197.32 ± 3.4, 361.41 ± 4.2 and 1040.11 ± 3.2 mm3 for Grafts 1-4, respectively, and the mean CBCT volumes of the corresponding grafts were 115.39 ± 7.01, 205.97 ± 9.91, 404.05 ± 16.81 and 1138.04 ± 20.98 mm3. CBCT measurements were statistically significantly different from micro-CT measurements (p = 0.001). Intraobserver reliability was good (r = 0.78).
Conclusions:: In every case, CBCT overestimated the maxillary graft volume in comparison with micro-CT. However, the measurement differences were limited and might not influence clinical performance.
Keywords: CBCT; dental implants; sinus floor augmentation.