Objectives. This study evaluates the capability and accuracy of near-infrared fluorescence (NIRF) imaging technique in detecting cavities beneath zirconia and ceramic-containing restorations. It compares NIRF with conventional radiography using controlled artificial cavity models and mounted crowns to assess diagnostic accuracy. Materials and Methods. Standardized cavities (1 mm, 2 mm, and 3 mm in diameter; 1.5 mm in depth) were prepared manually on composite blocks (G10) and paired with four classes of ceramic-containing restorative materials—zirconia (3Y-TZP, 4Y-TZP, 5Y-TZP), glass-ceramic (IPS e.max CAD), feldspathic porcelain (VITA Mark II), and resin composite (CERASMART)—at two thicknesses (1 mm and 2 mm). A total of 15 measurements were obtained for each material-thickness-cavity size combination. After sealing the cavities with Cavit, ceramic specimens were cemented using RelyX Universal Resin Cement under standardized protocols. Additional crowns were fabricated and cemented on extracted human teeth to demonstrate clinical application. All samples underwent optical, radiographic, and near-infrared fluorescence (NIRF) imaging. Accuracy was assessed using trueness, precision, and root mean square error (RMSE). Normality of each dataset was first assessed using the Shapiro─Wilk test. For datasets that followed a normal distribution, one-way ANOVA followed by Tukey’s post-hoc test was applied. For non-normally distributed data, the Kruskal-Wallis followed by Dunn’s post-hoc tests was utilized. Results. NIRF imaging demonstrated equivalent accuracy to conventional radiography across all evaluated metrics, including trueness (p = 0.8283), precision (p = 0.5559), and RMSE (p = 0.7973). Importantly, NIRF provided a distinct diagnostic advantage by successfully detecting cavities beneath zirconia specimens (3Y-, 4Y-, and 5Y-TZP), where radiographic images failed due to radiopacity. Detection accuracy declined with increased material thickness and cavity size, with significantly higher RMSE values observed at 2 mm thickness and 3 mm cavity size (p < 0.05). Among all materials, CERASMART consistently exhibited the highest detection accuracy in both flat specimens and anatomical crown models. Visual comparisons from cemented crown samples further supported these findings, with NIRF imaging offering clearer cavity visualization than radiographs across zirconia and hybrid ceramic crowns. Conclusions. NIRF imaging demonstrated comparable accuracy to conventional radiographs in detecting cavities beneath ceramics such as IPS e.max CAD, VITA Mark II, and CERASMART. NIRF proved effective in detecting cavities beneath zirconia restorations, overcoming a key limitation of radiographic imaging. Detection accuracy improved with thinner restorative materials and smaller cavity sizes, emphasizing the influence of material thickness and lesiofin dimensions on imaging outcomes. These results support NIRF as a promising, radiation-free diagnostic tool in restorative dentistry.