Does Radiolucency Around Composite Restoration Justify Restoration Replacement?

Radiolucent areas beneath composite restorations can be interpreted as secondary or residual caries leading to restoration replacement. Objective: to relate the presence of radiolucent areas adjacent to conventional restorations with gap and remaining demineralized tissue (RDT). Methods: fifty extracted permanent teeth, 25 sound and 25 carious, were studied. Caries removal (hardness criteria) was performed. Cavities with similar dimensions (Mann Whitney U Test p<0.005) were performed in sound teeth. Cavities were restored with composite. Teeth were serially sectioned in mesial-distal direction (n= 119). Three areas per section (mesial, distal and pulpal walls) were analyzed with stereomicroscopy (25x) (n=349; 8 sections lost during preparation). The sections from each tooth were grouped and one histological result was obtained per tooth area. Results: the prevalence of gap in sound sample was 38.9% (95%CI= 28.2–50.5) and the prevalence of gap/RDT in carious sample was 68.9% (95%CI= 57–78.6) (p=0,001). There was significant association between presence of gap/RDT and presence of radiolucency, and absence of gap/RTC and absence of radiolucency (Chi-square test p<0,001). However the sensibility, specificity, predictive positive values (PPV), predictive negative value (PNV) and accuracy for carious [77.1% (95%CI = 63.7–87.3), 54.5% (95%CI = 33.8–74.1), 78.7% (95%CI = 65.3–88.7), 52.2% (95%CI = 32.1–71.7), 70% (95%CI = 58.5–79.8)] and sound teeth [73.7% (95%CI = 62.9-82.6), 59.1% (95%CI = 47.0-70.4), 67.5% (95%CI = 56.9–76.9), 66.1% (95%CI = 53.4-77.3), 66.9% (95%CI = 58.9-74.3)] were low. There was no difference between sound and carious teeth regarding these diagnosis values, with exception of PPV (Chi-square test p=0.024). Conclusion: although there is a relationship between radiolucent areas adjacent to restorations and presence of gap/RDT, low values of specificity were observed due to a high number of false positives. The presence of radiolucency beneath restoration cannot indicate restoration replacement.