## 3 Results  
Table 2 summarizes the results of the radiographic findings. Of 669 bitewing radiographs, 335 were excluded for meeting the exclusion criteria; therefore, 334 bitewings were used in the current study. 55 (16.5%) BW did not show any atypical radiographic findings. However, 279 (83.5%) radiographs showed radiolucent or radiopaque areas in the restoration, suggesting atypical radiographic findings.  
There were 91 of 279 (27.2%) restorations that had at least one atypical finding in the body of the composite recorded and were classified as follows: 55(16.5%) presented with internal body voids, 26 (7.8%) interlayer lines, 10 (3%) demonstrated radiopacity suggesting overhang. Sixty-nine (20.7%) restorations showed a discontinuity in the adhesive bond area, leaving a gap between the tooth structure and the composite. Thirty-seven (53.6%) of these restorations had notch-like appearance suggesting a noticeable gap at or around the gingival margin, and 32 (46.4%) out of the 69 had an internal inconsistency between tooth structure and resin-base material not involved with the exogenous seal of the restoration. Secondary carious lesions were in 42 (12.6%) restorations. Of the 42 restorations suggesting secondary caries, 20 (47.6%) had other radiographic findings, and 22 (52.4%) did not present with additional radiographic findings other than secondary caries.  
Furthermore, 77 (23.1%) restorations presented multiple radiolucencies or mixed radiolucency and radiopacity abnormal radiographic findings. In addition, 11(3.3%) BWs indicate the tooth bond interface gap and interlayer gaps between the body of composite layers. Next, the remaining bitewing radiographs with multiple radiolucent findings were classified as follows: 58 (17.4%) restorations presented with voids within the composite and bonding interface, 2 (0.6%) restorations had void interlayer radiolucencies, and 3 (0.9%) BWs revealed radiolucencies of interlayer lines and voids within composite with the interface.  
\begin{table}
\begin{tabular}{c c c} \hline
**Radiographic Finding** & **Frequency/Total** & **Percentage \%** \\ \hline No atypical findings & 55/334 & 16.5\% \\ \hline Atypical findings & 279/334 & 83.5\% \\ \hline Bonding interface & 69/334 & 20.7\% \\ \hline External bonding interface & 37/334 & 11.1\% \\ \hline Internal bonding interface & 32/334 & 9.6\% \\ \hline Body of composite & 91/334 & 27.2\% \\ \hline Internal Void & 55/334 & 16.5\% \\ \hline Interlayer lines & 26/334 & 7.8\% \\ \hline Overhang & 10/334 & 3.0\% \\ \hline Secondary caries & 42/334 & 12.6\% \\ \hline With other radiographic findings & 20/334 & 6.0\% \\ \hline Without other findings & 22/334 & 6.6\% \\ \hline Other findings & 77/334 & 23.1\% \\ \hline Interlayer/interface & 11/334 & 3.3\% \\ \hline Void interface & 58/334 & 17.4\% \\ \hline Void/overhang & 1/334 & 0.3\% \\ \hline Void/interlayer & 2/334 & 0.6\% \\ \hline Void/interlayer/interface & 3/334 & 0.9\% \\ \hline Interlayer/overhang & 2/334 & 0.6\% \\ \hline \end{tabular}
\end{table}
Table 2: The prevalence of radiographic abnormalities found in class II composite restorations.  
Three bitewings presented heterogenous radiographic findings composing radiopaque and radiolucent areas. Of the three, 1 (0.3%) restoration had radiolucent composite body pore and radiopaque excess composite, indicating an overhang on the gingival margin. The other 2 (0.6%) BWs showed radiolucent lines within the composite body and radiopaque overhang. Table 3 describes the information recorded for each patient, including age, sex, tooth, and restored surface.