Objective: The purpose of this study was to compare the quality of bitewing radiographs using paper wing and loop and XCP instrument(Rinn). Methods: Twenty subjects were selected purposely. The subjects'teeth alignment was anatomically correct. Premolar and molar bitewing radiographs were obtained using paper wing and loop on one side and XCP instrument on the other side. Four observers evaluated the radiographs for overlapping, positioning error, distortion, blurred and cone cutting image. Chi- square was used to compare the two different film holders with 95% confidence interval. Observer agreement was evaluated and represented as Kappa value. Results: Intraobserver agreement was between 0.588 to 0.801. Interobserver agreement was between 0.375 to 0.841. Overlapping in radiographs using paper wing and loop (24.16%) was more often found than using XCP instrument (19.82%) significantly (P=0.049). Positioning error, i.e. not covering the area wanted to see, using paper wing and loop (16.45%) was more frequently found than using XCP instrument (45.39%) significantly (P=0.000). Positioning error was mostly found in the premolar area (81.16%). Whilst, there are no differences in distortion and blurred image between two techniques (P=1.000 and P=0.520, respectively). Cone cutting was not found. Conclusion: The results suggested that to examine the interproximal caries using XCP instrument might be more suitable than paper wing and loop. However, film positioning in premolars area should be carefully performed. This study was supported by Dental Research Fund, Faculty of Dentistry, Chulalongkorn University.