1：Experimental Design and Method Selection:

An in vivo study was conducted to measure radiation dose in the remnant beam during intra-oral radiography. Transmission values were calculated by comparing measurements with and without a patient present, using statistical analysis to assess differences based on exposure type, side, gender, and age. A reference value was derived by adding a safety margin of two standard deviations to the highest mean transmission percentage and rounding up.

2：Sample Selection and Data Sources:

43 adult patients referred for intra-oral radiography were included, with 323 exposures measured. Data included radiation dose, exposure type, side, time, and detector measurement time.

3：List of Experimental Equipment and Materials:

X-ray device (Instrumentarium Focus), dosemeter (RaySafe Xi Survey Detector), image detector (VistaScan Image Plates Plus PSP), beam-aiming devices (X-Act), custom-made plywood extension, and software (Microsoft Excel 2013, SPSS v. 21).

4：1). Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Measurements were taken with the dosemeter fixed in the remnant beam at 93 cm from the focus. Baseline measurements without patients were performed, and all measurements were corrected for background radiation and normalized per mAs. Statistical tests (Wilcoxon Signed Rank, Mann-Whitney U, Kruskal-Wallis, mixed model analysis) were used to analyze data.

5：Data Analysis Methods:

Transmission percentages were calculated, and statistical significance was assessed with p < 0.05. The reference value was computed from the highest mean transmission plus twice the standard deviation, rounded up.