Enhancing Radiographic Precision: The Role of Digital Subtraction Radiography and Histogram Analysis in Radiographic Evaluation of Early Approximal Caries

Evaluating initial approximal caries lesions through radiographs remains a cornerstone of clinical research, with a variety of methods available to address this challenge. Traditionally, bitewing radiographs have served as the primary tool for assessing changes in lesion depth, but as dental practices continue shifting toward prevention rather than intervention, the demand for reliable techniques capable of detecting early lesion size changes has grown. This study builds upon the foundational work of the doctoral dissertation of the first author, which focused on the effectiveness of preventive measures on the progression of approximal caries lesions using radiographic follow-up methods. Expanding on that groundwork, this manuscript explores different approaches to radiographic-evaluation techniques, addressing critical gaps in the field. Specifically, the paper explains three radiographic interpretation methods: 1. digital subtraction radiography (DSR), 2. histogram analysis (HA), and 3. a combination of the two. Our findings reinforce the value of DSR as a highly sensitive tool that complements visual interpretation, especially in high-risk caries cases. Yet, challenges in correctly performing and interpreting DSR radiographs persist. To address this, we provide practical guidance for performing and interpreting DSR and propose a novel method that integrates DSR with HA, enhancing diagnostic accuracy and offering a new perspective on radiographic evaluations.