The use of preheated resin-containing materials is of increasing interest in contemporary dentistry. This study aimed to determine the effect of preheating on the radiopacity values of various fissure sealants.

In this study, four resin-based fissure sealants were utilised. The materials were divided into two groups, one with and one without preheating, with 18 samples in each group. Each sample was prepared in a cylindrical form (6 × 2 mm) using a Teflon mould. For radiopacity assessment, three radiographs were obtained, each containing 18 samples arranged in sets of six, alongside an eight-step aluminium step-wedge with 0.5-mm increments. The object-focal spot distance, kVp, and mAs values were kept constant while taking radiographs. After obtaining the mean gray values of the samples using ImageJ software, the values were converted to equivalent aluminium thickness using CurveExpert Pro software. One-way analysis of variance (ANOVA), the Tukey multiple comparison test, and the t-test were used for statistical analysis.

A significant difference was found between different fissure sealants (p < 0.05). The radiopacity ranking was found to be Clinpro™ < Helioseal® F Plus < RubyDent® < Fissurit FX in both the preheated and unheated groups. No statistically significant difference was found between preheated and unheated groups of the same material (p > 0.05).

The radiopacity of the fissure sealants varied among manufacturers; however, preheating at 55 °C did not produce any change in radiopacity in any of the materials tested.