BACKGROUND: SureFil SDR as a lining material has better adaptability and unique automatic leveling characteristics as compared with other flowing resins, but its application in preventive resin filling has not been reported. OBJECTIVE: To compare the roughness and bacterial adhesion among pit and fissure sealant, Z350 XT fluid resin and SureFil SDR resin, and to explore the feasibility of preventive resin filling with SureFil SDR resin. METHODS: Pit and fissure sealant, Z350 XT fluid resin and SureFil SDR resin were prepared into 8 mm× 2 mm× 2 mm cuboid specimens respectively. The surface roughness of the three specimens was measured by MarSurf roughness meter. Pit and fissure sealant, Z350 XT fluid resin and SureFil SDR resin were prepared into 8 mm× 8 mm× 2 mm cylinder specimens respectively. The specimens were cultured in Streptococcus mutans suspension for 48 hours to detect the bacterial adhesion on the material surface. RESULTS AND CONCLUSION: The roughness of the three materials was ranked as follows: SureFil SDR resin < Z350 XT fluid resin < pit and fissure sealant, and there were significant differences between groups (P < 0.05). The bacterial adhesion on the surface of the three materials was ranked as follows: SureFil SDR resin < Z350 XT fluid resin < pit and fissure sealant, and there were significant difference between groups (P < 0.05). The correlation between roughness and bacterial adhesion was analyzed, and there was a high positive correlation between roughness and bacterial adhesion, indicating, with the decrease of material roughness, bacterial adhesion decreased (r=0.962, P=0.017 6). The results show that SureFil SDR is an ideal preventive resin filling and sealing material relative to pit and fissure sealant and Z350 XT fluid resin.