Introduction: The microbial flora in children’s oral cavities is diverse, with Streptococcus mutans (S. mutans) and Lactobacillus playing key roles in the development of dental caries and periodontal inflammation. Resin restorations, commonly used for carious lesions, may lead to secondary decay and complications over time, making dental crowns a preferred option in pediatric dentistry. Metal crowns are effective for multiple surface lesions, while zirconium crowns offer superior aesthetics and biocompatibility. However, crown placement can promote bacterial adhesion, particularly by S. Mutans on enamel and cementum, and Lactobacillus on dentin, potentially affecting long-term restoration success. Bacterial adhesion can be assessed through plaque samples to evaluate restoration durability. Aim of the study: The purpose of the study is to evaluate the microbial adhesion of S. mutans and Lactobacillus on pedodontic crown surfaces. Material and methods: 60 patients with metal and zirconium pedodontic crowns were included in the study. We analyzed the bacterial load with KariesScreenTests. Conclusion: Metal pedodontic crowns have higher microbial adhesion, with S. mutans outnumbering Lactobacillus. Zirconium crowns show lower microbial adhesion, with fewer bacteria overall. S. mutans is present in higher quantities than Lactobacillus, but still less than in metal crowns. Zirconium crowns are a better option for restoring primary teeth, as they reduce plaque buildup and bacterial growth, offering improved long-term oral health benefits.

DOI: https://doi.org/10.62838/ASMJ.2025.1.03