Introduction: The extensive plaque formation on dental restoratives may contribute to secondary caries or periodontal inflammation. Therefore, it is important to know how different types of dental restoratives may prevent or promote the accumulation of microorganisms. Hence, this study aims to evaluate the oral hygiene and microbial adhesion on the titanium (Ti)—coated stainless steel crown (Ti-coated SSC) and conventional SSC on a primary molar. Materials and methods: A total of 15 children aged 4–10 years who visited the Department of Pediatric and Preventive Dentistry and required performed crowns were selected for the study. The tooth was randomly restored with Ti-coated on one side SSC and conventional SSC on the other side. The subgingival plaque samples were taken from the lingual and buccal surfaces using Gracey Curette before and immediately after the cementation of crowns and after 1 week. The plaque index (PI) (PI, modified Silness, and Loe) was also recoded. The plaque samples were incubated in mitis salivarius bacitracin agar, and the total number of Streptococcus mutans (S. mutans) was counted and expressed in colony-forming units (CFU). Results: The test results showed a statistically significant difference in the microbial count expressed in CFU and PI (PI, modified Silness, and Loe PI) between Ti-coated SSC and conventional SSC after 1 week of crown placement. Conclusion: The microbial adhesion of S. mutans and plaque accumulation was seen less on the Ti-coated SSC when compared with conventional SSC, which was statistically significant.