Bacterial biofilms play a major etiological role in dental diseases worldwide. Currently, toothpastes with bactericidal chemicals and abrasive materials are used as preventive care methods. However, chemicals can cause adverse side effects, with the use of antibiotics, fluorides, and antiseptics drastically reducing quality of life. At the same time, the rational design of bulk toothpaste materials has remained unexplored. In this work, we demonstrated a mechano-bactericidal strategy as an antibiotic-free and tooth-safe approach for dental biofilm elimination based on shape-anisotropy CaCO3 (cubic-, stick-, and urchin-shaped). As proof-of-concept, we demonstrated superior efficiency during biofilm eradication from ex vivo teeth using urchin- and stick-shaped microparticles involving both Escherichia coli K12 (227 ± 32.6% and 215 ± 33%, respectively) and Staphylococcus aureus ATCC 209P (210 ± 54.7% and 202 ± 55.5%, respectively) compared to the spherical particles that are employed in conventional toothpastes. These findings will potentially give rise to the development of novel and safer toothpastes with antibiotic-free bactericidal activity for the prevention of dental diseases.