The present paper tries to observe short and long term antibacterial effects of some toothpaste in order to establish criteria which must be used when selecting toothpaste as a personal hygiene product. Microorganisms represent one of the causing factors of bacterial plaque. Microbial cultures develop in warm, dark and highly acid environments, conditions which may be found inside the oral cavity. In order to fight bacterial colonization on dental surfaces, various hygiene materials were developed such as mouth rinses and toothpastes containing various antibacterial agents with harmful potential on microorganisms involved in initiating carious lesions such as Streptococcus mutans, Streptococcus sobrinus and in their progression such as Lactobacillus, Actinomyces, Candida. Triclosane is one of the antibacterial agents used in dental products. This study shows the prevalence of aerobic and conditionally anaerobic germs isolated from the oral cavity, before and after the use of toothpastes containing triclosane. Together with detergent, abrasive, binding, moisturizing, flavor, preserving agents, toothpastes must also contain antimicrobial agents to reduce oral microbial flora. Thus, toothpastes with fluoride and active agents like triclosane, may be effective in maintaining an adequate oral hygiene.