Teeth should be brushed twice a day, with evening brushing being more thorough, Oleg Yanushevich, chief dental specialist at the Russian Ministry of Health and academician of the Russian Academy of Sciences, told RIA Novosti.

"There are standard recommendations we give our patients to brush their teeth in the morning and evening," the specialist noted.

According to him, morning brushing is for hygienic purposes and is necessary to cleanse the oral cavity after sleep. It doesn't have to be very long—one or two minutes.

"Evening brushing should be done more thoroughly to remove plaque that accumulates on the surface of the teeth after eating," Yanushevich explained.