About the timing and frequency of tooth cleaning, there are various theories, that have not yet be proved scientifically. However, it is said that brushing at least twice a day and flossing once a day should be done.

Every theory said that the tooth cleaning before bedtime is the most effective. Although the oral cavity is always while awake washed by saliva, only a little amount of saliva is secreted while sleeping. Therefore, the brushing and flossing before bedtime and reducing the amount of plaque is important.

Similarly, the tooth cleaning in the morning is also effective. While sleeping, the bacteria in your mouth is increasing. So you should do brushing after waking and decrease the plaque in your mouth.

There are various theories about brushing after meals. One of them said that it is better to do brushing immediately after eating. Another said that because of a large amount of salvia there is no need of brushing after meals. And the other said that it is better to do brushing 30 to 60 minutes after eating. However brushing is not only for removing plaque, but also for removing the food remaining in the mouth that is nutrients of bacteria. Especially in today's work environment and school environment, because of the air conditioning equipments making your mouth dry, the plaque tends to grow. So it would be ideal to do brushing after meals. However, immediately after ingestion or highly acidic foods and in the case of the illness making the oral cavity acidic, the teeth may be weaken and could be collapsed by the brushing immediately after meals. In such cases, it is said that the brushing immediately after eating should not be done.