The brushing teeth' most important goal is to prevent various diseases in the mouth, especially dental caries and periodontal disease. The other benefits of brushing teeth are: it gives a fresh sensation, eliminates bad breath, prevents sensitive teeth, and removes stains. These objectives are achieved by two tooth brushing mechanisms: removing plaque mechanically and administering chemical-therapeutic agents through toothpaste, in particular fluoride.

Which is Better Brushing Teeth Before or After Eating?
Brushing Teeth
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The Effectiveness of Brushing Teeth

Cleaning the teeth and oral cavity can use a manual toothbrush or an electric toothbrush and be added using dental flossing. The effectiveness of brushing depends on the frequency, duration, technique, and type of toothbrush used.

If only considering to clean dental plaque mechanically, the more brushing teeth make less plaque accumulates. Although the results largely depend on the brushing technique's effectiveness and each individual's susceptibility to different plaque accumulations.

However, practically speaking, it is not appropriate to advise patients to brush their teeth frequently. Tooth brushing that is too aggressive can lead to gingival recession and tooth abrasion.

Which is more effective in brushing teeth, before or after eating?

Brushing teeth after breakfast and before bed aims to clean food debris that sticks to the tooth surface. Brushing teeth before going to bed is important because bacteria's activity in the mouth is doubled during sleep—a silent mouth results in reduced saliva's ability to neutralize bacteria in the mouth.

Brandini et al., In 2011, conducted a study on the relation between the number of non-carious cervical lesions that may be caused by abrasion due to brushing. The factors studied were frequency, technique, pressure, type of toothpaste (abrasiveness, pH, and quantity), and the toothbrush (size, flexibility, and softness of the bristles). The study results showed that only coarse toothbrush bristles and too much pressure when brushing the teeth affected significantly non-carious cervical lesions' severity. Furthermore, this study did not find a significant association between toothbrush frequency (3 or 4 or 5 x / day) and the addition of non-carious cervical lesions.

Factors that cause tooth abrasion and erosion

Abrasion is the loss of the tooth surface due to the friction force of exogenous materials. Meanwhile, dental erosion is the irreversible loss of dental hard tissue from acids without bacteria's involvement.

There are intrinsic and extrinsic factors that can cause tooth erosion. The intrinsic factor is stomach acid regurgitation, such as GERD (gastroesophageal reflux). Meanwhile, extrinsic factors include consuming acidic foods. Exposure to acid can dissolve the hydroxyapatite component, which causes demineralization and decreases surface hardness. This softer enamel becomes more susceptible to abrasive erosion, which can cause tissue loss.

Exposure to fluids with a pH of less than 5.5 can cause erosion of the teeth' hard tissues if they occur over a long period or continuously. In vitro studies show that tooth erosion rate also depends on the acid concentration and enamel/dentin temperature apart from pH and exposure time. However, in clinical conditions, various other factors can influence the potential for erosion, such as salivary pellicle, salivary flow rate, and salivary buffer capacity. The early stages of erosional damage cannot be detected clinically until an identifiable pathological lesion is formed.

Brushing Teeth Before or After Eating

There are differences of opinion regarding brushing teeth in the morning, namely the opinion that it is better to do it before or after breakfast. This difference relates to the risk of loss of tissue in the teeth due to abrasion and erosion.

Brushing Teeth Before Eating

Before breakfast, performing brushing teeth aims to remove dental plaque accumulated since the night, thereby minimizing bacteria's acidogenic response to food. Using toothpaste containing fluoride, performing brushing teeth will form intra-oral fluoride, prevent demineralization, and increase enamel and dentin's remineralization. This raises the hypothesis that the brushing teeth before eating can protect by increasing the ions which function for remineralization.

However, the in vitro study showed that the fluoride type strongly influences the protective effect of brushing before meals in toothpaste and the severity/intensity of tooth erosion. Therefore, the hypothesis of the protection of brushing against erosion still requires further research at the clinical level.

Fluoride Type:
Research on the use of stannous fluoride (SnF2) and sodium fluoride (NaF) mouthwash as enamel protection against erosive forces showed that SnF2 could further reduce repetitive erosive damage forces. Meanwhile, NaF only protects the enamel at the beginning of erosion, not from repeated erosive forces. Also, SnF2 showed higher erosion protection than NaF when applied before immersing the teeth in citric acid. Conversely, NaF will provide protection when applied to tooth enamel after immersion in citric acid and only when saliva is present.

Brushing Teeth After Eating

When brushing teeth after eating, there is an acidogenic response due to decreased intraoral pH from the critical limit of 5.5. This decrease in pH is due to the digestive activity of food in the oral cavity. This condition is thought to make the tooth surface softer. Therefore, brushing teeth after eating can cause the teeth to lose more minerals on the tooth surface due to abrasion from brushing and erosion caused by food, especially acidic foods. In this condition, fluoride is predicted to be no longer effective in preventing demineralization and increasing remineralization. However, several studies do not prove this hypothesis.

Epidemiological studies in 7 countries in Europe involving a sample of about 3000 participants showed no statistically significant relationship between brushing teeth (either before or after eating) and tooth erosion due to erosion.

Research by Praptiningsih and Ningtyas in 2010 showed decreased salivary pH up to 15 minutes after eating but brushing your teeth before eating did not affect this pH reduction. Also, there was no difference in the number of bacteria on the surface of the teeth related to the action of brushing teeth before or after eating.

Research by O'Toole et al. in 2016 showed that brushing teeth after eating is not associated with tooth erosion, so delaying brushing after eating is deemed unnecessary. The risk factors that cause tooth erosion are consuming foods or drinks that contain acid in the middle of a meal and the habit of sucking or holding acidic drinks in the mouth when eating continuously for a long time. Erosion can occur if brushing your teeth is done less than 10 minutes after consuming these acids' foods or beverages.

Brushing is a proven method of removing plaque and providing topical protective agents to maintain healthy teeth and oral cavity. Therefore, brushing teeth' habit needs to be widely taught from an early age and applied regularly.

The timing of brushing your teeth, either before or after eating, did not make a difference in tooth tissue loss. Dental abrasion and erosion are more influenced by the type of food consumed, namely acidic foods. Additionally, brushing is also affected by using proper pressure and using a toothbrush with soft bristles.

More important advice given to patients is to brush their teeth at least two times a day for 2-3 minutes, use a toothpaste containing fluoride, and with the right technique.

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