Periodontal diseases are common diseases caused by oral bacteria, and dental plaque is the major pathogenic factor. However, what you may not know is that saliva may also increase the risk of periodontal diseases.
Dental plaque is a glycoprotein film accumulated on teeth by bacteria in the oral cavity, food debris, and epithelial cells shed from the oral mucosa. This plaque membrane is also the main attachment area for oral bacteria.
When people eat sugary or starchy foods, the bacteria in a plaque can chemically react with the carbohydrate in those foods, producing acids that can damage enamel and cause tooth decay.
Dr. George Chiou is the doctor-in-charge of the Periodontology Department at Taoyuan Armed Forces General Hospital’s Hsinchu Branch in Taiwan. He pointed out that if a plaque is not cleaned, it will combine with metal ions such as calcium, magnesium, and sodium in saliva and harden into dental calculus.
A chronic inflammatory reaction caused by bacteria attached to dental calculus may destroy periodontal tissues and alveolar bones, leading to periodontal diseases.
In particular, near the outlets of the salivary glands, there is a lot of saliva. If the plaques near these outlets are not removed often, it is easy for one to develop dental calculus.
One of the main glands that secrete saliva in the mouth is the sublingual gland, which is close to the teeth. It is at the outlet of the sublingual gland, which is at the position on the lingual side of the lower jaw and the inner side of the front teeth, where dental calculi are commonly seen. Other types of salivary glands are the parotid glands on both sides of the cheeks, where the teeth are closer to the outside of the posterior dental area of the lower jaw. If your toothbrush is too large to brush the teeth in the back, it will cause plaque residue and tooth problems.
Even so, saliva can actually protect our teeth, too. Saliva contains proteins such as amylase, protease, and lysozyme, although lysozyme has only a slight bactericidal effect. Most importantly, saliva contributes to acid-base neutralization in the mouth. After eating, the bacteria in a plaque will produce acidic substances, and saliva, with a neutral pH value, can neutralize the acid and alkali to prevent and reduce tooth decay.
Thus, regarding the effects of saliva on teeth, Chiou says, “Personally, I think that saliva is like ‘the same knife that cuts bread and fingers.’”
Warning: The latter half of this article includes dental images which may be disturbing to some.
2 Tips to End Plaques, Tilt Your Toothbrush at This Angle
To prevent periodontal diseases, we should eliminate their root cause—dental plaques.
Dr. Chih-Chung Hsu from Center Union Dental Clinic in Tainan, Taiwan, said that the three-dimensional structure of a dental plaque is not so easy to disintegrate by liquid rinsing alone, such as the use of a dental irrigator or a simple mouthwash. Physical cleaning by dental cleaning appliances, such as toothbrushes, dental floss, and interdental brushes, can effectively remove plaques.
After eating, plaques will form. So how can we effectively end dental plaque formation? There are two practical methods:
- Using the Bass brushing technique
Many think that they do a good job brushing their teeth. However, there are many hard-to-clean blind spots on the teeth that prevent one from completely removing them.
Hsu pointed out that when a plaque display agent is applied to the teeth, we can discover that some parts are not easy to clean, such as the interdental triangles, the necks of the teeth where the teeth and the gums are connected, and the inner side of the teeth near the tongue.

He emphasized that especially in the gingival sulcus in the tooth neck area, there are often a lot of plaques accumulated due to poor oral hygiene, thus becoming a breeding ground for the proliferation of bacteria. The gingival sulcus is the groove where the gums meet the teeth, with a depth of about 1 to 3 mm.
Only by using the bass brushing techniques in this area—to gently squeeze and massage the gingival grooves with the bristles at a 45-degree angle—can the plaques hidden in the grooves be effectively removed. This avoids the accumulation of more bacteria, so as to end the formation of periodontal problems.
In contrast, horizontal brushing can only reach the crown and irritate the gums. Many people tend to brush too hard without realizing it. This way of brushing your teeth can be fine in the short term, but it may cause gingival atrophy in the long run.
Therefore, in addition to properly brushing and removing the plaques on the inside and outside of the teeth with a toothbrush, it is also necessary to brush the neck of the teeth at a 45-degree angle and to use dental floss or an interdental brush to clean the triangular spaces between the teeth.
- Make sure to carry dental floss with you
Plaques build up after we eat food. So ideally, we should always make sure to floss or brush our teeth after eating.
However, most people don’t have sufficient time to brush their teeth immediately after eating. What can we do then? Hsu suggests taking dental floss with you. He emphasized, “As long as the triangular gaps between the teeth are cleaned, the risk of tooth decay and periodontal disease can be much reduced.”
Some seniors are unable to floss their teeth flexibly with their fingers, and it’s recommended they use a dental floss stick instead. Although a dental floss stick may not be as flexible as dental floss, which can clean each tooth with a new section, it is very user-friendly. Hsu said that it is best to rinse the dental floss stick with water between teeth, to rinse away bacteria and food residues, and then continue cleaning.
The above two methods can prevent the formation of dental plaques, but the general public may have some blind spots that cannot be cleaned. When plaques build up at a place for weeks without being brushed off, dental calculus can easily form. As the hard dental calculus cannot be removed with a toothbrush, a dentist needs to use ultrasonic tools to clean the teeth. Thus, it is recommended to go to the dentist every six months for a full-mouth scaling and oral health examination.
In addition, Hsu shared with us another method to protect teeth: to reduce the frequency of eating, to eat only at the three meals, and try to avoid snacks in between. This prevents tooth decay, which is another common disease caused by oral bacteria.
This is because during the half hour after eating, the bacteria in the plaques will produce acid, destroy the enamel, and then slowly neutralize the acidity of the oral cavity by saliva. If you eat frequently for a long time, the bacteria will continue to produce acid to destroy your teeth. Furthermore, the protective mechanism of saliva to restore the neutrality of oral cavity will also be constantly destroyed, which will increase the risk of tooth decay.
.