The question of whether chewing gum helps or harms dental health has a complex answer that depends almost entirely on the ingredients. The benefits of gum chewing are not universal; they rely on selecting products that actively promote a healthy oral environment while avoiding those that can accelerate decay.
How Chewing Gum Increases Saliva Flow
The simple physical action of chewing provides an immediate benefit by stimulating the salivary glands. This mechanical stimulation can increase the rate of saliva flow by ten to twelve times the resting rate.
Increased saliva volume is the mouth’s natural defense mechanism against the acids produced by plaque bacteria after a meal. Saliva contains bicarbonate and other compounds that rapidly neutralize the harmful acids that erode tooth enamel. The flow of saliva also acts as a physical rinse, helping to wash away food debris, sugars, and loose bacteria. This natural cleansing process is particularly helpful in the twenty minutes following eating, when the acid attack is at its peak.
The Essential Difference Between Sugar and Sugar-Free Gum
The distinction between gum containing sugar and a sugar-free variety is the single most important factor determining the dental outcome. Regular gum is sweetened with fermentable carbohydrates like sucrose or glucose, which provide a direct food source for plaque bacteria. As these bacteria metabolize the sugar, they produce acids that quickly lower the pH level in the mouth, leading to the demineralization of tooth enamel.
This acid production effectively cancels out the positive effects of increased saliva flow, negating the benefits of mechanical chewing due to prolonged sugar exposure. Sugar-free gums, in contrast, use non-fermentable sweeteners such as aspartame, sucralose, or sugar alcohols like sorbitol and mannitol. These alternatives provide sweetness without fueling the decay-causing bacteria. By stimulating saliva without fueling the acid-producing process, sugar-free gum allows the mouth’s natural defenses to work unimpeded.
Targeted Dental Benefits of Active Ingredients
Beyond the basic sugar-free distinction, certain active ingredients provide specific therapeutic advantages that enhance anti-cavity effects. Xylitol, a natural sugar alcohol, is one of the most studied and effective additions because it disrupts the metabolism of Streptococcus mutans, the primary bacteria responsible for tooth decay. When these bacteria consume xylitol, they cannot process it properly, which inhibits their growth and reduces their ability to adhere to the tooth surface and form plaque.
To achieve a clinically meaningful effect, it is recommended to consume at least 6 to 10 grams of xylitol per day, divided into three to five chewing sessions. High-quality gum should have xylitol listed as the first ingredient to ensure adequate concentration, often aiming for one gram per piece.
Other Active Ingredients
Another beneficial compound is Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP), often marketed as Recaldent, which is derived from milk protein. This ingredient releases calcium and phosphate ions that help remineralize microscopic lesions on the enamel surface, actively strengthening the teeth against future acid attacks.
Addressing Potential Side Effects
While sugar-free gum offers clear dental benefits, excessive or prolonged chewing can lead to certain physical drawbacks. The constant, repetitive motion can overwork the muscles and joints of the jaw, potentially leading to discomfort in the temporomandibular joint (TMJ). Individuals who already have temporomandibular disorders (TMD) may find that chewing gum aggravates symptoms such as muscle fatigue, clicking, or jaw pain.
The sticky nature of gum can occasionally pull out or loosen existing dental restorations, such as older fillings or crowns. Furthermore, sugar alcohols like sorbitol and xylitol are not fully absorbed by the body. Consuming large amounts can cause gastrointestinal distress, including bloating or a laxative effect, in sensitive individuals. Limiting chewing to short periods after meals, such as twenty minutes, is recommended to gain the dental benefits without the associated risks.