Dental plaque is a sticky, colorless film of microorganisms, primarily bacteria, that constantly forms on the surfaces of teeth. If not regularly removed, it can lead to oral health issues.
The Initial Stage of Plaque Formation
The process of dental plaque formation begins almost immediately after teeth are cleaned. Within seconds to minutes, a thin, acellular protein film called the acquired pellicle forms on the tooth enamel. This pellicle acts as a foundation for bacterial attachment.
Following the pellicle’s formation, pioneer bacteria, mainly Streptococcus species, begin to adhere to its surface. Initially, this attachment is reversible, but as these early colonizers bind to specific receptors in the pellicle, the adhesion becomes more stable and irreversible. These first bacteria start to multiply and excrete extracellular substances, laying the groundwork for a more complex microbial community.
Maturation and Accumulation of Plaque
Once the initial bacterial layer is established, it rapidly grows and matures into a thicker, more complex biofilm. Within a few hours, typically 4 to 12 hours, the bacterial colonies multiply significantly, transforming the initial film into a noticeable layer of soft plaque. This developing biofilm produces an extracellular matrix of polysaccharides, which helps consolidate the bacterial attachment and provides structural integrity to the plaque.
If left undisturbed, this soft plaque continues to accumulate and mature, becoming more resilient and challenging to remove within 24 to 72 hours. As the biofilm develops, the environment within the plaque changes, allowing for the colonization of a more diverse range of bacteria, known as secondary colonizers, such as Fusobacteria. This maturation process makes the plaque denser and more established, increasing its potential for causing dental problems.
Factors Influencing Plaque Formation Rate
Several factors influence how quickly and extensively dental plaque forms in an individual’s mouth. Oral hygiene habits, including the frequency and thoroughness of brushing and flossing, are primary determinants. Regular and effective cleaning disrupts the developing biofilm, preventing it from maturing and accumulating.
Diet plays a significant role, as bacteria in the mouth thrive on sugars and starches from food and beverages. These carbohydrates are metabolized by bacteria, leading to the production of acids that accelerate plaque formation and can damage tooth enamel. Frequent consumption of sugary or starchy snacks provides a continuous food source for these bacteria.
Saliva flow and its composition also impact plaque formation. Saliva naturally helps to rinse away food particles and bacteria, and it contains minerals that contribute to remineralization of tooth enamel, counteracting acid attacks. A reduced salivary flow, often referred to as dry mouth, can lead to an increased rate of plaque accumulation. The unique composition of an individual’s oral bacterial community also influences the speed and characteristics of plaque development.
From Plaque to Tartar
If dental plaque is not regularly and thoroughly removed through brushing and flossing, it can undergo a process called calcification, hardening into a substance known as tartar, or dental calculus. This occurs when minerals naturally present in saliva, primarily calcium and phosphate, begin to deposit into the soft plaque biofilm.
The transformation from soft plaque to hardened tartar can begin within 24 to 72 hours if the plaque remains undisturbed. However, it typically takes days to weeks for tartar to become significant and firmly attached to the tooth surfaces. Once hardened, tartar forms a rough, yellowish or brownish deposit that cannot be removed by regular brushing or flossing alone. Professional dental cleaning is necessary to remove tartar, which otherwise provides an ideal, rough surface for even more plaque to accumulate, perpetuating the cycle of buildup.