Final answer:
After consumption of fermentable carbohydrates, the pH of plaque biofilm typically returns to neutral within 30 minutes to 2 hours. Good oral hygiene, reduced sugar intake, and fluoride use can aid in maintaining a neutral pH and preventing tooth decay.
Step-by-step explanation:
Upon the ingestion of fermentable carbohydrates, the pH level of plaque biofilm in the mouth decreases due to the metabolic activity of microbes, particularly Streptococcus mutans. These microbes ferment sugars forming organic acids such as lactic acid, which can dissolve tooth minerals including enamel and dentin. The process of returning the pH to neutral after ingesting these carbohydrates typically takes around 30 minutes to 2 hours, depending on factors like saliva flow and composition, the presence or absence of fluoride, and whether or not there is continued exposure to sugars or acids. Regular dental cleaning, reduced sugar consumption, and the use of sugar alcohols or fluoride can help manage the pH levels and prevent tooth decay.
It's important to note that these microbes thrive in a close to neutral pH and that ingestion of products like sugarless candies or gum with xylitol can reduce acid production, thus minimizing dental caries. Fluoride also helps strengthen tooth minerals and may contribute to quicker neutralization of acidic conditions.