Dental Plaque and Oral Health Concepts

Dental caries is a microbial disease affecting tooth tissues, characterized by a balance shift towards demineralization. Factors like tooth structure, plaque, and diet influence this process. Dental plaque, a biofilm on teeth, plays a significant role in caries formation. Various hypotheses explain plaque's pathogenicity, with ecological imbalance being a key factor. Bacteria like S. mutans metabolize sucrose, producing acids that lower pH, leading to caries. Acidic environments disrupt mineral balance, causing tooth decay.

What is the primary characteristic of dental caries?

• Mineralization of the tooth

• Demineralization and dissolution of tooth tissues

• Increase in tooth size

• Formation of new tooth enamel

Which factor is NOT mentioned as influencing the balance between mineralization and demineralization?

• Tooth color

• Saliva

• Dental plaque

• Tooth structure

What is dental plaque primarily composed of?

• Tooth enamel

• Salivary enzymes

• Bacterial communities and a matrix of proteins

• Calcium deposits

How can dental plaque be effectively removed?

• By salivary flow

• By tooth brushing

• By drinking water

• By tongue movements

What does the Non-Specific Plaque Hypothesis suggest?

• Only specific bacteria in plaque are pathogenic

• The entire microflora in plaque is collectively pathogenic

• Plaque is beneficial for teeth

• Plaque has no role in dental caries

According to the Ecological Plaque Hypothesis, what causes disease?

• Presence of specific bacteria

• Ecological imbalance in the plaque microflora

• Excessive tooth brushing

• Lack of saliva

Which bacteria are primarily implicated in causing dental caries?

• Escherichia coli

• Staphylococcus aureus

• Streptococcus mutans and lactobacilli

• Streptococcus pneumoniae

What is the role of glucans in dental plaque?

• They dissolve tooth enamel

• They help in further adherence of bacteria

• They neutralize acids

• They provide nutrients to the tooth

What happens when the pH drops to 5.5 or below in the oral environment?

• Hydroxy-apatite crystals start to disintegrate

• Tooth enamel becomes stronger

• Bacteria stop growing

• Saliva becomes more alkaline

How does saliva help in maintaining tooth health?

• By changing tooth color

• By providing nutrients

• By buffering and neutralizing acids

• By increasing tooth size