• Definition

Multifactoral disease - affected by flora of mouth, tooth, time, substrate

• Dental plaque definition

Acidogenic - acid producing Acidoduric - acid loving

Fermentable sugar produces acid → environmental change to low pH → ecological shift to acidogenic/duric species → demineralisation of tooth

• Enamel caries aetiology
• Dentine caries

Sugar uptake systems by bacteria - diff systems allow to adapt to metabolic changes.

• Higher affinity systems - operates in low sugar levels. inhibited by acidic conditions
• Low affinity (PMS) - operates max at 5.5pH. S mutans have this system and allows them to dominate in carcinogenic plaque.

Plaque pH measuring

• using electrode
• probing
• sample

Pathway - lots of fructose → activates LDH enzyme → lactate produced. also → inhibits PFL enzyme → less formate produced

Dentine critical pH is 6

• Minimise caries progression