Dr Holika Devikar, an aesthetic dentist, said when people eat glucose biscuits, they easily turn sticky and get stuck in teeth and gums. "Bacteria...quickly act on them to produce acids that damage...enamel. This makes biscuits harmful...especially if eaten often," Dr Devikar added. Chocolates, on the other hand, melt faster and are cleared away more quickly by saliva, Dr Devikar stated.