​Timing the "treats". Avoid a treat becoming a bad habit

The trick to enjoying sweet Halloween treats …without giving your dentist a scare
It's okay to let your children join in the fun of Halloween, including the Trick or Treating. A one off binge on sugary treats probably wont do your children any harm …but stashing up loads of sweets and eating them over a few weeks or months might cause some dental problems.
Dental decay is caused by sugar attacks between meals.
Sugar attacks can be eating sweets, chocolate, biscuits, cakes, dried fruit and yoghurts, or drinking sugar-full fizzy pop, juice, cordials and squash (including “no-added-sugar” cordials and squash).
Myth – brushing your teeth after eating sweets will prevent cavities
Brushing or using mouthwash after eating sweets sounds like a good idea, but unfortunately won’t undo a sugar attack. Remember – the more sugar attacks each day, the higher the risk of dental decay.
Truth – avoiding sugary snacks and drinks between mealtimes will prevent cavities
The best times to enjoy sweet Halloween treats are just before or just after mealtimes. So a sweet treat at lunch time, tea time or even breakfast is fine, but not between meals …so not at break time, after school/nursery, or in the evening after tea time.
If you want your children to enjoy Trick or Treating without giving your dentist a scare at their next dental checkup, let your children enjoy some sweet treats on Halloween, but then keep leftover sweets out-of-reach to be given back a few at at time, but only at mealtimes.

Text and further Advice via Dentalchoices.org