If the thought of your kids downing enough M&Ms on Halloween night to fill a beanbag before racing to conquer the 32 newly acquisitioned Kit Kat bars makes you feel a bit queasy, rest assured: Their primal chocolate gorging is the lesser of two evils for their teeth.

It is far worse to make them ration the candy all through the day, day after day, says Mark Helpin, a pediatric dentist at Temple University in Philadelphia. This is because snacking on candy keeps your teeth bathed in enamel-corroding acid, which is produced by bacteria feeding on sugar and other carbohydrates in your mouth.

In scenario one, your gluttonous little angel coats his teeth with sugar; the oral bacteria experience their own version of Halloween; and the acidity level in the mouth rises. But this can be neutralized regardless of the amount of candy eaten when the child brushes his teeth. Even if he doesn't brush, saliva will eventually wash away the sugar in about an hour, starve the bacteria, and neutralize the acid.

In scenario two, the child builds up acid in his mouth with the first candy bar; but if he has a second one an hour later, he pumps up the acid level again. Constant snacking on candy ensures the mouth stays acidic, which can lead to tooth decay.

The best scenario is to brush after every meal or snack, but good luck with that.

Battle of the junk foods

Helpin also says there's little use in substituting those Reese's Cups for a bag of potato chips. Acid-producing bacteria feed on the carbohydrates in potatoes just as readily as they do on the sugar in chocolate. What you need to worry about, he says, is not the sugary factor per se but rather the stickiness factor.

The cooked starches in potato chips cling to teeth longer than the sugar in chocolate does, making potato chips the greater risk for tooth-decay. Worse yet are gummy candies and taffies that stay wedged in teeth for what can seem like days.

So, perhaps counterintuitive, those healthy sounding 100-percent fruit strips that stay locked in one's molars until Christmas are worse for the teeth than a pack of Pez, which comprise just two ingredients: sugar and purple.

Watch your mouth

All of this "good news" about candy applies only to oral health, of course, and should not be an excuse to substitute whole wheat bread in your diet with a box of Zagnut bars. Candy constitutes empty calories, largely devoid of nutrients, save for the 2 percent of your daily recommended allowance of iron per Zagnut serving.

Oral health is nothing to neglect, though. Tooth decay and gum disease are major public health problems, associated with poor digestion, heart attacks, strokes, cancers and low-birth-weight babies, stemming from oral bacteria, inflammation and subsequent infections.

And as for your kids, considering the continuing collapse of the stock market, you might not be able to afford a visit from the tooth fairy.

Christopher Wanjek is the author of the books "Bad Medicine" and "Food At Work." Got a question about Bad Medicine? Email Wanjek. If it’s really bad, he just might answer it in a future column. Bad Medicine appears each Tuesday on LiveScience.