Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. Fans of period dramas often love seeing fabulous costumes and sets on-screen. However, in recent years, critics have pointed out that one thing can immediately dispel historical accuracy: actors’ blindingly white, perfect teeth.  Even though many societies put great value on white teeth throughout history, the limitations of pre-modern dentistry meant that our ancestors often suffered from painful, visible tooth decay.  While modern dental practices have spared many of us from suffering the worst types of dental diseases, people today are still very preoccupied with how white their smile looks. According to the American Dental Association, Americans are expected to spend $8.21 billion dollars in 2026 on whitening products and procedures. But are white teeth actually healthier? Dentists say not necessarily. Do everyone’s teeth start off white? Not everyone’s teeth start out pearly white, Dr.…