Permanent teeth are thicker, denser, and more calcified than primary teeth. When children are in mixed dentition the permanent teeth can appear more “yellow” than the baby teeth because when the light reflects off the thinner more transparent baby teeth they appear bright white. 

Other reasons why new teeth coming in may appear discolored is:

-Calculus build up

-Poor oral hygiene and stained plaque. When primary teeth are exfoliating and permanent teeth are erupting it is common for children to avoid these areas as they are tender for brushing and flossing, therefore build up occurs more easily. 

-Hypoplastic or Hypomineralized enamel

*Overall permanent teeth will appear less “yellow” when in full mixed dentition. We are a culture that values good smiles and white teeth and many people have bleached their teeth, therefore the natural hue of our teeth may seem discolored nowadays. Regular dental exams and cleanings can address removal of hard calculus, plaque, and staining build up. Oral hygiene instruction at regular dental visits can help with improving home care and preventing discolorations.