Children with ECC had 1.15±0.97 new affected surfaces per year, while cariesfree children had an increment per year of 0.41±0.60, and children with posterior caries
only showed an increment per year of 0.74±0.64. A statistically significant difference
was found between the ECC and caries-free groups, and between the ECC and posterior caries groups. The high increment in the ECC group is influenced by the high number
of affected surfaces in the primary teeth.