As stated by the American Academy of Pediatric Dentistry:
The American Academy of Pediatric Dentistry recognizes the importance of regular school attendance and the effect of chronic absence on academic performance. We encourage dentists to work with parents and educators to minimize school absence whenever possible. It is not always possible or appropriate to provide all the care children need during non-school hours. School policies that prevent ligitimate school absence for the purpose of dental visits may hae a negative impact on the health and well being of children.
The American Academy of Pediatric Dentistry urges parents, school administrators, and dentists to work together to ensure that children receive needed health care while minimizing school absences. The American Academy of Pediatric Dentistry encourages parents to return their children to school for the remainder of the day after their dental visit when possible. In the case of an appointment later in the day, a child should attend school and be excused prior to his/her dental appointment.