Their mouths were coded according to the recommendations of the CPITN ( Community Periodontal Index of Treatment Needs ) .
Eres 2009 examined 3,056 students between the ages of 13 to 19 years at public schools in Turkey .
students ' mouths were coded according to the recommendations of the CPITN ( Community Periodontal Index of Treatment Needs ) .
Eres 2009 examined 3,056 students between the ages of 13 to 19 years at public schools in Turkey .