Caries experience and periodontal pathology in erupting third molars

This study was conducted to document the prevalence of occlusal caries experience and periodontal pathology for erupting third molars in young adults.

The data are from 49 subjects enrolled in an institutional review board-approved trial with at least one third molar below the occlusal plane at baseline that erupted by longest follow-up. Teeth were considered erupted if they reached the occlusal plane. Caries experience on the occlusal surface of third molars was assessed by a visual-tactile examination. At least 1 periodontal probing depth (PD) >or=4 mm in the third molar region was considered indicative of periodontal pathology. The third molar region was defined as the 6 probing sites around third molars and 2 sites on the distal of second molars. The prevalence of third molar caries experience and periodontal pathology at longest follow-up was assessed.

Most of the 49 subjects were female (51%), Caucasian (76%), and educated at least through high school (82%). Median age was 20.5 years (interquartile range [IQR] 18.4 to 24.1 years). Median follow-up was 5.1 years (IQR = 3.4 to 6.9 years). At baseline, none of the subjects had occlusal caries experience in a third molar; 51% of subjects had at least 1 PD >or=4 mm in a third molar region. At follow-up, 27% of the subjects had occlusal caries experience in at least 1 third molar that erupted to the occlusal plane; 61% had at least 1 PD >or=4 mm in a third molar region. Twenty-nine percent had occlusal caries in at least 1 third molar at the occlusal plane and at least 1 PD >or=4 mm in a third molar region. Thirty-seven percent had no third molar occlusal caries experience and all third molar region PD <4 mm.

For third molars that erupted "late," periodontal pathology was more prevalent than occlusal caries.