The micromorphology in vivo of the buccocervical region of premolar teeth in young adults. A replica study by scanning electron microscopy.

The buccal surfaces of premolar teeth are common sites of gingival recession, generally attributed to overzealous oral hygiene. Scanning electron microscopy (SEM) of replicas made from dental impressions was applied to document the micromorphology of the buccocervical region of all premolar teeth in 27 dentally healthy, young adults. The SEM observations were correlated with clinical examination. Of the 216 sites, one-third, predominantly the maxillary first premolars, had gingival recession, but fewer than 50% were clinically discernible. The exposed roots were devoid of cementum, and the dentinal surface was smear-like or dotted with tubular apertures from which droplets of fluid extruded. SEM of replicas of gingiva, recorded as clinically healthy, frequently showed signs of inflammation: fluid exudate and distortion of gingival contour by swelling. The cervical enamel of healthy and affected sites showed characteristic periodic fissure-like cracks, probably enamel tufts. The high frequency of subclinical gingival recession, exposed cervical dentin, and gingival inflammation in dentally healthy young adults, in the absence of abrasion of hard or soft tissues, indicates the need to review conventional concepts of initiation of buccal recession and root exposure.