Dentinal tubules at the root ends of apicected teeth: a scanning electron microscopic study

By Tidmarsh BG, Arrowsmith MG

Date: 09/1989
Journal: JOE

Purpose: to establish the existence and orientation of dentinal tubules at the level at which resection is normally performed.

N= 22 teeth (1st : 10 ant. Teeth unknown ag / 2nd: age  (35-81y)

Materials/Methods:

•Apicectomy done  in 1st gp at al level 2-4 mm from the apex, while in 2nd gp was 3mm at an angle of 45-60°.

•The cut root face was examined under the scanning electron microscope (SEM) at 3 locations, i.e. close to the root canal,  about half-way between the canal and the (CDJ) and just inside the dentine-cementum junction.

•The number of tubule orifices per square millimeters was calculated.

Most highlighted Results:

  •1st group:  superficial tubules could be seen to communicate with the root canal at their proximal ends with the external surface at their peripheral ends (fig.2).

•2nd group:

  •At a point approximately 3 mm from the apex, and half-way between the root canal and CDJ, the average number of tubules was 27,000 tubules per mm2.

•Close to the dentine-cementum junction, an area which may communicate with the root canal even in the presence of a retrograde root filling, an average of 13,000 tubules per mm2 were found.

• Older teeth also displayed large numbers of tubules.

 Clinical significance: 

the angle of the beveled root face should be kept to a minimum, and the retrograde root filling should extend back into the canal at least to the level of the coronal end of the bevel.