Clinical, Radiographic, & Histological Study of Endodontically Treated Retained Roots To Preserve Alveolar Bone

By Reames RL, Nickle JS, Patterson SS, Boone M, El-Kafrawy AH

Date: 06/1976
Journal: JOE


Purpose: to determine whether new bone will form coronal to retained endodontically treated roots

N= 2 Macaca Speciosa monkeys


•Conventional RCT was done for central incisor, lateral incisor, second premolar & first molar.

•Contralateral teeth were extracted to serve as a control group.

•The crown has been removed  to the level of the alveolar bone, then the roots  amputated  2-3 mm below the crest of the alveolar bone,  and sharp edges Rounded

•Approximation of the labial flaps to the lingual tissue, suturing with no. 3-0 silk sutures.

•Clinical & radiographic examination  were conducted  at 6, 12 & 20 weeks intervals.

•Procion Dye was administered to label newly bone formed a week before they were killed.

Most highlighted Results:


 – normal and uncomplicated healing of the soft tissue with normal attached, unattached alveolar muccosa & and adequate vestibule

– The extreme distobuccal aspect of the posterior segment was the only site of inflammation after 5 months in both monkeys.


–  The normal resorpative process continued & at 5 months it had slowed to an indiscernible amount

 – Bone formation was apparent in 1 / 4 anteriors & 4 / 8 posterior retained root tips

Histologic:  was made at 5 months revealing quite similar results, with slight differences between the two monkeys, which are:

• Success of soft tissue coverage except for two areas of communication with the oral environment  (fig1)

•Bone formation even with the presence of the inflammation over the amputation sites

•Osteocementum was occasionally formed over the cut dentinal surface (fig2)

Clinical significance:

Root submergence could be considered as a treatment option; when the tooth is not restorable and the extraction is contraindicated  or to preserve the alveolar bone