J. inax.-fac. Surg. i (1973) 207-208 (g) Georg Thieme Verlag, Stuttgart
Pulp Vitality of Multirooted Teeth after Injury to one Root Peter Egyedi, Walter J. Visser Department of Maxillo-Facial Surgery (Head: P. Egyedi, M.D., D.M.D.) University of Utred#. The Netherlands
Summary An a.picectomy of or~e root in m ultirooted teeth was performed on adult cats in order to find out whether blood circulation through the remaining root(s) was sufficien~t to keep the pulp vital. Of 22 teeth, 21 appear histologically vi.tal, after six weeks. The clinical implications are briefly disc~s,sed.
Key-Words: Apicectomy, tooth vitality. Introduction Several investigations on tooth-vitality after subapical osteotomies have been carried out (M~adritsch 1968, Bell 1969, Johnson and Hinds 1969). As far as we know one experiment has been performed in which, after surgical t r a u m a of one root of a multirooted tooth, the vitality of the pulp was investigated (Waldhart and Linares 1972). T h e y used young dogs of which the apical foramina were still wide open. Results of such an investigation on adult animals have not yet been published. In a clinical case the mesial root of the lower first molar on the left was cut during a Koele osteotomy for correction of anterior open bite. Postoperatively the tooth reacted n o r m a l l y to testing with CO2 snow. Therefore it could be left.
Material and Methods
Fig. 2 Apicectomized tooth (H.E., 48x). a) Surgical bone defect with formation of new bone. b) Pulp with several vessels with stasis. c) Dentine of root.
T h r e e adult cats of unknown origin were used in the experiment: U n d e r general anaesthesia flaps were raised in the buccal vestible of the molar regions of the upper and the lower jaw. W i t h a
Fig. 1 Mandible of cat with diagram of the apicectomy.
Fig. 3 Higher magnification (H.E., 130x) from the pulp of an apicectomized tooth. Odontoblastic layer is normal. Several vessels show stasis (see arrows).
208
P. Egyedi, W . J. Visser: Pulp Vitality of Multirooted Teeth after Injury to one Root
Histological p r e p a r a t i o n and staining with haematoxiline-eosine were done in the usual way. Results In the 22 teeth that could be evaluated the appearance of the pulp was as follows: In 18 pulps stasis in m a n y vessels was seen (Figs. 2 and 3). The other tissues of the pulps, however, looked healthy, including the row of odontoblasts lining the wall of the pulp. A p p a r e n t l y , the remaining vascular circulation was sufficient to prevent necrosis (Figs. 2 and 3). In three more cases, reticular atrophy of the layer of odontoblasts was observed (Fig. 4). This might be an artefact, necrosis did not occur in these teeth either, Finally, in one tooth infection of the peri-apicat area, spreading into the root canal, occurred. Discussion
Fig. 4 Reticular atrophy in odontoblastic layer (H.E.,
45x). No. 6 dental bur some bone was removed over the apex of the distal root of the first molar and the mesial root of the second molar. A f t e r exposing the apices an apicectomy was carried out (Fig. 1). The wounds were closed with interrupted catgut sutures. Six weeks after the operations the j a w fragments containing the teeth were removed and subsequently decalcified in 5°/0 nitric acid.
Blood circulation through one root seems sufficient in most cases to ensure vitality of a multirooted tooth. T h e ,reticular atrophy of the odontoblastic layer in three cases does not seem very important, since the other structures in the pulp appeared vital. Moreover, W a l d h a r t and Linares (1972) found a tendency to regeneration of the odontoblasts after four to eight weeks. Therefore the pulps m a y still have been in the process of regeneration. From the clinical point of view, we suggest that there are no objections to cutting through one root of a multirooted tooth, if surgery requires it. This principle might be applied in j a w resections, osteotomies and removal of impacted teeth.
References Bell, reV. H.: Revascularization and bone healing after
Waldhart, E., H. A. Lblares: Zur Frage der Regenera-
anterior maxillary osteotomy: a study using adult rhesus monkeys. J. Oral Surg. 27 (1969) 249 Johnson, ]. V., E. C. Hinds: Evaluation of teeth vitality after subapieal osteotomy. J. Oral Surg. 27 (1969) 256 Madritsch, E.: Sp/itergebnisse nach Korrektur yon Dysgnathien und Zah'nstellungsanomalien durcla A1veolarfortsatzbewegungen und Kortikotomie. Dissertation, Zfirich 1968
tionsffihigkeit der Odontoblasten. Dtsch. Zahn-, Mund- u. Kieferheilk. 58 (1972) 10 Peter Egyedl, M.D., D.M.D., Walter ]. Visser, M.D., D.M.D., Academisch Ziel~enhuls Utrecht, Universiteizskllniek voor Mondziekte~ en Kaakchirurgie, Catharijnesingel I0l Utrecht~Holland