the purpose of this experimental study was to observe the pulpal and periodontal tissue changes of the teeth in the line of fracture, in cases of rigid fixation with miniplate and reduction without fixation of fractured bone fragments.
In order to perform this experimental study, 3 adult male dogs weighing about 10kg were selected.
Under the general anesthesia with Pentobarbital sodium (Entobar), buccal cortical osteotomy on the left and right mandibular body was carried out with a #700 fissure bur and a disc. Then, fractures were induced with a bone chisel and a mallet in
both
sites. The fractured fragments in the left mandibular body were fixated with a noncompressive miniplate and screws, but the fractured fragments in the right mandibular body were reduced without fixation.
The experimental animals were sacrificed in the 4th, 6th and 8th week after operation, and the mandibles were dissected out to take the tissue specimens.
The specimens were fixed with 10% N-formalin solution and decalcified with 5% nitric acid solution. Then, the specimens were sectioned in 4-6μm with a microtome, and observed through light microscopic study after staining with Hematoxylin-Eosin
and
Masson's trichrome.
@ES The results were as follows:
@EN 1. Periodontal tissues were degenerated severely in the lapse of time, the root surface was resorbed in the group of non-fixation.
2. Periodontal tissues were healed and matured form 4 weeks after experiment, and repaired gradually in the group of fixation.
3. Pulpal tissues of the tooth involved in the fracture line, were degenerated partly or generally in the group of non-fixation.
4. Pulpal tissues of the tooth involved in the fracture line, were degenerated slightly and had congested blood vessels, but were almost sound in the group of fixation.
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