The present study aimed at assesssing – by clinical,
histological and radiological investigations – the influence
of some external factors on the pulp-dentin complex, and
at providing a causal interpretation of the structural
changes observed.
Materials and methods. Clinical and radiological
exams were performed on 65 old patients with ages
between 60-75, and also on 40 young patients with ages
between 20-35, presenting different dental-periodontal
pathologies. The pulp-dentin complex was submitted to a
morphopathological examination, to highlight the structural
changes observed at microscopic level. Fragments of
dental pulp were imersed in a 4% formaldehyde solution
with phosphate buffer 0.1 M., pH 7.2, for 12 -14 hours, at a
temperature of 4ºC, and 3-5 µm thick slices were prepared.
The slices were coloured with hematoxylin-eosine (HE), by
the trichromic technique – Masson. Photographies were
taken with a Zeiss microscope, with Kodak 200 ASA.
Results. Significant differences were observed, between
the two groups of patients, as to the external factors that
produce structural changes on pulp-dentin organ. In the
group of young patients dental caries and coronal fillings
prevailed, while the group of old patients was mostly associated
with atrition and chronic marginal periodontitis.
Out of the 40 young patients, 30 presented chronic dental
caries (75%), while, among the 65 old patients, only 24 presented
dental caries (36.9%). The percentages of coronary
fillings between the two study groups were close, which
could be considered as one of the causes producing changes
in the pulp-dentin organ, following aggresive preparation
of cavities, the action of materials used for the protection
of pulp-dentin complex or of the materials used for coronry
fillings.
Conclusions. Dental pulp has a remarkable ability to
counteract the action of harmful factors, producing a mineral
barrier and stimulating the reparatory processes.
Changes in the endodontic space can be produced in both
experimental groups, but more intensely and more frequently
in the old patients. The endodontic space is modified,
both physiologically and pathologically, including
deposition of secondary or tertiary dentin (reactionary or
reparative dentin), as well as pulp reactions, such as:
inflammation, fibrosis, calcium degeneration or vacuolisis.
At cell level, microsocopic images showed a decrease of
the odontoblasts number and sizes, as well as a reduced
fibroblasts/fibrocytes ratios. These changes are associated
with progressive vascular and nervous changes, that can
be considered both theis cause and effect. These pathological
transformations are related with a more difficult
preparation of the endodontic space and can be considered
as having a major role in the failure of endodontic therapy