Dissertação
Avaliação do desenvolvimento de lesões periapicais em ratas com osteoporose induzida
Fecha
2016-07-23Registro en:
MELLO, Juliana Heckler. ASSESSMENT OF THE DEVELOPMENT OF PERIAPICAL LESIONS IN RATS
WITH INDUCED OSTEOPOROSIS. 2016. 50 f. Dissertação (Mestrado em Odontologia) - Universidade Federal de Santa Maria, Santa Maria, 2016.
Autor
Mello, Juliana Heckler
Institución
Resumen
Osteoporosis is a systemic condition characterized by reduced bone mineral density (BMD)
and microarchitectural deterioration of bone tissue. The most common kind of Osteoporosis is
found in the postmenopausal period. Among the factors that lead to a decrease in BMD during
this period, estrogen deficiency stands out due to atrophy of the ovaries and increased
oxidative stress generated by the production of reactive oxygen species. Oxidative stress is
responsible for the occurrence of cellular damage and is closely related to the loss in bone
density which occurs in osteoporosis. Studies have shown that some systemic conditions, such
as osteoporosis, can alter the progression and severity of periapical lesions, because of
decreased bone density and increased speed of reabsorption. Thus, the aim of this study was
to evaluate the influence of osteoporosis on periapical lesions induced in rats. Twenty Wistar
lineage rats were used on the study, divided into 2 experimental groups (n = 10):
ovariectomized (OVX) and sham ovariectomized (sham). After 21 days, all animals were
submitted to the periapical lesion induction procedures by endodontic opening of the
mandibular first molar and exposure of the pulp to the oral environment by the end of the trial
period. After 35 days from the date of induction of periapical lesions, the animals were
euthanized. Estrogen level analyzes were performed, of oxidative stress in the liver (nitric
oxide), and the measurement of the area of periapical lesions by digital radiography and
femoral BMD and jaw tomography multislice. The data were submitted to the unpaired t test
with significance level set at 5% (P <0.05). The results showed no statistical difference in the
size of the periapical lesion between the OVX and SHAM groups. However, the levels of
estrogen and uterine weight was significantly lower for the OVX group than for the SHAM,
showing the model of osteoporosis. In addition, oxidative stress analysis showed that
ovariectomy induced a significant increase of nitric oxide in the OVX group compared to the
SHAM group. Regarding bone parameters, BMD in the condyle of the femur was
significantly lower in the OVX group than in the SHAM group, but the jaw significant
differences were found between the two groups. Although osteoporosis have influenced the
level of nitric oxide and have had an effect on BMD of the femur in ovariectomized rats, the
data revealed that the systemic condition did not change the size of periapical lesions induced
in Wistar rats.