The effect of traumatic dental occlusion on the degradation of periodontal bone in rats.
BACKGROUND
A better understanding of the relation between traumatic dental occlusion and periodontal changes is needed.


OBJECTIVE
This study aimed to evaluate the pattern of osteoclastic activity in the periodontal bone in front of the traumatic dental occlusion in rat molars.


METHODS
Traumatic dental occlusion (TO) was induced in twenty rats, which were sacrificed after periods of 2, 5, 7, and 14 days. Transversal histological sections of both jaws were stained with tartrate-resistant acid phosphatase and hematoxylin and eosin. Mann-Whitney U-test was used for group comparison, and Pearson's correlation test was applied for the number of osteoclasts and bone area (BA).


RESULTS
Traumatic dental occlusion caused an increase in the number of osteoclasts in the bone of the upper and lower right first molar from days 2-5 to 2-14, respectively. In the TO groups, the number of osteoclasts on the lamina dura and in the center of the alveolar bone septum, respectively, increased almost 4-fold and 9-fold in the lower jaw; and 3-fold and 5-fold in the upper jaw, during all periods. In the TO groups, the BA of the alveolar bone septum was substantially reduced. There was a negative correlation between the number of osteoclasts and BA in both jaws during all experimental periods.


CONCLUSIONS
Traumatic dental occlusion increases osteoclast activity in the alveolar lamina dura and in the center of alveolar bone and stimulates a higher degradation in the center of the alveolar bone septum.
Department of Surgery and Integrated Clinic, Dentistry School of Araçatuba, São Paulo State University (UNESP), São Paulo, Brazil.
Daniela Atili
DA
Brandini
Department of Surgery and Integrated Clinic, Dentistry School of Araçatuba, São Paulo State University (UNESP), São Paulo, Brazil.
Marina Fuzette
MF
Amaral
Department of Surgery and Integrated Clinic, Dentistry School of Araçatuba, São Paulo State University (UNESP), São Paulo, Brazil.
Wilson Roberto
WR
Poi
Department of Physiology and Morphology, Dentistry School of Araçatuba, São Paulo State University (UNESP), São Paulo, Brazil.
Cláudio Aparecido
CA
Casatti
Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, MOVE Research Institute Amsterdam, Amsterdam University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
Antonius Ljj
AL
Bronckers
Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, MOVE Research Institute Amsterdam, Amsterdam University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
Vincent
V
Everts
Department of Surgery and Integrated Clinic, Dentistry School of Araçatuba, São Paulo State University (UNESP), São Paulo, Brazil.
Igor Mariotto
IM
Beneti
D016301:Alveolar Bone Loss / Q000209:etiology* / Q000473:pathology; D000539:Alveolar Process / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D003769:Dental Occlusion, Traumatic / Q000150:complications*; D008334:Mandible / Q000473:pathology; D008963:Molar / Q000473:pathology; D010010:Osteoclasts / Q000378:metabolism / Q000473:pathology*; D010519:Periodontium / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D014092:Tooth Root / Q000473:pathology
D000071681:Tartrate-Resistant Acid Phosphatase