IADR Abstract Archives
Alteration in post-tooth extraction healing events in a rat model of hyposalivation.
Objectives: The clinical course of post-tooth extraction tissue repair requires a synchronized molecular response for proper tissue repair. Saliva plays a key role in modulating oral wound healing. Matrix metalloproteinases (MMP) play an important role in the course of tissue repair. Nevertheless, the participation of saliva in tissue healing remains unclear.
The aim of the present work was to explore the activity pattern of MMP and microstructural changes in the alveolar repair process following tooth extraction in a model of hyposalivation induced by submandibular and sublingual gland excision (SMx).
Methods: Male Wistar rats aged 21 days (n=48) were divided into two groups: SMx (SMxG) and Control (CG). Under anesthesia, the rats were subjected to SMx and to bilateral extraction of the 1st lower molar seven days post-SMx. They were fed a soft diet and euthanized (n=6) on days 3-7-14-30, following FOUBA CICUAL guidelines. Post-tooth extraction, socket tissue was obtained from one hemimandible for MMP activity assessment by zymography. The other hemimandible was used for histomorphometric evaluation using microcomputed tomography (micro-CT). Data were analyzed and groups of interest were compared using Student’s t Test. Statistical significance was set at a value of *p<0.05.
Results: Activity pattern of MMP2 and MMP9 was similar in both groups; however, MMP2 and MMP9 activity decreased significantly at 3 days but increased significantly at 14 days in SMxG. Gelatinolytic activity (intensity pixel area %) in CG vs. SMxG: MMP2- 3d (19.98±3.96 vs. *5.02±2.03) 14d (7.86±1.34 vs. *17.14±3.09); MMP9- 3d (18.31±4.26 vs. *6.69±2.84), 14d (4.63±4.37 vs. *20.37±7.09). In regard to the measured histomorphometric parameters, bone volume (BV/TV) significantly decreased in SMxG at 14 and 30 days. Micro-CT= BV/TV (%): 14d (42.67±1.12 vs. *38.9±0.81), 30d (45.04±2.18 vs. *37.31±0.95).
Conclusions: In conclusion, the lack of saliva altered the gelatinolytic tissue pattern of MMP activity during post-tooth extraction socket healing. This could lead to the decrease in bone volume found in SMxG at the later study time points.
The aim of the present work was to explore the activity pattern of MMP and microstructural changes in the alveolar repair process following tooth extraction in a model of hyposalivation induced by submandibular and sublingual gland excision (SMx).
Methods: Male Wistar rats aged 21 days (n=48) were divided into two groups: SMx (SMxG) and Control (CG). Under anesthesia, the rats were subjected to SMx and to bilateral extraction of the 1st lower molar seven days post-SMx. They were fed a soft diet and euthanized (n=6) on days 3-7-14-30, following FOUBA CICUAL guidelines. Post-tooth extraction, socket tissue was obtained from one hemimandible for MMP activity assessment by zymography. The other hemimandible was used for histomorphometric evaluation using microcomputed tomography (micro-CT). Data were analyzed and groups of interest were compared using Student’s t Test. Statistical significance was set at a value of *p<0.05.
Results: Activity pattern of MMP2 and MMP9 was similar in both groups; however, MMP2 and MMP9 activity decreased significantly at 3 days but increased significantly at 14 days in SMxG. Gelatinolytic activity (intensity pixel area %) in CG vs. SMxG: MMP2- 3d (19.98±3.96 vs. *5.02±2.03) 14d (7.86±1.34 vs. *17.14±3.09); MMP9- 3d (18.31±4.26 vs. *6.69±2.84), 14d (4.63±4.37 vs. *20.37±7.09). In regard to the measured histomorphometric parameters, bone volume (BV/TV) significantly decreased in SMxG at 14 and 30 days. Micro-CT= BV/TV (%): 14d (42.67±1.12 vs. *38.9±0.81), 30d (45.04±2.18 vs. *37.31±0.95).
Conclusions: In conclusion, the lack of saliva altered the gelatinolytic tissue pattern of MMP activity during post-tooth extraction socket healing. This could lead to the decrease in bone volume found in SMxG at the later study time points.