IADR Abstract Archives
Evaluation of bone changes produced in experimental periodontitis and hyposalivation
Objectives: Periodontitis is a progressive oral disease associated with bacterial plaque characterized by damage to the dental support structures. On the other hand, the decrease in total salivary flow can facilitate the appearance of infectious processes in the oral cavity or increase the severity of pre-existing ones.The aim of this work was to analyze the changes in the external cortical and interradicular alveolar bone of rats submitted to experimental periodontitis (EP) in concomitance with submandibulectomy (SMx)-induced hyposalivation.
Methods: Sixteen male Wistar rats were distributed into 4 groups (n=6): control, EP, hyposialia (H) and H+EP. EP was induced by injections of Escherichia coli LPS (1 mg/ml) in the gingiva surrounding lower first molars for 6 weeks, in three sessions (days 1, 3 and 5) per week. SMx was performed a week before the injections began. After animals were euthanized, both hemimandibles were removed. One of them was scanned in a microtomograph to perform microCT analysis measurements, the other was used to macroscopic evaluations. MMP’s activity was measured in the gingival tissue of the first molars by zymography technique. Data were analyzed by two-way ANOVA. Significance: *p<0.05.
Results: Interradicular bone volume (BV/TV%) decreased significantly in the three experimental groups compared to control group, showing H+EP the lowest value (C: 74.5±2.11; EP: 65.18±2.66*; H: 68.99±2.88*; H+EP: 61.47±1.75*). Similarly, the distance (mm) between alveolar crest and the cement-enamel junction increased in these experimental groups, being differences specially marked in the lingual side (C: 1.02±0.01; EP: 1.32±0.04*; H: 1.15±0.04*; H+EP: 1.26±0.05*). MMP’s activity significantly increased their levels in all experimental groups compared to control group.
Conclusions: Previous reports from our lab informed deleterious effects of EP and SMx on periodontal tissues based on histomorphometric and morphometric measurements. But with the advent of new technologies more precise results can be achieved, in effect, micoCT analysis showed alterations in the interradicular bone of EP rats that were exacerbated by concomitant H.
Methods: Sixteen male Wistar rats were distributed into 4 groups (n=6): control, EP, hyposialia (H) and H+EP. EP was induced by injections of Escherichia coli LPS (1 mg/ml) in the gingiva surrounding lower first molars for 6 weeks, in three sessions (days 1, 3 and 5) per week. SMx was performed a week before the injections began. After animals were euthanized, both hemimandibles were removed. One of them was scanned in a microtomograph to perform microCT analysis measurements, the other was used to macroscopic evaluations. MMP’s activity was measured in the gingival tissue of the first molars by zymography technique. Data were analyzed by two-way ANOVA. Significance: *p<0.05.
Results: Interradicular bone volume (BV/TV%) decreased significantly in the three experimental groups compared to control group, showing H+EP the lowest value (C: 74.5±2.11; EP: 65.18±2.66*; H: 68.99±2.88*; H+EP: 61.47±1.75*). Similarly, the distance (mm) between alveolar crest and the cement-enamel junction increased in these experimental groups, being differences specially marked in the lingual side (C: 1.02±0.01; EP: 1.32±0.04*; H: 1.15±0.04*; H+EP: 1.26±0.05*). MMP’s activity significantly increased their levels in all experimental groups compared to control group.
Conclusions: Previous reports from our lab informed deleterious effects of EP and SMx on periodontal tissues based on histomorphometric and morphometric measurements. But with the advent of new technologies more precise results can be achieved, in effect, micoCT analysis showed alterations in the interradicular bone of EP rats that were exacerbated by concomitant H.