Experimental-induced periodontitis is exacerbated in spontaneously hypertensive rats

Studies show that systemic diseases such as diabetes, hyperthyroidism, osteoporosis, and dyslipidemia may influence periodontal inflammation. However, few studies relate the influence of arterial hypertension on periodontitis. The present study was undertaken to assess the severity of the experimental ligature-induced periodontitis in an experimental model of genetic arterial hypertension. The experimental periodontitis model was induced in 6 spontaneously hypertensive rats (SHR) and 6 Wistar normotensive rats (NT) by cotton ligature, which was placed subgingivaly around the neck of the first left inferior molar tooth. In the same animal, the first right molar tooth was sham-ligated and used as a control. After 7 days, the mean arterial pressure (MAP) and heart rate (HR) were recorded in conscious animals. As expected, MAP was significantly higher in SHR (151 +/- 6 mmHg) than in NT (105 +/- 3 mmHg), without significant differences in HR. The histopathologic examination of the periodontal structure showed alveolar integrity and lack of neutrophils and osteoclasts in the control side of both SHR and NT. In contrast, examination of the ligated side in all animals showed collagen degradation in the alveolar process from a moderate (50%) to severe (50%) level in SHR and mild in NT (100%). These data show that experimental periodontitis, characterized by the spreading of the inflammatory process from the gingiva deep into periodontium tissues, is greatly exacerbated in SHR.