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Few articles have shown changes in bone metabolism caused by hypertension. The objective of this study was to investigate the relationship between hypertension and bone healing. Circular critical-size defects 5 mm and 2 mm in diameter were created, respectively, on the left and right side of the mandible in 40 spontaneously hypertensive and 40 control Wistar-Kyoto rats. Five animals from each strain were killed 2, 3, 5, 10, 15, 30, 60 and 90 days after surgery. The macroscopic evaluation showed great mandibular angle deformation on the left side and non-healed defects on both sides and groups. Histological evaluation revealed similar bone healing on both sides, with initial necrosis in the central area, and fibrosis and angiogenesis within the first 5 days. From the 10 th postoperative day on, the newly formed bone displayed progressive thickening until the 90 th postoperative day, when the defect margins presented a compact bone structure. Furthermore, the statistical analysis of the histometric data did not reveal any significant hypertension effect on bone healing in the defect area. These results suggest that bone healing was not different between spontaneously hypertensive rats and control rats.

The origin of paradental cysts is related to inflammatory processes, especially pericoronaritis involving impacted or semi-impacted teeth. The authors present a case of paradental cyst related to lower second molar that did not show clinical evidence of inflammatory process. The main aspects related to its classification, diagnosis and clinical characteristics are also discussed.

The use of demineralized bone (DB), in special from bovine source, has been evaluated extensively in experimental models; however, doubts exist if there is sufficient quantity of bone morphogenetic proteins (BMP) to induce the bone repairing. The combination of membranes avoids the encapsulating of DB particles and also it could prevent the early dissolution of the few BMPs present in the DB. The aim of this study was to carry out a histological evaluation of the bone repairing induced by DB on defects created in the rat mandibles, and the effect of using resorbable collagen membranes impregnated with calcium salts. The study involves 25 Wistar rats, in which DB discs were employed to fill bicortical defects in the region of mandibular angle; at the left side, membranes recovered the lingual and buccal side. The animals were divided into groups of five individuals each one and then killed after three, 10, 20, 30 and 60 postoperative days. Within first 20 days, the histological analysis revealed intense bone proliferation in the two bone ends, buccal as much lingual, and it is also probable the proliferation has occurred all around of the circular margin defect. However, from 30 days, there was an inversion in the histological findings: the inflammatory reaction until then moderate became an intense inflammatory infiltrate that was involving the DB, with total absence of the membrane, and then reducing the intensity at 60-days group, which presented remnants of foreign body reaction enveloping the DB, without new bone filling of the defect. From these results, it can conclude by the presence of BMPs, responsible by the great initial bone proliferation; the physical form of DB in sheets, of which discs were prepared, seemed to have prevented resorption of the remnant bone matrix and raised foreign body reaction. Finally, the calcium-collagen membrane had l ittle effect in the bone proliferation, raising moderate inflammatory infiltrate around it.