Histological evaluation of combined platelet-rich fibrin membrane and piezo-incision application in orthodontic tooth movement.

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) membrane on tooth movement in comparison with shunt control and piezoelectric surgery. Sixteen White Vienna rabbits were included in the study and divided into two groups. Reciprocal forces (20 g) were applied on the maxillary incisors by an orthodontic appliance. In group 1, PRF membrane was placed sub-periosteally on the distal alveolar bone surface of the right central incisors and the left side was kept as control. In group 2, piezo-incisions 3 mm in depth were performed and combined with PRF membrane on the distal alveolar bone surface of the right central incisors, while the left side was kept as control. All rabbits were euthanized on day 21 and bilateral alveolar bone segments from the distal regions were removed for histological evaluation. Isolated PRF membrane application increased the blood vessel (8.3 ± 1.0; P = 0.026), osteoblast (6 ± 0.8; P = 0.027), and osteoclast (2.3 ± 0.8; P = 0.026) counts significantly compared to shunt control. Combined application of PRF membrane + piezo-incision increased the blood vessel (15.3 ± 0.8; P = 0.027), osteoblast (9.8 ± 1.4; P = 0.026), and osteoclast (3.3 ± 0.8; P = 0.024) counts significantly compared to shunt control. The increases in blood vessel count and osteoblast cell count were more evident in the combined application group (both P = 0.002). PRF membrane application significantly increased bone turnover, and the combined application of PRF membrane + piezo-incision was found to be the best method for increasing bone turnover.

Apoptosis and proliferation in gastric epithelium due to Helicobacter pylori: an immunohistochemical and ultrastructural study.

UNLABELLED: The effect of H. pylori infection on gastric epithelial cell apoptosis and proliferation is contradictory. Using immunohistochemistry and electron microscopy, this study sought to demonstrate gastric epithelial changes (ie, apoptosis and proliferation) due to chronic H. pylori infection. METHODS: Eighteen female 6- to 8-week old Swiss Albino mice were inoculated intragastrically with 3 doses of 10(9) CFU/mL H. pylori prepared in a Brucella Broth in 5 days. Nine others served as a control group. At the end of 28 weeks, tissue specimens from the gastric antrum were excised and examined immunohistochemically (epithelial growth factor for regeneration and Caspase-3 for apoptosis) and electron microscopically. Immunohistochemical assessment was performed using the indirect peroxidase-antiperoxidase method. RESULTS: In the H. pylori-infected group, EGF staining in gastric epithelium was found to be decreased significantly compared to that in control group (P < 0.001). Caspase-3 reactivity was commonly observed in surface epithelial cells and glandular epithelial cells in H. pylori-infected group and totally it was statistically significant compared to Caspase-3 staining in control group (P < 0.001). Electron micrograph images demonstrated numerous apoptotic cells with condensed chromatin. CONCLUSION: Chronic H. pylori infection of 28 weeks' duration increases apoptosis in gastric epithelium; however, increased apoptosis does not induce proliferation.