[IMMUNOMORPHOLOGICAL ASPECTS OF BACTERIAL SENSITIZATION IN THE EXPERIMENT].

This study investigates the morphological structure of lungs, liver and kidneys of the experimental animals. To reproduce the inflammation in maxilla-facial region under the periosteum of guinea pigs' mandible a suspension of S.aureus was inoculated. The infected site was exposed by a constant electric current of positive polarity of 5-10 µA strength. Allergotests were used to determine the level of sensitization. Structural changes in the organs were determined by microscopic examination. The results of the study showed that as the contact with the antigen increased, the number of positive allergic tests also increased. Histologically, a generalized damage to the microstructure of the internal organs, depending on the degree of bacterial sensitization of the animals was observed.

Saturation of the biological response to orthodontic forces and its effect on the rate of tooth movement.

OBJECTIVES: Investigate the expression and activity of inflammatory markers in response to different magnitudes of orthodontic forces and correlate this response with other molecular and cellular events during orthodontic tooth movement. SETTING AND SAMPLE POPULATION: CTOR Laboratory; 245 Sprague Dawley male rats. METHODS AND MATERIALS: Control, sham, and 5 different experimental groups received different magnitudes of force on the right maxillary first molar using a coil spring. In the sham group, the spring was not activated. Control group did not receive any appliance. At days 1, 3, 7, 14, and 28, the maxillae were collected for RNA and protein analysis, immunohistochemistry, and micro-CT. RESULTS: There was a linear relation between the force and the level of cytokine expression at lower magnitudes of force. Higher magnitudes of force did not increase the expression of cytokines. Activity of CCL2, CCL5, IL-1, TNF-α, RANKL, and number of osteoclasts reached a saturation point in response to higher magnitudes of force, with unchanged rate of tooth movement. CONCLUSION: After a certain magnitude of force, there is a saturation in the biological response, and higher forces do not increase inflammatory markers, osteoclasts, nor the amount of tooth movement. Therefore, higher forces to accelerate the rate of tooth movement are not justified.

Cytokine expression and accelerated tooth movement.

It has been shown that inhibiting the expression of certain cytokines decreases the rate of tooth movement. Here, we hypothesized that stimulating the expression of inflammatory cytokines, through small perforations of cortical bone, increases the rate of bone remodeling and tooth movement. Forty-eight rats were divided into 4 groups: 50-cN force applied to the maxillary first molar (O), force application plus soft tissue flap (OF), force application plus flap plus 3 small perforations of the cortical plate (OFP), and a control group (C). From the 92 cytokines studied, the expression of 37 cytokines increased significantly in all experimental groups, with 21 cytokines showing the highest levels in the OFP group. After 28 days, micro-computed tomography, light and fluorescent microscopy, and immunohistochemistry demonstrated higher numbers of osteoclasts and bone remodeling activity in the OFP group, accompanied by generalized osteoporosity and increased rate of tooth movement.

[Histocompatibility of porous ceramics in the jaw bones of Cavia cobaya]. / Histokompatibilität poröser Keramik im Kieferknochen von Cavia cobaya.

Porous ceramic basically fuses hard in osseous connective tissue of the jaw if closed implantation has been successful. The date were derived from ground serial sections in different postoperative intervals. Light, fluorescence (after intravital staining), and scanning electron microscopy were used for the evaluation. The positive results obtained with this test series do not imply that porous ceramic material used as root replacements persists under normal masticatory stress and in the same type of tissue.