Résumé
BACKGROUND:The occurrence and severity of denture stomatitis are closely related to denture cleaning methods and wearing time. Therefore, it is of great significance to explore the effects of denture cleansers on denture surface roughness and color stability.OBJECTIVE:To investigate the effects of four different denture cleansers on the surface roughness and color stability of heat-curing denture base resins and elastic denture base materials by means of soaking test.METHODS: Samples of heat-curing denture base resins (n=25) and elastic denture base materials (n=25) were polished and soaked in NaClO, Efferdent, Polident partial, Polident overnight and water, respectively. The soak process was repeated 90 times. Then the color aberration and surface roughness were tested using color meter and roughmeter before soaking and after 30, 60, 90 times of soaking.RESULTS AND CONCLUSION:These four kinds of denture cleansers have greater influence on the elastic denture base materials than on the heat-curing denture base resins. With the increasing of soaking time, the color aberration and surface roughness of the two kinds of denture materials were increased gradualy after treatment with different denture cleansers, and the values were ranked as follows: NaClO > Efferdent > Polident overnight > Polident partial and water. To conclude, denture cleansers can induce the changes in denture surface roughness and color stability of heat-curing denture base resins and elastic denture base materials. NaClO exerts the strongest effect, followed by Efferdent and Polident overnight, and Polident partial exhibits the weakest effect.
Résumé
Objective; To investigate the expression and distribution of IL-6 in periodontal tissues and the change of the alveolar bone of rats during orthodontic tooth movement, and to study the effects of orthodontic force on the periodontal tissue remodeling. Methods: SO gram orthodontic force was loaded on the left first maxillary molars of 25 rats in experimental group. Immunohistochem-istry and histomorphometric analysis were performed to measure the expression of IL-6 and the loss of alveolar bone at 0, 1, 3, 5, 7 " and 10 days after the application of orthodontic force. Results; The expression of IL-6 was observed to reach maximum level on day 3 and to decline thereafter in experimental group. No obvious alveolar bone loss was detected in the mesial side of the first molars. Conclusion; Although orthodontic force can evoke the local inflammatory response of periodontal tissue and the expression of pro-inflammation cytokines such as IL-6, it can not cause severe periodontal destruction and alveolar bone loss.