Objective To investigate whether 5% strontium-containing brushite bone cements(DCPD) has repair effect on alveolar bone defects in osteoporotic rabbits. Methods Eighteen healthy adult female rabbits were used to establish osteoporosis models and were randomly divided into three groups:the blank control group, DCPD group,doped 5%DCPD group(5%strontium),with 6 rats in each group.In addition to the blank group, rats the other groups were filled with the corresponding bone cements in the bilateral alveolar bone defects. At 4 weeks and 8 weeks after operation,3 rats in each group were killed and given shooting the defect area X-ray.The expression of b-FGF was detected by immunohistochemistry. Results X-ray results showed that the defected of doped 5% DCPD group have been nearly completedat the 8 week,DCPD group partially completed repair,but blank group was not fully repaired. The results of immunohistochemistry showed that the expression of b-FGF was the highest at 4 weeks and decreased at 8 weeks after operation.Expression of b-FGF was significantly different at 4 weeks and 8 weeks among the three groups.Conclusion The 5%strontium-containing brushite bone cements can repair bone defect in osteoporotic rabbits.

Objective: To investigate the effect of a nanohydroxyapatite suspension with a 10% mass fraction on enamel demineralization after adjacent enamel removal and to provide a reference for the clinical use of nanohydroxyapatite to prevent enamel demineralization after adjacent enamel removal. Methods : Forty fresh extracted premolars were incised from the coronal surface of the crown after glazing and polishing with sand strips. Each tooth was made into two specimens. Eighty teeth were randomly divided into four groups: a blank group, a dolofluoride group, a dental mousse group and a 10% nanohydroxyapatite group. After 30 days of pH cycling in vitro, a microhardness tester was used to detect the enamel surface elements before and after deglazing treatment. Scanning electron microscopy (SEM) and X-ray energy dispersive spectrometry (EDS) were used to analyze the enamel surface elements. Results: After the experiment, the microhardness values of the adjacent glazed specimens of the four groups were (128.18 ± 6.89) kg/mm2 in the blank group, (216.75 ±9.87) kg/mm2 in the dolefluoride group, (198.88 ± 4.76) kg/mm2 in the dental care group and (218.44 ± 7.88) kg/mm2 in the 10% nanohydroxyapatite group, which were significantly different (F=189.14, P＜ 0.001). The LSD-t test showed that there was no significant difference between the dolefluoride group and the 10% nanohydroxyapatite group (P＜ 0.05), but the differences between the other groups were statistically significant (P > 0.05). There were significant differences in the Ca/P ratio among the blank group (1.39 ± 0.08), the dolefluoride group (1.70 ± 0.11), the dental care group (1.54 ± 0.12) and the 10% nanohydroxyapatite group (1.71 ± 0.14) (F=10.539, P＜ 0.001). There was no significant difference between the dolefluoride group and the nanohydroxyapatite group after the experiment (P > 0.05), but there were significant differences among the other groups (P＜ 0.05). Conclusion Dolerofluoride, dental protector and 10% nanohydroxyapatite can promote remineralization of enamel after enamel removal. The remineralization induced by 10% nanohydroxyapatite is similar to that induced by dolerofluoride.

OBJECTIVES: Currently, the research results regarding the bilateral temporomandibular joint symmetry in patients at different ages with unilateral complete cleft lip and palate (UCLP) are still controversial. In this study, the position of condyle in the articular fossa and morphology of condyle in UCLP patients at different developmental stages was measured and analyzed to explore the asymmetry difference, which can provide a new theoretical basis for the sequential therapy. METHODS: A total of 90 patients with UCLP were divided into a mixed dentition group (31 cases), a young permanent dentition group (31 cases) and an old permanent dentition group (28 cases) according to age and dentition development. Cone beam computed tomography (CBCT) images were imported into Invivo5 software for 3D reconstruction, and the joint space, anteroposterior diameter, medio-lateral diameter, and height of condylar were measured, and its asymmetry index was calculated. RESULTS: The asymmetry index of condylar height and anteroposterior diameter among the 3 groups, from small to large, was the mixed dentition groupP<0.05). There was no significant difference in condylar anteroposterior diameter and asymmetry index between the mixed dentition group and the young permanent dentition group (both P>0.05), all of them were lower than those in the old permanent dentition group (both P<0.05). Compared with the normal side, the height of fracture condyle was smaller among the 3 groups (all P<0.05), and the anterior joint space was smaller (P<0.05) and the posterior joint space was larger (P<0.05) in the mixed dentition group. CONCLUSIONS In patients with UCLP, the asymmetry of condylar morphology increases with age, but the condylar position tends to normal. These results suggest that early treatment has important clinical significance for the morphologic development of temporomandibular joint in UCLP patients.
Humans ; Cleft Lip/diagnostic imaging* ; Cleft Palate/diagnostic imaging* ; Temporomandibular Joint/diagnostic imaging* ; Clinical Relevance