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Objective To study the clinical effect of bone-anchored pendulum in treatment for class Ⅱ malocclusion .Methods Twelve patients treated by bone-anchored pendulum were chosen .In each patient ,two microscrews were inserted in the anterior paramedian region of the median palatal suture ,6-9 mm posterior to the incisive foramen and 3 – 6 mm lateral to the median line .Pendulum that based on the microscrews was used to distalize maxillary first molar ,and the force applied was 250 g .Skeletal and dental changes were measured on cephalograms before (T1 ) and after (T2 ) distal-ization .Results Class Ⅰ molar relationship had been obtained 7 month after distalization .The aver-age distal movement of the maxillary first molars was 7 .07 mm ,and the inclination was 9 .93° .The second premolars were distalized an average of 5 .44 mm with inclinations of 5 .22° .The first premolars were distalized an average of 4 .09 mm with inclinations of 3 .95° .The maxillary anterior teeth were re-truded 0 .93 mm and palatally inclined 1 .66° .There was statistical difference in that change .Conclusions By the use of microscrew ,pendulum can distalize maxillary molar effectively without mesial move-ment of premolar and labial movement of incisor ,and no loss of dental anchorage is observed during the distal movement .
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Objective To investigate the effects of the different concentration of mineral trioxide aggregate (MTA) on the proliferation and differentiation of dental pulp stem cells (DPSCs) from the young permanent teeth.Methods DPSCs were isolated from the young permanent teeth and cultured by tissue explant method.The expression of STRO-1 was detected by using immunofluorescence technology.DPSCs were cultured with different concentrations of MTA (0.02,0.20,2.00,20.00 g/L).Cell proliferation was detected by MTT array.Cells were cultured in the appropriate concentration of MTA for 4 weeks,and then stained by Alizarin red to detect their mineralized nodule formation capacity.The cells were cultured with the appropriate concentration of MTA and collected after 12,24,36,48 h.The mRNA expression of ALP,BSP,OC and DSP after the treatment of MTA were detected by quantitative PCR.Results DPSCs were positive for STRO-1.The capacity of 0.20 g/L MTA promoting the proliferation of DPSCs was stronger than other concentrations.After 4 weeks,the mineralized nodules of DPSCs were observed after alizarin red staining.The PCR showed that with increasing induction time,the expression levels of DSP and OC were up-regulated.But that of ALP and BSP was increased first and then decreased.Conclusions In this study,MTA can promote the proliferation of DPSCs at 0.02,0.20,2.00 g/L concentration.It can induce odontoblast differentiation effectively by 0.20 g/L MTA.
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<p><b>OBJECTIVE</b>To evaluate the effects of casein osphopeptide-amorphous calcium phosphate (CPP-ACP) in preventing enamel demineralization.</p><p><b>METHODS</b>Enamel blocks were prepared from premolars extracted from orthodontic patients. The specimens were treated for 30 min daily for 7 days with one of the following agents: deionized water (negative control), CPP-ACP paste, and NaF solutions (positive controls) (0.2% and 2%). After the treatments, the specimens were immersed in a demineralizing solution (pH 4.5) for 7 days. The morphology and depth of the lesion were observed using scanning electron microscopy, and the content of Ca, P, Mg in the demineralized enamel was measured by electron probe micro-analyzer.</p><p><b>RESULTS</b>The demineralization rates in all the treatment groups were significantly smaller than those in the control group after 7 days of demineralization.</p><p><b>CONCLUSION</b>The application of CPP-ACP to the enamel surfaces can inhibit enamel demineralization with an equivalent effect to 0.2% NaF.</p>