ABSTRACT
Objective To investigate the therapeutic effects of penetrating resin and fluoride on early enamel caries. Methods Sixty intact bovine incisors were immersed in demineralized solution for 24 hours to make bovine incisor enamel caries.The specimens were divided into four groups(n=15 for each group)according to the treatment methods:control group (CON)-immersion in artificial saliva, DF group-immersion in 0.05% fluoride solution daily, WF group-2% fluoride gel weekly and IC group-resin infiltration.After processing for four and eighe weeks,the microhardness of the surface of each group was measured.After the treatment for four weeks,the depth of penetration and the microhardness of the samples were measured. After 8-week treatment, all samples were reintroduced into the demineralized solution for 24 hours and the microhardness of the samples was measured again.Results Results of microhardness assessment showed that there were no significant differences in baseline values(after white spots)between four groups(P>0.05).After treatment for four weeks the microhardness value reached the peak in IC group. After treatment for eight weeks the microhardness values reached the peak in DF group and WF group.The values of microhardness were significantly higher at different time points in IC group than those of other groups(P<0.05).After 4-week treatment,the percentages of penetration depth were significantly higher in DF,WF and IC groups than those of control group(P<0.01).The penetration depth was significantly higher in IC group than that of DF group and WF group (P<0.05). There was no significant difference in the penetration depth between DF group and WF group(P>0.05).Conclusion For the early enamel caries penetration resin,the penetration percentage is significantly higher than the fluoride treatment.
ABSTRACT
Objective To investigate the effects of the relationship between bone cement polymethyl methacrylate (PMMA) and endplate on the vertebral height loss after percutaneous vertebroplasty (PVP).Methods A retrospective analysis of 84 female patients with single segment osteoportic vertebral compression fracture who had undergone PVP between Jun.,2013 and May,2016 was conducted.According to the X-ray radiographs and CT scans,all subjects were divided into the doPMMA-endplate-contact group (40 cases,average age 76.88 years) and the non-PMMA-endplatecontact group (44 cases,average age 77.96 years).The volume of bone cement,operation time,fractured vertebral height restoration rate,3-month postoperative vertebral height loss rate,changes in local sagitta view Cobb angle and bone cement leakage rate were respectively recorded and compared.Results There were no significant difference in age,body mass index,the levels of serum calcium and phosphorus,bone mineral density and preoperative vertebral body compression rate between the two groups (P＞0.05).Postoperative vertebral height loss rate and changes in local sagitta view Cobb angle in the do-PMMA-endplate-contact group were significantly less than the non-PMMA-endplate-contact group (P＜0.05).However,there was no significant difference in bone cement leakage rate between the two groups (P＞0.05).Conclusions Making bone cement contact with endplate would reduce the height loss of cemented vertebrae without increasing the rate of cement leakage.