Comparison of bonding properties of five adhesives in primary dentin / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the microtensile bond strength (µTBS) of five dentin adhesives and their respective fracture modes.</p><p><b>METHODS</b>The flat dentine surfaces of 75 primary teeth were randomly divided into five groups,which was treated with FL-BondII(group A), Clearfil Protect Bond(group B), Clearfil SE Bond(group C), Adper(TM) Easy One(group D), and Single Bond 2(group E) respectively. The µTBS was determined with microtensile tester and the fracture mode was observed by scanning electron microscope(SEM).</p><p><b>RESULTS</b>The mean µTBS for group A,B,C,D and E was (28.3 ± 2.2), (32.4 ± 2.5), (38.3 ± 2.8), (32.9 ± 3.4) and (23.2 ± 1.9) MPa respectively. There was significant difference between group C and group A,E (P < 0.01), and no significant difference between group C and group B,D. There was no significant difference between group A and group E (P > 0.05). The SEM indicated that there was no significant difference in the fracture mode.</p><p><b>CONCLUSIONS</b>The bonding property of Clearfil Protect Bond is equivalent to Clearfil SE Bond and Adper(TM) Easy One, superior to Single Bond 2 and more suitable for primary dentin bonding .</p>

Chemopreventive effect of boswellic acid and curcumin on 7,12-dimethyl benzanthracene-induced hamster cheek pouch carcinogenesis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the chemopreventive effects of boswellic acid and curcumin on 7,12-dimethyl benzanthracene(DMBA)-induced oral carcinogenesis in the hamster cheek pouch model.</p><p><b>METHODS</b>Male Syrian golden hamsters (6 - 8 weeks old, 80 - 130 g in weight) were randomly divided into seven groups, with group A serving as the untreated negative control. The left cheek pouch of the remaining hamsters was topically treated with 0.5% DMBA in mineral oil three times a week for 6 weeks. They were then randomized to six groups with group B serving as a positive control and receiving no further treatment. Groups C-G were treated topically with 5, 10 mg/L boswellic acid, 5, 10 µmol/L curcumin, or the combination of 5 mg/L boswellic acid and 5 µmol/L curcumin three times per week for 18 weeks. The animals were injected with bromodeoxyuridine intraperitoneally at 50 mg/kg 2 h prior to killing. At the 25 th week all the hamsters were sacrificed and cheek pouch tissue was harvested. One half of the tissue was snap frozen in liquid nitrogen for analysis of arachidonic acid metabolites, and the other half was fixed in 10% phosphate-buffered saline(PBS)-buffered formalin for histopathological examination.</p><p><b>RESULTS</b>Six-weeks of DMBA followed by 18-weeks of topical application of boswellic acid and curcumin, both boswellic acid (5, 10 mg/L) and curcumin (5, 10 µmol/L) significantly inhibited the incidence from 93.8% to 73.9% (P > 0.05), numbers from 2.19 ± 0.98 to 1.13 ± 0.81 (P < 0.01) and size of visible tumors. Microscopically the incidence of squamous cell carcinoma and BrdU index were also significantly suppressed by boswellic acid and curcumin.</p><p><b>CONCLUSIONS</b>Both boswellic acid and curcumin were effective in preventing oral carcinogenesis in DMBA-induced hamster cheek pouch model.</p>

Effects of dentine phosphoprotein on remineralization of demineralized dentine / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between dentine phosphoprotein (DPP) and remineralization of demineralized dentine.</p><p><b>METHODS</b>(1) Soluble DPP was extracted with 1 mol/L NaCl from demineralized dentine and was evaluated. (2) Soluble DPP was removed with 0.1 mol/L NaCl or was not removed from demineralized dentine sections in human tooth roots. Then all sections were subjected to remineralization treatment, and remineralization degrees were compared by atomic absorption spectrum, SEM and microradiography.</p><p><b>RESULTS</b>(1) Soluble DPP was extracted with 1 mol/L NaCl. (2) Removal of soluble DPP resulted in significantly lower calcium concentration in remineralization solution (P < 0.01), less mean light-absorbed value in demineralized dentin sections by microradiography (P < 0.01).</p><p><b>CONCLUSIONS</b>Soluble DPP may have an inhibiting effect on remineralization of demineralized dentine, this study suggests that the remove of soluble DPP from root caries lesions may enhance their remineralization potential.</p>