Research progress in CPP-ACP combined with fluoride on enamel remineralization / 国际生物医学工程杂志

With the improvement of people's living standard and the strengthening of people's recognition of dental caries prevention and treatment, enamel remineralization has attracted extensive attention. Fluoride, bioactive glass and casein phosphopeptide-amorphic calcium phosphate (CPP-ACP) are the most widely studied remineralisation agents at present, which have a certain effect of promoting enamel remineralization. The results of different studies shown that the effect of CPP-ACP combined with fluoride was quite different, which may be affected by many factors. In this paper, the recent progress of the combined application of CPP-ACP and fluoride on enamel remineralization was reviewed, and various influencing factors were analyzed in order to provide references for future experimental design and clinical applications.

Occluding dentin tubules with monetite paste / 华西口腔医学杂志

OBJECTIVES@#This study was performed to evaluate the occlusion of monetite paste on dentine tubule and provide a new potential method for treating dentine hypersensitivity.@*METHODS@#Calcium oxide, strontium chloride, and polyethylene glycol phosphate were mixed in a certain proportion and ground in a planetary ball mill. The reaction was carried out by adjusting the pH to obtain monetite and hydroxyapatite paste. The morphological characteristics of the paste were observed through scanning electron microscope (SEM). The structure and composition were analyzed through X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FTIR). The extracted third molar was selected to undergo demineralization to establish the @*RESULTS@#XRD and FTIR showed that the composition of the paste was mainly monetite, and the composition of hydroxyapatite paste was mainly composed of hydroxyapatite. SEM revealed that the size of the crystal particles of the synthesized paste was tens to hundreds of nanometers. Monetite and hydroxyapatite paste could produce a thicker mineralization layer on the dentin surface, and the mineralization of the dentin tubules of monetite was deeper than that of hydroxyapatite paste. The microhardness of the monetite paste group was significantly less than those of the hydroxyapatite paste groups (@*CONCLUSIONS@#Monetite paste could effectively block the exposed dentin tubules and be used for treating dentin hypersensitivity.

Effects of casein phosphopeptide-amorphic calcium phosphate on enamel erosion: an in situ study / 中华口腔医学杂志

Objective@#To evaluate the effects of casein phosphopeptide-amorphic calcium phosphate (CPP-ACP) on enamel erosion using an improved in situ experimental protocol.@*Methods@#Forty-eight enamel blocks were prepared from fresh-extracted human premolars and further embedded in the acrylic resins. The present study was divided into 2 parts. In part 1 of the study, two volunteers were recruited to test the availability and safety of the in situ erosion protocol. Customized intraoral appliance was made with 4 reservoirs containing the specimens for each volunteer. For each intraoral applicance, 2 reservoirs were made with the openings and the other 2 remained intact. All volunteers were instructed to drink 150 ml cola within 5 min using the gargling method after placing appliances intraorally for 2 h. After erosion, the appliances were remained undisturbed intraorally for 1 h until the next erosive attack. The in situ erosion cycles were performed 4 times daily over 7 d. In part 2 of the study, forty specimens were randomly divided into 2 groups (n=20): CPP-ACP group and control group. The surfaces of specimens in CPP-ACP group were pretreated with CPP-ACP for 3 min before in situ erosion, whereas the specimens in control group were pretreated with deionized water for 3 min. For each intraoral applicance, 4 reservoirs were made with openings. Ten healthy volunteers were recruited and the above-mentioned in situ erosion protocol was applied to test the effects of CPP-ACP on enamel erosion. The surface microhardness and surface microstructure of the samples were examined before and after erosion in both parts of the study. The data were statistically analyzed using ANOVA and LSD tests. Data were considered statistically significant at a level of P<0.05.@*Results@#Significant surface softening was observed in all specimens after erosion (P<0.001). The surface microhardness in the CPP-ACP group and control group were (198.8±23.2) and (152.4±42.1) HV, respectively (P=0.040). The specimens in the CPP-ACP group showed significantly fewer changes in surface microstructure compared with those in the control group.@*Conclusions@#Based on this in situ experimental protocol, short-time consuming of acid beverages would produce significant effects on the surface microhardness of the human enamel, whereas the application of CPP-ACP can increase the erosion resistance of the enamel.

Genotype/phenotype association in indian congenital aniridia.

The developmental birth eye disorder of iris is known as aniridia. Heterozygous PAX6 gene, which causes human aniridia and small eye in mice, is located on chromosome 11p13. The variability had been documented between the affected individuals within the families, is due to genotypic variation. Haploinsufficiency renders PAX6 allele non-functional or amorphic, however it presents hypomorphic or neomorphic alleles. India is not a well-studied ethnic group, hence the focus on congenital aniridia gene analysis supports the literature and the phenotypic association were analysed both in sporadic as well as familial. The consistent association of truncating PAX6 mutations with the phenotype is owing to non-sensemediated decay (NMD). It is presumed that the genetic impact of increased homozygosity and heterozygocity in Indian counter part arises as the consequence of consanguineous marriages. The real fact involved in congenital aniridia with other related phenotypes with PAX6 mutations are still controversial.