OBJECTIVEThis study aims to evaluate the effects of Pinus massoniana needle extract (PMNE) on inhibiting demineralization of root dentin.

METHODSRoot dentin blocks were randomly divided into distilled deionized water (DDW) group, fluoride sodium (NaF) group, and 4%, 8% and 12% PMNE groups according to the experimental solution used in the process of pH cycling in each group. All specimens in each group experienced pH cycling for 8 d. The dentin mineral density (DMD) of the normal dentin and demineralized dentin and their D-value (ΔDMD) were determined using micro computed tomography. The morphology of dentin surface after pH cycling was also observed using a scanning electron microscope.

RESULTSThe ΔDMD values in all PMNE groups and the NaF group were considerably lower than the ΔDMD in the DDW group (P<0.05). The ΔDMD values of the 8% and 12% PMNE groups had no difference (P>0.05), both of which were lower than the ΔDMD in the 4% PMNE group and higher than that in the NaF group (P<0.05). The dentin tubules were partly opened in the PMNE groups. The opening degrees of the dentin tubule in PMNE groups were significantly less and smaller than the opening degree in the DDW group and were larger than that in the NaF group.

CONCLUSIONSPMNE can inhibit the deminera-lization of root dentin and can slow down the reduction in DMD. PMNE has the potential to prevent caries, and 8% PMNE can effectively inhibit dentin demineralization.

Dental Caries ; Dentin ; Humans ; Needles ; Pinus ; Sodium Fluoride ; Tooth Demineralization ; Tooth Root ; X-Ray Microtomography

OBJECTIVETo analyze the mechanism of fluorine by systemic analysis of fluorination-demineralization-remineralization experiments.

METHODSThe enamel specimens were randomly assigned to untreated group (group A), non-fluoride group (group B), low-fluoride group (group C) and high-fluoride group (group D). The in vitro model of fluoride enamel was established in group C and D. Based on that, the establishment of demineralization model and remineralization experiment by pH-cycling in group B, C and D were followed. All enamel specimens were observed by stereomicroscope and scanning electron microscope and compared in surface microhardness value.

RESULTSThere was distinct difference in micro-morphologic appearance on fluoride enamel surface. Artificial caries of fluoride enamel showed a relatively complete surface, the surface microhardness after demineralization and remineralization in fluoride group was higher than non-fluoride group (P < 0.05).

CONCLUSIONThe fluorinated enamel can enhance cariostatic potential and remineralization capacity of dental enamel.

Dental Caries ; Dental Enamel ; Fluorides ; Fluorine ; Humans ; Phosphates ; Tooth Demineralization ; Tooth Remineralization

OBJECTIVETo evaluate the effect of infiltration resin on masking white spot lesions by assessing the change in the white spot area.

METHODSSeventy-four maxillary anterior teeth with post-orthodontic decalcification teeth were investigated in this study. All teeth were treated with infiltration resin according to manufacturer recommendation. Standardized digital images were taken before, immediately after, and one week after treatment. The results were classified into three groups: com-pletely masked, partially masked and unchanged. The images of partially masked teeth were analyzed using an image analysis software. The size of the white spot lesion (W) and the whole-tooth facial surface (T) were measured, and the W:Tratio (%) was calculated. Statistical evaluation of the lesions was performed using Kruskal-Wallis and Mann-Whitney tests.

RESULTSAmong the 74 teeth, 20 (27%) teeth were classified as completely masked and 54 (73%) teeth were classified as partially masked; no tooth was unchanged. The W:T ratio significantly decreased from 39.28% before treatment to 9.46% after treatment (P < 0.05).

CONCLUSIONResin infiltration is an effective treatment for masking white spot lesion. However, the masking effect depends on the lesion depth and activity.

Acid Etching, Dental ; Color ; Dental Caries ; Dental Enamel ; Humans ; Lip ; Tooth Demineralization

OBJECTIVETo explore the efficacy of optical coherence tomography (OCT) in imaging and quantitatively evaluating early enamel caries and provide experimental evidence for the clinical diagnosis of early caries.

METHODSThe smooth surface of bovine teeth showing early artificial caries and demineralization changes was scanned by an all fiber-based OCT for images and optical profiles, which were compared with images from a polarized light microscope (PLM) and mineral loss from an atomic absorption spectrometer. Data were analyzed by paired-sample t-test and Pearson correlation analysis using SPSS software.

RESULTSThe images of enamel with early caries and demineralization from OCT coincided with those from PLM. The integrated reflectivity loss in the early caries group was significantly lower than that in the demineralized group (P < 0.05), whereas no significant difference in demineralized depth was found between the two groups (P > 0.05). A linear correlation was observed between integrated reflectivity loss and mineral loss (P < 0.05).

CONCLUSIONOCT can be used to nondestructively and accurately image early caries and quantify lesion extent and degree, suggesting the extensive use of this approach in the clinical diagnosis of early caries.

Animals ; Cattle ; Dental Caries ; Dental Enamel ; Tomography, Optical Coherence ; Tooth Demineralization

OBJECTIVETo investigate the preventive effectiveness in reducing tooth decay and decalcification of different concentration of fluoride toothpaste for orthodontic patients.

METHODS86 patients were divided into the first test group and the second test group. The patients of the first test group brushed tooth with 1.1% sodium fluoride and acidulated phosphate gel. The patients of the second test group brushed tooth with 0.243% sodium fluoride in a silica base. The extent of facial tooth decay and decalcification of the twelve upper and lower teeth from right cuspid to left cuspid was scored blindly and independently by four observers after 12 months of product use. The scores were rated either one (having tooth cavity/decalcification) or zero (no tooth cavity/decalcification). Four observer's readings were averaged per tooth, and then per patient for the two treatment groups.

RESULTSAfter 12 months of product use, the mean caries score of the first test group was 0.326, and the mean caries score of the second test group was 0.490. There was significant difference between them.

CONCLUSIONA gel system containing 1.1% sodium fluoride and acidulated phosphate provides a clinically better efficacy in reducing tooth decay and decalcification than does a toothpaste containing 0.243% sodium fluoride in a silica base under and adjacent to orthodontic brackets used in orthodontic therapy.

Dental Caries ; Female ; Fluorides ; Humans ; Male ; Phosphates ; Sodium Fluoride ; Tooth Demineralization ; Toothpastes

OBJECTIVETo investigate the transformation of microhardness and microstructures of human dental fluorosis after demineralization and remineralization in vitro.

METHODSForty human dental fluorosis enamel blocks were demineralized by acid-etching gel, then subjected to 1.0% casein phosphopeptides stabilized calcium phosphate (CPP-CP) for remineralization. Surface enamel microhardness was measured on the enamel blocks before and after demineralization and after remineralization. The enamel specimens was observed by stereomicroscope and scanning electron microscope, then sectioned (100 microm) and examined by transmission light microscope and polarized light microscope.

RESULTSBefore demineralization, the average knoop hardness value of the fluorosed teeth was (241.53 +/- 21.31) kHV. After demineralization, obvious decrease of the surface hardness of the enamel was observed, the mean value was (175.76 +/- 24.99) kHV (P < 0.05), the percent of the surface microhardness demineralization (% SMHD) was (27.23 +/- 1 4.79)%, and major demineralization was under the surface of the enamel, which was similar to the early natural enamel caries. After remineralization, obvious increase of the surface hardness of the enamel was observed, the mean value was (210.17 +/- 21.48) kHV (P < 0.05), the percent of the surface microhardness remineralization (% SMHR) was (52.32 +/- 4.23)%, major remineralization was under the surface of the enamel.

CONCLUSIONRemineralization could be used to prevent and cure the early natural enamel caries of fluorosed dental teeth.

Calcium Phosphates ; Cariostatic Agents ; Caseins ; Dental Caries ; Dental Enamel ; Hardness ; Humans ; In Vitro Techniques ; Tooth Demineralization ; Tooth Remineralization

OBJECTIVETo evaluate remineralization efficacy of an arginine containing dentifrice on initial enamel carious lesions in vitro.

METHODSHuman enamel blocks with early lesions were prepared and randomly divided into three treatment groups: negative control group (distilled and deionized water), positive control group (fluoride containing dentifrice and 0.14% sodium monofluorophosphate), and test dentifrice group (8.0% arginine and 0.14% sodium monofluorophosphate). The lesions were subjected to a pH-cycling regime for 10 days. Surface enamel microhardness of the enamel blocks from each group was measured before and after pH cycling, and the surface microhardness recovery was calculated. Then, specimens were analyzed for enamel fluoride uptake (EFU) through acid etching method, after which they were treated in demineralization solution for a 2 h period of acid challenge. The other specimens were sectioned and examined through polarized light microscopy.

RESULTSIn the test dentifrice group, microhardness recovery and EFU were significantly higher than those in the negative control and positive groups. The test dentifrice group was significantly resistant to the acid challenge compared with the other groups. Conspicuous remineralization of enamel subsurface lesions was observed under polarized light microscopy among samples treated with test dentifrice, whereas the control groups showed no significant changes on enamel subsurface lesions.

CONCLUSIONThis study presents the potential superiority of Pro-Argin dentifrice over conventional fluoride dentifrice in promoting the remineralization of initial enamel lesions.

Arginine ; Calcium Carbonate ; Cariostatic Agents ; Dental Caries ; Dental Enamel ; Dentifrices ; Fluorides ; Hardness ; Humans ; Phosphates ; Tooth Demineralization ; Tooth Remineralization

OBJECTIVETo evaluate the anti-demineralization efficacy of Galla Chinesis in pH cycling model for elucidating the anti-root caries mechanism.

METHODAnti-demineralization efficacy evaluation of the natural medicine in the pH-cycling models was used . Sound human root blocks were pH-cycled through the treatment solution, acidic buffer and neutral buffer. The cycling times for demineralization study were 12 times, 2 times per day. The acidic buffers were retained for calcium analysis by atomic adsorption spectroscopy. The sections of blocks were analysed after pH-cycling by CLSM. Treatments were 4 g x L(-1). Galla Chinesis, 1 g x L(-1) NaF solution and distilled water.

RESULTGalla Chinesis was found to inhibit the demineralization in the pH cycling model. Although the effect was not as good as fluoride, there was no significant difference between the two groups.

CONCLUSIONThese data suggest that Galla Chinesis could modulate the mineralisation behaviour of root tissue in a defined chemical circumstance. These findings support the proposition that Galla Chinesis may be a promising anticaries natural medicine in the future.

Animals ; Calcium ; metabolism ; Cuspid ; drug effects ; pathology ; Dental Caries ; prevention & control ; Humans ; Hydrogen-Ion Concentration ; Insecta ; chemistry ; Materia Medica ; isolation & purification ; pharmacology ; Microscopy, Confocal ; Sodium Fluoride ; pharmacology ; Tooth Demineralization ; metabolism ; pathology ; prevention & control ; Tooth Remineralization ; Tooth Root ; drug effects ; metabolism ; pathology

OBJECTIVETo evaluate the efficacy of Tooth Mousse in reducing enamel demineralization lesions adjacent to bonded orthodontic brackets and promoting remineralization in vitro.

METHODS60 bovine teeth with bonded orthodontic brackets were randomly divided into three groups, negative control group, positive control group and experimental group, applied separately with distilled water, Duraphat fluoride varnish, Tooth Mousse. 3 groups were dipped into an artificial caries solution and an artificial saliva solution, cycling between them. All samples were detected by polarized light microscope, scanning electron microscope and electron probe micro-analysis.

RESULTSPolarized light microscope showed that the enamel surface of the experimental group were completed, the areas of positive birefringence were decreased obviously. Scanning electron microscope showed that a large number of deposits were found on the dental enamel surface of the experimental group, filled in the small local concave of enamel surface. Compared with the control group, electron probe micro-analysis showed that calcium and phosphate concentration of enamel surface was higher in experimental group than in negative control group (P<0.05), there was no significant differences between experimental group and positive control group (P>0.05).

CONCLUSIONTooth Mousse can reduce enamel demineralization and promoting remineralization in vitro.

Animals ; Cariostatic Agents ; Caseins ; Cattle ; Dental Caries ; Dental Enamel ; Fluorides ; Fluorides, Topical ; Orthodontic Brackets ; Phosphates ; Sodium Fluoride ; Tooth Demineralization

OBJECTIVETo evaluate the microtensile bond strength and bond interface of total-etch or self-etch adhesives to normal dentin and caries-affected dentin.

METHODSA total of 20 molars with occlusal caries lesion were used. The caries-affected dentin was obtained by removing the caries-infected dentin under the guidance of the caries detector. Beyond the level of caries-affected dentin all the enamel and partial dentin were removed. The adhesive systems, two total-etch adhesives (All-Bond 2, Prime&Bond NT) and two self-etch adhesives (Clearfil SE Bond, Xeno III) were applied respectively under the instructions of manufacturers. A block of composite resin was build up superficially. All the teeth were sectioned to obtain bar-shaped specimens with bonded surface area about 0.9 mm x 0.9 mm. The specimens were divided into normal dentin group and caries-affected dentin group via stereomicroscope. The bond strength was tested in a microtensile tester with a crosshead speed of 1 mm/min. The mean values of bond strength were compared using two-way ANOVA. The bonding interface between the dentin and adhesives was qualitatively evaluated under the observation of scanning electron microscope (SEM).

RESULTSTwo-way ANOVA revealed a significant influence of both the type of dentin and the adhesive systems tested on microtensile bond strength values. All the adhesives attained higher strength in normal dentin. In normal dentin, there was no significant difference between total-etch and self-etch adhesives. In caries-affected dentin, bond strength of Xeno III was significantly lower than the others. For SEM, the hybrid layer in caries-affected dentin was thicker but more porous than that in normal dentin. Compared with normal dentin, there was fewer resin tag exhibited in caries-affected dentin and no lateral branches were observed.

CONCLUSIONSThe total-etch adhesive had higher bond strength than self-etch adhesive systems in caries-affected dentin.

Acid Etching, Dental ; Adult ; Dental Caries ; therapy ; Dentin ; ultrastructure ; Dentin-Bonding Agents ; classification ; Humans ; Middle Aged ; Tensile Strength ; Tooth Demineralization ; therapy