Aim. The aim of this randomized, double-blind crossover in situ study was to compare the efficacy of three commercially available sugar-free chewing gums: Trident White, Orbit, and Orbit Professional, in remineralizing enamel subsurface lesions in situ .
Design. Specimens containing enamel subsurface lesions were sectioned into test and control half-slabs with the test half-slabs inserted into removable palatal appliances. For each test chewing period, subjects were randomly allocated one of three test gums. Subjects ( n = 10) chewed the randomly allocated gum for a 20-min period four times per day for 14 days. Each subject chewed all three test gums, with a 7-day washout period between crossovers. After each 14-day cycle, test and control half-slabs were paired, embedded in resin, sectioned, and subjected to microradiography to determine remineralization.
Results. The gum TW produced significantly greater remineralization (18.4 ± 0.9%) than Orbit (8.9 ± 0.5%) and Orbit Professional (10.5 ± 0.9%).
Conclusion. The superior remineralization activity of the TW gum in situ was attributed to the presence of casein phosphopeptide–amorphous calcium phosphate nanocomplexes. 相似文献
Objectives
Manufacturers are adding fluoride (F) to calcium-containing chewing gums to further promote enamel remineralization. The aim of this study was to assess the effect of a chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and fluoride on remineralization of enamel subsurface lesions, in a double-blind, randomized controlled in situ trial.Methods
Thirty-six volunteer subjects wore removable buccal appliances with three different insets of bovine enamel with subsurface demineralized lesions. For 14 days the subjects chewed one of the three chewing gums (placebo, POs-Ca, POs-Ca + F), three times a day. After each treatment period, the insets were removed from the appliance, embedded, sectioned, polished and then subjected to laboratory tests; mineral level was determined by transverse microradiography (TMR; n = 36), and hydroxyapatite (HAp) crystallites were assessed by synchrotron radiation wide-angle X-ray diffraction (WAXRD; n = 13). Data were analysed by t-test or Wilcoxon rank-sum test with Bonferroni corrections at 0.05 significance level.Results
Chewing POs-Ca and POs-Ca + F gums resulted in 21.9 ± 10.6 and 26.3 ± 9.4 (mean ± SD) percentage mineral recovery, which was significantly higher than that of placebo gum (15.0 ± 11.4) (p < 0.05). Chewing POs-Ca + F gum resulted in 24.9 ± 5.4 (mean ± SD) percentage HAp crystallites recovery, which was significantly higher compared to POs-Ca (16.0 ± 4.1%) or placebo (11.1 ± 4.8%) gums (p < 0.05).Conclusions
Addition of POs-Ca to the chewing gum resulted in significant remineralization of enamel subsurface lesions. Although POs-Ca + F gum was not superior in TMR recovery rate when compared with POs-Ca gum, WAXRD results highlighted the importance of fluoride ion bioavailability in the formation of HAp crystallites in enamel subsurface lesions in situ (NCT01377493). 相似文献Objectives
To quantify swallowing threshold parameters of subjects with a moderate shortened dental arch dentition (SDA: missing molar teeth, but premolar teeth in occluding position and uninterrupted anterior regions) compared to subjects with a complete dental arch dentition (CDA).Methods
Fourteen females with SDA (3–4 occlusal premolar units) and 14 females with CDA were instructed to chew silicone test ‘food’ (cubic particles with a total volume of 3 cm3). They spit it out the moment they felt the urge to swallow and the pulverized particles were collected. Swallowing threshold parameters were number of chewing cycles, time until ‘swallowing’, and median particle size of the pulverized particles as determined by sieving the food. Chewing tests were performed twice and outcomes were averaged.Results
The number of chewing cycles until ‘swallowing’ of subjects with SDA was approximately 1.7 times (p < 0.005) that of the controls and this took approximately 1.6 times more time (p < 0.01). The median particle size until ‘swallowing’ did not differ significantly between the groups, but demonstrated large individual differences. Regression analyses indicated that the ratio of median particle size until ‘swallowing’ of SDA and CDA becomes progressively unfavourable for SDA with increasing numbers of chewing cycles.Conclusions
Subjects with SDA pulverized test ‘food’ particles to sizes comparable to subjects with CDA, but chewed longer with more chewing cycles until ‘swallowing’. Higher numbers of chewing cycles were associated with increasing difference between SDA and CDA regarding the median particle size until ‘swallowing’.Clinical significance
Compared to subjects with CDA, subjects with moderate SDA pulverize test food particles to comparable size by chewing longer before “swallowing”. Therefore, overloading the digestive system by swallowing courser food particles is unlikely in SDA. Consequently, replacement of absent molars just to optimize chewing function is not advised. 相似文献Objectives
The aim of this study was to investigate the effects of decreasing fluoride concentrations on repeated demineralizing challenges on human enamel.Materials and methods
In 24 teeth, 3 mm × 3 mm windows were prepared on the buccal and lingual sides and treated in a cycling demineralization–remineralization model. Remineralization was achieved with 100, 10 and 0.1 ppm fluoride from anime fluoride. Coronal sections were cut through the artificial lesions, and three sections per tooth were investigated using polarized light microscopy and scanning electron microscopy with quantitative element analysis.Results
The morphology of the lesions was studied, and the extensions of the superficial layer and the body of the lesion were measured. Using element analysis, the Ca, P and F content were determined. The body of the lesion appeared remineralized after application of 100 ppm fluoride, while remineralization of the lesion was less successful after application of 10 and 0.1 ppm fluoride. The thickness of the superficial layer increased with decreasing fluoride concentrations, and also the extension of the body of the lesion increased. Ca and P content increased with increasing fluoride concentrations.Conclusions
The effectiveness of fluoride in enamel remineralization increased with increasing fluoride concentration.Clinical relevance
A consistently higher level of fluoride in saliva should be a goal in caries prevention. 相似文献Objective
Remineralization is an indispensable phenomenon during the natural healing process of enamel decay. The incorporation of zinc (Zn) into enamel crystal could accelerate this remineralization. The present study was designed to investigate the concentration and distribution of Zn in remineralized enamel after gum chewing.Methods
The experiment was performed at the Photon Factory. Synchrotron radiation was monochromatized and X-rays were focused into a small beam spot. The X-ray fluorescence (XRF) from the sample was detected with a silicon (Si) (lithium (Li)) detector. X-ray beam energy was tuned to detect Zn. The examined samples were small enamel fragments remineralized after chewing calcium phosphate-containing gum in situ. The incorporation of Zn atom into hydroxyapatite (OHAP), the main component of enamel, was measured using Zn K-edge extended X-ray absorption fine structure (EXAFS) with fluorescence mode at the SPring-8.Results
A high concentration of Zn was detected in a superficial area 10-μm deep of the sectioned enamel after gum chewing. This concentration increased over that in the intact enamel. The atomic distance between Zn and O in the enamel was calculated using the EXAFS data. The analyzed atomic distances between Zn and O in two sections were 0.237 and 0.240 nm.Conclusion
The present experiments suggest that Zn is effectively incorporated into remineralized enamel through the physiological processes of mineral deposition in the oral cavity through gum-chewing and that Zn substitution probably occurred at the calcium position in enamel hydroxyapatite. 相似文献Objective
To assess the effect of a fluoride varnish and gel on the erosive wear of primary and permanent teeth.Design
Sixty human primary (n = 30) and permanent (n = 30) enamel specimens were randomly assigned to one of the following groups: APF gel (1.23% F), NaF varnish (2.26% F), and control (no treatment). Fluoride gel was applied for 4 min and fluoride varnish for 24 h. Six daily demineralisation-remineralization cycles of 5 min of immersion in a cola drink (pH 2.3) and 30 min in artificial saliva were conducted during 7 days. All specimens were stored in artificial saliva between and after cycles. Surface Knoop microhardness (%SMHC) readings were performed at baseline, 48 h and 7 days. Data were tested using ANOVA and Tukey's tests (p < 0.05).Results
For primary enamel, the mean %SMHC (±SD) after 48 h and 7 days was, respectively: gel (31.0 ± 14.4 and 36.9 ± 7.5), varnish (26.7 ± 9.5 and 38.3 ± 8.7), and control (35.8 ± 8.6 and 45.0 ± 8.6). For permanent enamel, such values were: gel (37.5 ± 7.7 and 27.8 ± 7.5), varnish (31.7 ± 9.6 and 27.4 ± 11.1) and control (48.6 ± 6.4 and 43.1 ± 6.4). In primary enamel, erosion inhibition by fluoride was not significant at 48 h (p = 0.203) and 7 days (p = 0.082). In permanent specimens, both products showed a significant effect (p < 0.001).Conclusions
Both fluoride varnish and gel were able to inhibit erosive enamel loss but mainly in the permanent experimental groups. Primary and permanent enamel substrates reacted differently to both demineralization by a cola drink and remineralization by fluoridated compounds. 相似文献Objectives
Eroded teeth are more susceptible to toothbrushing wear than sound teeth. We tested the hypothesis that fluoride and abrasivity of dentifrices can interact, modulating the development of erosive–abrasive lesions.Methods
Human enamel and root dentin specimens were submitted to cycles of demineralization, remineralization and toothbrushing using six dentifrices formulated with three different abrasivity levels: low (L), medium (M) and high (H); with (+F) and without (−F) fluoride. Surface loss was quantified by optical profilometry and compared among groups (α = 0.05).Results
In dentin, it was ranked: L < M < H, for both +F and −F dentifrices. In enamel, +F dentifrices had similar results; however for −F formulations, M and H did not differ. Fluoride reduced surface loss in enamel, at all abrasive levels. In dentin, the same fluoride effect was observed but only for the low abrasive formulation.Conclusions
Both fluoride and abrasivity were important modulators of enamel surface loss, while abrasivity had a higher impact than fluoride on dentin. 相似文献Objectives
Tooth bleaching agents may adversely affect tooth structure. The aim of this study was to investigate the effect of hydrogen peroxide concentration on mineral loss and microhardness of bovine teeth.Methods
Twenty-six freshly extracted intact bovine incisor teeth were stored in distilled water. Five teeth were sectioned and four samples (2 mm × 2 mm × 1.5 mm) each of enamel and dentine were obtained from each tooth. The samples of enamel and dentine were divided into four groups and immersed in either 0%, 3%, 10% or 30% (w/v) hydrogen peroxide solutions for 24 h at 37 °C. Samples from the solutions were taken for ion release analysis using inductively coupled plasma mass spectrometry. The remaining 21 teeth were mounted in epoxy resin and the upper surface of the specimens were ground and polished to expose the enamel and dentine for microhardness measurements. These specimens were randomly divided into three equal groups and Vickers microhardness values were recorded on the enamel and dentine surfaces of each group before and after bleaching.Results
The differences in ion release concentration after treatment with 0% (control) and each of 3%, 10% and 30% hydrogen peroxide (w/v) were statistically significant (p < 0.025). The release of calcium and phosphorous ions increased with increasing hydrogen peroxide concentrations. A significant reduction (p < 0.05) in Vickers microhardness values for enamel was recorded after bleaching.Conclusions
Ion release from both enamel and dentine increased with increasing hydrogen peroxide concentration. Microhardness of enamel decreased significantly with bleaching. 相似文献Objective
To determine whether chewing of gum facilitates spatial task performance in healthy participants, two behavioral experiments were performed.Design
In the first experiment, spatial task performance of 349 men and women preceding and after treatment administration (saccharated chewing gum, sugar-free chewing gum, no chewing gum) was assessed using effect modeling by means of Item Response Theory. In the second experiment, another 100 participants were either administered sugar-free chewing gum or no chewing gum during spatial task performance. Effects of gum in the second study were assessed by standard means of data analysis.Results
Results indicated no significant effects of either chewing gum or sugar on spatial task performance in either experiment.Conclusions
Our findings are consistent with recent studies investigating the influences of chewing gum on various memory functions, extending them by another measure of cognitive ability. Thus, further doubt is cast on enhancing effects of chewing gum on cognitive task performance. 相似文献The purpose of this study is to analyze the in situ effect of a casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) chewing gum on human enamel erosion lesion associated or not with abrasion.
Material and methodsA three-way crossover study of 7 days was conducted involving 10 volunteers subjected to the same protocol: (G1) CPP-ACP sugar-free chewing gum, (G2) regular sugar-free chewing gum without CPP-ACP, and (G3) saliva—no chewing gum. An abrasion test was included in each phase. A 3D non-contact profilometry measurement of lesion depth and surface roughness was obtained of sound and eroded surfaces. A salivary calcium concentration was determined for all volunteers. ANOVA followed by Tukey’s test were used with a p < 0.05.
ResultsThe enamel depth and the enamel surface roughness of the CPP-ACP gum group were significantly lower than the others (ANOVA, p < 0.05). No significant differences were observed between the treatments when associated with abrasion (p > 0.05). A positive and significant correlation was seen between the lesion depth and enamel surface roughness for GI (r = 0.87, p = 0.00) and GIII (r = 0.79, p = 0.00) groups. The estimated total calcium presented in the saliva after the chewed CPP-ACP gum showed no statistical significance between the mean absorbance values at the different time collections (p > 0.05).
ConclusionsIt is demonstrated that the incorporation of the CPP-ACP into a sugar-free gum significantly increased the remineralization/protection of eroded enamel surface.
Clinical relevanceThe CPP-ACP added to gum may be a suitable alternative vehicle, to deliver calcium ions to saliva and therefore protecting enamel.
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