Although aluminum itself was reported to prevent dental caries, previous in vitro studies reported that the aluminum level in the whole saliva of children was independent of caries prevalence. Purposes of this study w...Although aluminum itself was reported to prevent dental caries, previous in vitro studies reported that the aluminum level in the whole saliva of children was independent of caries prevalence. Purposes of this study were to compare the elution levels of aluminum and calcium from deciduous enamel into acidic artificial saliva, and determine whether the degree of aluminum elution reflects individual caries risk. One hundred and eleven extracted human deciduous teeth were collected. Concentrations of aluminum and calcium eluted from sound regions of enamel into artificial saliva (pH 6.2 or 5.5) were determined using atomic absorption spectrophotometry. One hundred and four and 108 available data samples were obtained for aluminum and calcium evaluation, respectively, and were compared based on the sex, tooth type, caries history, and the number of the donor’s carious teeth at each pH. Calcium elution was not affected by the sex;however, more aluminum was eluted from boys’ than from girls’ teeth at pH 5.5. The aluminum release depended on the tooth type, and was significantly higher in incisors than in molars at a pH of 5.5. In relation to the caries history, aluminum (at pH 5.5) and calcium (at pH 6.2) dissolved more from sound regions of the enamel of caries-experienced teeth than from the enamel of teeth without caries experience. Moreover, aluminum markedly dissolved from enamel in artificial saliva at both pH 6.2 and 5.5 when the donor had more carious teeth, regardless of the presence or absence of caries experience in the sampled teeth. There is a possibility that the rate of aluminum elution from enamel into acidic fluid reflects individual caries sensitivity.展开更多
Dental enamel-like hydroxyapatite whiskers with high crystallinity and homogeneous morphology were synthesized by a hydrothermal homogeneous precipitation method.The composition,crystallinity and morphology of prepare...Dental enamel-like hydroxyapatite whiskers with high crystallinity and homogeneous morphology were synthesized by a hydrothermal homogeneous precipitation method.The composition,crystallinity and morphology of prepared hydroxyapatite whiskers were characterized by Ⅹ-ray diffraction and scanning electron microscopy.The effects of urea and sorbitol on their morphology and composition were investigated.Homogeneous and well crystallized enamel-like hydroxyapatite whiskers with 1.17±0.08 μm in length and 84± 14 nm in width were obtained at 0.80 mol · L-1 urea and 0.26 mol · L-1 sorbitol.These hydroxyapatite whiskers may be close to nature hydroxyapatite dental enamel in terms of the morphology and composition,suggesting that they could have potential application as dental restorative materials in the field of stomatology.展开更多
This in vitrostudy aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal...This in vitrostudy aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal （Group LP）, disto-buccal （Group P）, mesio-lingual （Group NP） and disto-lingual （Group L） specimens. These four groups were treated using the standard cold-light bleaching procedure, a bleaching agent, a peroxide-free bleaching agent and cold-light, respectively. Before and after treatment, all specimens were analyzed by high-resolution, micro-area X-ray diffraction and scanning electron microscopy. Using a spectrometer, tooth color of all specimens was measured before and after treatment. The phase of the enamel crystals was identified as hydroxyapatite and carbonated hydroxyapatite. After treatment, specimens in Groups LP and P showed significantly weaker X-ray diffraction peaks, significant reduction in crystal size and crystallinity, significant increase in L~ but decrease in a＊ and b＊, and obvious alterations in the surface morphology. However, specimens in Groups NP and L did not show any significant changes. The cold-light bleaching treatment leads to demineralization in the enamel surface. The acidic peroxide-containing bleaching agent was the major cause of demineralization, whereas cold-light did not exhibit significant increase or decrease effect on this demineralization.展开更多
Superficial stains and irregularities of the enamelare generally what prompt patients to seek dental intervention to improve their smile. These stains or defects may be due to hypoplasia, amelogenesis imperfecta, mine...Superficial stains and irregularities of the enamelare generally what prompt patients to seek dental intervention to improve their smile. These stains or defects may be due to hypoplasia, amelogenesis imperfecta, mineralized white spots, or fluorosis, for which enamel microabrasion is primarily indicated. Enamel microabrasion involves the use of acidic and abrasive agents, such as with 37% phosphoric acid and pumice or 6% hydrochloric acid and silica, applied to the altered enamel surface with mechanical pressure from a rubber cup coupled to a rotatory mandrel of a lowrotation micromotor. If necessary, this treatment can be safely combined with bleaching for better esthetic results. Recent studies show that microabrasion is a conservative treatment when the enamel wear is minimal and clinically imperceptible. The most important factor contributing to the success of enamel microabrasion is the depth of the defect, as deeper, opaque stains, such as those resulting from hypoplasia, cannot be resolved with microabrasion, and require a restorative approach. Surface enamel alterations that result from microabrasion, such as roughness and microhardness, are easily restored by saliva. Clinical studies support the efficacy and longevity of this safe and minimally invasive treatment. The present article presents the clinical and scientific aspects concerning the microabrasion technique, and discusses the indications for and effects of the treatment, including recent works describing microscopic and clinical evaluations.展开更多
Microcrystalline structure changes of teeth enamel crystals during the artificial caries and synthetic saliva reminerlization were reported. Enamel samples were thinned by argon-ion-milling and examined by high-resolu...Microcrystalline structure changes of teeth enamel crystals during the artificial caries and synthetic saliva reminerlization were reported. Enamel samples were thinned by argon-ion-milling and examined by high-resolution transmitting electron microscope. The results revealed that the lattice dissolution of enamel hydroxyapatite started from central parts and grain boundaries of crystals, the former were often parallel to (1010) plane and advancing along the [0001] zone axis of crystals. The results also shown that synthetic saliva may reduce the quantity of bright contrast spots in lattice image for artificial carious crystals. In addition, some defects such as dislocations were found in grains, and they are believed to be related to the dissolution of lattice. Three kinds of structural weak sites revealed in crystals, i. e. (1)dislocations, (2) vacancies or impurities, and (3) grain boundaries.展开更多
Aim: The oral cavity has the particularity to host multiple hard and soft tissues, in this paper, we will discuss the current therapies that lead to cell differentiation by regenerative therapies and the future altern...Aim: The oral cavity has the particularity to host multiple hard and soft tissues, in this paper, we will discuss the current therapies that lead to cell differentiation by regenerative therapies and the future alternatives proposed by medicinal plants and all the regenerative potential of these different tissues. Material and Methods: A detailed review of the literature through the various search engines: Scopus, PubMed, google scholar, Cochrane, etc., uses the selected keywords to explore the effect of the regenerative potential of several medicinal plants. Results: Through our research, we have proceeded to sort different medicinal plants, according to their repairing and regenerative potential on the different tissues of the oral cavity. Conclusion: Future studies are conceivable to explore the opportunities and potential provided by medicinal plants in the field of regenerative dentistry.展开更多
文摘Although aluminum itself was reported to prevent dental caries, previous in vitro studies reported that the aluminum level in the whole saliva of children was independent of caries prevalence. Purposes of this study were to compare the elution levels of aluminum and calcium from deciduous enamel into acidic artificial saliva, and determine whether the degree of aluminum elution reflects individual caries risk. One hundred and eleven extracted human deciduous teeth were collected. Concentrations of aluminum and calcium eluted from sound regions of enamel into artificial saliva (pH 6.2 or 5.5) were determined using atomic absorption spectrophotometry. One hundred and four and 108 available data samples were obtained for aluminum and calcium evaluation, respectively, and were compared based on the sex, tooth type, caries history, and the number of the donor’s carious teeth at each pH. Calcium elution was not affected by the sex;however, more aluminum was eluted from boys’ than from girls’ teeth at pH 5.5. The aluminum release depended on the tooth type, and was significantly higher in incisors than in molars at a pH of 5.5. In relation to the caries history, aluminum (at pH 5.5) and calcium (at pH 6.2) dissolved more from sound regions of the enamel of caries-experienced teeth than from the enamel of teeth without caries experience. Moreover, aluminum markedly dissolved from enamel in artificial saliva at both pH 6.2 and 5.5 when the donor had more carious teeth, regardless of the presence or absence of caries experience in the sampled teeth. There is a possibility that the rate of aluminum elution from enamel into acidic fluid reflects individual caries sensitivity.
基金Sponsored by the Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.2010066)the Natural Science Foundation of Heilongjiang Province(Grant No.E201006)the Key Scientific and Technological Projects of Heilongjiang Province(Grant No.GC10A107)
文摘Dental enamel-like hydroxyapatite whiskers with high crystallinity and homogeneous morphology were synthesized by a hydrothermal homogeneous precipitation method.The composition,crystallinity and morphology of prepared hydroxyapatite whiskers were characterized by Ⅹ-ray diffraction and scanning electron microscopy.The effects of urea and sorbitol on their morphology and composition were investigated.Homogeneous and well crystallized enamel-like hydroxyapatite whiskers with 1.17±0.08 μm in length and 84± 14 nm in width were obtained at 0.80 mol · L-1 urea and 0.26 mol · L-1 sorbitol.These hydroxyapatite whiskers may be close to nature hydroxyapatite dental enamel in terms of the morphology and composition,suggesting that they could have potential application as dental restorative materials in the field of stomatology.
文摘This in vitrostudy aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal （Group LP）, disto-buccal （Group P）, mesio-lingual （Group NP） and disto-lingual （Group L） specimens. These four groups were treated using the standard cold-light bleaching procedure, a bleaching agent, a peroxide-free bleaching agent and cold-light, respectively. Before and after treatment, all specimens were analyzed by high-resolution, micro-area X-ray diffraction and scanning electron microscopy. Using a spectrometer, tooth color of all specimens was measured before and after treatment. The phase of the enamel crystals was identified as hydroxyapatite and carbonated hydroxyapatite. After treatment, specimens in Groups LP and P showed significantly weaker X-ray diffraction peaks, significant reduction in crystal size and crystallinity, significant increase in L~ but decrease in a＊ and b＊, and obvious alterations in the surface morphology. However, specimens in Groups NP and L did not show any significant changes. The cold-light bleaching treatment leads to demineralization in the enamel surface. The acidic peroxide-containing bleaching agent was the major cause of demineralization, whereas cold-light did not exhibit significant increase or decrease effect on this demineralization.
文摘Superficial stains and irregularities of the enamelare generally what prompt patients to seek dental intervention to improve their smile. These stains or defects may be due to hypoplasia, amelogenesis imperfecta, mineralized white spots, or fluorosis, for which enamel microabrasion is primarily indicated. Enamel microabrasion involves the use of acidic and abrasive agents, such as with 37% phosphoric acid and pumice or 6% hydrochloric acid and silica, applied to the altered enamel surface with mechanical pressure from a rubber cup coupled to a rotatory mandrel of a lowrotation micromotor. If necessary, this treatment can be safely combined with bleaching for better esthetic results. Recent studies show that microabrasion is a conservative treatment when the enamel wear is minimal and clinically imperceptible. The most important factor contributing to the success of enamel microabrasion is the depth of the defect, as deeper, opaque stains, such as those resulting from hypoplasia, cannot be resolved with microabrasion, and require a restorative approach. Surface enamel alterations that result from microabrasion, such as roughness and microhardness, are easily restored by saliva. Clinical studies support the efficacy and longevity of this safe and minimally invasive treatment. The present article presents the clinical and scientific aspects concerning the microabrasion technique, and discusses the indications for and effects of the treatment, including recent works describing microscopic and clinical evaluations.
文摘Microcrystalline structure changes of teeth enamel crystals during the artificial caries and synthetic saliva reminerlization were reported. Enamel samples were thinned by argon-ion-milling and examined by high-resolution transmitting electron microscope. The results revealed that the lattice dissolution of enamel hydroxyapatite started from central parts and grain boundaries of crystals, the former were often parallel to (1010) plane and advancing along the [0001] zone axis of crystals. The results also shown that synthetic saliva may reduce the quantity of bright contrast spots in lattice image for artificial carious crystals. In addition, some defects such as dislocations were found in grains, and they are believed to be related to the dissolution of lattice. Three kinds of structural weak sites revealed in crystals, i. e. (1)dislocations, (2) vacancies or impurities, and (3) grain boundaries.
文摘Aim: The oral cavity has the particularity to host multiple hard and soft tissues, in this paper, we will discuss the current therapies that lead to cell differentiation by regenerative therapies and the future alternatives proposed by medicinal plants and all the regenerative potential of these different tissues. Material and Methods: A detailed review of the literature through the various search engines: Scopus, PubMed, google scholar, Cochrane, etc., uses the selected keywords to explore the effect of the regenerative potential of several medicinal plants. Results: Through our research, we have proceeded to sort different medicinal plants, according to their repairing and regenerative potential on the different tissues of the oral cavity. Conclusion: Future studies are conceivable to explore the opportunities and potential provided by medicinal plants in the field of regenerative dentistry.
