The main mineral component of natural tooth was determined as calcium apatite many years ago; most of them exist in the form of hydroxyapatite with different crystallites. If a tooth decayed, the crystalline of hydroxyapatite would be changed and decomposed. In our experiment, a natural tooth with caries was measured by high resolution XRD equipment: X'pert Pro. Three spots which included normal enamel, normal dentin and caries tissue were analyzed. The results showed that tooth was a kind of biological mixed crystal composed of many crystal phases, the main crystal phase was hydroxyapatite. From normal enamel to normal dentin and to caries tissue, the length of the a-axis of hydroxyapatite crystallite increased, the length of the c-axis of hydroxyapatite crystallite remained unchanged. The crystal sizes were: normal enamel D002 = 27.600 nm; normal dentin D002 = 16.561 nm; caries tissue D002 = 13.163 nm. Crystallinity: normal enamel>normal dentin>caries tissue. According to our experiment, tooth could be conveniently studied by high resolution microdiffracion XRD equipment.
Dental Caries ; metabolism ; Dental Enamel ; chemistry ; Dentin ; chemistry ; Humans ; Tooth ; chemistry ; X-Ray Diffraction ; methods

Tooth decay is prevalent, and secondary caries causes restoration failures, both of which are related to demineralization. There is an urgent need to develop new therapeutic materials with remineralization functions. This article represents the first review on the cutting edge research of poly(amido amine) (PAMAM) in combination with nanoparticles of amorphous calcium phosphate (NACP). PAMAM was excellent nucleation template, and could absorb calcium (Ca) and phosphate (P) ions via its functional groups to activate remineralization. NACP composite and adhesive showed acid-neutralization and Ca and P ion release capabilities. PAMAM+NACP together showed synergistic effects and produced triple benefits: excellent nucleation templates, superior acid-neutralization, and ions release. Therefore, the PAMAM+NACP strategy possessed much greater remineralization capacity than using PAMAM or NACP alone. PAMAM+NACP achieved dentin remineralization even in an acidic solution without any initial Ca and P ions. Besides, the long-term remineralization capability of PAMAM+NACP was established. After prolonged fluid challenge, the immersed PAMAM with the recharged NACP still induced effective dentin mineral regeneration. Furthermore, the hardness of pre-demineralized dentin was increased back to that of healthy dentin, indicating a complete remineralization. Therefore, the novel PAMAM+NACP approach is promising to provide long-term therapeutic effects including tooth remineralization, hardness increase, and caries-inhibition capabilities.
Amines ; pharmacology ; Calcium ; Calcium Phosphates ; chemistry ; pharmacology ; Dentin ; chemistry ; Humans ; Nanocomposites ; chemistry ; Nanoparticles ; Tooth Remineralization ; methods

This study sought to determine the impact of dental fluorosis severity on demineralization and remineralization of human fluorosed teeth in vitro. Surface enamel microhardness was measured on the enamel blocks before and after demineralization and after remineralization. The results showed that after demineralization, the sequence of % Surface microhardness demineralization (% SMHD) was TFI4 (18.92 +/- 1.31) < TFI3 (20.50 +/- 1.32) < TFI2 (25.08 +/- 1.69) < TFI1 (27.77 +/- 1.79) < TFI0 (30.70 +/- 1.35) (P < 0.05), and there was no statistically significant differences between TFI1 (27.77 +/- 1.79) and the normal group TFI0 (30.70 +/- 1.35). After remineralization, the sequence of % Surface microhardness remineralization (% SMHR) was TFI1 (55.17 +/- 1.23) > TFI0 (53.97 +/- 3.05) > TFI2 (49.17 +/- 1.81) > TFI3 (44.85 +/- 1.89) > TFI4 (36.51 +/- 2.95) (P < 0.05). Moderately fluorosed enamel showed a significatnt resistance to caries, but mildly fluorosed enamel could get better remineralization. These facts and figures deserve clinicians' attention.
Dental Enamel ; chemistry ; pathology ; Fluorosis, Dental ; metabolism ; Humans ; In Vitro Techniques ; Tooth Demineralization ; Tooth Remineralization

OBJECTIVETo investigate the relationship between dentine phosphoprotein (DPP) and remineralization of demineralized dentine.

METHODS(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.

RESULTS(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).

CONCLUSIONSSoluble 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.

Adolescent ; Child ; Dentin ; chemistry ; Humans ; In Vitro Techniques ; Phosphoproteins ; isolation & purification ; physiology ; Tooth Demineralization ; Tooth Remineralization

OBJECTIVETo investigate the effect of removing EDTA-soluble phosphate protein in dentin on the later remineralization for the purpose of better understanding of mechanism of dentin phosphate proteins on dentin mineralization.

METHODSTo remove soluble phosphate protein by EDTA dissolution, then the remineralization rate was monitored by a constant composition crystal growth technique. The results were compared with those from the normal dentin and the dentin partially demineralized by acetic acid.

RESULTSFaster remineralization rates were found with dentin demineralized by EDTA (0.5 and 2 h) compared with normal dentin powder, while a slower rate was found with dentin demineralized by acetic acid. The increase of remineralization rate by removing phosphate protein from dentin was 100% more at 200 min after the start of the reaction.

CONCLUSIONEDTA-soluble phosphate protein in dentin has a great potential to inhibit remineralization.

Dental Cementum ; chemistry ; metabolism ; Dentin ; chemistry ; Edetic Acid ; Humans ; Phosphoproteins ; analysis ; physiology ; Tooth Demineralization ; metabolism ; Tooth Remineralization

OBJECTIVETo study the influence of various active groups grafted on the enamel surface by means of self assembly on enamel biomineralization.

METHODSThe enamel was prepared by immersing the bicuspid tooth into 1 mmol/L ethanolic solution of a omega-functionalized (omega=PO4H2, SO3H, COOH or OH) group and deionized water solution of HSCH2CH2SO3Na for 24 h at room temperature. The contact angles and infrared (IR) images were used to identify the morphological changes of the enamel with chemisorption of the functional groups.

RESULTSThe contact angles and IR images showed that the omega-functionalized (omega=-PO4H2, -SO3H, -COOH, -OH or -CH3) group was chemisorbed on the enamel surface.

CONCLUSIONSelf assembled monolayers with omega-functionalized (omega=-PO4H2, -SO3H, -COOH, -OH or -CH3) group can be successfully formed on the enamel surface by hydrolyzation.

Dental Cements ; chemistry ; Dental Enamel ; chemistry ; Humans ; Organophosphorus Compounds ; chemistry ; Phosphorus Compounds ; chemistry ; Surface Properties ; Tooth Demineralization ; therapy

We present the binding ability of a new peptide (CMPQVMPMC-) with dental enamel after being evaluated in the present study. Under a standard procedure, the recovery of M13 filamentous phage was greatly enhanced by displaying the peptide in phage coat protein p III. Then the cyclic peptide was synthesized using a solid method. The effect of the cyclic peptide in vitro biomineralization was tested in a single-diffusion microtiter plate gel system. Absorbance at 405 nm of each sample was recorded for 24 h at every 6 h intervals. The relatively increased values of each sample were expressed as percentages relative to the blank group (100%). The cyclic peptide resulted in a concentration-dependent delayed nucleation. In addition, the overall values of peptide groups at the end of 24 h were lower than those in the control group but much higher than those in the BSA control group.
Dental Enamel ; chemistry ; Peptides ; chemical synthesis ; chemistry ; Protein Binding ; Tooth Calcification

OBJECTIVETo observe root surfaces and analyze the mineral contents in cementum of patients with rapidly progressive periodontitis (RPP).

METHODSTen teeth were selected from RPP patients, adult periodontitis (AP) patients and healthy (H) control subjects respectively, and prepared for scanning electron microscopy (JSM-35C). The energy-dispersive X-ray analysis was used to measure the mineral contents in cementum (Ca, P, Mg).

RESULTSThe root surfaces of RPP teeth were similar to that of AP teeth. Ca: 64.60% +/- 2.29% vs 63.54% +/- 2.97%, P > 0.05; P: 32.54% +/- 1.29% vs 32.97% +/- 2.40%, P > 0.05; Mg: 2.86% +/- 1.29% vs 3.48% +/- 1.02%, P > 0.05; Ca/P: 2.00 +/- 0.17 vs 1.95 +/- 0.25, P > 0.05. There were no differences in Ca, P, Mg contents and Ca/P ratio between RPP teeth and AP teeth.

CONCLUSIONThere may not be cementoplasia in a part of RPP teeth.

Adult ; Dental Cementum ; chemistry ; ultrastructure ; Humans ; Microscopy, Electron, Scanning ; Periodontitis ; pathology ; Tooth Root ; chemistry ; ultrastructure

OBJECTIVEThe purposes of this study were to investigate effects of chloroqquine (CQ) on inhibiting the decomposition of hydrogen peroxides (HP), and to optimize composition of the tooth-bleaching agent.

METHODSAccording to the principle of the color-changing reaction between horse radish peroxidase and substrate, the tooth-bleaching agent made of HP was divided into four groups with different amounts of CQ. The stability of HP was observed using ELISA for 3 months.

RESULTSWith the prolongation of store time, the absorbance of HP solutions containing different concentrations of CQ declined at different degrees, which showed a dependent relation between absorbance values and concentrations of CQ. Within the range of experiment concentrations of CQ, the higher the concentration of CQ was, the stronger the stability of HP was. And the duration of tooth-bleaching effects in 150.0 mg/ml of CQ was prolonged 4 to 6 times compared to that without CQ.

CONCLUSIONThe data indicate that CQ can inhibit the decomposition of HP. The bleaching effect of the tooth-bleaching agent which is made of HP and proper amount of CQ is satisfactory.

Chloroquine ; chemistry ; Drug Combinations ; Drug Interactions ; Humans ; Hydrogen Peroxide ; chemistry ; Tooth Bleaching ; methods

Enamel crystals are unique in shape, orientation and organization. They are hundreds of thousands times longer than they are wide, run parallel to each other, are oriented with respect to the ameloblast membrane at the mineralization front and are organized into rod or interrod enamel. The classical theory of amelogenesis postulates that extracellular matrix proteins shape crystallites by specifically inhibiting ion deposition on the crystal sides, orient them by binding multiple crystallites and establish higher levels of crystal organization. Elements of the classical theory are supported in principle by in vitro studies; however, the classical theory does not explain how enamel forms in vivo. In this review, we describe how amelogenesis is highly integrated with ameloblast cell activities and how the shape, orientation and organization of enamel mineral ribbons are established by a mineralization front apparatus along the secretory surface of the ameloblast cell membrane.
Ameloblasts ; chemistry ; cytology ; Amelogenesis ; physiology ; Basement Membrane ; chemistry ; Crystallization ; Dental Enamel ; chemistry ; Dental Enamel Proteins ; secretion ; Humans ; Tooth Calcification