Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dentin Solubility”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed1976

Remineralization of dentin in vitro.

The remineralization of completely demineralized bovine dentin was studied in vitro by monitoring the velocities of fall of small particles through calcifying solutions. The density of a particle of dentin may be found from its velocity of fall through a fluid using Stokes' law. The minimum concentration product of calcium and acid phosphate ions of the solution in which remineralization would take place was 3.6 (mM)2 in the presence of 22 mM bicarbonate, pH 7.35, and ionic strength 0.1. This just above the solubility product of brushite (CaHPO4-2H2O). Incubation of decalcified dentin in a phosphoprotein removed from dentin during demineralization, or in phosvitin, had no effect on remineralization. The rates of remineralization and of the fraction remineralized were inversely proportional to particle size. This inverse correlation may be due to deposition of mineral in a surface layer of constant depth irrespective of particle size. The fraction of a particle remineralized was greatly increased by the use of highly supersaturated calcifying solutions or by the incorporation of fluoride into the solutions. The empirical reaction order of remineralization for both calcium and phosphate ions was found to be unity, which is, within the error limits, equal to the order of growth of seed crystals of hydroxyapatite in calcifying solutions of the same composition.

Animals↗
PubMed1990

Annexins I-VI in secretory ameloblasts and odontoblasts of rat incisor.

Immunoblot analyses and ultrastructural immunogold studies have been conducted on annexins in the secretory ameloblasts and odontoblasts of the rat incisor. Annexins I and II were seen in the soluble and particulate fractions of the enamel-related portion but not in the dentin-related portion. These proteins were visualized in the cytosol, near to the plasma membrane of Tomes' processes and in secretory vesicles in the ameloblasts. The forming enamel was also labeled. Annexins III, VI an V were detected in both the soluble and particulate fractions of the enamel-and dentin-related portions. Annexin IV was mainly localized in the proximal and distal areas of the secretory ameloblasts and virtually absent from in the supranuclear area. Annexin V was mainly detected in the cytosol of the cells and to a lesser extent near the plasma membrane. Annexin VI was mainly detected in the particulate fraction of enamel- and dentin-related portions. It was seen in the mitochondria and in the subplasmalemmal undercoat. All these proteins may play a role in exocytosis and endocytosis. They are implied in the regulation of cell calcium, but not in the transfer of calcium through the cells in the direction of the forming enamel and dentin, except annexins I and II since they are both present in the secretory vesicles and in the forming enamel.

Ameloblasts↗
PubMed1998

Micromorphological spectrum of acid-conditioned dentin following the application of a water-based adhesive.

OBJECTIVES: The goal of this study was to illustrate the micromorphological spectrum along the resin-dentin interface when a water-based, dentin adhesive (Scotchbond Multi-purpose) was applied to acid-conditioned dentin under different dry and wet bonding conditions. METHODS: Twenty-eight 1 mm dentin discs were each conditioned with 10% maleic acid for 15 s. Twenty-four of these discs were randomly divided into four groups, based upon the status of the remaining surface moisture: Group I (30 s dry); Group II (3 s dry); Group III (visibly moist) and Group IV (overwet). They were bonded using Scotchbond Multi-purpose. The remaining four discs were bonded using an experimental water-based primer containing 35 vol.% HEMA (Group V). Laminated dentin disc pairs were prepared for transmission electron microscopic examination. RESULTS: In all groups, diffusion of the polyalkenoic acid copolymer component of the primer into acid-conditioned dentin was localized to the surface region of the hybrid layer. The remaining part of the hybrid layer (the subsurface region) appeared variable. In Group I (30 s dry), collagen fibrils were collapsed. In Group II (3 s dry) and Group III (visibly moist), stained collagen fibrils were surrounded by wide electron-lucent interfibrillar spaces. In Group IV (overwet), a marked diffusion gradient was observed representing dilution of part of the primer components. In addition, an electron-dense primer phase, containing electron-lucent globular domains was invariably observed, irrespective of the hydration status of the demineralized collagen matrix. This electron dense phase was absent when HEMA alone was used as the primer (Group V). SIGNIFICANCE: With the use of a water-based adhesive, one could briefly air-dry the acid-conditioned dentin and allow the water in the primer to rehydrate the collapsed collagen matrix, without the risk of incomplete hybridization or tubular seal along the resin-dentin interface. However, care should be exercised to minimize dilution of the water-soluble primer component.

Acid Etching, Dental↗
PubMed1989

[Age estimation by amino acid racemization in dentin--application of fractionation and extraction].

This study was made to improve the validity of age estimation from teeth using amino acid racemization. The correlation between actual age and the D/L ratio of aspartic acid was investigated by analyzing not only total amino acid but its fractionated substances, insoluble collagen and soluble peptide. The coefficient values of correlation between the D/L ratio and actual age in lower central incisors were 0.996 (sigma = 1.0 years) for total amino acid, 0.998 (sigma = +/- 1.8 years) for insoluble collagen, and 0.997 (sigma = +/- 0.9 years) for soluble peptide. The corresponding figures in upper and lower first premolars were 0.991 (sigma = +/- 1.6 years), 0.989 (sigma = +/- 1.9 years), and 0.994 (sigma = +/- 1.4 years), respectively. The reactive velocity of aspartic acid racemization was highest for soluble peptide both in lower central incisors and upper and lower first premolars, approximately three times as rapid as that for total amino acid. The velocity for insoluble collagen was slightly lower than that for total amino acid. Age estimation was attempted from the teeth of an unknown body. As a result, age estimated from the analysis of soluble peptide was most accurate. These results suggest that the analysis not only of total amino acid in dentin but its fractionated and extracted substances can lead to higher reliability in age estimation. Soluble peptide, in particular, has been found to be most effective.

Age Determination by Teeth↗
PubMed2001

Dual regulation of osteoclast differentiation by periodontal ligament cells through RANKL stimulation and OPG inhibition.

Periodontal ligament (PDL) cells play an important role in maintaining the homeostasis of periodontal tissues. However, it is not known how PDL cells contribute to osteoclastogenesis. In this study, we examined the consequences of cell-to-cell interactions between peripheral blood mononuclear cells (PBMCs) and PDL cells during osteoclastogenesis. PBMCs were co-cultured directly or indirectly with PDL cells for two to four weeks. PBMCs that were directly co-cultured with PDL cells formed significantly more resorption pits on dentin slices than did PBMCs that were cultured alone. However, soluble factor(s) produced from PDL cells inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells. Furthermore, PDL cells expressed both receptor activator nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) mRNA. In conclusion, PDL cells support osteoclastogenesis through cell-to-cell contact. PDL cells might regulate osteoclastogenesis by opposing mechanisms--stimulation of resorptive activity by RANKL and inhibition by OPG--thus affecting processes such as periodontitis and orthodontic tooth movement.

Acid Phosphatase↗
PubMed1979

[Changes in microhardness of hard dental tissues of rabbits after internal medication of antibiotics (author's transl)].

Comparative Vickers hardness measurements on hard dental tissues mineralized under normal conditions and under the influence of antibiotic substances showed substance-and dose-dependent variations in quality of superficial enamel and dentine. They were found to correlate with other physicochemical properties (acid solubility) and must be considered as belonging to what is generally referred to as structural anomalies. - Consequently, the administration of antibiotics to babies and young children should be reexamined because of possible late effects.

Animals↗
PubMed2005

NO-cGMP signaling molecules in cells of the rat molar dentin-pulp complex.

By the formation of cyclic guanosine 3',5'-monophosphate (cGMP), nitric oxide (NO)-sensitive enzyme-soluble guanylate cyclase (sGC) plays a receptor role for NO within the NO-cGMP signaling cascade, which is involved in vasodilatation and neurotransmission. The hypothesis that NO-cGMP signaling molecules modulate cells of the dentin-pulp complex was investigated in rat molars by histochemical, immunohistochemical, immuno-ultrastructural, and organ bath techniques. NO synthase (NOS) I-III, the sGC alpha(2)-subunit/beta(1)-subunit, and cGMP were detected in odontoblasts and blood vessels. NOS I, sGC alpha(2), and cGMP were identified in nerve fibers. Treatment of rat molars with the NO donor NONOate (10(-5) M) increased cGMP staining intensities in blood vessels and odontoblasts, while NO synthase inhibitor L-NAME (10(-4) M) attenuated intensity of the reaction products for cGMP, suggesting an effect of endogenous NO on sGC. These correlations of patterns and alterations of cGMP staining intensities after treatment with the NO donor or NO inhibitor might represent an NO-sGC-cGMP signaling-dependent modulation of odontoblasts, blood vessels, and nerve fibers in the dentin-pulp complex.

Animals↗
PubMed2003

Dimensional changes in acid-demineralized dentin matrices following the use of HEMA-water versus HEMA-alcohol primers.

Although dried acid-etched dentin can be reexpanded by hydroxyethyl methacrylate (HEMA)/water primers, the primed dentin collapses when the water is evaporated. Experimental HEMA/alcohol primers should stiffen the matrix and permit less shrinkage when the solvent is evaporated. The purpose of this study was to test the hypotheses that matrix shrinkage induced by solvent evaporation from HEMA primers is inversely related to solvent-induced matrix stiffness. Dentine discs were prepared from midcoronal dentine of unerupted human third molars. After demineralization in 37% phosphoric acid, the specimens were placed in the well of a linear variable differential transformer instrument, which measures changes in the matrix height and stiffness by load displacement after the application of weights. This was done in their hydrated state after water had been applied, after drying with dry nitrogen gas, and after the application of 35 vol % HEMA-water, HEMA-methanol, HEMA-ethanol, or HEMA-propanol primers. The degree of reexpansion after the application of the primers to the dentine in the dried state was found to be highest using the HEMA-water primer, followed by HEMA-methanol and HEMA-ethanol, with the HEMA-propanol primer producing no expansion. However, when the solvents were evaporated the HEMA-water-treated specimens shrank the most, the HEMA-ethanol-treated specimens shrank an intermediate amount, and the HEMA-methanol-treated specimens shrank the least. The net result of expansion minus shrinkage produced by evaporation determines how much HEMA remains in the hybrid layer just prior to polymerization.

Acids↗
PubMed2003

Resistance of marginal enamel to acid solubility is influenced by restorative systems: an in vitro scanning electron microscopic study.

The aim of this study was to evaluate the morphology of the enamel surface along margins of class V restorations following exposure to cariogenic solution. Restorations were placed in vitro in human third molars. The specimens were divided into groups according to resin composition: (1) Scotchbond 1 + Filtek Flow, (2) Scotchbond 1 + F2000, and (3) Prompt L-Pop + experimental flowable composite. Samples were stored in a demineralizing solution (lactic acid, pH 4.5, 0.1 M) at 37 degrees for 1-4 weeks or in deionized water (control group). The solution was changed every day. Replicas of the specimens were obtained in order to exclude drying artifacts. Scanning electron microscopy (SEM) of original and replica specimens identified a distinct enamel zone, defined as perimarginal enamel showing numerous fractures, porosities, voids, and pits. After the 4-week treatment, perimarginal prismatic enamel was greatly removed, while interprismatic enamel was still in place and only partially dissolved. Enamel not in relation with composite/compomer margins (0.5-1 mm away) showed minor alterations. Perimarginal enamel fractures probably due to composite/compomer shrinkage or the bur preparation may greatly contribute to this marginal enamel demineralization by increasing the number and size of porosities, that enhance the penetration and diffusion of cariogenic solution and create a sort of demineralized enamel subsurface. Only compomer restorations revealed a thin caries inhibition zone (1-2 micro m) probably related to fluoride release. Below this protected area, we observed the typical alterations of the other samples. These morphological alterations are probably related to secondary demineralization lesions and may affect the clinical life of restorations.

Adult↗
PubMed2005

Incompatibility of oxalate desensitizers with acidic, fluoride-containing total-etch adhesives.

The use of oxalate desensitizers on acid-etched dentin prior to adhesive application can result in subsurface tubular occlusion by calcium oxalate crystals. However, the solubility of calcium oxalate increases in acidic solution. We hypothesized that total-etch adhesives can, depending upon their pH, interact with oxalate-desensitizer-treated dentin in an adverse manner. Acid-etched human dentin treated with 2 oxalate desensitizers (BisBlock and Super Seal) was bonded with 4 simplified total-etch adhesives: One-Step (OS), Single Bond (SB), OptiBond Solo Plus (OB), and Prime&Bond NT (PB). Composite-dentin beams were examined by SEM and TEM, both of which revealed numerous spherical globules on OB- and PB-bonded, desensitizer-treated dentin, but not in OS or SB samples. Bond strengths produced by OB and PB were significantly lower in oxalate-treated specimens than those produced by OS or SB. These surface globules may have interfered with hybridization of demineralized dentin with OB and PB resins and caused compromised bond strengths.

Analysis of Variance↗
PubMed1984

Long-term (8 days) effects of exposure to low concentrations of fluoride on enamel formation in hamster tooth-germs in organ culture in vitro.

Second maxillary molars of 3-4-day-old hamsters were cultured for 7-8 days in the continuous presence of fluoride (F-) or chloride in concentrations between 2.63 microM and 1.31 mM. For biochemical study, explants were labelled during the last 24 h of culture with a triple label of [3H]-proline, 45Ca and 32PO4. The 3H-labelled presumptive amelogenins were separated from the 3H-labelled dentine collagens by a three-step extraction procedure. Histologically, chronic exposure to F- had no obvious effects below 26.3 microM; at 26.3 microM of F-, a non-mineralizing enamel matrix was observed besides that of a normal mineralizing enamel. From 52 microM of F- onwards, only a non-mineralizing enamel matrix was found in decreasing amounts extracellularly as F- concentrations increased. Except for the presence of globular dentine, dentinogenesis was not obviously affected by F-. Biochemically, total synthesis of presumptive amelogenins was hardly disturbed, but their solubility was changed by chronic F- treatment; more amelogenins became formic-acid soluble at the expense of water-soluble amelogenins. Chronic exposure to F- decreased the water-soluble amelogenin fraction according to a logarithmic function of the medium F- concentration. By extrapolation, it was calculated that concentrations higher than 1-2 microM of F- affect amelogenesis in vitro. Synthesis of dentine collagen was not affected by chronic exposure to F- in vitro. Chronic exposure to F- decreased uptake of 45Ca and to a less extent trichloroacetic acid-soluble 32PO4. Chronic F- exposure may inhibit energy production in the enamel organ resulting in an impairment of enamel matrix secretion as well as that of a trans-epithelial transport mechanism for calcium.

Amelogenesis↗
PubMed1979

Dentin proteins: chemistry, structure and biosynthesis.

One of the most abundant noncollagenous proteins of dentin is a phosphoprotein rich in aspartic acid and phosphoserine. This protein occurs in soluble and inextractable forms, the latter being associated with the insoluble collagenous matrix. This protein is capable of tightly binding a relatively high level of calcium. Biosynthetic and radioautographic data suggest that shortly after its biosynthesis, the phosphoprotein is transported and bound to the collagen at the predentin-dentin junction. This event is probably central to the mineralization process, though other glycoproteins may be involved.

Amino Acids↗
PubMed1990

Amine-induced polymerization of aqueous HEMA/aldehyde during action as a dentin bonding agent.

Aqueous mixtures of HEMA with glutaraldehyde or propionaldehyde polymerize by addition of catalytic amounts of amines or amino acids. The maximal reaction velocity of the transformation of HEMA/glutaraldehyde with glycine was obtained at pH 0.8. Kinetic data suggested a second-order reaction between glutaraldehyde and glycine, and solubility data suggested formation of a cross-linked polymer. A relatively high bond strength between dentin and resin composite was obtained by pre-treatment of dentin with Gluma (35% HEMA, 5% glutaraldehyde in water) adjusted to pH 1.0 with hydrochloric acid. It is proposed that on application of Gluma, amino-group-containing substances in dentin react with glutaraldehyde and start the formation of a HEMA polymer. This product may be cross-linked by an alpha,beta-unsaturated glutaraldehyde aldol condensation product and may bond to dentin by aldehyde fixation to dentin proteins. Resin composite will bond to this product by copolymerization.

Acrylates↗
PubMed1986

Histological distribution of phosphophoryn in normal and pathological human dentins.

Dentin phosphophoryn is a highly phosphorylated protein which has a hydrophilic character but is not soluble in dilute acetic acid. A histochemical method was developed for staining this protein with Stains-all in situ utilizing those chemical properties. We have succeeded in detecting the presence of this protein in circumpulpal orthodentin of human permanent and deciduous teeth, but not in mantle dentin, secondary dentin and reparative dentin. Phosphophoryn staining was also absent in the dentin of dentinogenesis imperfecta (DI) Type II, a genetic disorder of dentin formation. From these results, it is suggested that phosphophoryn is synthesized and secreted only by physiologically-differentiated odontoblasts and that the mineralization processes of mantle, secondary, reparative and DI dentins may be different from that of circumpulpal orthodentin.

Child↗
PubMed1998

Effect of the application of dentin primers and a dentin bonding agent on the adhesion between the resin-modified glass-ionomer cement and dentin.

OBJECTIVES: This study was designed to evaluate the influence of the application of dentin primer and/or dentin bonding agent on the adhesion of a resin-modified glass-ionomer cement to dentin. METHODS: Bovine dentin was pretreated with Dentin Conditioner or EDTA 3-2 solution, primed by an experimental dentin primer, and applied with a dentin bonding agent. A resin-modified glass-ionomer cement, Fuji II LC, was then adhered to the dentin. The tensile bond strength between the light-cured glass-ionomer cement and the pretreated dentin was measured. The components of the experimental dentin primers were 2-hydroxyethyl methacrylate (HEMA), glyceryl methacrylate (GM) and a water-soluble photo-polymerization initiator, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N, N-trimethyl-1- propanaminium chloride (OTX). Significant differences in the data were examined by an analysis of variance and Scheffe's test for multiple comparisons between the means at p = 0.05. RESULTS: A significantly higher mean bond strength between the Fuji II LC and dentin was obtained by EDTA 3-2 pretreatment, QTX/GM priming, and LB Bond application. This value was comparable with that obtained with the resin composite system. Scanning electron microscopy observation showed the formation of a hybrid layer with a thickness of 1-1.5 microns. SIGNIFICANCE: The data obtained in this investigation suggest that the adhesion of Fuji II LC to dentin is closer to that provided by a resin composite system than to that of conventional glass-ionomer cements.

Adhesiveness↗
PubMed1996

Laboratory evaluation of three visible light-cured resinous liners.

OBJECTIVES: The aim of the present study was to evaluate the composition and the laboratory performance of three visible light-cured resinous liners (Cavalite, Ionoseal and Timeline). METHODS: Monomers were separated from fillers and were analysed by HPLC. Set pastes were analysed by FTIR spectroscopy and diametral strengths and water solubility were measured. RESULTS: The monomers identified in the liners were BisEMA/2-HEMA (Cavalite), BisDMA/BisGMA (Ionoseal) and UEDMA (Timeline). Significant variations were found in the filler content but the mechanical response as assessed by the diametral tensile strength showed no statistical differences. The curing efficiency ranged from 24.2 to 31.0% (top surfaces) to 26.0-54.0% (bottom surfaces) of remaining C = C bonds. No positive correlations were found between curing efficiency and optical properties. The bond strength of the liners to dentine was negligible compared with that to composite. All the liners demonstrated extensive gap formation and debonding at the liner-dentine interfaces in marginal adaptation testing. Statistical differences were noticed in the water absorption and water solubility values of the products. Ionoseal showed extensive hydrolytic degradation compared with the other liners. No evidence of acid-base reaction was found in the set products.

Acrylic Resins↗
PubMed1993

Atomic force microscopy of acid effects on dentin.

Atomic force microscopy (AFM) was used in the examination of the early stages of acid treatment of dentin. Disks of highly polished dentin were initially examined under deionized water and following exposure to 0.025 M nitric acid for 20 s intervals from 0-100 s. Peritubular depth changes were linear (0.005 microns/s). The intertubular dentin surface initially moved at approximately 1/2 the peritubular rate and then reached a plateau as the demineralized collagen scaffold collapsed. There was no apparent difference in the tubule center-to-center distance during the treatment. Differences in the movement and morphology of the zones are of importance in dentin bonding applications relying on penetration of the demineralized dentin by adhesive monomers. The changes are probably related to the partial collapse of the collagen matrix. Alternatively, access to the apatite crystals and solubility may be higher in the peritubular zone. AFM appears to hold exceptional promise for the study of conditioning and priming agents for dentin bonding.

Acid Etching, Dental↗