A new polymeric resin with amino sulfonic acid pendant functions has been prepared for the extraction of acidic and basic dyes from water. Beaded polymer supports were prepared by suspension polymerization of vinyl benzyl chloride (0.9 mol) and ethylene glycol dimethacrylate (0.1 mol). The resulting copolymer beads were modified with ...

Helix-coil transition kinetics of polyadenylic acid [poly(A)] inside a small protein channel is investigated for the first time, at the single molecule level. The confinement of a RNA molecule inside the channel slows its kinetics by nearly 3 orders of magnitude as compared to bulk measurements of free poly(A). These ...

Hydrofluoric acid can be used for intra-oral repair of restorations. Contamination of tooth substrate with hydrofluoric acid cannot always be avoided. OBJECTIVES: To investigate the bonding effectiveness to hydrofluoric acid contaminated dentin by, micro-tensile bond strength testing, SEM and TEM. METHODS: For this study, 15 molar teeth were used of ...

Understanding the composition and function of the acquired enamel pellicle (AEP) has been a major goal in oral biology. The aim of this study was to test the hypothesis that intact histatins are part of the in vivo AEP and that histatins after adsorption to HA have effects on in ...

In order to achieve the sustained release of 3-ethyl-4-(4-methylisoxazol-5-yl)-5-(methylthio) thiophene-2-carboxamide (BFB0261), a new potent osteogenic compound for the treatment of bone disorders, we prepared microspheres containing BFB0261 and newly synthesized three poly (D, L-lactic acid) (PLA), four poly (D, L-lactic acid-co-glycolic acid) (PLGA), and eight poly (D, L-lactic acid)-block-poly(ethylene glycol) ...

Osteocytes are the most abundant of the bone cells. Each osteocyte is contained within its own lacuna and connected to adjacent osteocytes via fillipodial processes, which form an intricate network of canaliculi within the matrix. Studying this intricate network of cells and their processes is difficult, because it exists embedded ...

OBJECTIVES: The purpose of this in vitro study was to quantify the alterations in human root dentin permeability after exposure to dietary acids and to evaluate the effect of toothbrushing after acid application. METHOD AND MATERIALS: Extracted human third molars had their crowns sectioned above the CEJ, pulp tissue removed, ...

In this study, the electrophoretic mobilities (mu) for a series of poly(N-acryloyl-amino acid)s were determined by capillary zone electrophoresis to investigate the effect of substituent on the electrophoretic behavior of polyelectrolytes. The mu values determined showed a strong correlation with the molar volume of the corresponding amino acids.

STATEMENT OF PROBLEM: Acidic food and sour fruits and drinks have been investigated for their destructive effects on enamel. However, their effect on porcelain restorations has not been widely examined. PURPOSE: The purpose of this study was to evaluate the ion leaching of porcelains immersed in acidic agents. MATERIAL AND ...

A series of biodegradable functional amino acid-based poly(ester amide)s (PEA-AG) were designed and synthesized by the solution co-polycondensation of amino acid (L-phenylalanine and DL-2-allylglycine) based monomers and dicarboxylic acid based monomers. Pendant carbon-carbon double bonds located in the DL-2-allylglycine were incorporated into these PEA-AGs, and the double bond contents could ...

Bifunctional superparamagnetic magnetite/poly(dl-lactic acid-co-alpha,beta-malic acid) composite nanoparticles (PLMA-MNPs) detectable by both magnetic resonance imaging (MRI) and fluorescence microscopy were synthesized by coating Fe(3)O(4) nanoparticles with biodegradable poly(dl-lactic acid-co-alpha,beta-malic acid) copolymer (PLMA) with covalently bound fluorescein isothiocyanate (FITC). The FITC modified PLMA-MNPs (FITC-PLMA-MNPs) have a hydrodynamic diameter of 100nm and an ...

OBJECTIVE: The protective effect of fluoride solutions against acidic challenge on enamel was tested in vitro using calcium- and profilometer analyses. METHODS: HF-, SnF(2)-, TiF(4)- and NaF solutions (0.1M F(-), with a pH of 2.0, 2.9, 1.5, 7.3, respectively) and H(2)O were tested on a total of 60 enamel specimens ...

OBJECTIVES/HYPOTHESIS: Lidocaine is a local anesthetic that is known to suppress tinnitus via systemic or local application; however, this effect has only limited duration. The current study aimed to establish a method for the sustained delivery of lidocaine into the cochlea using poly lactic/glycolic acid (PLGA) microparticles. STUDY DESIGN: Experimental ...

Significant conductivity enhancement was observed on transparent and conductive poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films after a treatment with organic and inorganic acids, including acetic acid, propionic acid, butyric acid, oxalic acid, sulfurous acid, and hydrochloric acid. The conductivity could be enhanced from 0.2 to over 200 S cm(-1), that is, ...

PURPOSE: The authors conducted an in vitro study to evaluate the shear bond strength of a fissure sealant to enamel pretreated with erbium,chromium:yttrium, scandium,gallium,garnet (Er,Cr:YSGG) laser or air abrasion followed by acid etching. METHODS: The authors sectioned extracted sound premolars mesiodistally and used the buccal and lingual surfaces for experimental ...

This study assessed the long-term effects of dietary vaccenic acid (VA) and elaidic acid (EA) on plasma and splenocyte phospholipid (PL) composition and related changes in inflammation and splenocyte phenotypes and cytokine responses in obese/insulin resistant JCR:LA-cp rats. Relative to lean control (Ctl), obese Ctl rats had higher serum haptoglobin ...

Due to the low solubility of poly(glycolic acid) (PGA), its use is generally limited to the synthesis of random copolyesters with other hydroxy acids, such as lactic acid, or to applications that permit direct processing from the polymer melt. Insolubility is generally observed for PGA when the degree of polymerization ...

OBJECTIVE: The objective of this study was to evaluate the utility of a novel acid challenge-based dentin disc occlusion model, and to compare the occluding effect and acid resistance exhibited by currently marketed occlusion dentifrices in vitro. METHODS: Ninety-six bovine dentin discs were polished and etched in citric acid (6% ...

Conducting polyaniline nanofibers (nf-PANI) were successfully synthesized by simple polymerization of aniline in presence of single and binary dopant agents. Strong hydrochloride acid (HCl), two weak organic acids (poly acrylic acid, PAA, 2-acrylamido-2-methyl-1-propanesulfonic acid, AMPSA) and one anionic surfactant (sodium dodecyl sulfate, SDS) were used to form the binary dopant ...

Hydroxyapatite coating on metal implants is an effective method to enhance bioactive properties of the metal surface. We report here a method to coat the Ti-6Al-4V alloy with hydroxyapatite crystals. After alkaline/heat treatment, the spontaneous growth of organoapatite on titanium alloy surface involves sequential preadsorption of titanium isopropoxide (TIPO) and ...

To examine the effects from the chemical structure of acidic methacrylate monomers on the primer's shelf life, N-methacryloyl-2aminoethylphosphonic acid (NMEP)- N-methacryloyl glycine (NMGly), 2-methacryloyloxyethyl dihydrogen phosphate (MEP)-NMGly and 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-NMGly primers were designed. Immediately after preparation, these primers were stored at 40 degrees C for 0, 6 and ...

Acid etching procedures may disrupt residual bacteria and contribute to the success of incomplete caries removal followed by adhesive restoration. This study evaluated the in vivo effect of acid etching on cariogenic bacterial activity within affected dentin after minimally invasive treatment of caries lesions. Twenty-eight carious permanent teeth received standardized ...

The purpose of the study was to determine if the irradiation of enamel with laser of different output powers might be viable alternatives to acid etching for the bonding of resin luting agents. Seventy-seven maxillary central incisors, extracted for periodontal reasons, were used. The enamel was etched with an erbium, ...

The nanostructure and its transition of in a poly(acrylic acid) (PAA) brush in the water surface monolayers of poly(hydrogenated isoprene)-b-poly(acrylic acid) with different block lengths and block ratios were investigated by X-ray reflectivity as a function of surface pressure (brush density) and salt concentration in the subphase. The PAA brush ...

Spontaneous precipitation of calcium carbonate was investigated in two precipitation systems: (1) with initial supersaturation lower than that corresponding to the solubility of amorphous calcium carbonate (ACC), at which vaterite precipitated, and (2) with initial supersaturation higher than that of ACC solubility, at which a mixture of calcite and vaterite ...

PURPOSE: To investigate the effect of a phosphoric acid/sodium hypochlorite (NaOCl) mixture as a dentin conditioner on shear bond strength, the resin/dentin interface, as well as the surface area and tubular diameter of dentin. MATERIALS AND METHODS: Thirty human molars were prepared for shear bond strength testing. The teeth were ...

Chiral polyelectrolyte multilayers (PEMs) consisting of poly(l-lysine) (PLL), poly(N-(S)alkylated 4-vinylpyridinium iodide), or poly(ethyleneimine maltose) (PEI-m) as polycations and poly(styrenesulfonic acid) sodium salt (PSS) or poly(vinyl sulfate) as polyanions, as well as a nonchiral PEM composed of poly(ethyleneimine) (PEI) and PSS were deposited on silicon substrates and poly(tetrafluoroethylene) membranes using the ...

For rapid monomerization of biodegradable plastics, various microorganisms were screened and TB-71 was selected as the best strain. TB-71 degraded solid poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ethylene succinate), and poly(epsilon-caprolactone) but not poly(butylene succinate), poly(2-hydroxybutylate-co-valerate) or poly(lactic acid). Esterase activity was observed in the culture broth during PBSA degradation, which was ...

Bifunctional periodic mesoporous organosilicas (BPMOs) with thiophene- and isocyanurate-bridging groups were prepared by one-pot co-condensation of 2,5-bis(triethoxysilyl)thiophene and tris[3-(trimethoxysilyl)propyl]isocyanurate precursors in the presence of a poly(ethylene oxide)-poly(DL-lactic acid-co-glycolic acid)-poly(ethylene oxide) (PEO-PLGA-PEO) triblock copolymer under acidic conditions. The resulting BPMOs exhibited 2D hexagonal ordering (p6mm), large mesopores of approximately 7.7 nm, ...

Hollow microcapsules are expected to be integral components of drug delivery systems in medical and pharmaceutical applications. Among the methods studied, the bubble template method (Makuta et al. Mater. Lett. 2009, 63, 703-705) should easily fabricate uniform hollow microcapsules covered with biodegradable polymers. In this study, we clarified the two ...

Poly(ethylene glycol)-block-poly(acrylic acid-co-acrylamidophenylboronic acid) [PEG(114)-b-(PAA(63)-co-PAAPBA(107))] was synthesized by the modification of poly(ethylene glycol)-block-poly(acrylic acid) (PEG(114)-b-PAA(170)) with 3-aminophenylboronic acid (APBA). Glucose-responsive PEG(114)-b-(PAA(63)-co-PAAPBA(107)) self-assembled into core-shell micelles with the hydrophobic core composed of PAAPBA and hydrophilic shell composed of PEG in aqueous solution. The swelling and disaggregating behaviors of micelles responding to ...

AIM: This in vitro study evaluated the abrasiveness of acidic fluoride (F) dentifrices with different F concentrations on bovine enamel. METHODS: Enamel blocks (4.0 x 4.0 mm2, n=120) were selected according to their surface microhardness and divided into 12 groups. Slurries of dentifrices were used containing 0 (placebo), 275, 412, ...

An acid-base resistant zone has been found to exist after acid-base challenge adjacent to the hybrid layer using SEM. The aim of this study was to examine the acid-base resistant zone using three different bonding systems. Dentin disks were applied with three different bonding systems, and then a resin composite ...

Acid erosion is the chemical effect of dietary or gastric acids on enamel and dentine. Unlike dental caries, which is a bacterially mediated condition, acid erosion normally is combined with physical forms of attrition and abrasion. The clinical appearance of acid erosion in the early stages is seen characteristically as ...

To broaden the application scope of lactic acid polymers, a new miniemulsion of poly(alkyl methacrylate-graft-lactic acid)s has been developed. The graft copolymer synthesis was based on a poly(lactic acid) macromonomer having a methacryloyl polymerizable group. The macromonomer and a comonomer of n-butyl methacrylate together with a suitable surfactant formed a ...

Burkholderia sp. IS-01 capable of biosynthesizing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [poly(3HB-co-3HV)] copolyesters with a high molar fraction of 3HV was isolated from the gut of the adult longicorn beetle, Moechotypa diphysis. The strain IS-01 was relatively tolerant to high concentrations of levulinic acid and accumulated a poly(13.5 mol% 3HB-co-86.5 mol% 3HV) copolyester when ...

We report here the integration of ring-opening metathesis polymerization (ROMP) and ring-opening polymerization of the amino acid N-carboxyanhydride (NCA) to allow facile synthesis of brush-like polymers containing polypeptide as the brush side chains. ROMP of N-trimethylsilyl norbornenes rendered the preparation of poly(norbornene)s bearing pendant N-TMS groups. With no need to ...

In order to obtain nontoxic functional polymer gels for biomedical applications, chemically crosslinked poly(aspartic acid) gels have been prepared using 1,4-diaminobutane as crosslinker. The presence of COOH and amino groups on the network chains renders these gels pH sensitive. Due to the specific hydrophobic-hydrophilic balance, these gels show a significant ...

Streptococcus mutans is considered a major causative of tooth decay due to its ability to rapidly metabolize carbohydrates such as sucrose. One prominent excreted end product of sucrose metabolism is lactic acid. Lactic acid causes a decrease in the pH of the oral environment with subsequent demineralization of the tooth ...

PURPOSE: The purpose of this study was to evaluate the effects of different repairing techniques of a fractured sealant on microleakage in vitro. METHODS: A nono-filled flowable composite (Filtek Z350) was placed on the occlusal surfaces of 112 intact extracted molars following cleoning by prophylaxis and acid etching. Sealant failure ...

In general, most bioabsorbable polymers used for internal fixation are composed of copolymers of glycolic acid and lactic acid (L and/or DL). Within this family of polymers resides the latitude to design materials with specific degradation properties to meet a variety of clinical needs. One material with an extensive clinical ...

There is a gap in the literature concerning the chemical effects that household products may produce on human remains. The present study examines the effects of household chemical products on teeth. A total of eight chemicals were utilized for this experiment. The corrosive chemical categories include: hydrochloric acid, sulfuric acid, ...

PEGylated poly(carboxylic acid)s, PEG-b-PCAs, were evaluated as additives for solubilized oral formulations of weakly acidic compounds. Micelles of poly(ethylene glycol)-block-poly(acrylic acid), PEG-b-PAA, and poly(ethylene glycol)-block-poly(methacrylic acid), PEG-b-PMAA, were prepared. Fluorescence spectroscopy and dynamic light scattering revealed that both polymers assemble into nanoscopic structures (< 200 nm) in acidic media and ...

The aim was to compare the enamel surface roughness (ESR) and absolute depth profile (ADP) (mean peak-to-valley height) by atomic force microscopy (AFM) before and after using four different phosphoric acids. A total of 160 enamel samples from 40 upper premolars were prepared. The inclusion criterion was that the teeth ...

The purpose of this study was to compare the tensile bond strength of composite resin bonded to erbium:yttrium-aluminium-garnet (Er:YAG) laser-prepared dentine after different durations of acid etching. The occlusal third of 68 human third molars was removed in order to expose the dentine surface. The teeth were randomly divided into ...

Poly(lactic-co-glycolic acid) (PLGA) meshes loaded with retinoic acid (RA) were prepared by applying the electrospinning technique. The purpose of the present work was to combine the biological effects of RA and the advantages of electrospun meshes to enhancing the mass transfer features of controlled release systems and cell interaction with ...

Poly(malic acid) is water-soluble, functionalizable, and biodegradable, making it attractive as a precursor of hydrogels for biomedical applications. However, homopoly(malic acid), with pK(1/2) of 4.3, is too acidic for biocompatibility. To overcome the acidity, we have synthesized beta-malic acid-containing poly(ethylene glycol) dimethacrylate (PEGMAc) with pK(a) of 5.02. Solutions of methacrylated ...

The aim of this in vitro study was to evaluate the effect of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser pretreatment alone, or associated with acid etching, on the quality of marginal integrity (microleakage and marginal gap) of a resin-based fissure sealant in primary teeth. Fifty sound primary molar teeth were randomly assigned ...

BACKGROUND: Chitosan-EDTA is an interesting matrix for dermal delivery; however, the adhesiveness is too small. Therefore, the purpose of this study was to investigate chitosan-glycolic acid as possible dermal matrix for progesterone in comparison to chitosan-EDTA and carrageenan. METHOD: After preparation of the chitosan-glycolic acid salt and characterization by NMR ...

Currently a diverse range of injectable agents are used for noninvasive facial enhancement. Injectable poly-L-lactic acid (PLLA) is a biocompatible, biodegradable, synthetic polymer that is approved for correction of HIV-related facial lipoatrophy in Europe, Canada, and the United States. PLLA is also approved in several countries for cosmetic purposes, and ...