Synthesis and characterization of the dental adhesive monomer 10-MDP.

Many studies have demonstrated the excellent performance of 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate) as a functional monomer for dental adhesive materials and as a primer for ceramic surfaces. Although adhesive performance is affected by the purity level of 10-MDP, this parameter is rarely described, and possible byproducts have been suggested in the literature, but have not been identified to date. The present study aims to present an accessible 10-MDP synthesis strategy with easily handled reagents and address the characterization challenges, especially in identifying byproducts.

New dimethacrylate monomers based on phenolphthalein and resveratrol for the application of dental materials.

Unlabelled: Potential estrogenic effects and changes in fertility are some of the health problems associated with bisphenol A (BPA) derivatives used to produce some polymers, including dental materials that contain Bis-GMA. Those issues drove this study proposing the synthesis of methacrylate resveratrol and phenolphthalein monomers that, combined with diluent monomers, generate copolymers. Their key characteristics were determined and analyzed on the chemical structure-property perspective considering monomer planarity and flexibility based on molecular dynamic simulations.

Synthesis and characterization of experimental endodontic sealers containing bioactive glasses particles of NbG or 45S5.

Objective: This study evaluated the influence of adding bioactive glasses particles [Niobophosphate (NbG) or bioglass (45S5)] into endodontic cements in relation to physical, chemical and biological properties.

Methods: The following commercial cements were used as comparison: AH Plus (Dentsply), Endofill (Dentsply), MTA Fillapex (Angelus) and EndoSequence (BC Sealer, Brasseler). Setting time, radiopacity, flow rate, weight loss/variation, alkaline capacity (pH) at different time-intervals (24h/48h/7d/14d/28d), bioactivity (assessed under SEM/EDS, FTIR/ATR and XDR) and cell viability were measured.

Bioactive bacterial cellulose membrane with prolonged release of chlorhexidine for dental medical application.

Bioabsorbable barrier membrane is desired in dental medicine for treatment of periodontal diseases caused by different types of bacteria. Bioactive and bioabsorbable bacterial cellulose (BC) is a promising material for such application. However, a key challenge to implement this approach is produce BC membranes selectively oxidized and loaded with a bactericide, in order to modulate bioabsortion time and bactericide effect, respectively.

Development of calcium phosphate/ethylene glycol dimethacrylate particles for dental applications.

This study describes the synthesis of dicalcium phosphate dihydrate (DCPD) particles in the presence of different ethylene glycol dimethacrylates (EGDMA, ethylene glycol/EG units: 1, 2, 3 or 4) at two monomer-to-ammonium phosphate molar ratios (1:1 and 2:1), as a strategy to develop CaP-monomer particles with improved interaction with resin matrices. Particles displaying high surface areas and organic contents were added to a photocurable BisGMA-TEGDMA resin and the resulting materials were tested for degree of conversion (DC), biaxial flexural strength (BFS), flexural modulus, and ion release. Data were subjected to one-way ANOVA or Kruskal-Wallis/Dunn test (alpha: 0.

Ion-releasing dental restorative composites containing functionalized brushite nanoparticles for improved mechanical strength.

Objectives: This study describes the synthesis of brushite nanoparticles (CaHPO·2HO) functionalized with triethylene glycol dimethacrylate (TEGDMA) and their application in dental restorative composites with remineralizing capabilities.

Methods: Nanoparticles were synthesized, with TEGDMA being added to one of the precursor solutions at three different molar ratios (0:1, 0.5:1 and 1:1, in relation to the ammonium phosphate precursor).

Bioactivity and properties of an adhesive system functionalized with an experimental niobium-based glass.

Objective: This study evaluated the incorporation of niobophosphate bioactive glass (NbG) fillers into a commercial adhesive resin.

Materials And Methods: The silanized (NbGs) or non-silanized (NbG) NbG was added to the commercial adhesive system One Step (OS) at 30% by weight; unfilled adhesive served as control. The bioactivity of adhesives was analyzed by SEM and FTIR/ATR after 28 days in PBS.

Adhesives Doped with Bioactive Niobophosphate Micro-Filler: Degree of Conversion and Microtensile Bond Strength.

To evaluate the effect of incorporating niobium phosphate bioactive glass (NbG) into commercial etch-and-rinse adhesive systems, with and without silane, on their degree of conversion (DC) (%) and microtensile bond strength (μTBS). The NbG micro-filler was added to two etch-and-rinse adhesive systems: One Step (OS) and Prime & Bond (PB) at 40% concentration. The following groups were formed: control without glass addition OS; addition of unsilanized NbG (OSNbG); addition of silanized NbG (OSNbGS); control without glass PB; addition of unsilanized NbG (PBNbG); addition of silanized NbG (PBNbGS).

Fracture toughness and cyclic fatigue resistance of resin composites with different filler size distributions.

Objectives: To verify the influence of filler size distributions on fracture toughness (KIc), initial fracture strength (IFS) and cyclic fatigue resistance (CFR) of experimental resin composites.

Methods: Four composites were prepared with same inorganic content (78 wt%), in which 67 wt% was constituted by glass particles with d50 of 0.5; 0.

Influence of the base and diluent monomer on network characteristics and mechanical properties of neat resin and composite materials.

This study evaluated the effect of the combination of two dimethacrylate-based monomers [bisphenol A diglycidyl dimethacrylate (BisGMA) or bisphenol A ethoxylated dimethacrylate (BisEMA)] with diluents either derived from ethylene glycol dimethacrylate (ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate) or 1,10-decanediol dimethacrylate (D3MA) on network characteristics and mechanical properties of neat resin and composite materials. The degree of conversion, maximum rate of polymerization and water sorption/solubility of unfilled resins and the flexural strength and microhardness of composites (after 24 h storage in water and 3 months storage in a 75 vol% ethanol aqueous solution) were evaluated. Data were analyzed with two-way ANOVA and Tukey's test (α = 0.

Mechanical properties and modeling of drug release from chlorhexidine-containing etch-and-rinse adhesives.

Objectives: To evaluate the effects of chlorhexidine (CHX) addition in different concentrations into simplified etch-and-rinse adhesives on the ultimate tensile strength (UTS), water sorption (WS), solubility (SO) and the rate of CHX release over time.

Methods: We added CHX diacetate to Ambar [AM] (FGM) and XP Bond [XP] (Dentsply) in concentrations of 0, 0.01, 0.

Effects of adding barium-borosilicate glass to a simplified etch-and-rinse adhesive on radiopacity and selected properties.

Purpose: To evaluate the radiopacity, ultimate tensile strength (UTS), microhardness (KHN), degree of conversion (DC), water sorption (WS) and solubility (SL) of experimental adhesives.

Materials And Methods: Five experimental adhesives with different concentrations of barium-borosilicate oxide microfillers [0% (R0), 30% (R30), 40% (R40), 50% (R50), 60% (R60)] were formulated based on the adhesive system Ambar (FGM). The adhesive Adper Single Bond 2 (SB, 3M ESPE) was used as commercial reference.

Effects of diphenyliodonium salt addition on the adhesive and mechanical properties of an experimental adhesive.

Objectives: The aim of this study was to assess the microtensile bond strength (μTBS), nanoleakage (NL), nano-hardness (NH) and Young's modulus (YM) of resin-dentine bonding components formed by an experimental adhesive system with or without inclusion of diphenyliodonium salt (DPIH) in the camphorquinone-amine (CQ) system.

Methods: On 12 human molars, a flat superficial dentine surface was exposed by wet abrasion. A model simplified adhesive system was formulated (40 wt.

Subcritical crack growth and in vitro lifetime prediction of resin composites with different filler distributions.

Objectives: Verify the influence of different filler distributions on the subcritical crack growth (SCG) susceptibility, Weibull parameters (m and σ(0)) and longevity estimated by the strength-probability-time (SPT) diagram of experimental resin composites.

Methods: Four composites were prepared, each one containing 59 vol% of glass powder with different filler sizes (d(50)=0.5; 0.

Improvement of exposure times: effects on adhesive properties and resin-dentin bond strengths of etch-and-rinse adhesives.

Purpose: This study evaluated the effect of prolonged polymerization times on the microtensile resin-dentin bond strength (μTBS), degree of conversion of adhesive films (DC) and silver nitrate uptake (SNU) for an ethanol/water- (Adper Single Bond 2, [SB]) and an acetone-based (One Step Plus, [OS]) etch-and-rinse adhesive.

Materials And Methods: Thirty caries-free extracted molars were included in this study. The occlusal enamel of all teeth was removed by wet grinding the occlusal enamel on 180-grit SiC paper.

Effects of immersion time and frequency of water exchange on durability of etch-and-rinse adhesive.

This study evaluated the immediate and long-term bond strength to dentin (microtensile bond strength, μTBS) and silver nitrate uptake (SNU) of a three- and two-step etch-and-rinse adhesive under different water immersion times and frequency of water exchange. The adhesives and composite resin were applied according to the manufacturer's instructions in a flat occlusal demineralized dentin of 48 molars. Teeth were assigned to four groups of immersion time (immediate and 1, 3, and 6 months), sectioned to obtain resin-dentin beams, and then subdivided into three groups of water exchange (daily, weekly, and monthly) before being tested in tension.

Effects of increased exposure times of simplified etch-and-rinse adhesives on the degradation of resin-dentin bonds and quality of the polymer network.

One of the reasons for resin-dentin degradation is poor polymerization of the adhesive layer. This study evaluated the effect of prolonged polymerization times on the immediate and 6-month resin-dentin bond strengths, silver nitrate uptake, and polymer quality of etch-and-rinse adhesives. Thirty extracted teeth were obtained, and a flat dentin surface was exposed on each tooth.

Evaporating solvents with a warm air-stream: effects on adhesive layer properties and resin-dentin bond strengths.

Objectives: This study evaluated the effect of a warm or cold air-dry stream for solvent evaporation on the microtensile resin-dentin bond strength (muTBS), nanoleakage pattern (SEM), degree of conversion (DC) and solvent evaporation rates (SE) of an ethanol/water- (Adper Single Bond, [SB] 3MESPE) and an acetone-based (Prime & Bond 2.1, [PB] Dentsply), two-step etch-and-rinse adhesive system.

Materials And Methods: Adhesives were applied on demineralized dentin surfaces.

Poly(ethylene-co-methyl acrylate) membranes as rate-controlling barriers for drug delivery systems: characterization, mechanical properties and permeability.

Poly(ethylene-co-methyl acrylate) (EMA) membranes with different amounts of methyl acrylate (MA) content were studied in terms of the thermal and mechanical properties, swelling and drug permeation. The increase in MA content in the copolymer significantly increased the percentage of elongation and decreased the tensile strength and modulus of elasticity of the membranes. The degree of swelling of the EMA membranes increased with the ethanol composition and MA content.

Characterization and drug-permeation profiles of microporous and dense cellulose acetate membranes: influence of plasticizer and pore forming agent.

The use of pore forming agents and plasticizers are efficient ways to obtain membranes for controlled drug permeation through polymeric membranes. The challenge of the present study was to combine these two strategies to obtain cellulose acetate (CA) membranes, where poly(caprolactone triol) (PCL-T) was used as a plasticizer and water, dissolved in a casting solution, was used as a pore forming agent. First, the influence of water on membrane morphology, porosity and the permeation coefficient of a model drug (paracetamol) was analyzed.