Inhibition of incipient caries lesion progression by different fluoridated varnishes.

The aim of this in vitro study was to evaluate the potential of different fluoridated varnishes to inhibit the progression of incipient caries lesions after cariogenic challenge. Seventy-five enamel specimens of bovine teeth were prepared and selected based on the initial surface microhardness (SMH). The specimens were first subjected to artificial demineralization (in buffer solution) after which SMH was re-analyzed (SM1).

On the correlation between thermal imagery and fugitive CH emissions from MSW landfills.

Landfill gas (LFG) is related to the biochemical processes generating heat and releasing CH, CO, and other gases in lower concentrations, which result in environmental impacts and risk of local explosion. Thermal infrared imagery (TIR) is employed to detect CH leakage as a risk control approach. However, the challenge for LFG leakage detection using TIR is establishing a relation between the gas flux and the ground temperature.

Influence of the calcium orthophosphate:glass ratio and calcium orthophosphate functionalization on the degree of conversion and mechanical properties of resin-based composites.

The study verified the influence of calcium orthophosphate (CaP):glass ratio on the degree of conversion and mechanical properties of resin-based composites containing either TEGDMA-functionalized dicalcium phosphate anhydrous (DCPA) or non-functionalized DCPA particles. The null hypotheses were that the evaluated variables are not affected by (1) CaP:glass ratio or (2) DCPA functionalization. DCPA particles were synthesized and half of them were functionalized with TEGDMA.

Preventive effect of chitosan gel containing CaneCPI-5 against enamel erosive wear in situ.

Objective: This study evaluated the preventive effect of a chitosan gel containing CaneCPI-5 against enamel erosion and erosion + abrasion in situ.

Methods: Sixteen volunteers participated in a crossover, double-blind protocol, comprising 4 phases: (1) no treatment (Nt); (2) chitosan gel (Cg); (3) chitosan gel + 12,300 ppm NaF (Cg + NaF); and (4) chitosan gel + 0.1 mg/mL CaneCPI-5 (Cg + Cane).

Experimental composite containing silicon dioxide-coated silver nanoparticles for orthodontic bonding: Antimicrobial activity and shear bond strength.

Objective: This study aimed to investigate the antimicrobial activity and shear bond strength (SBS) of orthodontic brackets to bovine enamel using experimental composites with different concentrations of silicon dioxide-coated silver nanoparticles (Ag@SiO2 NPs).

Methods: Fifty bovine incisors were divided into five groups according to the composite (n = 10): G1 - Control Group (Transbond XT Resin), G2 - Experimental composite without Ag@SiO2 NPs; G3 - Experimental composite with 0.5% of Ag@SiO2 NPs; G4 - Experimental composite with 1% of Ag@SiO2 NPs; G5 - Experimental composite with 3% of Ag@SiO2 NPs.

Effect of xylitol varnishes on enamel remineralization of immature teeth: in vitro and in situ studies.

Background: We evaluated the efficacy of xylitol varnishes on the remineralization of newly erupted permanent and deciduous teeth in vitro and in situ. Human enamel specimens were randomly allocated to 8 groups (n = 15/group). Artificial caries lesions were produced and enamel alterations were quantified by surface/subsurface hardness and transverse microradiography.

Mechanical properties and surface roughness of polymer-based materials containing DCPD particles.

The purpose of this study was to synthesize dicalcium phosphate dihydrate (DCPD) particles functionalized with triethylene glycol dimethacrylate (TEGDMA) through different routes by varying the receptor solution: ammonium phosphate (AP groups) or calcium nitrate (CN groups) and the moment in which TEGDMA was incorporated: ab initio (ab) or at the end of dripping the solution (ap). Two syntheses were performed without adding TEGDMA (nf). The particles were characterized by X-ray diffractometry, true density (using a helium pycnometer), surface area, and scanning electron microscopy.

Development of brushite particles synthesized in the presence of acidic monomers for dental applications.

Objectives: To synthesize and characterize brushite particles in the presence of acidic monomers (acrylic acid/AA, citric acid/CA, and methacryloyloxyethyl phosphate/MOEP) and evaluate the effect of these particles on degree of conversion (DC), flexural strength/modulus (FS/FM) and ion release of experimental composites.

Methods: Particles were synthesized by co-precipitation with monomers added to the phosphate precursor solution and characterized for monomer content, size and morphology. Composites containing 20 vol% brushite and 40 vol% reinforcing glass were tested for DC, FS and FM (after 24 h and 60 d in water), and 60-day ion release.

Biogenic synthesis and antimicrobial activity of silica-coated silver nanoparticles for esthetic dental applications.

Objectives: this study aimed to synthesize AgNPs from green tea (GT) extract, forming GT-AgNPs, and to coat their surfaces with silica, resulting in light-colored Ag@SiO nanoparticles.

Materials And Methods: particles were characterized and tested for minimal inhibitory concentration (MIC), biofilm formation against Streptococcus mutans and cytotoxicity evaluation on dental pulp fibroblasts.

Results: X-ray diffraction (XRD) confirmed the formation of pure AgNPs, whereas energy dispersive X-ray spectroscopy (EDS) mapped their elemental atoms.

Conservative approach to the restoration of vital teeth affected by severe tissue wear.

Dental wear is a multifactorial progressive condition of hard tissue loss, often decreasing the vertical dimension and leading to functional and esthetic consequences. Regaining space by using contemporary restorative materials has enabled less invasive treatment options. This clinical report describes a complete mouth restoration of a patient with severe generalized dental wear by progressively increasing the vertical dimension and using conservative prosthetic treatment options to maintain pulp vitality.

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.

Mechanical characterization and ion release of bioactive dental composites containing calcium phosphate particles.

Objective: to verify the effect of the addition of dicalcium phosphate dihydrate (DCPD) particles functionalized with di- or triethylene glycol dimethacrylate (DEGDMA or TEGDMA) on the degree of conversion (DC), post-gel shrinkage (PS), mechanical properties, and ion release of experimental composites.

Methods: Four composites were prepared containing a BisGMA/TEGDMA matrix and 60 vol% of fillers. The positive control contained only barium glass fillers, while in the other composites 15 vol% of the barium was replaced by DCPD.

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).

Trends in restorative composites research: what is in the future?

Clinical trials have identified secondary caries and bulk fracture as the main causes for composite restoration failure. As a measure to avoid frequent reinterventions for restoration replacement, composites with some sort of defense mechanism against biofilm formation and demineralization, as well as materials with lower susceptibility to crack propagation are necessary. Also, the restorative procedure with composites are very time-consuming and technically demanding, particularly concerning the application of the adhesive system.

Streptococcus mutans adherence and biofilm formation on experimental composites containing dicalcium phosphate dihydrate nanoparticles.

Unlabelled: This study aimed at evaluating bacterial adhesion and biofilm formation on resin-based composites (RBC) including dicalcium phosphate dihydrate nanoparticles (nDCPD).

Methods: Specimens were prepared from experimental RBCs with BisGMA/TEGDMA resin matrix including 20 vol% of either nDCPD (nDCPD-RBC), TEGDMA-functionalized nDPCD (F-nDCPD-RBC) or silanized silica (SiO-RBC). Neat resin blend (control-Resin), conventional nanohybrid RBC (control-RBC) and human enamel were used for reference.

Synthesis and characterization of silver phosphate/calcium phosphate mixed particles capable of silver nanoparticle formation by photoreduction.

Silver phosphate is a semi-conductor sensitive to UV-Vis radiation (<530nm). Exposure to radiation removes electrons from the oxygen valence shell, which are scavenged by silver cations (Ag), forming metallic silver (Ag) nanoparticles. The possibility of silver nanoparticle formation in situ by a photoreduction process was the basis for the application of mixed calcium phosphate/silver phosphate particles as remineralizing and antibacterial fillers in resin-based dental materials.

Polymer-based material containing calcium phosphate particles functionalized with a dimethacrylate monomer for use in restorative dentistry.

Dicalcium phosphate dihydrate particles functionalized with triethyleneglycol dimethacrylate were synthesized and added to a photocurable mixture of bisphenol-A glycidyl dimethacrylate and triethyleneglycol dimethacrylate with the purpose of developing a resin composite capable of releasing calcium and phosphate ions to foster dental remineralization. Particle functionalization would minimize the deleterious effect of adding low cohesive strength nano-structured particles with no chemical interaction with the organic matrix on the material's mechanical properties. The results showed that calcium release over 28 days was not impaired by particle functionalization.

Bioactive composites containing TEGDMA-functionalized calcium phosphate particles: Degree of conversion, fracture strength and ion release evaluation.

Objective: To evaluate the strength and ion release of experimental composites containing TEGDMA-functionalized calcium phosphate particles.

Methods: Seven composites containing equal parts (in mols) of BisGMA and TEGDMA and 60vol% of fillers were manipulated. Filler phase was constituted by silanized barium glass and 0% (control), 10% or 20% (volume) of dicalcium phosphate dihydrate (DPCD) particles, either non-functionalized or functionalized with two different TEDGMA contents.

Mechanical properties and ion release from bioactive restorative composites containing glass fillers and calcium phosphate nano-structured particles.

Objective: To evaluate the effect of the replacement of barium glass by dicalcium phosphate dihydrate (DCPD) particles on the mechanical properties and degree of conversion (DC) of composites. Additionally, calcium and hydrogen phosphate (HPO4(2-)) release were followed for 28 days.

Methods: Nine composites containing equal parts (in mols) of BisGMA and TEGDMA and 40, 50 or 60 vol% of total filler were manipulated.

Calcium and phosphate release from resin-based materials containing different calcium orthophosphate nanoparticles.

The study compared ion release from resin-based materials containing calcium orthophosphates. Amorphous calcium phosphate (ACP), dicalcium phosphate anhydrous (DCPA), dicalcium phosphate dihydrate (DCPD), and tricalcium phosphate (β-TCP) nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and surface area (nitrogen adsorption isotherms, BET method). Nanoparticles were added to a dimethacrylate-based resin and materials were tested for degree of conversion (DC) and calcium/phosphate release up to 28 days under pH 5.

Calcium phosphate nanoparticles functionalized with a dimethacrylate monomer.

The synthesis of calcium phosphate nanoparticles may include modifying agents to tailor particle size, reduce agglomeration and add specific functionalities. This study describes the synthesis of dicalcium phosphate dihydrate (DCPD) nanoparticles functionalized with triethylene glycol dimethacrylate (TEGDMA), added to one of the reacting solutions, with the purpose of reducing agglomeration and improving the compatibility with vinyl-based resin matrices. The nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), elemental analysis, thermogravimetric analysis (TGA), transmission electronic microscopy (TEM), dynamic light scattering (DLS), and surface area (BET).

Minimal alterations on the enamel surface by micro-abrasion: in vitro roughness and wear assessments.

Objective: To evaluate the in vitro changes on the enamel surface after a micro-abrasion treatment promoted by different products.

Material And Methods: Fifty (50) fragments of bovine enamel (15 mm × 5 mm) were randomly assigned to five groups (n=10) according to the product utilized: G1 (control)= silicone polisher (TDV), G2= 37% phosphoric acid (3M/ESPE) + pumice stone (SS White), G3= Micropol (DMC Equipment), G4= Opalustre (Ultradent) and G5= Whiteness RM (FGM Dental Products). Roughness and wear were the responsible variables used to analyze these surfaces in four stages: baseline, 60 s and 120 s after the micro-abrasion and after polishing, using a Hommel Tester T1000 device.

Epigenetic regulation of matrix metalloproteinase expression in ameloblastoma.

Background: An ameloblastoma is a benign odontogenic neoplasm with aggressive behaviour and high recurrence rates. The increased expression of matrix metalloproteinases (MMPs) has been reported in ameloblastomas. In the present study, we hypothesised that epigenetic alterations may regulate MMP expression in ameloblastomas.