Dentin remineralization induced by experimental composites containing calcium orthophosphate particles.

Objectives: This study aimed to verify if composites containing dicalcium phosphate dihydrate particles (DCPD) are able to induce dentin remineralization in vitro. Additionally, the mechanical properties of the materials were tested.

Methods: Four composites with 50 vol% inorganic content and 1 BisGMA: 1 TEGDMA (mols) were prepared, with different DCPD:glass ratios (50:0, 40:10, 30:20 and 0:50).

Influence of radiant exposure and material shade on the degree of conversion and microhardness of a resin-based composite.

This in vitro study evaluated the influence of radiant exposure and material shade on the degree of conversion (DC) and microhardness of a resin-based composite (RBC). Sixty-four RBC specimens in shades A1E (enamel) and A4D (dentin) were light cured at a calibrated exitance of 1000 mW/cm for 5, 10, 15, or 20 seconds, resulting in radiant exposure levels of 5, 10, 15, or 20 J/cm. The DC was determined using Fourier-transform infrared spectroscopy (n = 3 per shade per exposure level).

Ion release mechanisms in composites containing CaP particles and hydrophilic monomers.

Objective: To investigate the effect of hydrophilic/permeable polymer matrices on water sorption/solubility (WS/SL), Ca release, mechanical properties and hydrolytic degradation of composites containing dicalcium phosphate dihydrate (DCPD) particles.

Methods: Six composites were tested, all with 10 vol% of glass particles and either 30 vol% or 40 vol% DCPD. Composites containing 1BisGMA:1TEGDMA in mols (at both inorganic levels) were considered controls.

Toxicity and cytokine release from human dental pulp stem cells after exposure to universal dental adhesives cured by single peak and polywave LEDs.

Objectives: to assess the impact of universal adhesives, cured with single-peak and polywave LEDs, on the metabolic activity and cytokine release of human dental pulp stem cells (hDPSCs). In addition, analyze the degree of conversion (DC) of the adhesives cured with the different LEDs.

Methods: Discs (5 mm diameter, 1 mm thick) were prepared using three universal adhesives: Single Bond Universal (SBU, 3 M ESPE), Optibond Universal (OBU, Kerr), and Zipbond Universal (ZBU, SDI).

Antimicrobial and optical properties of a new biogenic silica-coated silver nanoparticles incorporated into experimental resin.

Background: Evaluate the effects of incorporating silica-coated silver nanoparticles (Ag@SiO2 NPs) into odontological clinic resin materials.

Material And Methods: Silver nanoparticles coated with silicon dioxide were added to the experimental resin matrix at 1, 3, and 5wt%. Degree of conversion (DC), optical properties (total transmittance and color change), and microstructural analysis were evaluated.

Poly(Aspartic Acid) Promotes Odontoblast-like Cell Differentiation in Rat Molars with Exposed Pulp.

Unlabelled: In recent years, alternative pulpal therapies targeting dentinogenesis signaling pathways using different peptides have been investigated. The aim of this study was to verify the effectiveness of poly(aspartic acid), pAsp, in dentin regeneration using an animal model.

Methods: Mechanical pulp exposure was performed in the upper molars of 56 Wistar rats, randomly divided as follows (n = 14): control (no treatment); MTA group-pulp capping with mineral trioxide aggregate (MTA Angelus); pAsp group-application of 20 μL of pAsp solution (25 mg·mL); MTA+pAsp group-application of MTA mixed with pAsp (5:1 by mass).

Comparison between a bulk-fill resin-based composite and three luting materials on the cementation of fiberglass-reinforced posts.

Objectives: This study verified the possibility of cementing fiberglass-reinforced posts using a flowable bulk-fill composite (BF), comparing its push-out bond strength and microhardness with these properties of 3 luting materials.

Materials And Methods: Sixty endodontically treated bovine roots were used. Posts were cemented using conventional dual-cured cement (CC); self-adhesive cement (SA); dual-cured composite (RC); and BF.

Effect of calcium orthophosphate particle size and CaP:glass ratio on optical, mechanical and physicochemical characteristics of experimental composites.

Objective: Evaluate light transmittance (%T), color change (ΔE), degree of conversion (DC), bottom-to-top Knoop microhardness (KHN), flexural strength (BFS) and modulus (FM), water sorption/solubility (WS/SL) and calcium release of resin composites containing different dicalcium phosphate dihydrate (DCPD)-to-barium glass ratios (DCPD:BG) and DCPD particle sizes.

Methods: Ten resin-based composites (50 vol% inorganic fraction) were prepared using BG (0.4 µm) and DCPD particles (12 µm, 3 µm or mixture) with DCPD:BG of 1:3, 1:1 or 3:1.

TEGDMA-Functionalized Dicalcium Phosphate Dihydrate Resin-Based Composites Prevent Secondary Caries in an In Vitro Biofilm Model.

This study evaluated the efficacy of experimental TEGDMA-functionalized dicalcium phosphate dihydrate (T-DCPD) filler-based resin-based composites (RBC) in preventing caries lesions around the restoration margins (secondary caries, SC). Standardized Class-II cavities were made in sound molars with the cervical margin in dentin. Cavities were filled with a commercial resin-modified glass-ionomer cement (RMGIC) or experimental RBCs containing a bisGMA-TEGDMA resin blend and one of the following inorganic fractions: 60 wt.

Dental Adhesives-Surface Modifications of Dentin Structure for Stable Bonding.

The latest advancements in dentin bonding have focused on strategies to impair degradation mechanisms in order to extend the longevity of bonded interfaces. Protease inhibitors can reduce collagen degradation within the hybrid layer (HL). Collagen cross-linkers allow better adhesive infiltration and also inhibit proteases activity.

Polymerization Kinetics, Shrinkage Stress, and Bond Strength to Dentin of Conventional and Self-adhesive Resin Cements.

Purpose: To evaluate the kinetics of polymerization and shrinkage stress of resin cements, as well as their bond strength to dentin after 24-h or one-year water storage.

Materials And Methods: Three conventional resin cements were evaluated: RelyX Ultimate (RUL), Panavia V5 (PNV), and Multilink N (MLN); and three self-adhesive resin cements: RelyX Unicem 2 (RUN), Panavia SA Cement Plus (PSA), and G-CEM LinkAce (GCL). Degree of conversion (DC), maximum polymerization rate (RPmax) and gel time values were obtained using Fourier-transform infrared spectroscopy (FTIR/ATR).

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.

Effects of the crosslinking of chitosan/DCPA particles in the antimicrobial and mechanical properties of dental restorative composites.

Unlabelled: The development of restorative materials containing antibacterial agents is an alternative to reduce the progression of caries lesions.

Objective: to compare the influence of the degree of crosslinking of chitosan particles loaded with dibasic calcium phosphate (DCPA) on the mechanical properties, degree of conversion (DC), and antimicrobial properties of experimental composites.

Methods: Chitosan/DCPA particles were synthesized by the electrospraying, crosslinked by 0, 8, or 16 h in glutaraldehyde, and characterized by zeta potential and minimum inhibitory concentration (MIC) against S.

Influence of different concentrations of an iodonium salt on properties of amine-free resins.

Objectives: to evaluate the effect of different concentrations of an iodonium salt on the degree of conversion, polymerisation rate, flexural strength and modulus of an amine-free photopolymerizable resin system.

Methods: Two series of UDMA/TEGDMA resin mixtures (1:1 mass ratio) containing 0, 0.5, 1.

Physicochemical properties of dental resins formulated with amine-free photoinitiation systems.

Objective: To assess the mechanical properties of two different dimethacrylate resin blends containing the photosensitizer camphorquinone (CQ) alone or in combination with one or more synergists including an amine and/or an iodonium.

Methods: Two co-monomer resin blends were formulated using Bis-GMA/TEGDMA and UDMA/TEGDMA, both at 1:1 mass ratio. Each resin blend was divided into four groups, comprising the following four photoinitiation systems: (1) CQ + 2-(dimethylamino)ethyl methacrylate (DMAEMA); (2) CQ + DMAEMA + bis(4-methyl phenyl)iodonium hexafluorophosphate (BPI); (3) CQ; and (4) CQ + BPI.

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.

The use of bioactive particles and biomimetic analogues for increasing the longevity of resin-dentin interfaces: A literature review.

Protecting resin-dentin interfaces from hydrolytic and enzymatic degradation is critical for the longevity of adhesive restorations. In recent years, several strategies have been tested in vitro to induce apatite precipitation within interfibrillar and intrafibrillar collagen spaces, as well as in resin-sparse regions where the adhesive infiltration was incomplete. Also, the presence of calcium ions and other metallic ions has shown an inhibitory effect on enzymatic activity.

Antibacterial resin-based composite containing chlorhexidine for dental applications.

Objeticve: The aim of this study was to develop a composite material with antibacterial activity using MMT loaded with clorhexidine (CHX). For that it was used a BisGMA/TEGDMA matrix and added low concentration of MMT/CHX. The aim was to evaluate the drug release capacity of MMT, and not to provide reinforcement.

Effect of diphenyliodonium hexafluorophosphate salt on experimental infiltrants containing different diluents.

Non-invasive treatments for caries lesions are increasingly required for oral health; resin infiltration is one possible conservative option. In this study, we evaluated the effects of diphenyliodonium hexafluorophosphate salt (DPI) on experimental resin infiltrants with either (hydroxyethyl)methacrylate (HEMA) or ethanol as the diluent. A monomeric base with diglycidyl methacrylate ethoxylated (BisEMA, 25 wt%) and triethylene glycol dimethacrylate (TEGDMA, 75 wt%), 0.

Calcium phosphates as ion-releasing fillers in restorative resin-based materials.

Calcium phosphates (CaP) are the main constituents of the mineral phase in bones and teeth and, along with calcium silicates and bioactive glasses, have been extensively investigated in remineralization of enamel and dentin. When used as ion-releasing fillers in resin-based materials, they could contribute to extend the service life of adhesive restorations, remineralize caries-affected dentin or prevent caries lesions under sealants and orthodontic brackets. However, the development of resin-based bioactive materials is not straightforward because of the several compositional variables involved in ion release.

Effect of light curing units on the polymerization of bulk fill resin-based composites.

Objective: To determine the potential effect of four different light curing units (LCUs) on the curing profile of two bulk fill resin-based composites (RBCs).

Methods: Four LCUs (Bluephase 20i, Celalux 3, Elipar DeepCure-S and Valo Grand) were used to light cure two RBCs (Filtek Bulk Fill Posterior Restorative and Tetric EvoCeram Bulk Fill). The effective tip diameter, radiant power, radiant emittance, emission spectrum and light beam profile of the LCUs were measured.

A comparative study of bulk-fill composites: degree of conversion, post-gel shrinkage and cytotoxicity.

Bulk-fill composites are claimed to be restorative materials used in deep preparations and effectively photoactivated in layers up to 4 mm. The aim of the present study was to evaluate the degree of conversion, post-gel volumetric shrinkage, and cytotoxicity of six bulk-fill and two conventional composites. Degree of conversion was determined by FTIR spectroscopy; post-gel volumetric shrinkage was determined using the strain gauge method; and cytotoxicity in human fibroblasts was evaluated indirectly by the MTT assay.

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.