The purpose of the study was to verify the linear displacement of teeth in maxillary complete dentures influenced by different monomer-polymer ratios - according to the manufacturer's instructions, with 25% excess or 25% less monomer content - in the conventional and microwaved polymerization techniques. Wax base plates and wax planes were made on edentulous maxillary stone casts according to traditional method. The set was assembled in semi-adjustable articulator with a lower toothed stone cast as guide to mounting of the maxillary artificial teeth. Impressions were taken from this tooth arrangement with silicone and the mold was used to standardize the mounting of the teeth of all dentures. Referential points were made on the artificial teeth for linear measurements with optical microscope before processing of the dentures and after deflasking. Denture bases were conventionally packed with acrylic resin according to the monomer-polymer ratio protocol. Tooth displacement data were submitted to ANOVA and Tukey test (α=0.05). There were no statistically significant differences (p>0.05) between the group with monomer content recommended by the manufacturer and groups with 25% more and 25% less monomer, in both conventional and microwaved polymerizations. Excess or less monomer in the monomer-polymer ratio and polymerization types did not change the linear distance between teeth.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1590/s0103-64402011000300010 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Advances in polyhydroxyalkanoate (PHA) production from renewable waste materials using halophilic microorganisms: A comprehensive review.
Sci Total Environ
January 2025
Biotechnology Program, Center for Sustainable Development, College of Arts and Sciences, Qatar University, Doha 2713, Qatar. Electronic address:
Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polymers that can replace conventional plastics in different sectors. However, PHA commercialization is hampered due to their high production cost resulting from the use of high purity substrates, their low conversion into PHAs by using conventional microbial chassis and the high downstream processing cost. Taking these challenges into account, researchers are focusing on the use of waste by-products as alternative low-cost feedstocks for fast-growing and contamination-resistant halophilic microorganisms (Bacteria, Archaea…).
View Article and Find Full Text PDFPreparation of molecularly imprinted polymer nanoparticles for the extraction and purification of progesterone combined with UPLC-ESI-MS mass spectrometry detection in royal jelly.
J Chromatogr B Analyt Technol Biomed Life Sci
January 2025
Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun 130117 China. Electronic address:
This study aimed to develop molecularly imprinted polymer (MIP) nanoparticles specifically for the selective extraction and enrichment of progesterone (P) from royal jelly (RJ), and quantitatively analyzed them by ultra-performance-liquid chromatography electrospray ionization mass spectrometry (UPLC-ESI-MS). Gaussian software-based theoretical calculations identified methacrylic acid (MAA) as the optimal functional monomer for its strong binding affinity to P. MIP was synthesized by precipitation polymerization, and the preparation process of MIP was optimized by one-way variance design and response surface methodology.
View Article and Find Full Text PDFEmulsion Polymerization of Styrene to Polystyrene Nanoparticles with Self-Emulsifying Nanodroplets as Nucleus.
Langmuir
January 2025
Research Center for Water Resources and Interface Science, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
The mechanism of the emulsion polymerization of styrene to polystyrene nanoparticles (PSNPs) remains a subject of debate. Herein, a series of reaction parameters with different surfactant concentrations, monomer contents, temperatures, and equilibration times were investigated to understand the formation mechanism of PSNPs, which demonstrate a correlation between the properties of PSNPs and the mesostructure of the premix. Cooling the model systems with self-emulsifying nanodroplets (SENDs) in the early reaction stages resulted in the hollow polystyrene spheres (H-PSSs), ruptured PSNPs, and dandelion-like PSNPs, further indicating that the oil nanodroplets are the key sites for the formation of PSNPs.
View Article and Find Full Text PDFsynthesis of degradable polymer prodrug nanoparticles.
Chem Sci
January 2025
Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay 91400 Orsay France +33-180006081.
The synthesis of degradable polymer prodrug nanoparticles is still a challenge to be met, which would make it possible to remedy both the shortcomings of traditional formulation of preformed polymers (, low nanoparticle concentrations) and those of the physical encapsulation of drugs (, burst release and poor drug loadings). Herein, through the combination of radical ring-opening polymerization (rROP) and polymerization-induced self-assembly (PISA) under appropriate experimental conditions, we report the successful preparation of high-solid content, degradable polymer prodrug nanoparticles, exhibiting multiple drug moieties covalently linked to a degradable vinyl copolymer backbone. Such a rROPISA process relied on the chain extension of a biocompatible poly(ethylene glycol)-based solvophilic block with a mixture of lauryl methacrylate (LMA), cyclic ketene acetal (CKA) and drug-bearing methacrylic esters by reversible addition fragmentation chain transfer (RAFT) copolymerization at 20 wt% solid content.
View Article and Find Full Text PDFStabilizing effect of HP-β-CD on infliximab in liquid formulations and a solid formulation produced by electrospinning.
Eur J Pharm Sci
January 2025
Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111, Budapest, Hungary. Electronic address:
The development of stable biopharmaceutical formulations, such as monoclonal antibodies, poses a great challenge in the pharmaceutical industry. This study investigated the stabilizing effect of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) in liquid and solid formulations of infliximab during processing and storage. The solid formulation was produced by a scaled-up high-speed electrospinning method, resulting in a product suitable for reconstitution with excellent dissolution properties.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!