Surface dissolution and transesterification of thermoset dimethacrylate polymer by dimethacrylate adhesive resin and organic catalyst-alcohol solution.

Objectives: To evaluate transesterification based dissolution of dimethacrylate and epoxy polymers, the former containing ester groups. Polymer substrates were treated with an adhesive resin (Stick™ Resin) and an organic catalyst-alcohol solution (ethylene glycol and triazabicyclodecene). The surface was chemically and nanomechanically analyzed with Fourier Transform-Infrared (FTIR) spectroscopy, surface profile peak (R) and nanohardness and modulus of elasticity.

The effect of ethanol on surface of semi-interpenetrating polymer network (IPN) polymer matrix of glass-fibre reinforced composite.

Aim Of The Study: The aim of this laboratory study was to evaluate the effect of ethanol treatment on the surface roughness (S), nano-mechanical properties (NMP) and surface characterization of dental fiber reinforced composite (FRC) with semi-interpenetrating polymer network (IPN).

Materials And Methods: A total of 240 FRC specimens with bisphenol A-glycidyl methacrylate - triethyleneglycol dimethacrylate - Poly (methylmetahcrylate) (bis-GMA-TEGDMA-PMMA) IPN matrix system were light cured for 40 s and divided into 2 groups (L and LH). The group LH was further post-cured by heat at 95 °C for 25 min.

Effect of smoking on the genetic makeup of toll-like receptors 2 and 6.

Background: Cigarette smoking is a major risk factor for lung cancer, asthma, and oral cancer, and is central to the altered innate immune responsiveness to infection. Many hypotheses have provided evidence that cigarette smoking induces more genetic changes in genes involved in the development of many cigarette-related diseases. This alteration may be from single-nucleotide polymorphisms (SNPs) in innate immunity genes, especially the toll-like receptors (TLRs).

Effect of solvent/disinfectant ethanol on the micro-surface structure and properties of multiphase denture base polymers.

Aim Of The Study: The aim of this study was to evaluate the effect of solvent/disinfectant ethanol on the surface of denture base polymers. Changes in surface roughness, topography and some nanomechanical properties were assessed by SEM and nanoindentation plotted against different concentrations of ethanol on heat cured and autopolymerized polymetyl methacrylate based acrylic denture base polymers.

Materials And Methods: Test specimens (10×10×3mm(3)) of heat-curing (HC) and auto-polymerizing (AP) acrylic resin were prepared and polished to obtain uniform smoothness which were further grouped into 3 sub-groups HC1, HC2, HC3 and AP1, AP2, AP3 respectively 10 specimens (n) in each group.

The effect of mechanical and chemical polishing techniques on the surface roughness of heat-polymerized and visible light-polymerized acrylic denture base resins.

Objective: The purpose of this study was to compare the effects of mechanical polishing (MP) and chemical polishing (CP) on the average surface roughness (Ra) of heat-cured (HC) and light-cured (LC) denture base acrylic resins.

Methods: A total of 120 specimens (30 × 15 × 3 mm) were prepared from one HC and one LC acrylic resin. To remove nodules and gross surface irregularities, all specimens were finished with a lathe-mounted small acrylic bur and 360-grit sandpaper.

The prevalence of malocclusion and its association with dental caries among 12-18-year-old disabled adolescents.

Background: To assess the prevalence of malocclusion among 12-18-year-old disabled adolescents in Chennai, Tamil Nadu, India, by using the Dental Aesthetic Index (DAI) and to determine the association of malocclusion with dental caries.

Methods: This cross-sectional study included 243 children with various mental disabilities with or without physical infirmities. The Dental Aesthetic Index (DAI) and the dentition status were recorded using the World Health Organization Oral Health Surveys - Basic Methods (1997) Pro-forma.

Effect of different beverages on the color stability and degree of conversion of nano and microhybrid composites.

This study sought to evaluate the effects of different staining solutions on the colour stability of nanocomposites compared with microhybrid resin and to evaluate the degree of conversion of these two materials. Two different shades of two different composites were cured in polytetraflouroethylene disk rings. Coffee, tea and cola drinks were used as staining solutions, and distilled water was used as a control.

A comparison of the mechanical properties of a modified silorane based dental composite with those of commercially available composite material.

Objectives: The aim of this study was to compare the mechanical properties of the nano-hydroxyapatite incorporated silorane composite material with the commercially available dental composites.

Methods: Filtek Silorane resin composite was incorporated with 5% and 10% nano-hydroxyapatite crystals and then mechanically tested in comparison along with the commercially available Filtek Silorane and Filtek Supreme XT after 1, 14, 30 and 90 days period.

Results: The mechanical tests revealed that the modified silorane based dental composite had a significant increase in the mechanical properties than the commercially available Filtek Silorane and Filtek Supreme XT.