Translucency changes of direct esthetic restorative materials after curing, aging and treatment.

The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP) of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.

Opalescence of human teeth and dental esthetic restorative materials.

Human tooth enamel is opalescent, which renders teeth bluish in reflected and orange in transmitted color. The aim was to review opalescent property of teeth and application and mimetic reproduction in esthetic restorations. A PubMed search for articles published in English till 2015 on the opalescence of teeth and esthetic materials revealed 29 relevant papers.

Bone cement with a modified polyphosphate network structure stimulates hard tissue regeneration.

In this study, a calcium polyphosphate cement (CpPC) consisting of basic components was investigated to assess its potential for hard tissue regeneration. The added basic components for improving the structural stability, which controlled the setting time, where the setting reaction resulted in the formation of amorphous structure with a re-constructed polyphosphate. Moreover, the characteristics were controlled by the composition, which determined the polyphosphate structure.

Criteria for clinical translucency evaluation of direct esthetic restorative materials.

The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel.

Translucency and color match with a shade guide of esthetic brackets with the aid of a spectroradiometer.

Objective: Since the color of esthetic brackets should match that of teeth, the aims of this study were to determine the color and translucency of esthetic brackets by means of the clinically relevant use of a spectroradiometer, and to compare the color of brackets with that of a commercial shade guide.

Methods: The color of central and tie-wing regions of four plastic and four ceramic brackets was measured according to the CIE L*a*b* color scale over white and black backgrounds. Brackets were classified into five groups based on their composition.

Color Correlations among Six Types of Permanent Anterior Teeth.

Statement Of Problem: When multiple teeth are missing, the color for missing teeth should be estimated based on the color of remaining teeth.

Purpose: The purpose was to determine the strength of color correlations among six types of permanent anterior teeth.

Methods: Color of 12 anterior teeth was measured by Shade Vision System for 47 volunteers.

Translucency of Dental Ceramic, Post and Bracket.

Translucency of dental ceramics, esthetic posts and orthodontic brackets was reviewed. Translucency parameter () and contrast ratio () are generally used for translucency evaluation. For the evaluation of translucency, two criteria such as the translucency of human teeth ( = 15-19, 1 mm thick) and the visual perceptibility threshold for the translucency difference (∆ > 0.

Bone Tissue Engineering by Using Calcium Phosphate Glass Scaffolds and the Avidin-Biotin Binding System.

Highly porous and interconnected scaffolds were fabricated using calcium phosphate glass (CPG) for bone tissue engineering. An avidin-biotin binding system was used to improve osteoblast-like cell adhesion to the scaffold. The scaffolds had open macro- and micro-scale pores, and continuous struts without cracks or defects.

Translucency of human teeth and dental restorative materials and its clinical relevance.

The purpose was to review the translucency of human teeth and related dental materials that should be considered for the development of esthetic restorative materials. Translucency is the relative amount of light transmission or diffuse reflection from a substrate surface through a turbid medium. Translucency influences the masking ability, color blending effect, and the degree of light curing through these materials.

Fluorescence properties of human teeth and dental calculus for clinical applications.

Fluorescent emission of human teeth and dental calculus is important for the esthetic rehabilitation of teeth, diagnosis of dental caries, and detection of dental calculus. The purposes of this review were to summarize the fluorescence and phosphorescence of human teeth by ambient ultraviolet (UV) light, to investigate the clinically relevant fluorescence measurement methods in dentistry, and to review the fluorescence of teeth and dental calculus by specific wavelength light. Dentine was three times more phosphorescent than enamel.

Engineered microstructure granules for tailored drug release rate.

Biomaterials developed for controlled drug delivery have demonstrated excellent results in the present study. A biomaterial prepared using hydroxyapatite (HAp) was shown to have a hollow structure with the presence of interconnected pores to house drug carriers. The poly(lactic-co-glycolic acid) particles were used as drug carriers loaded with dexamethasone, a corticosteroid that is known to promote osteoinduction.

Color assimilation of resin composites with adjacent color according to the distance.

Statement Of Problem: Color of esthetic restorative materials shifts toward color of adjacent material.

Purpose: The purposes were to determine the amount of distance-dependent color shift in resin composites toward the color of adjacent materials and to define a color shift parameter (CSP) that can quantify this phenomenon.

Methods: Three brands of resin composites, two shades for each, were investigated.

Correlation between three color coordinates of human teeth.

The objective was to determine whether there were significant correlations in the three color coordinates within each of two color coordinate systems, such as the Commission Internationale de l’Eclairage (CIE) L*a*b* system, and the lightness, chroma, and hue angle system, of human vital teeth. The color of six maxillary and six mandibular anterior teeth was measured by the Shade Vision System. Pearson correlations between each pair of the color coordinates were determined (α=0.

Tomographic and histometric analysis of autogenous bone block and synthetic hydroxyapatite block grafts without rigid fixation on rabbit calvaria.

Purpose: The preferred material for bone augmentation beyond the envelope of skeletal bone is the bone block graft, due to its dimensional stability. We evaluated the necessity of rigid fixation for the bone block graft, and compared the bone regeneration and volume maintenance associated with grafting using a synthetic hydroxyapatite block (HAB) and an autogenous bone block (ABB) without rigid fixation on rabbit calvaria over two different periods.

Methods: Cylinder-shaped synthetic HAB and ABB were positioned without fixation on the rabbit calvarium (n=16).

Illuminating light-dependent color shifts in core and veneer layers of dental all-ceramics.

The color of an object is perceived differently depending on the ambient light conditions. Since dental all-ceramic restorations are fabricated by building up several layers to reproduce the tooth shade, the optical properties of each layer should be optimized for successful shade reproduction. This study aimed to determine the separate contributions of the color shifts in each of the core and veneer layers of all-ceramics by switching the illuminating lights on the color shifts of layered ceramics.

Acid neutralizing, mechanical and physical properties of pit and fissure sealants containing melt-derived 45S5 bioactive glass.

Objectives: The aim of this study was to examine the effects of 45S5 bioactive glass (BAG) on the acid neutralizing, mechanical and physical properties of pit and fissure sealants.

Methods: 45S5BAG (<25 μm) was mixed with the silanized glass (180 ± 30 nm) and added into a resin matrix [Bis-GMA/TEGDMA 50/50 (wt%) containing 1% of DMAEMA/CQ 2:1 (wt%)] with varying filler proportions; 0% 45S5BAG+50% glass (BAG0); 12.5% 45S5BAG+37.

Seeding cells on calcium phosphate scaffolds using hydrogel enhanced osteoblast proliferation and differentiation.

Internal pores in calcium phosphate (CaP) scaffolds pose an obstacle in cell seeding efficiency. Previous studies have shown inverse relationships between cell attachment and internal pore size, which mainly resulted from cells flowing to the bottom of culture plates. In order to overcome this structure-based setback, we have designed a method for cell seeding that involves hydrogel.

Perceived color shift of ceramics according to the change of illuminating light with spectroradiometer.

Purpose: Perceived color of ceramics changes by the spectral power distribution of ambient light. This study aimed to quantify the amount of shifts in color and color coordinates of clinically simulated seven all-ceramics due to the switch of three ambient light sources using a human vision simulating spectroradiometer.

Materials And Methods: CIE color coordinates, such as L*, a* and b*,of ceramic specimens were measured under three light sources, which simulate the CIE standard illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp).

Vitapan 3D-master shade guide showed no fluorescence emission.

Objectives: To determine the fluorescence property of Vitapan 3D-Master shade guide tabs with a spectrophotometer.

Materials And Methods: Fluorescence property of 29 shade tabs, in both of original and ground-to-flat forms, was determined by a reflection spectrophotometer. Color difference (ΔE*ab-FL) by the inclusion and exclusion of the UV component of a standard daylight simulator (CIE standard illuminant D65) was calculated to determine the fluorescence color change.

Cytotoxicity test of dentin bonding agents using millipore filters as dentin substitutes in a dentin barrier test.

Objectives: The purpose of this study was to find proper dentin substitute for standardized dentin barrier test and perform the cytotoxicity test of commercial bonding agents with the proper substitute.

Materials And Methods: The three-dimensional cells attached to dentin disc or millipore filters as the dentin substitute were tested in a dentin barrier test by perfusion. MTT assay was performed as an evaluation method for the cell survival rate.

Reciprocal influence of masticatory apparatus, craniofacial structure and whole body homeostasis.

There are evidences that the evolution into Homo erectus was partially induced by masticatory muscular dystrophy caused by a gene mutation, which in turn increased brain capacity and led to bipedalism. It is generally accepted that the morphology and function of mammalian skull are partially controlled by epigenetic mechanisms. Archeologic evidences support that the masticatory apparatus have influenced the mechanical stress distribution in hominin skull, and consequently changed craniofacial morphology and function.

Bioactivity and mechanical properties of collagen composite membranes reinforced by chitosan and β-tricalcium phosphate.

In this study, we analyzed the effects of varying concentrations of chitosan (CS) and β-tricalcium phosphate [β-TCP, Ca(3)(PO(4))(2)] on the mechanical and cell-adhesion properties of a collagen (CG) matrix for use in guided bone regeneration (GBR). Three different CS concentrations (0.5, 1, and 2%) and five different contents of β-TCP (0, 17, 29, 38, and 44%) were investigated.

Comparative evaluation of three calcium phosphate synthetic block bone graft materials for bone regeneration in rabbit calvaria.

Various synthetic materials were developed to be used for implant dentistry and periodontal treatments. Among the various synthetic bone substitutes, calcium phosphate ceramics have been extensively investigated because their mineral chemistry resembles that of human bone. We evaluated the regeneration of three calcium phosphate synthetic block bone grafts in rabbit calvarial noncritical size defects.

Periodontal tissue reaction to customized nano-hydroxyapatite block scaffold in one-wall intrabony defect: a histologic study in dogs.

Purpose: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model.

Methods: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral 4×4×5 mm (buccolingual width×mesiodistal width×depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs.