Color Penetration Research Articles

Usefulness of orthodontic adhesive-containing fluorescent dye

Orthodontic adhesive is often left on the tooth surface when a multibracket appliance is debonded, and it is difficult to remove because its colour is similar to that of the tooth. If the adhesive changed colour during debonding, residual adhesive could be more easily removed. This in vitro study evaluated the usefulness of adhesive mixed with a small amount of fluorescent dye for clinical orthodontics. Sixty-four metal brackets were bonded to flattened bovine enamel surfaces using adhesives with three concentrations (0.001, 0.002, and 0.003 per cent) of fluorescent dye, and the shear bond strength (SBS) and adhesive remnant index (ARI) scores for each adhesive were determined. Colour penetrating through the transparent bracket was measured using a colour analyser. SBS and fluorescence intensity were examined to determine the stability of the adhesives after they were subjected to a thermal cycle test (1000 cycles). For data that were normally distributed, one-way analysis of variance followed by the Student-Newman-Keuls test was used to identify significant differences among the groups. If the data were not normally distributed, the Kruskal-Wallis H-test followed by the Mann-Whitney U-test with Bonferroni correction was used. Differences in ARI were determined with the chi-square test. The SBS of the adhesive with 0.003 per cent fluorescent dye was significantly lower than that of the control (Transbond). In ARI tests, significantly more of the adhesive with 0.003 per cent dye was left on the tooth surface after 24 hours compared with the other adhesives. With regard to colour penetration, the adhesive with 0.003 per cent dye was five times more visible than to others. SBS and fluorescence intensity of the adhesives were not affected by thermal cycling. Therefore, an adhesive containing less than 0.002 per cent fluorescent dye provides both sufficient bond strength for orthodontic brackets and sufficient fluorescent colour for easy visualization without aesthetic impairment.

Ön Emdirme İşleminde Kullanılan Kıvamlaştırıcı Türünün Reaktif Ink Jet Baskı Kalitesi Üzerine Etkileri

In this article, the effects of various thickeners used in the pre-padding processes for reactive ink jet printing were investigated. For this purpose, firstly, bleached 100% cotton fabric samples were pre-padded with pre-treatment liquors prepared using high, medium and low viscosity alginates and a synthetic thickener. After- wards, the pre-padded fabric samples were dried. Then, printings were carried out on the pre-padded fabric sam- ples using Cyan, Magenta, Yellow and Black colours (CMYK colours) which are basic process colours in the ink jet printing. Finally, colour strength (K/S values), colour penetration, contour sharpness, wash fastness and crock fastness properties were tested and evaluated. The results showed that the most suitable thickener type is the high viscosity alginate.

Effect of marinating time and low pH on marinade performance and sensory acceptability of poultry meat

The effects of marinating time (30, 60, 120 and 180 min) and acidic marinade pH (3.0, 3.2, 3.4, 3.6, 3.8, 4.0 and 4.2) on the instrumental and sensory properties of cooked Chinese-style marinated chicken were investigated. With increasing marinating time up to 180 min, a significant (P<0.05) increase in surface redness (a* value) and the dark pink sensory attribute was observed, along with a corresponding decrease in lightness (L* value) and colour penetration. Increased marinating times of 120-180 min were found to produce more acceptable end products with increased scores for colour, aroma and flavour attributes. Marinade uptake was greater at higher marinade pH levels of 3.8, 4.0 and 4.2, with the highest marinade uptake (3.34%) recorded at pH 4.0. As changes to core meat pH were not observed, the effect of marinating time (up to 180 min) and marinade pH on the instrumental and sensory properties of Chinese-style marinated chicken were located principally at the surface of samples. Consumers considered surface colour as contributing to acceptability of marinated chicken to a greater degree compared to colour penetration.

Effect of halogene light source on marginal microleakage of resin composite restorations

Introduction. Although the technology of production resin composite materials has been improved in the past years, polymerization shrinkage and microleakage still remain the main problem of the resin composite restorations. The most important issues are polymerization control, light source choice, quality and polymerization technique. The aim of this study was to evaluate the effect of the halogen light source on the marginal microleakage of the resin composite restorations class V. Material and Methods. The study included 40 extracted human teeth (20 intact and 20 with caries lesion). Class V cavity was prepared in each tooth. The light curing unit used in this study had irradiance 540 mW/cm2. Cavities were restored with the two resin composite materials, Filtek Supreme (3M ESPE) and Luksogal - Galenika. Microleakage was determined using colored solution of 50% silver-nitrate. Results were obtained using stereomicroscope with 6 times magnification. Color penetration was evaluated on the occlusal and gingival wall. Results. Linear color penetration was observed in all cavities restored using Luksogal. There was significant difference (p&lt;0.01) in color penetration between the occlusal (20.30 ?m) and gingival wall (34.00 ?m). Color penetration was shown in all cavities prepared on intact and caries teeth and restored using Filtek Supreme. Also, color penetration on the occlusal wall (13.80 ?m) was significantly lower (p&lt;0.01) than the penetration on the gingival wall (33.00 ?m). Conclusion. All the tested cavities showed marginal leakage, regardless the tooth or material used. Greater microleakage was noticed when Luksogal was used.

The effect of temporary filling materials on the microleakage in endodontically treated teeth

Introduction. Besides anatomo-morphological characteristics of the root canal system, instrumentation techniques, obturation materials as well as temporary filling materials can influence the coronal microleakage. The aim of this study was to assess in vitro coronal microleakage of temporary filling materials in endodontically treated teeth by the method of colored solutions. Material and Methods. Forty extracted human teeth (single-rooted and multi-rooted) divided into two groups of (intact and caries affected) were used. The root canals were instrumented by step-back preparation technique and 2.5% NaOCl as irigant solution. Obturation was performed by lateral condensation technique with Apexit paste and gutta-percha. Cavit and Glass Ionomer Cement were used as temporary filling materials. The solution of 50% AgNO3 was used for microleakage assessment. The penetration of the color was evaluated using Light Microscope. Results. Of intact teeth, 60% temporarily filled by Cavit showed the color penetration, while only 25% of the teeth temporarily filled by combination of GIC and Cavit. The difference was statistically significant (p&lt;0.05). In caries affected teeth, the penetration of the color was observed in 55% of the samples when Cavit was used and in 32% when combination of GIC and Cavit was used as temporary filling material. The difference was statistically significant (p&lt;0.05). Less color penetration occured in single-rooted than in multi-rooted teeth in both groups, but the differences were not statistically significant. Conclusion. Glass Ionomer Cements in combination with Cavit provide better sealing of endodontically treated teeth. The least color penetration was observed in intact single-rooted teeth.

SENSORY EVALUATION OF CHINESE‐STYLE MARINATED CHICKEN BY CHINESE AND EUROPEAN NAÏVE ASSESSORS

ABSTRACT This study was carried out in order to determine the sensory acceptability of chicken breast fillet marinated with retail and commercially available Chinese‐style marinades. Forty‐nine naïve assessors, including 25 European and 24 Chinese, were selected to assess 17 sensory attribute of 18 Chinese‐style marinades, anonymously coded according to their specific flavor group: (1) Szechuan, SZ (A–D); (2) Sweet and Sour, SS (E–J); (3) Hoisin, HO (K–P); and (4) Chinese 5 Spice, FS (Q–R). The attributes includes color (bright red, dark brown, color penetration), aroma (liking, pungency, spiciness), flavor (liking, spiciness, hotness), specific flavor ratings (Szechuan, Sweet and Sour, Hoisin, Barbeque, Chinese 5 Spice, authenticity), juiciness and overall acceptability. The instrumental color of the cooked samples and pH, moisture and fat content of the marinades were also analyzed instrumentally. Marinades were applied to the chicken fillets and dry cooked at 170C for 15 min to an internal temperature of 73C. Sensory evaluation showed that there were significant differences between both naïve assessor groups in all attributes measured, excluding bright red color, sweet and sour and flavor authenticity (P &lt; 0.05). Samples marinated with marinades FS‐Q and SS‐G received the highest score in term of overall acceptability by the European assessors, whereas HO‐L was chosen by the Chinese assessor group. The European naïve assessors were also found to successfully differentiate the Chinese marinade products according to four specific flavors (Szechuan, Sweet and Sour, Hoisin and Chinese 5 Spice). Although the optimal characteristics of an ideal Chinese marinade were identified by the European group, the Chinese perception for Chinese‐style marinated products available in the Irish market were less acceptable and were considered non‐authentic.PRACTICAL APPLICATIONSThe findings from this research will benefit marinade and marinated chicken product manufacturers, when developing or optimizing their ethnic products for the local and international markets. The European naïve consumers were found to successfully differentiate the Chinese marinade products according to four specific flavors. Although the optimal characteristics of an ideal Chinese marinade were identified by the European, the Chinese naïve assessor's perception for Chinese‐style marinade products available in the Irish market were less acceptable and lacking in authenticity. These results are of interest to individuals undertaking cross cultural consumer studies, even though the results presented here used naïve assessors.

Characterization of Coating Color Penetration by Laser Scanning Microscopy

塗工層の品質や塗工の効率性は，支持体への塗料沈み込みによって大きく左右されるが，塗料沈み込みを調査する手法は限定されている。共焦点蛍光顕微鏡（CLSM）と画像処理を組み合わせることにより，非破壊で塗工層が分析可能な手法の開発を試みた。塗工層厚みの測定に関し，従来手法の走査型電子顕微鏡（SEM）と本手法を比較した結果，両者の傾向は一致し，本手法の有意性が確認された。また，本手法では塗料中に蛍光染料を添加することにより，水系成分の原紙への浸透が分析可能であることが示唆された。

Apical leakage of root canal system obturation materials

Hermetical obturation on dentine-cement junction is one of the conditions for success in endodontic treatment. The aim of this paper was to evaluate apical obturation of three different root canal obturation materials. Methods consisted of in vitro semiquantitatively measured penetration of colored solutions. Total number of 55 single-canal teeth was used and obturation test materials were AH-plus, Ketac-Endo and Endomethasone. Linear color penetration was evaluated following illumination of teeth in 2% sol. Metylsalicilate. Results obtained have shown better adhesion between sealer and root canal walls, i.e. better apical obturation when AH-plus (0.25mm) and Ketac-Endo (0.52mm) were used and highest rate of apical leakage when Endomethasone was used (2.35mm). None of the tested obturation materials have sealed apical portion completely.

The carbon dioxide laser as an aid in apicoectomy: an in vitro study.

To achieve the required goal of optimally sealing the apical section and the root-canal when performing an apicoectomy, the authors decided to use the CO2 laser as an additional aid. The CO2 laser has previously shown to have an excellent sealing effect on dentin surfaces. In this in vitro study, the authors examined the effects of CO2 laser application in apicoectomies with the help of color penetration tests and scanning electron microscopic (SEM) examinations. Sections and root canals were irradiated with low power (0.5 W) in continuous wave mode for totally 20 sec. The thermal stress for the adjacent tissues attaching thereto is moderate as shown by infrared-spectroscopy. A comparison with nonirradiated samples revealed that CO2 laser irradiation reduced color penetration at the section to a minimum. Also, irradiation of the root-canal wall resulted in satisfactory sealing of the surface. These findings were supported by the results of the SEM examinations. CO2 laser treatment optimally prepares the tooth for final intraoperative filling because of sealing of the dentinal tubules, the resultant elimination of niches for bacteria and the sterilizing effect of the laser.