The papaya leaf has many biochemical components such as glycoside, proteins, polyphenol, alkaloid, flavonoid, fatty acid, phytosterol, triglyceride, etc. They have the different chemical, physical and biological characters. The fixed material and processing, preparation methods influence strongly to proteins, sugar, polyphenol and flavonoid content and their antioxidation character
Peroxides ; blood

No abstract available.
Animals ; Lipid Peroxides ; Mice* ; Skin*

In clinic, esthetic restoration of a defective natural tooth with composite resin is challenging procedure and needs complete understanding of the color of tooth itself and materials used. The optical characteristics of the composites are different because the chemical compositions and microstructures are not same. This review provided basic knowledge of the color and the color measurement devices, and analyze the color of the natural tooth. Further, the accuracy of the shade tab, color of the composite resins before and after curing, effect of the water, food and bleaching agent, and translucency, opalescence, and fluorescence effects were evaluated.
Composite Resins ; Fluorescence ; Peroxides ; Tooth ; Urea ; Water

This clinical study evaluated the whitening effect and safety of polymer based-pen type BlancTis Forte (NIBEC) containing 8.3% carbamide peroxide. Twenty volunteers used the BlancTis Forte whitening agent for 2 hours twice a day for 4 weeks. As a control, Whitening Effect Pen (LG) containing 3% hydrogen peroxide was used by 20 volunteers using the same protocol. The change in shade (DeltaE*, color difference) was measured using Shadepilot(TM) (DeguDent) before, during, and after bleaching (2 weeks, 4 weeks, and post-bleaching 4 weeks). A clinical examination for any side effects (tooth hypersensitivity or soft tissue complications) was also performed at each check-up. The following results were obtained. 1. Both the experimental and control groups displayed a noticeable change in shade (DeltaE) of over 2. No significant differences were found between the two groups (p > 0.05), implying that the two agents have a similar whitening effect. 2. The whitening effect was mainly due to changes in a and b values rather than in L value (brightness). The experimental group showed a significantly higher change in b value, thus yellow shade, than the control (p < 0.05). 3. None of the participants complained of tooth hypersensitivity or soft tissue complications, confirming the safety of both whitening agents.
Bleaching Agents ; Hydrogen Peroxide ; Hypersensitivity ; Peroxides ; Polymers ; Tooth ; Urea

This study investigated the clinical effectiveness and safety of sealed bleaching compared to conventional in-office bleaching using a randomized clinical trial of split arch design. Ten participants received a chairside bleaching treatment on the upper anterior teeth, and each side was randomly designated as sealed or control side. A mixture of Brite powder (PacDent, Walnut, USA), 3% hydrogen peroxide and carbamide peroxide (KoolWhite, PacDent, Walnut, USA) were used as bleaching agent. The control side was unwrapped and the experimental side was covered with a linear low density polyethylene (LLDPE) wrap for sealed bleaching. The bleaching gel was light activated for 1 hour. The tooth shades were evaluated before treatment, after treatment, and at one week check up by means of a visual shade (VS) assessment using a value oriented shade guide and a computer assisted shade assessment using a spectrophotometer (SP). The data were analyzed by paired t-test. In the control and sealed groups, the visual shade scores after bleaching treatment and at check up showed statistically significant difference from the preoperative shade scores (p < .05). The shade scores of the sealed group were significantly lighter than the control immediately after bleaching and at the check-up appointment (p < 0.05). Compared to prebleaching status, the DeltaE values at post-bleaching condition were 4.35 +/- 1.38 and 5.08 +/- 1.34 for the control and sealed groups, respectively. The DeltaE values at check up were 3.73 +/- 1.95 and 4.38 +/- 2.08 for the control and sealed groups. DeltaE values were greater for the sealed group both after bleaching (p < .05) and at check up (p < .05). In conclusion, both DeltaE and shade score changes were greater for the sealed bleaching group than the conventional bleaching group, effectively demonstrating the improvement of effectiveness through sealing.
Hydrogen Peroxide ; Juglans ; Light ; Peroxides ; Polyethylene ; Tooth ; Urea

OBJECTIVETo evaluate the clinical efficacy of a combined in-office cold light bleaching and night-guard vital bleaching (NGVB) system for treating tetracycline stained teeth (TST).

METHODS90 patients with light, medium and heavy TST were randomly and evenly divided into 3 groups. 30 patients with 472 TST from the treatment group were treated with in-office cold light bleaching and NGVB, 30 patients with 466 TST from the control group 1 were treated with in-office cold light bleaching and 30 patients with 469 TST from control group 2 were treated with NGVB. At the time of treatment completion, after half a year and after one year, Vitalescence esthetic restorative masters shade guide was used to record the change of color. Bleaching efficacy and course of treatment were calculated, and lightening stability were evaluated.

RESULTS1) Three groups had satisfied lightening efficacy for light TST with 100% bleaching efficacy. The overall efficacy of treatment group and control group 2 were superior to the in-office cold light bleaching system (P < 0.05). Though there was no significant lightening efficacy difference between the treatment group and control group 2 (P > 0.05), the periods of treatment of the treatment group for light, medium and heavy TST were shortened by 43%, 46% and 49%, respectively, compared to the control group 2. 2) All three groups' treatment efficacy for light, medium and heavy TST became weaker progressively (P < 0.05). 3) For the treatment efficacy between the time of treatment completion and after half a year and one year, there was significant statistical difference (P < 0.01) for the control group 1, while there was no significant difference for both the treatment group and the control group 2 (P > 0.05). Both treatment group and control group 2 had better performance in treatment stability than control group 1.

CONCLUSIONIn treating the light and medium tetracycline stained teeth, the combined in-office cold light bleaching and NGVB system can achieve a more satisfied whitening result in much shorter period, and significantly enhance the long term whitening stability.

OBJECTIVETo evaluate the effect of bleaching agents on the color of indirect and direct composite resins.

METHODSFive resin composite materials were tested in this in vitro study. The five composites were as follow: two indirect composite resins (Adoro SR, Ceramage) and three direct composite resins (Filtek Z350, Clearfil Majesty Esthetic, and Gradia Direct Anterior). For each material, twenty disk-shaped specimens were prepared and randomly divided into five groups according to the color parameters of specimens before bleaching treatment. The composite resin specimens were treated by one of five sample solutions which were at-home bleaching agents (10% and 15% carbarmide peroxide), in- office bleaching agents (38% H(2)O(2) and 35%H(2)O(2)) and deionized water (control group). The color parameters of specimens were measured by spectrophotometer at baseline and after bleaching treatments. The color differences (ΔE values) between baseline and post-treatments were calculated. The data of color differences were evaluated statistically using two-way analysis with a significance level of 0.05.

RESULTSThe color changes of the resin composites were less than 2.0 after bleaching agent treatment, therefore were not perceptible. Slight increase of L(*) values and decrease of C(*)ab values in color parameters of specimens were observed. There were statistically significant differences in ΔE values for different bleaching treatments and resin materials (P = 0.001).

CONCLUSIONSThe bleaching agents did not affect the color of indirect and direct composite resins tested.

STATEMENT OF PROBLEM: There is a reduction of dentin bonding strength when the bonding procedure is carried out immediately after bleaching with peroxides. PURPOSE: The aim of this study is to evaluate a proper time interval for in-office bleaching technique using 35% hydrogen peroxide. MATERIAL AND METHODS: Fifty extracted non-caries human third molars were used in this study. Buccal enamel of each tooth was removed and polished by 600 grits silicone carbide paper. They were randomly divided into five groups and bleached 35% hydrogen peroxide except control group. All groups were bonded with Single Bond/Z 350 after each time intervals ; Group-A: control, no bleaching treatment. Group-B: resin bonding immediately after bleaching. Group-C: resin bonding 1day after bleaching. Group-D: resin bonding 2 days after bleaching. Group-E: resin bonding 7days after bleaching. Shear bond strengths were measured with a cross-head speed of 1.0 mm/min using an Instron machine. The data of results were statistically analyzed by analysis of variance (ANOVA) and Tukey multiple comparison test. (P = .05) RESULTS: There were significant decreases in mean shear strength in immediately bonding group after bleaching. The reduction of bond strengths was 78% compared with the group of no bleaching treatment. Group C showed the recovery of 51%, and Group D showed recovery of 63%. Both of them have no statistical difference with non-bleaching group. Group E showed no statistical difference with no bleaching treatment group. CONCLUSION: Dentin bonding strength is significantly reduced when bonding is performed immediately after bleaching for in-office bleaching regimens using 35% hydrogen peroxide, and increases as time goes by. One week of elapsed time between bleaching and resin bonding significantly increases bonding strengths for the in-office bleaching technique.
Dental Enamel ; Dentin ; Humans ; Hydrogen Peroxide ; Molar, Third ; Peroxides ; Shear Strength ; Silicones ; Tooth

OBJECTIVES: To evaluate the accuracy of the Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigants, such as saline, 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine liquid, 2% chlorhexidine gel, and RC-Prep, and also to determine the electrical conductivities of these endodontic irrigants. MATERIALS AND METHODS: A root perforation was simulated on twenty freshly extracted teeth by means of a small perforation made on the proximal surface of the root at 4 mm from the anatomic apex. Root ZX was used to locate root perforation and measure the electronic working lengths. The results obtained were compared with the actual working length (AWL) and the actual location of perforations (AP), allowing tolerances of 0.5 or 1.0 mm. Measurements within these limits were considered as acceptable. Chi-square test or the Fisher's exact test was used to evaluate significance. Electrical conductivities of each irrigant were also measured with an electrical conductivity tester. RESULTS: The accuracies of the Root ZX in perforated teeth were significantly different between liquid types (saline, NaOCl) and gel types (chlorhexidine gel, RC-Prep). The accuracies of electronic working lengths in perforated teeth were higher in gel types than in liquid types. The accuracy in locating root perforation was higher in liquid types than gel types. 5.25% NaOCl had the highest electrical conductivity, whereas 2% chlorhexidine gel and RC-Prep gel had the lowest electrical conductivities among the five irrigants. CONCLUSIONS: Different canal irrigants with different electrical conductivities may affect the accuracy of the Root ZX in perforated teeth.
Chlorhexidine ; Edetic Acid ; Electric Conductivity ; Electronics ; Electrons ; Peroxides ; Root Canal Irrigants ; Sodium Hypochlorite ; Tooth ; Urea ; Waxes

PURPOSE: To compare clinical outcomes of a 2.2 mm microcoaxial cataract surgery, using torsional mode and longitudinal mode. METHODS: In this comparative study, patients with bilateral cataract were assigned to get microcoaxial cataract surgery by torsional mode of infiniti in one eye and longitudinal mode of Stellaris(R) in the other eye. Primary outcome measures were US time (UST), cumulative dissipated energy (CDE), mean amount of balanced salt solution (BSS) used and surgical complications. Patients were seen 1, 7, 30, and 60 days after surgery. Postoperative outcome measures were the final best corrected visual acuity (BCVA), central corneal thickness (CCT), endothelial cell count and surgically induced astigmatism (SIA). RESULTS: The study evaluated 68 eyes of 34 patients (nuclear opalescence (NO)2: 40 eyes, and NO3: 28 eyes). CDE was significantly lower in torsional mode (3.52 +/- 2.93) than in longitudinal mode (6.20 +/- 3.32) (p = 0.001). Torsional mode (60.88 +/- 21.18 ml) had more BSS use than longitudinal mode (34.58 +/- 13.54 ml) (p < 0.001). There were no significant differences in postoperative BCVA, CCT change, endothelial change, and SIA (p > 0.05). CONCLUSIONS: The torsional mode may provide lower level of phacoemulsification energy than the longitudinal mode and Torsional mode is considered effective and safe phacoemulsification. However the surgical outcomes were not significantly different in 2.2 mm microcoaxial cataract surgery of moderate cataract. So surgeon can choose any phaco machine based on experience and preference.
Astigmatism ; Cataract ; Endothelial Cells ; Eye ; Humans ; Outcome Assessment (Health Care) ; Peroxides ; Phacoemulsification* ; Urea ; Visual Acuity