research centers


Search results: Found 2

Listing 1 - 2 of 2
Sort by

Article
Changes in Color and Roughness with Laser Bleaching using different Peroxide Concentrations

Author: Fadi Al Hano
Journal: Journal of Oral and Dental Research مجلة طب الفم والاسنان ISSN: 23106417 Year: 2013 Volume: 1 Issue: 1 Pages: 6-12
Publisher: Iraqi Association for Oral Research الجمعية العراقية لبحوث طب الفم

Loading...
Loading...
Abstract

Purpose: The use of different H2O2 concentrations for in-office bleaching has been questioned. Thus, theaim of this study was to evaluate the efficiency of laser bleaching on color changes and surface roughnessof bovine enamel with different peroxide concentrations. Materials and methods: Forty eight bovine incisors cleaned and labial surface polished up to #1200. Halfof them were artificially stained with black tea and divided into three subgroups and bleached according tothe concentration of H2O2 (15%, 25% and 35% ) (n=8). Specimens were bleached with laser hybrid system(DMC Whitening Lase II, Sao Paulo, Brazil). CIE Lab color system was used to evaluate color using VitaEasyshade Spectrophotometer (Ivoclar Vivadent, Liechtenstien). The remaining specimens were used forsurface roughness evaluation following bleaching. The enamel roughness (Ra) values were measured by StylusProfilometer (Suf-Corder SE 1200, Tokyo, Japan) and Atomic force microscopy (AA3000,Bosten,USA)before and after bleaching. Data were analyzed with Paired sample T-test to evaluate color changes andRa values at each concentration. ANOVA and Tukey test were used to evaluate the difference between thegroups with different bleaching agent concentrations. All tests were computed at 5% significance level. Results: Significant increases in degree of lightness (L*) values observed following bleaching at all concentrations.Different concentrations of peroxide produced significantly different Ra values. Bleachingwith 35% agent produced significantly higher L* value than 15% but similar to 25%. Exposing enamel tohigh peroxide concentration (25% and 35%) significantly increased Ra value in comparison to unbleachedenamel.Conclusion: Color changes and surface roughness of bovine enamel were influenced by hydrogen peroxideconcentrations of DMC laser bleaching system.


Article
In Vitro Evaluation of Shear Bond Strength of Sapphire Brackets after Dental Bleaching

Author: Zainab M. Kadhom زينب موسى كاظم
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2016 Volume: 28 Issue: 1 Pages: 158-163
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Background: The present study was conducted to evaluate the effects of different bleaching methods on the shearbond strength of orthodontic Sapphire brackets bonded to human premolars teeth using light cured composite resinand to determine the predominant site of bond failure.Materials and Methods: Thirty freshly extracted human premolars were selected and randomly divided into threegroups (10 per group). These groups are: control (unbleached) group, hydrogen peroxide group (HP) 37.5% ; which isthe in- office bleaching method group, carbamide peroxide group (CP) 16%; which is the at- home bleachingmethod group. After bleaching process was performed, all the teeth stored in distilled water in a sealed container atroom temperature for 24 hours before bonding was initiated, then orthodontic brackets were bonded with a lightcure composite resin, stored in distilled water at room temperature for another 24 hours before debonding then thebrackets de-bonded and tested for shear bond strength using an Instron universal testing machine. For adhesiveremnant index (ARI) the enamel surface and bracket base of each tooth were inspected under magnifying lens(20X) of a stereomicroscope.Results and Conclusions: Non-statistically significant differences of shear bond strengths were found between thecontrol group and the bleached groups, the dental bleaching in both methods did not affect the SBS of Sapphirebrackets. The mode of failure was mostly between the adhesive and the enamel and the bond failure between thebracket base and the adhesive were also observed

Listing 1 - 2 of 2
Sort by
Narrow your search

Resource type

article (2)


Language

English (2)


Year
From To Submit

2016 (1)

2013 (1)