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Article
Bleaching effect on surface roughness and microhardness of dentin

Authors: Abdul-haq A SULIMAN --- Neam N YUOSFANI
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2002 Volume: 2 Issue: 3 Pages: 20-26
Publisher: Mosul University جامعة الموصل

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Abstract

The main objectives of this study were to determine the effects of the bleaching solutions on the surface characteristics of dentin namely, microhardness and surface roughness. Sixteen dentin samples were prepared for the measurements. Teeth mounted in an acrylic resin blocks for microhardness measurements and surface roughness. The bleaching was performed by immersion of each sample in (35%) hydrogen peroxide at (37)°C in an incubator for a period of one hour. Vicker'smicrohardness instruments used for microhardness measurements and profilometertesting machine was used to evaluate surface Toughness. Two measurements were taken from each samples one before and the other after bleaching procedure. The data were collected and analyzed using analysis of variance and t-test, The results showed that the microhardness of dentin is greater before bleaching than the mean after bleaching procedures. This indicated that the bleaching solution used in this study reduced the microhardness of the dentin in vitro. There are slight changes in the mean value of the surface roughness of dentin after bleaching, which is statistically not significant.

Keywords

Bleaching --- roughness --- microhardness


Article
The effect of 35% H2O2 and 22%carbamide peroxide on compressive strength of composite resin

Authors: Majida K.W. AL-Hashimi ماجدة الهاشمي --- Aliaa M. Jabbar علياء محمد جبار
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2011 Volume: 23 Issue: 4 Pages: 16-19
Publisher: Baghdad University جامعة بغداد

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Abstract

Back ground: The compressive strength of composite resin may be affected by bleaching agent. This study wasconducted to evaluate the effect of two different bleaching agents; at home (22% carbamide peroxide) and inoffice; light activated (35% hydrogen peroxide) bleaching agent on the compressive strength of light curedcomposite resin; spectrum (submicron hybrid composite).Material and methods: A total number of 20 samples were prepared,10 samples for each type of bleaching agentwhich were divided in to 2 groups; first group was subjected to at-home bleaching for one day. The second groupwas subjected to at-home bleaching for one week, The third group was subjected to the in-office (35% H2O2) for oneday. The forth group was subjected to in-office bleaching for three days.Results: There were statistically significant differences between the tested groups (p=0.048). Highly significantreduction of the compressive strength of composite was observed subsequent to treatment with H2O2 for three times.Conclusion: Reduced compressive strength was detected in composite when it was subjected to bleaching processwith H2O2 carbamide peroxide.


Article
Effect of in-dental clinic bleaching agents on the releases of mercury from the specimen of amalgam restoration in relation to their times intervals

Authors: Afnan AL-Shimmer افنان الشمر --- Mohammad Al-Casey محمد القيسي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 1 Pages: 82-84
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Measuring the effect of bleaching agents on mercury release from dental amalgam is important fromboth restorative and toxicological points view. The aims of the study was to evaluate the effects of two differenttypes of bleaching agents for vital teeth by using with light source on the release of mercury from the specimen ofamalgam restoration .Materials and methods: Fifty three specimen of amalgam restoration, were subject to treated with bleaching agents( 35% hydrogen peroxide and carbamide peroxide ) and then application of light and laser radiation to activate thebleaching agents. Flameless atomic absorption spectrophotometer with Gold Vapor Generator was used tomeasure the release of mercury from the specimen of amalgam restoration.Results: Highly significant increase in the release of release of mercury from the specimen of amalgam restoration inrelation to the times intervals.Conclusions: In this study showed that release of release of mercury from the specimen of amalgam restoration,after treated with both 35% carbamide peroxide and 35% hydrogen peroxide increase with increase the time andcompared with control groups.


Article
Effect of in-dental clinic bleaching agents on the releases of mineral ions from the enamel surfaces in relation to their times intervals

Authors: Afnan AL-Shimmer افنان الشمر --- Mohammad Al-Casey محمد القيسي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 2 Pages: 91-93
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: alterations of the enamel after topical application of bleaching agents, presenting as majorconsequences are: ions release, increased superficial roughness, stronger bacterial attachment and hardnessalteration. The aims of the study were to evaluate the effects of two different types of bleaching agents for vital teethby using with light source on the release of ions (Calcium and phosphate ions) from the enamel surface.Materials and methods: Fifty three sound enamel surface for calcium ions release and Fifty three sound enamel surfaces forphosphate ions, were subject to treated with bleaching agents (35% hydrogen peroxide and carbamide peroxide) andthen application of light and laser radiation to activate the bleaching agents. Spectrophotometer and Buck scientificatomic absorption spectrophotometer were used to measure the ions release from enamel surface.Results: highly significant increase in the release of ions (calcium ions), while significant increase in the release of ions(phosphate ions) in relation to the times intervals.Conclusions: In this study showed that release of calcium ions from enamel surface after treated with both 35%carbamide peroxide and 35% hydrogen peroxide increase with increase the time and compared with release ofphosphate ions release and control groups.


Article
The effect of anti-oxidant agents as neutralizers of bleaching agents on dentin bond strength

Authors: Ayad Mahmoud Al-Bayaty اياد محمود البياتي --- Inas I. Al-Rawi ايناس الراوي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 2 Pages: 18-23
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Reduction in bond strength when bonding was done immediately after intracoronal bleachingprocedure has been recognized. The purpose of this study is to assess the effect of antioxidants (10% sodiumascorbate (SA), 0.1M thiourea and7% sodium bicarbonate (SB)) on reversing bonding strength of compositeresin to bleached dentin.Materials and method: Sixty upper 1st premolar teeth, were selected, the crowns of the teeth were embedded inacrylic resin blocks exposing a flat dentin from the buccal surface, then divided into 6 groups (10 sampleseach). Bleaching for the experimental groups was performed using 35% hydrogen peroxide bleaching gel(pola–office).Group A (Negative control group; dentin samples immediately bonded with composite withoutbleaching)Group B (Positive control group; dentin samples bleached and immediately bonded with composite).Group C (Dentin samples bleached and stored for 14 days in DDW then bonded with composite). Group D (Dentinsamples bleached and treated with 10% (SA) then immediately bonded with composite). Group E (Dentin samplesbleached and treated with 0.1M thiourea then immediately bonded with composite). Group F (Dentin samplesbleached and treated with 7% SB then immediately bonded with composite).The shear bond strength wasdetermine using instron testing machine.Results: Bleaching the dentin with 35 % hydrogen peroxide gel for 24 minutes resulted in reduction in bondstrength of the bleached teeth when bonding was performed immediately after bleaching. Delayedbonding of composite to the bleached dentin for 14 days will result in a highly significant increase in theshear bond strength.Conclusion: Treating the bleached dentin with 10% (SA) in water base showed a highly significant increase inthe shear bond strength of the composite to dentin and reversing the bond strength value to the level of theunbleached dentin. Treating the bleached dentin with 0.1M thiourea significantly increased the shear bondstrength of the composite to dentin

خلال السنوات الماضیھ لاحظ الباحثون النقص الحاصل في قوة الربط القصي عن اجراء اللصق الاني للحشوة الضوئیھ مباشرة بعد عملیة قصر الاسنان داخل التاج 0 الغرض مناجراء ھذا البحث ھو لتقییم تأثیر موادمضادات التأكسد( 10 % اسكوربات الصودیوم ، 0,1 مول ثایویوریا و 7% بیكاربونات الصودیوم) على قدرتھاعلى اعادة الربط القصي لمادة0 والنتائج % الراتنج المركب الى سابق عھدھاقبل عملیة القصر 0 ولھذا الغرض الغرض تم اختیار ستون سن من الضواحك وتم قصرھا بأستخدام بیروكسید الھیدروجین بتركیز 35اثبتت بعد معالجھ عینات العاج المقصورة بمادة 10 % اسكوربیدات الصودیوم نتج عنھ زیادة عالیة في قوة الربط القصي بین مادة الكمبوزیت والعاج واعادة قیمة قوة الالتصاق الىمستوى الالتصاق مع العاج الغیر مقصور 0 احصائیا لم تكن ھناك زیادة ملموسة في قوة الربط القصي بین مادة الكمبوزیت والعاج المقصور عند معالجة عینات العاج المقصورة بمادة%7 بیكاربونات الصودیوم 0


Article
Study of The Adherence of St. mutans on Bleached and Fluoridated Tooth Surfaces. (An In Vitro Study)

Author: Sawsan H Al-Jubori
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2013 Volume: 13 Issue: 25 Pages: 116-121
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate Streptococcus mutans adherence on bleached enamel surface with (7.5% hydrogen peroxide , 16% carbamide peroxide) with or without topical fluoride theraby. Materials and Meth-ods: Sixty specimens obtained from thirty maxillary premolars extracted for orthodontic reasons, cleaned, polished, and examined for any surface structural damage. The roots were discarded and crowns sectioned in two pieces (mesiodistaly) using diamond separating disc in low speed hand piece. The specimens randomly divided into six groups and exposed to one of the bleaching agents (7.5% hydrogen peroxide , 16% carbamide peroxide) with or without topical fluoride application. The nega-tive control group specimens stored in deionized water. The positive control group specimens stored in artificial saliva. Adherence of Streptococcus mutans count to enamel surfaces was determined bacte-riologically. The data analyzed statistically using one way ANOVA and Tukey test (p≤0.05). Results: there is significant increasing in Streptococcus mutans adherence on enamel surface after bleaching procedure, which was decreased significantly when used fluoride application technique after bleach-ing. Conclusions: Topical fluoride therapy has beneficial effect on reducing the Streptococcus mutans adherence on enamel surface after bleaching regimens which attributed in reducing the possibility of dental caries


Article
An Overview on the Effects of 10% and 15% Carbamide Peroxide and its Relationship to Dentine Sensitivity

Author: Suhayla Reda Albanai
Journal: Medical Journal of Babylon مجلة بابل الطبية ISSN: 1812156X 23126760 Year: 2014 Volume: 11 Issue: 2 Pages: 297-310
Publisher: Babylon University جامعة بابل

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Abstract

Tooth bleaching or whitening is not a new technique in dentistry and it is evident from the published literature that the technique has been in use for over one hundred and fifty years . The question concerning the whiteness of teeth is a complex one since tooth whiteness may vary from individual to individual, and is also dependent on the age of the individual and culture etc. Tooth whitening following treatment may also be dependent on the type of whitening system used to whiten the teeth. There are a number of side-effects to this process and these include dentine sensitivity and gingival irritation . Normally these side effects should resolve after approximately 48 hours following treatment although in extreme situations may last for several months. The purpose of this overview was therefore to review the available published literature in order to determine whether there was any evidence that the application of 10% and 15% carbamide peroxide in tooth whitening procedures resulted in tooth (dentine) sensitivity. The conclusions from the review would indicate that tooth whitening with either 10% or 15% carbamide peroxide was an effective and safe treatment under a dental professionals’ supervision following careful diagnosis and treatment planning. Reported side-effects from these studies, namely dentine sensitivity and gingival irritation were considered mild to moderate in nature and were transient in duration. Reported incidences of dentine sensitivity range from 15-65% of patients using 10% carbamide peroxide whereas higher incidences (67-78%) were reported when using hydrogen peroxide in combination with heat.

قصر او تبييض الاسنان ليست تقنية جديدة في مجال طب الاسنان ويتضح من البحوث المنشورة ان هذه التقنية قد تم استخدامها لاكثر من مائة وخمسين عاما بياض الاسنان عملية معقدة بسبب ان بياض الاسنان قد يختلف من من شخص الى آخر ، ويعتمد ايضا على العمر والثقافة .. الخ تبييض الاسنان بعد العلاج ربما يعتمد على نوع نظام التبييض المستخدم لتبييض الاسنان . هناك عدد من الاثار الجانبية لهذه العملية ، منها حساسية الاسنان وتهيج اللثة هذه الاثار الجانبية ينبغي ان تزول عادة بعد حوالي 48 ساعة بعد العلاج رغم انه في الحالات الحادة قد تستمر لعدة اشهر . الغرض من هذا الاستعراض هو تحديد ما اذا كان هناك دليل على ان استخدام 10% و 15% من بيروكسيد كارباميد في عملية تبييض الاسنان تسبب في حساسية طبقة العاج في الاسنان . ان الاستنتاجات من هذا الاستعراض تشير الى ان تبييض الاسنان باستخدام كلا من 10% او 15% من بيروكسيد كارباميد هو علاج فعال وآمن باشراف اطباء الاسنان بعد التشخيص الدقيق والتخطيط للعلاج . الآثار الجانبية التي تم ملاحظتها من هذه الدراسات ، هي حساسية طبقة العاج وتهيج اللثة والتي تعد في طبيعتها خفيفة الى معتدلة وتكون قصيرة الفترة . تم ملاحظة حالات من حساسية طبقة العاج تراوحت نسبتها بين 15 – 65% من المرضى الذين استخدموا 10% من بيروكسيد اليوريا بينما حالات بنسبة اعلى (67 – 78%) عند استخدام بيروكسيد الهدروجين يرافقه حرارة .


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

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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
The Effect of Remineralizing Toothpastes on Enamel Surface Roughness after Hybrid Laser Bleaching (An In vitro Study)

Authors: Bahar Jaafar Selivany --- Fadi Al-Hano
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2015 Volume: 27 Issue: 4 Pages: 1-7
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: one of the complications of power bleaching is surface roughness of enamel which increases thepossibility of post bleaching teeth discoloration. The aim of the present study is to evaluate the effect of toothpastecontaining nano hydroxyapatite, NovaMin and kin sense fluoride on surface roughness of human tooth enamel afterlaser bleaching with 35% hydrogen peroxide bleaching gel.Materials and Methods: Twenty human enamel incisors were cleaned and their labial surface polished up to #1200,then categorized into four equal groups; first group kept without bleaching as a control group, while the remainingthree experimental groups were bleached with 35% hydrogen peroxide, and each group treated with a restorepaste containing one of the following: nano hydroxyapatite, NovaMin, and Kin fluoride. Bleaching was done withlaser hybrid system (DMC Whitening Lase II, Sao Paulo, Brazil). Enamel roughness values assessed by an atomic forcemicroscopy (AA3000, Bosten, USA) before and after treatment with restore tooth paste.Results: Paired t-test used to compare the mean roughness values before and after treatment with each restorepaste. One-way analysis of variance and Duncan post hoc tests used to determine the differences between meanroughness values of the groups. A p-value of 0.05 or less considered a significant. The results showed a highlysignificant statistical differences of remineralization of all types of restore tooth pastes.Conclusions: Nano hydroxyapatite past exhibiting a higher ability to reduce the surface roughness after laserbleaching than other tested pastes.


Article
The effect of bleaching on shear bond strength of resin bonded bridges

Author: Sabah A ISMAIL
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2001 Volume: 1 Issue: SpIss Pages: S291-S298
Publisher: Mosul University جامعة الموصل

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Abstract

Sixty intact upper central and lateral incisors were used in this study the teeth were divided into four groups, the first group was the control group the other groups were bleached with (10%)carbamide peroxide (Opalescence 10%) for two weeks the bleaching material was changed every (8) hours. Sixty discs shaped samples were cast from nickle chromium CB Blando 72 alloy the diameter of each sample was (5) mm and the thickness was (1) mm, the bonding surfaces were sandblasted. The discs were bonded to the teeth in the first and second groups one day after bleaching, the third group was bonded one week after bleaching while the fourth group was bonded two weeks after bleaching. The bonding material used for all groups was Super Bond Crown and Bridge Material. The shear bond strength of the samples was tested. The statistical analysis showed that the second group has the lowest bond strength while the fourth group showed the highest bond strength. This indicates that bleaching affects the bond strength of resin bonded bridges fabricated from CB Blando 72 nickel chromium alloy so that bridges must be fabricated at least two weeks after bleaching.

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