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Article
Effect of Type of Light Curing Unit on Shear Bond Strength of Resin Composite

Author: Kasim A Mohammad
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 3 Pages: S10-S17
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To compare the shear bond strength (SBS) of composite bonded to dentin cured by three light curing units (LCUs), which are quartz tungsten halogen (QTH) and two types of light emitting diode (LED) machines. Materials and Methods: Buccal dentin of 90 upper premolars was exposed, prior to restorative procedure. Samples divided into 3 groups, restoration of each group cured by Astralis 5 [Austria], Top Light, [Taiwan] and Ultradent [USA]. Each group further subdivided into three subgroups. After bonding application, each subgroup of every group restored by one of 3 composites: Point 4™, Tetric and Degufill mineral. Composite applied and cured for 40 seconds. Samples thermocycled and loaded at tooth–composite interface. Results: Analysis of variance (ANOVA) with significance p < 0.05 followed by Duncan Multiple Range Test, showed that SBS of subgroups that cured by Ultradent (400 mW/cm2) was significantly higher than Astralis 5 (405 mW/cm2) and Top Light (141 mW/cm2). The SBS of Astralis 5 was significantly higher than Top Light. No significant differences found among subgroups those cured by same LCU. Conclusions: Shear bond strength of resin composite bonded to dentin is directly proportional with the light intensity. However, better result obtained by a high intensity LEDs compared with an equivalent intensity QTH–LCUs.


Article
Effect of etchant type and the use of silane on the shearbond strength of composite resin to porcelain.

Author: Abdulla MWAl-Shamma عبد الله محمد وجيه الشماع
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2011 Volume: 23 Issue: 4 Pages: 1-6
Publisher: Baghdad University جامعة بغداد

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Background: This study was formulated to compare the effect of 5%hydrofluoric acid in comparison to37%phosphoric acid with and without the application of silane on bond strength of composite to porcelain.Materials and Methods: Specimen preparation was divided in to two phases, metal-disks fabrication (8mm-diameterand 4mm-thickness) and ceramic veneering. Thirty two specimens were prepared, sandblasted with 50 μm aluminumoxide, and divided into four groups of eight samples. Groups I and III were etched with 37%phosphoric acid whilegroups II and IV were etched with 5%hydrofluoric acid; and groups I and II were silaneted while groups III and IV werenot. Heliobond, and resin composite were applied to each specimen using a plastic transparent split mold (4mmdiameterand 4mm-height). Specimens were stored in distilled water for 24 hours then thermocycled for 100 cycles.Shear bond strength was determined by a Zwick universal machine at a cross-head speed 5 mm/minute.Results: Mean shear bond strength values were 21.02(group I), 23.31(group II), 4.00(group III), and 18.60(group IV).Paired-t revealed that specimens treated with 5%hydrofluoric acid were significantly higher than those treated with37%phosphoric acid regardless the use of silane. The use of silane dramatically enhanced the bond strength ofcomposite resin to porcelain for both acids. All specimens treated with 37%phosphoric acid without silane showedadhesive failure, while those treated with 5%hydrofluoric acid showed mostly cohesive failure within ceramic.Conclusion: Silane improved the shear bond strength of composite to ceramic, and hydrofluoric acid performedgreater bond strength compared to phosphoric acid.


Article
Effects of Curing Modes of Light Emitting Diode on Shear Bond Strength of Resin Composite

Authors: ALi M Rasheed --- Mohammad Gh Hamdoon --- Kasim A Mohammad
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2008 Volume: 8 Issue: 2 Pages: 168-176
Publisher: Mosul University جامعة الموصل

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Abstract

Aim: To evaluated the SBS of three resin composites (Tetric Flow, Tetric and Heliomolar) bonded to dentin and cured by different curing modes utilizing light emitting diode (LED) light curing unit. Materialsand Method: Buccal dentin of 90 upper premolars was expose and Clearfil SE Bond applied and cured prior to restorative procedure. Samples divided into 9 groups (3 groups for each composite type),photoactivation of groups of each composite was carried out using three modes: Continuous (CO: 600 mW/cm2 for 40 s), Soft-Start (SS: 100 mW/cm2 for 10 s + 600 mW/cm2 for 30 s) and Pulse-Delay (PD:100 mW/cm2 for 3 s + 3 min wait + 600 mW/cm2 for 37 s). Samples thermocycled and loaded at toothcomposite interface at 1 mm/min cross head speed until failure. Results: Two-way ANOVA (p < 0.05) followed by Duncan multiple range test revealed that SBS of SS mode (21.5 Kg) is significantly higherthan SBS of both CO (18.1 Kg) and PD (18.7 Kg) and its also revealed that although SBS of Tetric Flow (21.2 Kg) is higher than that of Tetric (20.1 Kg) and both are significantly higher than that of Heliomolar (16.9 Kg).Conclusions: Less material’s rigidity along with slower polymerization reaction by SS mode result in higher SBS due to lesser contraction stress at the adhesive interface


Article
An evaluation of the Effect of Surface Treatment On Amalgam Repair

Authors: Dr. Abdul Karim J. Al-Azzawi, B.D.S., M.Sc. د. عبد الكريم العزاوي --- Dr.Baidaa M. Zaidan, B.D.S., M.Sc. Prof. د. بيداء زيدان
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2008 Volume: 5 Issue: 4 Pages: 341-347
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The purpose of this in vitro study was to evaluate the effect of different surface treatments on shear bond strength of repaired amalgam using two types of amalgam. 120 acrylic blocks (2.7cm diameter by 2.0cm high) were constructed from cold cure resin, each one contained cylindrical hole (7mm diameter by 2mm high) on its circular face that filled with amalgam. The samples were divided into immediate repair group and delayed repair group, which was stored and incubated at 37C0 for one month. After aging the amalgam surface of delayed repair was finished with carbide bur and polished with abrasive rubber cup then divided into three groups according to the surface treatment that include group with out surface treatment, group roughened with diamond bur and the last group was abraded with aluminum oxide (50m) particles size, both immediate and delayed repair were further subdivided according to the type of amalgam used into three subgroups. The repair procedure was done by using a Teflon split mold which containing an opening (3mm diameter by 5mm high) then all the samples were storage and incubated at 37C0 for one week prior to testing.Testing was done by applying shear force at the interface between the initial and repair amalgam with special designed chisel shape rod by using Zwick testing machine at across head speed of 5mm/min.Analysis of the results showed that the shear bond strength in immediate repair were significant higher than of delayed repair and the group roughened with diamond bur is higher than group treated with aluminum oxide and untreated group.The shear bond strength of delayed repair of amalgam is less than that of immediate repair, the surface produced by roughening the samples with a diamond bur will give best strength than the surface treated by aluminum oxide and untreated surface (smooth surface) and the same types of amalgam restorations used in amalgam repair gave better result than different type of amalgam.


Article
Evaluation of the shear bond strength of four orthodontic adhesive systems

Author: Mahmood Kh Ahmed
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 1 Pages: 66-70
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate shear bond strength of four types of orthodontic adhesive systems including two–paste composite (Concise), light–cured composite (Transbond), no–mix composite (Alpha–dent) and light–cured glass ionomer cement (Fuji), and to compare shear bond strength between these four types of orthodontic adhesive systems. Materials and Methods: Forty extracted premolars and forty stainless steel mesh edge–wise brackets were used. Each type of orthodontic adhesives were used for bonding of ten brackets according to its manufacturer instructions, after setting the brackets were debonded and the shear bond strength were measured using Instron testing machine. Results: Showed that the two–paste composite (Concise) and the light–cured composite (Transbond) gives the highest bond strength, the bond strength of the glass ionomer cement (Fuji) significantly lower than that of Concise and Transbond but it was remained within the accepted level for clinical use, the no–mix composite (Alpha–dent) showed very low shear bond strength which was below the accepted value for clinical application. Conclusions: Concise and Transbond have high bond strength so that it can be used to fix orthodontic attachment in areas subjected to high force. The bond strength of the glass ionomer cement (Fuji) remains within the accepted level for clinical use with the benefit of fluoride release. Also the shear bond strength of the no–mix composite (Alpha–dent) is very low makes it not suitable for clinical use.


Article
Evaluation of shear bond strength of composite to newly condensed and set amalgam by using two adhesive systems.

Authors: Inas AL Rawi B.D.S.M.Sc د. ايناس الراوي --- Ahmmed hammed B.D.S.M.Sc د. احمد حامد
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2005 Volume: 2 Issue: 1 Pages: 130-137
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The introduction of adhesives has created a new opportunity to bond compositeresin to existing amalgam restoration on aesthetically disturbing surfaces. Further more ,the composite laminate would probably improve the restoration .This in vitro study was conducted to evaluate the shear bond strength ofcomposite resin to fresh and set amalgam by the use of two adhesive systems and to studythe effect of water storage time on the shear bond strength of composite resin to fresh andset amalgamOne hundred and eighty cylindrical specimens, 5mm high x 5 mm in diameter ,composed of 3 mm of amalgam and 2 mm of composite with a layer of bonding materialin between were prepared. Syntac Sc, Excite, control (non bonding) used to bondcomposite resin (Tetric) to the amalgam bases in three groups I, Il and lll (each onecomposed of 60 amalgam bases). Each group divided into two minor groups each of 30amalgam bases one for fresh amalgam bases referred (F) and the other one for setamalgam bases referred (S), each minor group, F and S subdivided into 3 subgroupsaccording to water immersion period into 48hrs, lmonth, 3months,stored at 37 C forscheduled period of time .Specimens were therrnocycled and subjected to shear bond strength testing, andthe mode of failure whether adhesive, mixed cohesive were recorded also. Resultsexpressed very highly statistically significant difference in shear bond strength valuesamong the all three groups with the highest shear bond strength mean values (SBS) forthe control group Ill (without bonding agent) with the greatest SBS values to setamalgam subgroups. While for group. I and II (Syntac SC, Excite) showed the highestSBS mean values to fresh amalgam .The Syntac SC bonding agent shows higher SBSmean than excite bonding agent to either fresh or set amalgam. In conclusion, for bothtypes of bonding agents, Syntac SC performed better in bonding composite resin toamalgam than Excite and the water immersion period has an effect on the SBS meanvalues and on the type of mode of failure


Article
Shear bond and rebond strengths of four composite systems

Authors: Hussain A Obaidi (BDS, MSc ** ) د. حسين العبيدي --- Raid Kh Mustafa BDS, MSc د.رائد مصطفى
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2005 Volume: 2 Issue: 2 Pages: 235-243
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

:The orthodontic composite bonding material is available in various systemwhich are chemically—cured composite such as Two—past and No—mix systems in whiclthe composite set by chemical reaction; Light—cured composite system, in whicl:composite set by light exposure; and Dual—cured composite system, by which thcomposite cured by chemical reaction and light exposure. Thus it is necessary tt.investigate and compare the commonly used composite bonding systemsThis study was aimed to determine and compare the shear bond and reboncstrength of: Two—past composite system (Concise, 3M, Unitek USA), No—mix composite,system (Right—On, TP Orthodontics UK), Light—cured composite system (Transbond XT.)M Unitek USA), and Dual—cured composite system (Sono—Cem ESPE, Germany3,Fifty six upper premolars were divided into four groups of fourteen, each groupmesh—backed metal advant edge brackets were bonded to the buccal surface ofthe teethusing one of the composite system according to the instruction of manufacturer. Then.bonded samples were thermocycled in an attempt to simulate oral circumstancesThe samples were subjected to shear force using the universal compressionmachine apparatus, then the results were recorded in Megapascal (Mpa). The remainingcomposite on the buccal surface of the tooth was removed by hand sealer and polished, anew bracket was bonded to the buccal surface of the tooth using the same type ofcomposite system. The rebonded samples were tested under shear strength using the.universal compression machine apparatus and the results were again recorded in Mpa,The data were statistically analyzed using descriptive analysis, ANOVA test.Dtu1can’s Multiple Range Test and Student’s t—test at p g 0.0lThe results showed that the Concise had no significant higher bond shear strengththan the Transbond and Sono—Cem composite systems, and there was signilicant increasebond strength of the Concise than the Right—On composite systems. Furthermore, therewere no significant differences in bond shear strength among the Right—On, Transbond.and Sono—Cem composite systemsThe shear rebond strength of composite systems was decreased, and there were The shear rebond strength of composite systems was decreased, and there were no.significant differences in bond and rebond shear strength of each composite systemConclusions of this study are that Concise has the higher shear bond strength but.has highest regression in its rebond shear strength


Article
Shear Bond Strength of Chemical and Light Cured Glass Ionomer Cements Bonded to Resin Composite

Authors: Sabah A. Ismail صباح عبد الوهاب اسماعيل --- Shaymaa SH. Hassan شيماء شاكر حسن
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2012 Volume: 1 Issue: 2 Pages: 27-32
Publisher: Tikrit University جامعة تكريت

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The purpose of this study was to compare the shear bond strength of chemically cured (Conventional) glass ionomer cement and light cured (Resin modified) glass ionomer cement to resin composite and to evaluate the effect of acid etching of the glass ionomer cements on the shear bond strength.Forty acrylic molds were prepared, a hole (6×2) mm was prepared in each mold to retain the glass ionomer cements (GICs). The samples were divided into two main groups. The first group were filled with Conventional GIC and the second group were filled with Resin modified glass ionomer cement (RMGIC), then each group were subdivided into two subgroups, the first subgroup were acid etched and the second subgroup were left without etching. The bonding agent applied to the demarcated bond area on the GIC surface, the composite resin cylinders were built up over the GIC base. The samples were stored for one week in deionized water then thermocycled. The samples then tested for shear bond strength (SBS) using universal testing machine.The result shows that Independent samples T-test used for statistical analysis. The result showed that RMGIC significantly had higher SBS than conventional GIC. No statistical difference was shown in SBS between subgroup etched and without etching for RMGIC, but the conventional GIC showed significantly higher SBS in subgroup without etching than with etching.This study Conclude that the SBS of RMGIC to resin composite was significantly higher than that of conventional GIC. Acid etching the GIC surface did not improve the SBS of GICs to resin composite.


Article
Flowable Composite for Orthodontic Bracket Bonding (in vitro study)

Author: Bahn G. Agha بان غانم اغا
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2012 Volume: 1 Issue: 2 Pages: 44-50
Publisher: Tikrit University جامعة تكريت

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Abstract

Flowable resin composites have been recommended for many clinical uses and have been formulated in a variety of compositions and viscosities to meet various uses. The aim of this study was to determine if flowable composite with or without resins could be used as orthodontic bracket bonding. Sixty noncarious human premolars were divided into three equal groups. Metal brackets were bonded to etched enamel using a composite resin control (Resilience® orthodontic adhesive) and flowable composite with and without sealant resin (Resilience® flowable composite). After 72 hours of incubation in deionized water at 37 C°, debonding was performed with a shearing force. The shear bond strength (SBS) and the mode of bond failure were examined. High significant difference was observed in the SBS between control and flowable groups. Clinically acceptable SBS was found for the two flowable adhesives with bond failures occurred mostly in the bracket–adhesive interface. No significant differences between flowable groups. In conclusion, the use of flowable composite with and without sealant resin is advocated for orthodontic bracket bonding.


Article
Effect of glass fiber reinforcement surface treatment on the soft liner retention and longevity

Authors: Inas Abdul-Sattar ايناس عبد الستار --- Nabeel Abdul-Fattah نبيل عبد الفتاح هاطور
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 3 Pages: 8-12
Publisher: Baghdad University جامعة بغداد

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Background: Denture liners have been used in dentistry for many years. Soft denture liner is one of the denture linerswhich used to enhance the fit of poor fitting dentures and prevent trauma to sensitive mucosa. One of thedisadvantages of the soft denture liner is the frequent debonding from the denture during clinical use thus reducingthe longevity of such prosthesis. Glass fibers integrated at or on the fitting surface of the denture used to improve thebonding of the silicone soft liner to the acrylic surface.Materials and methods: the shear bond strength calculated to evaluate the effect of the glass fiber surfacetreatment on the bonding between the acrylic surface and the silicon soft liner. 120 samples were prepared anddivided into 3 major groups: Group I for the conventional heat cure acrylic, Group II for the pour acrylic and Group IIIfor the light cure acrylic. Each one of these major groups divided into 2 subgroups, the first one for the Mollosil siliconsoft liner and the second one is for the Molloplast-B silicon soft liner. Each one of these sub groups consist of 2 types ofthe acrylic surface: smooth (control) and glass fiber net surface treatment.Results: this study revealed that some types of the surface treatment exhibited a highly significant improvement in thebonding between the acrylic surface and the soft liner.Conclusion: glass fiber surface treatment could improve the bonding between the acrylic surface and the soft liner

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