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Article
Monitoring and Instantaneous Evaluation of Composite Resin Linear Shrinkage with Computerized Topography

Author: Amer A Sultan
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2013 Volume: 13 Issue: 1 Pages: 102-107
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To measure the linear shrinkage of composite resin by digital image analysis, to evaluate the effect of light curing type on composite resin linear shrinkage, to evaluate the effect of light curing intensity on linear shrinkage of composite resin and to evaluate the linear shrinkage of composite resin after 24 hours. Materials and method: images of composite samples were obtained before curing. The samples were cured with four types of light curing units, halogen light curing unit 420 mW/cm2, LED light curing unit 420 mW/cm2, halogen light curing 300 mW/cm2 and LED light curing unit 300 mW/cm2. the curing time was 40 seconds. After curing, the cured composite surface was exposed to the microscope allowing the attached camera to capture an image. The samples were then stored in 37 degree centigrade incubator for 24 hours and another image for each sample, was obtained. The images were analyzed via specially prepared image analysis program and the linear shrinkage was measured.Results: Regarding the type of LCUs, statistical analysis showed that composite samples cured with QTH LCUs exhibit significantly higher linear shrinkage values than those cured with LED LCUs. While regarding the intensity of the curing light, it was shown that LCUs with higher curing light in-tensities produce a significant higher values of linear shrinkage. Conclusion: The type and the intensity of the light curing unit play a major role in the end result linear shrinkage of the cured composite resin. Image analysis system is an excellent method to determine linear shrinkage.


Article
Evaluation of the Surface Roughness for Three Different Types of Composite Resin Materials Using (Sof–Lex) Finishing and Polishing Systems: A Comparative Study

Author: Sabah A Ismail
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2013 Volume: 13 Issue: 2 Pages: 221-227
Publisher: Mosul University جامعة الموصل

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Abstract

Aim: To evaluate the surface roughness of three different types of light activated composite resin using (Sof-Lex) – polishing system, a profilometer study. Materials and Methods: A total of 30 resin com-posite disks were prepared from three different types of composite resin include 3 – groups. Group I: 10 specimens were prepared from light activated nano hybride (Tetric n – Ceram, Ivoclar – Vivadent – Liechtenstein). Group II: 10 specimens were prepared from light activated microhybride composite resin (Arabesk – Voco, Germany). Group III: 10 specimens were prepared from light activated poly-glas composite resin (Solitaire – 2, Heraeus, Kulzer, Germany). The resin blocks finished and polished using (Sof – Lex) polishing system. The specimens were analyzed for surface roughness using “Pro-filometer”. Results: Tetric n – Ceram composite resin showed the lowest roughness average (0.112 μm) followed by Arabesk composite (0.150 μm), Solitaire – 2 composite resin showed the highest roughness average (0.341 μm). Conclusions: Tetric n– Ceram (nano-hybride) was the best polished composite resin, showed the least roughness average.


Article
The evaluation of amalgam and composite restorations in Mosul private clinics

Author: Moataz Gh Al–Shaekh Ali
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2004 Volume: 4 Issue: 2 Pages: 113-118
Publisher: Mosul University جامعة الموصل

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Abstract

The aim of this study was to evaluate amalgam and composite resin restorations work in private practice in Mosul City. A list of dentist practicing in private clinics was obtained from the Iraqi Dental Association in Mosul City. One hundred sixty dentists involved in the questionnaire were selected randomly from a total of 200 dentists in the list supplied. The questionnaire concerned with the step–by–step restorative treatment including diagnosis and case selection, cavity preparation, types of liners and bases used, amalgam restoration and direct esthetic restorations. The results revealed that 100% of the respondents perform restorative dental therapy in their private clinics. The results also revealed an evaluation (as percentage) for most of steps concerned with direct restorative techniques.


Article
The Effect of Curing Time on Fluoride Release from Composite Resin Material

Authors: Amer A. Taqa --- Manal A. Sultan
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2008 Volume: 8 Issue: 2 Pages: 255-258
Publisher: Mosul University جامعة الموصل

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Abstract

Aim: This study aims to measure the amount of fluoride release in deionized water from two composite resins materials (Kerr and Tetric ceram)over period of one month. By using different curing time forcuring the composite.Materials and Methods : Two types of composite resin materials were used. They are Tetric ceram and Kerr composite resins divided into five groups for each type of materialsused, each group contain ten sample materials and cured with different time of curing which are(20,30,40,50,60) seconds.The samples measured fluoride release after storing in 5ml of deionized waterthen incubated incubator at 37°C for 24 hours.Results: The amount of fluoride release was affected by the period of curing time. The materials which cured at (20,30,40) seconds gave high amount of fluoriderelease while the materials which cured at (50,60)seconds gave low amount of fluoride release. Conclusions: The amount of fluoride release from composite resins materials were affected by curing time. There is an increase in the amount of fluoride release by decreasing the period of curing time and decreasing by increasing the period of curing time.


Article
Measurement of water sorption of five different composite resin materials

Author: Waleed M. Khalil وليد خليل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 3 Pages: 37-41
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Water sorption may affect composite resin materials by reducing their mechanical properties and wear resistance .The aim of this study is to measure the water sorption of five different composite resin materials, for different time intervals.Materials and methods: A stainless steel mold of 4 mm width, 8 mm length and 4 mm depth was constructed to form composite blocks. Seven blocks were made of each test resin composite material. All specimens were placed in a silica-gel desiccator for 48 hours. The samples were then weighed thrice using calibrated electronic microbalance, the average reading was recorded to the nearest 0.0001g. The specimens were kept in individual containers in deionized distilled water at 37 ºC.All specimens were periodically weighed. The weight measurements were taken at 2, 8, 14, 28,42,56,70,100,150 and 240 days intervals.Results: The statistical analysis of the results showed that all composite resin specimens continued to gain weight for a period of 28 days. After that period, the weight gain continued, although at a reduced rate. The changes after the 28 days period were small for the Herculite XRV, Tetric ceram and Tetric composite resins, and greater for the Filtek P60 and Composan LCM composite resins.Conclusion: In this study water absorption increased steadily for all materials. The percentage weight change showed a tendency to increase with the time of water storage. This study concludes that over a period of 8 months, the differences in water sorption capacity of the five composite resin materials are related to the differences in the amount of filler loading in the composite resin matrix. With one exception, the composite resin materials with the largest quantity of fillers had the least water sorption capacity after eight months of storage in water


Article
Temperature rise beneath a light–cured materials using two types of curing machines

Authors: Abdul–Haq A Suliman --- Sabah A Ismail
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2006 Volume: 6 Issue: 1 Pages: 20-25
Publisher: Mosul University جامعة الموصل

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Abstract

Aim: To measure the temperature rise induced by a light emitting diode (LED) curing unit and byquartz tungsten halogen (QTH) curing unit using two types of composite resin XRV Herculite andVenus. Materials and Methods: Forty extracted non–carious single canal premolars were cleaned andbisected longitudinally. Class V preparations were cut on the buccal surfaces. The teeth were dividedinto four groups; each of ten. The teeth in the first and second groups were restored with XR–Herculitecomposite resin. The teeth in the third and fourth groups were restored with Venus composite resin.The composite resin in the first and third groups were polymerized using QTH curing unit “Astralis”for 40 seconds; the light intensity was 502 mW/cm2. The distance between the tip of the light and thecomposite was 3 + 1 mm. The composite resin in the second and fourth groups was polymerized usingLEDs “Ultra–Lite 200 E plus” curing unit for 20 seconds; the light intensity was 536 mW/cm2 usingthe same distance as the first and third groups. The temperature rise at the pulpal wall was recorded byplacing a thermocouple on the pulpal wall directly under the restoration. Results: The lowesttemperature rise during LED irradiation with Venus composite resin followed by LED irradiation withXRV Herculite composite resin. Whereas QTH curing units with XRV Herculite composite resinproduced higher values, QTH curing units with Venus composite resin produced the highesttemperature rise. Conclusion: The temperature rise of LED curing units and QTH curing units used inthis study was under the limits that affect the integrity of the dental pulp.


Article
Evaluation of surface roughness of composite according to surface treatment

Author: Sabah A Ismail
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2005 Volume: 5 Issue: 2 Pages: 174-179
Publisher: Mosul University جامعة الموصل

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Abstract

The purpose of this study was to evaluate the effect ofvarious finishing and polishing procedures on the surface roughness(Ra) of two composite resins: An organically modifiedceramic (Definite) and a micro hybrid (Tetric).Thirty specimens of each composite resin were fabricatedusing a stainless steel mold of 5 mm in diameter and 2 mmin depth. The composite resin was covered by a Mylar stripand pressed flat with a microscopic glass slide and light cured.The specimens for each composite resin were divided intothree groups, each of ten. The specimens in group one receivedno treatment, while the specimens in group two and threewere finished with diamond bur. After finishing with diamondburs group three were polished with Sof–Lex discs.The surface profile of the specimens was obtained with asurface profile–testing machine (Profilometer). The roughnessvalue in micrometer (μm) was recorded as the average Ra.Results showed higher surface roughness in groups finishedwith diamond burs followed by groups finished with diamondburs and polished with Sof–Lex discs while groups setagainst Mylar strip showed the lowest roughness values. Theresult revealed no significant difference in surface roughnessvalues between the two composite resins.


Article
Water sorption of light–cured composites

Author: Ammar Kh Al–Nori
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2005 Volume: 5 Issue: 1 Pages: 1-5
Publisher: Mosul University جامعة الموصل

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The aim of the present research was to study the percentagewater sorption and solubility of Esthet compositeresin based on an ethoxylated bisphenol A glycol dimethacrylate(Bis–EMA) and Heliomolar composite resin basedon bisphenol A glycol dimethacrylate (Bis–GMA). Six specimenswere prepared for each material using aluminum disc 15mm in diameter and 1 mm in thickness between two glassslides; then they were light cured for 80 seconds on each side.Percentage water sorption and solubility were measured afterone week and one month. The results showed that water sorptionafter 1 week for Esthet composite and Heliomolar compositewere 0.433 and 1.12, respectively and solubility were0.074 and 1.066, respectively; while water sorption after 1month were 0.517 and 2.57, respectively and solubility were0.176 and 2.689, respectively.It could be concluded that the percentage sorption andsolubility of composite based on Bis–EMA were significantlylower than that based on Bis–GMA.


Article
The effect of storage on shear bond strength of three composite resins to dentin

Author: Sabah A Ismail
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2005 Volume: 5 Issue: 1 Pages: 75-82
Publisher: Mosul University جامعة الموصل

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The aim of this study was to determine the effect of storagetime on shear bond strength of three composite resin, twoutilize total etch technique and one utilize self etching bondingagent.One hundred twenty maxillary and mandibular molarswere used in this study. The teeth were prepared by cutting theocclusal enamel with diamond bur to expose dentin and groundwet with silicone carbide papers. The specimens were thendivided into three groups and stored in distilled water.Scotchbond Multipurpose Plus was used in the first groupand a stainless steel round mould, with a central hole of 4mm in diameter and 2 mm in height was used to build up thecomposite Z100. The composite resin was inserted in two increments,each one was light cured for 40 seconds. This gro-upis divided into four subgroups each of ten according to thestorage time (one day, fifteen days, three months and six months)then stored in distilled water accordingly.The same procedure was repeated in the second and thirdgroups. The composite used in the second group was Tetricwith Excite bonding agent. In the third group, Definite compositeand its bonding agent Etch and Prime was used.The bond strength was measured and the data were statisticallyanalyzed. Z100 composite had the greatest shear bondstrength followed by Tetric and Definite. One day and fifteendays storage time for all types of composite had greater shearbond strength than the three months and six months storagetime.In conclusion there was a gradual decrease in bond strengthwith increased storage time up to six months irrespectiveof the type of composite.


Article
The effect of drinking yogurt on the microhardness of posterior composites resin

Author: Dr. Saif Alarab A. Mohmmed,B.D.S.,M.Sc.
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2011 Volume: 8 Issue: 2 Pages: 93-99
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Background :This study was conducted to evaluate the effect of yogurt on thesurface microhardness of two types of composite resins; (Filtek™ P90 Low ShrinkPosterior Restorative, 3M ESPE,USA), and (Filtek™ Z350 Posterior Restorative, 3MESPE,USA).Forty samples of composite were prepared by using cylindrical mold (2mm inhight and 8mm in diameter )..All specimens were stored in plastic container thatcontain distilled water and incubated 37cº for 24 hours before they were tested. twentysamples of each type of composite were divided into two groups (10) for each ,baseline measurements for surface microhardness test was taken for all compositesamples using the micromet microhardness tester (Vichers hardness tester) with al00g load was applied for 15 seconds in which three indentations were made for eachsample and converted into Vickers Hardness Number (VHN ) .After baselinemeasurement 10 samples of each type of composite were alternately immersedmanually by holding the specimen by a pair of tweezers from its sides, , in drinkingyogurt (Activia ,KSA) and artificial saliva for 10 cycles 5 seconds each at roomtemperature (25cº). This was repeated three times a day (8am,4pm,12am) at 8hoursintervals for one week. the other 10 samples for each type of composite wereimmersed in artificial saliva only. The total soaking time in both drinking yogurt andsaliva was 100 seconds. After the soaking sequence was completed the specimen wasrinsed with distilled water and subjected to surface microhardness test (Vichershardness tester).Descriptive statistics(mean values and standard deviations with the minimum andmaximum values and Statistical analysis of data by using student t - test for all groupswas carried out between the means of each type of composites ,the results showed asignificant reduction in VHN values (at P<0.05)of Filtek™ Z350 PosteriorRestorative composites after immersion in artificial saliva, while the (Filtek™ Z350Posterior Restorative, 3M ESPE) composite showed a highly significant reduction inVHN values (at P<0.01)after immersion in drinking yogurt. Filtek™ P90 Low ShrinkPosterior Restorative composites showed a non significant reduction in VHN values(at P>0.05) after immersion in artificial saliva and after immersion in drinking yogurt.Filtek™ P90 Low Shrink Posterior Restorative composites have highest VHNvalue than Filtek™ Z350 Posterior Restorative composites, and surface microhardnessresults showed that drinking yogurt highly significantly effect on the Filtek™ Z350Posterior Restorative composites while it has non significant effect on the Filtek™P90 Low Shrink Posterior Restorative composite

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