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Article
An Evaluation of Some Mechanical Properties of Autopolymerizing Acrylic Resin with the Modified One after Changing the Curing Environment: (In vitro Study)

Author: Intisar J. Ismail
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2015 Volume: 27 Issue: 4 Pages: 62-71
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Studying and investigating the transverse strength(Ts), impact strength(Is), hardness (Hr) and surfaceroughness(Ra) of conventional and modified autopolymerizing acrylic resin with different weight percentages ofbiopolymer kraftlignin, after curing in different water temperatures; 40°C and 80°C.Material and Methods: Standard acrylic specimens were fabricated according to ADA specification No.12 fortransverse strength, ISO 179 was used for impact testing, Shore D for hardness and profilometerfor surface roughness.The material lignin first dispersed in the monomer, then the powder PMMA is immediately added. Lignin added indifferent weight percentages. Then cured using pressure pot (Ivomet) in two temperatures;40°C and 80°C under 2bar pressure, for 30 minutes.Atotal of 144samples were prepared for this study. Ts, Is, Ra, and Hr were tested, by usingInstron universal testing machine, charpy impact tester, shore D tester, and profilometer respectively.Results: The transverse strength increased in both the conventional and modified onewhen compared with thatcured in air. The addition of 0.5wt% lignin gave the higher effect (78.0017MPa) with highly significant difference foundbetween groups at 40°C polymerizing temperature. While the impact strength in both temperatures in the modifiedresin revealed increased results than conventional one, 1.25wt% of kraft lignin gave the highest value (12.7355KJ/m2)with highly significant differences found between groups at 80°C polymerizing temperature. Hardness and surfaceroughness showed also highly significant differences found between groups at 40°C polymerizing temperature, allthe groups had increased Hr. than the control one (78.95), while the Ra. decreased for 1.0% ,1.25,1.50 and 1.75 wt%lignin content to (0.26,0.10,0.063, 0.12μm) respectively in 40°C polymerizing temperature, the lowest value present in1.75 wt% lignin (0.05 μm) at 80°Cpolymerizing temperature.Conclusions: It seems that increasing the polymerizing temperature to 40°C had a positive effect on the mechanicalproperties of autopolymerizing acrylic resin and the one enforced by kraft lignin biopolymer in low percentages.Increasing the polymerizing temperature to 80°C will doesn’t have much positive effect but it doesn’t deteriorate themechanical properties. However, when submitted to increasing the temperature to 80°C, specimens showed asignificantincrease in impact strength


Article
Prevalence of torus palatinus and torus mandibularis in a sample of Baghdad population

Authors: Thikra I. Hamad --- Intisar J. Ismail
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2007 Volume: 19 Issue: 1 Pages: 42-46
Publisher: Baghdad University جامعة بغداد

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Abstract

ABSTRACT
Background: Although some oral lesions, such as torus palatinus and torus mandibularis are normal variants, but require prompt diagnosis and sometime treatment to reduce the potential for serious complication and enhance prosthodontic treatment. The purpose of this study is to inspect the prevalence of torus palatinus (TP) and torus mandibularis (TM), with their relations to TMJ dysfunction syndrome.
Material and method: The sample consisted of 932 persons, 301 males and 631 females were examined for the presence of TP and / or TM. Analysis was carried out according to age, gender, TMJ dysfunction and chronic diseases to the presence of TP and TM.
Results: indicated that 49 (5.3%) had TP; where as 67 (7.2) had TM. The male: female prevalence ratios of TP and TM were 1: 3.42 and 1: 1.81 respectively.
Conclusion: TP and TM were more frequent in females and there is significant relation between the TP and TM with presence of TMJ dysfunction syndrome (P< 0.05) especially TM, the presence of TM might be useful to look for sign of dysfunction.
Key words: Torus palatinus (TP), torus mandibularis (TM). (J Bagh Coll Dentistry 2007; 19(1) 42-46)

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Article
Frequency and suppliers of removable partial denturesamong group of Iraqi population

Authors: Basima M.A. Hussein --- Intisar J. Ismail
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2009 Volume: 21 Issue: 2 Pages: 48-53
Publisher: Baghdad University جامعة بغداد

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Abstract

ABSTRACT
Background: Need for dental services is generally considered as the treatment needs detect during oral examination by a dental professional, regardless of whether the patient demands care. If the patient with prosthodontic treatment needs, essks, and receives care, this is effective demand.
Material and method: The potential need for Prosthetic treatment among group of Iraqi subjects were evaluated by analyzing records of 986 patients attended to the dental college seeking for removable partial dentures (RPDs) treatment in both genders and distributed among different age groups.
Results: The results showed significant differences between male and female in different age groups, also highest frequencies of RPDs were found in the female oldest age group, with increase in number of RPDs constructed by progression in age. Regarding the type of kennedy classification of missing areas, it was shown that class III kennedy classification is the most frequent condition is all age groups and in both genders, 50.9% for maxillary arch and 41.0% in the mandibular arch in whole sample. Patients seeked for maxillary and mandibular RPD treatment would be inclined to more frequent (391=39.7%) condition.
Conclusions: Findings showed a strong positive association between frequency of kennedy classification and increase wearing of partial dentures more in maxillary compared with mandibular .
Key words: Partial denture, need and demands (J Bagh Coll Dentistry 2008; 20(2):53-58)

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Article
Frequency and suppliers of removable partial dentures among group of Iraqi population

Authors: Basima M. Ali Hussein --- Intisar J. Ismail
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2008 Volume: 20 Issue: 2 Pages: 53-58
Publisher: Baghdad University جامعة بغداد

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Abstract

ABSTRACT
Background: Need for dental services is generally considered as the treatment needs detect during oral
examination by a dental professional, regardless whether the patient demands care. If the patient with
prosthodontic treatment needs, essks, and receives care, this is effective demand.
Material and method: The potential need for Prosthetic treatment among group of Iraqi subjects were evaluated
by analyzing records of 986 patients attended to the dental college seeking for removable partial dentures (RPDs)
treatment in both sexes and distributed among different age groups.
Results: The results showed significant differences between male and female in different age groups, also highest
frequencies of RPDs were found in the female oldest age group, with increase in number of RPDs constructed by
progression in age. Regarding the type of kennedy classification of missing areas, it was shown that class III kennedy
classification is the most frequent condition is all age groups and in both sexes, 50.9% for upper arch and 41.0% in the
lower arch in whole sample. Patients seeked for upper and lower RPD treatment would be inclined to more frequent
(391=39.7%) condition.
Conclusions: Findings showed a strong positive association between frequency of kennedy classification and
increase wearing of partial dentures more in upper compared with lower .
Key words: Partial denture , need and demands. (J Bagh Coll Dentistry 2009; 21(2):49-54)

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Article
The effect of addition of untreated and oxygen plasma treated polypropylene fibers on some properties of heat cured acrylic resin

Authors: Waffaa I. Mohammed --- Intisar J. Ismail
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 4 Pages: 33-38
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The polymethyl methacrylate is the most reliable material for the construction of complete and partialdentures, despite satisfying esthetic demand itsuffered from having unsatisfactory properties like impact strength andtransverse strength.This study was designed to improve the impact strength and transverse strength of heat cure acrylic resin by addinguntreated and oxygen plasma treated polypropylene fibers and investigate the effect of this additive on someproperties of acrylic resin materials.Materials and methods: Untreated and oxygen plasma treated polypropylene fibers was added to PMMA powderby weight 2.5 %. Specimens were constructed and divided into 5 groups according to the using tests; each groupwas subdivided in to 3 subgroups. The tests conducted were impact strength, transverse strength, surface hardness,surface roughness, water sorption and solubility. Data were analyzed by one way analysis of variance (ANOVA) andleast significant differences (LSD).Results: After incorporation of untreated and oxygen plasma treated polypropylene fibers there was a highlysignificant increase in impact strength and surface hardness; while there was a non significant difference intransverse strength. Also the value of water sorption increase significantly but with the limit of ADA specification.Conclusion:Within the limit of this study it can be concluded that the reinforcement with polypropylene fiberseffective method to increase fracture resistance of denture base; while reinforcement with oxygen plasma treatedpolypropylene fibers further increase fracture resistance


Article
Studying the effect of addition a composite of silanized Nano-Al2O3 and plasma treated polypropylene fibers on some physical and mechanical properties of heat cured PMMA denture base material

Authors: Omar R. Muklif --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2015 Volume: 27 Issue: 3 Pages: 22-27
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. Thematerial is far from ideal in fulfilling the mechanical requirements, like low impact and transverse strength, poorthermal conductivity. The purpose of this study was to evaluate the effect of addition a composite of surface treatedNano Aluminum oxide (Al2O3) filler and plasma treated polypropylene fiber (PP) on some properties of denture basematerial.Materials and methods: One hundred fifty prepared specimens were divided into 5 groups according to the tests,each group consisted of 30 specimens and these were subdivided into 3 groups (unreinforced heat cured acrylicresin as control group),reinforced acrylic resin with( 0.5%wt Nano Al2O3 and2.5%wt plasma treated PP fibers) groupand reinforced acrylic with(1%wt Nano Al2O3 and 2.5%wt plasma treated PP fibers group).The tests were impactstrength, transverse strength, indentation hardness(shore D), surface roughness thermal conductivity. The results werestatistically analyzed using ANOVA test.Results: A highly significant increase in impact strength, surface hardness, thermal conductivity with the addition of0.5%wt. (Al2O3) and 2.5%wt PP fiber to(PMMA),also there is a significant increase in surface roughness and nonsignificant increase in transverse strength. At the concentration of 1%wt nano (Al2O3)and 2.5%wt PP fiber there is ahighly significant increase in impact strength surface hardness and thermal conductivity. Non-significant differenceswere shown in transverse strength and significant increase in surface roughness.Conclusion: The addition of a composite of Al2O3 nanoparticles and PP fiber to PMMA improves the impact strength,surface hardness and thermal properties, surface roughness while non-significant difference in transverse strength


Article
In vitro Performance of Polymethyl–methacrylate with Ultra High Density Poly Ethylene Fiber and Nano Zirconium Oxide Particles Composite

Authors: Ahmed A. Mohammed --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2018 Volume: 30 Issue: 1 Pages: 5-11
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Poly (methyl methacrylate) has been widely utilized for fabrication of dentures for many years as it has good advantages but not achieved all demands of the mechanical properties such as low transverse strength, low impact strength, low surface hardness, high water solubility and high water sorption.Material and method: To provide bonding between ZrO2 nanoparticles and PMMA matrix, the ZrO2 Nano-fillers were surface-treated with a saline coupling agent. Plasma surface treatment of polyethylene (PE) fiber was done to change surface fiber by using DC- glow discharge system. For characterization of interring any functional groups, the (FTIR) spectrum were done .then the mechanical properties studied to choose the appropriate percentages to complete study.Results: The results revealed that highly significant difference between groups in transverse strength, the highest mean value (96.1700 N/mm2) found in 2.0% polyethylene fibers and 1.5% salinized Zirconium oxide nanoparticles group, highly significant increase in impact strength (7.69 Kj/m2), surface hardness (92.35) and highly significant decrease in water sorption (0.0016 mg/cm2) and water solubility (0.0013 mg/cm2).Conclusion: the use of saline coupling agent with ZrO2 and oxygen plasma treatment PE fiber provided an effective procedure for getting good bonding with the PMMA matrix to give enhanced properties for the composite

Keywords

PMMA --- UHDPE --- ZrO2 --- FTIR --- PE --- oxygen plasma


Article
Effect of the addition of bio-polymer lignin on the Transverse and Impact strength of the autopolymerizing acrylic resin.

Authors: Basima M.A. Hussein باسمة محمد --- Thikra I. Hamad ذكرى حمد --- Intisar J. Ismail انتصار جاسم
Journal: Journal of the Faculty of Medicine مجلة كلية الطب ISSN: 00419419 Year: 2010 Volume: 52 Issue: 3 Pages: 359-363
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Acrylic resin dentures are susceptible to fracture; it is unresolved problem in prosthodontics. The repair procedure should be simple, strong, and accurate. This study evaluated the transverse and impact strength of autopolymerizing acrylic resin, the repair material was modified with kraft lignin as a new enforcement material and compared with the commercially available self cured acrylic resin. Materials and Methods: The addition of kraft lignin to the acrylic resin were done in percentages of 0.25%, 0.5%, 0.75%, 1.0%, 1.25%, and 1.5% (wt%). Seventy specimens were made according to the ADA specification No 12 for transverse strength using three point bending test and Impact strength test was conducted following the procedure given by the ISO 179 with Charpy Type Impact testing instrument.Results: Mean transverse strength of experimental specimens where increased only in 0.25wt% addition of lignin (61.3400 Mpa) then results tend to decrease, and no statistical differences found between the control and any one of the modified groups. The impact strength increased more than the control in the groups 0.25, 0.50, 0.75,and 1.0wt%,13.9700, 15.5900, 35.2100, 33.6900 Kj/m2 respectively, then has been decreased at 1.50wt% until reach value of the control (9.2525 Kj/m2).Highly significant difference was found at 0.5, 0.75 and 1.0wt% (p<0.05).Conclusions: The autopolymerizing acrylic resin exhibited significantly higher impact strength as a result of addition the biopolymer lignin. The transverse strength of the modified specimens was decreased after increasing the weight percent addition of lignin.Key words: Autopolymerizing acrylic resin, KL (kraft lignin), transverse strength, impact strength


Article
Retentive forces, tensile strength and deflection fatigue of Acetal thermoplastic clasp material in comparison with cobalt-chromium alloy

Authors: Samar S. Alwan سمر علوان --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 1 Pages: 59-66
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Nowadays there is an increasing of the emphasis on aesthetic, dentist have been concerned about providing aesthetics and functional removable partial dentures to their patients and this was make the mission more difficult because of the goal now is achieving optimal aesthetic of the denture - while maintaining retentive, stable, and conservative to the health of supporting tooth and supporting tissue. The traditional use of metal clasp like cobalt-chromium, gold, stainless-steel and titanium hampers esthetics because of its obvious display conflicts with patient’s prosthetic confidentiality. Acetal resin (poly oxy methylene) may be used as alternative denture clasp material. This material was promoted primarily on the basis of its superior esthetic.Material and method: In this study, Acetal resin of Flexite and co-cr alloy of Wirocast companies were used. Four metal models of two premolars and two molars were surveyed to have 0.25mm and 0.5mm undercut depth for each one of the materials. eighty clasps were prepared and tested by testing machine to measure the load required to dislodge Acetal and co-cr clasps of 2mm. thickness (for premolar and molar). Tensile test were utilized for both Acetal resin and co-cr. tensile values will be used in special formula to calculate the amount of deflection.Results: The results of this study revealed that Acetal resin clasp of molar with 0.5mm undercut depth have the higher retentive force, and premolar with 0.25 mm undercut depth have the lowest retentive force as compared to co-cr. Also Acetal had lower values of the tensile strength as compared to co-cr alloy but it had higher deflection value than co-cr and it can withstand higher deflections than those of co-cr before having permanent deformation or fractureConclusions: Acetal resin can be used with limitation as an alternative to co-cr alloy clasps in removable partial dentures.


Article
The effect of silanized alumina nano -fillers addition on some physical and mechanical properties of heat cured polymethyl methacrylate denture base material

Authors: Ban Saad Jasim بان سعد جاسم --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 2 Pages: 18-23
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. Thematerial is far from ideal in fulfilling the mechanical requirements. Midline fracture; poor thermal conductivity andwater sorption, are common problem in this material. The purpose of this study was to evaluate the effect of additionof surface treated Aluminum oxide nano fillers on some properties of heat cured (PMMA).Materials and methods: In addition to controlled group of heat cured PMMA the silanized (Al2O3) nanoparticles wasadded to PMMA powder by weight in three different percentages 1wt%, 2wt% and 3wt%, mixed by probe ultrasonicationmachine. 200 specimens were constructed and divided into 5 groups according to the test (each groupconsist of 40 specimens) and each group was subdivided into 4 sub-groups. The tests conducted were thermalconductivity, thermal diffusivity, transverse strength, indentation hardness (shore D), surface roughness, water sorptionand solubility. The results were statistically analyzed using ANOVA and Dunntt t-test.Results: A highly significant increase in transverse strength was observed with the addition of (Al2O3) nanoparticles to(PMMA) at the percentage of 1wt%, the value was 117.72 Mpa and significant increase at 2wt%; while a significantreduction occurred in transverse strength at the percentage of 3% the value was 90.110 Mpa. A significant increasein surface hardness and non significant differences in surface roughness were observed for all percentages.Conclusion: The addition of Al2O3 nanoparticles to acrylic resin improves the thermal properties and transversestrength of acrylic resin at the same time this addition decreases water sorption and solubility

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