research centers


Search results: Found 4

Listing 1 - 4 of 4
Sort by

Article
Effect of different denture cleanser solutions on some mechanical and physical properties of nylon and acrylic denture base materials

Authors: Mohamad Salman مهند سلمان --- Shatha Saleem شذى سليم
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2011 Volume: 23 Issue: special issue Pages: 19-24
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Background: Thermoplastic non –metal clasp denture became recently the most attractive option for patients dueto its esthetic outcome and many other advantages. The chemical immersed denture cleanser is the most widelyused method by the patients to maintain clean and healthy denture , but the use of such cleanser may haveharmful effect on the denture base materials .This study aimed to evaluate some physical and mechanicalproperties of one of the thermoplastic denture base materials which is (nylon) compared with those belong toconventional heat cured acrylic and to observe the effect of two prepared denture cleansers ( 4% oxalic acid ,4%tartaric acid ) in addition to one commercial denture cleanser (lacalut dent) on the indentation hardness , flexuralstrength , flexibility , surface roughness and color stability of nylon and conventional heat cured acrylic.Materials and method: Two hundred and sixty specimens (130 nylon and 130 acrylic) were prepared ,60 specimens(30 nylon ,30 acrylic ) were used to test each of the properties mentioned above except an 80 specimens were used(40 nylon ,40 acrylic ) to test flexural strength and flexibility.Results: The result obtained in the present study showed high significant difference between nylon and conventionalheat cured acrylic in four properties which were: indentation hardness , flexural strength , flexibility and color stability,with no difference in the surface roughness .Furthermore oxalic acid and tartaric acid cleansers significantlydecrease the indentation hardness and flexural strength of conventional heat cured acrylic while lacalut dent didn’tsignificantly affect those properties of acrylic, also all the three cleansers didn’t affect the indentation hardness andflexural strength of nylon .oxalic acid and tartaric acid cleansers significantly decreased the flexibility of nylon whilelacalut dent didn’t significantly changed this property. All the three cleanser had no effect on the flexibility ofacrylic. All the three cleanser had no effect on the surface roughness or color stability of nylon and acrylic.Conclusions: It can be concluded that nylon had better flexibility and translucency than conventional heat curedacrylic while conventional heat cured acrylic had better indentation hardness and flexural strength than nylon.Regarding surface roughness the two polymers show no significant difference between them.There were an adverse effect of the prepared denture cleansers which contain isopropyl alcohol on indentationhardness and flexural strength of conventional heat cured acrylic , it decreased both those properties , so it isadvised not to use solution containing alcohol as acrylic denture cleanser also it is advised not to use it withnylon denture because it decreased its flexibility. Lacalut dent which is an oxygenating commercial denturecleanser, had no adverse effects on both polymers used in the study, so it can be used safely with them


Article
Push-out bond strength and apical microleakage of (MTA Plus, Biodentine, and Bioceramic) as apical third filling (An in vitro study)

Authors: Dr. Abeer A. Abass B.D.S. د. عبير عباس --- Prof. Dr. Jamal A. Mehdi B.D.S., M.Sc. دز جمال عزيزىمهدي
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2016 Volume: 13 Issue: 1 Pages: 1-10
Publisher: Al-Mustansyriah University الجامعة المستنصرية

Loading...
Loading...
Abstract

Background: This study was conducted to evaluate the sealing ability of (MTA Plus,Biodentine Bioceramic root repair material) as an apical third filling by using(Push-out bond strength test, apical microleakage test).Materials and methods: Sixty straight palatal roots of the maxillary first molars teethwere used in this study, the roots were instrumented by using crown downtechnique with Protaper universal rotary system, the roots were randomly dividedinto three groups according to the materials used for filling apical third(n=20).Group (1): MTA Plus . Group (2): Biodentine. Group (3): Bioceramicrepair material. For all groups complete obturation with easy & quick obturationsystem was used. After incubation period of three days ten roots for each groupwere embedded in clear acrylic resin and each root sectioned in apical to provideslice 2mm in thickness. The bond strength was measured using computerizeduniversal testing machine. Ten roots remain from each group used for apicalmicroleakage study. The roots submerged in 2% methylene blue for three days.The roots were cleared and the degree of linear dye penetration was measured inmillimeter by stereomicroscope under 40 X magnification with calibrated scaleocular grid. The data were analyzed statistically using ANOVA and LSD test.Results: In push-out bond strength showed the Biodentine has the highest meanvalues (19.687) in comparison with other groups followed by MTA Plus groupwhich the mean value was (19.395), while the BC material group has the lowestmean value (10.977). In microleakage the BC material group has the high meanvalues (0.477) of apical dye penetration in comparison with other groups.Biodentine group has lowest mean values (0.359) of apical dye penetration.Conclusions: The Biodentine higher push-out bond strength and less apicalmicroleakage then other test materials.


Article
Adherence of Candida albicans to Flexi-ble Denture Base Material

Authors: Zeina M Ahmad --- Eman A Mustafa --- Inas A Jawad
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2012 Volume: 12 Issue: 20 Pages: 229-235
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

Assessment of Candida albicans adherence to flexible denture base material (Valplast) and con-ventional heat polymerized acrylic resin in the presence and absence of saliva. Materials and Me-thods: A total of 28 square specimens (10 mm x10 mm x3mm) were constructed from Valplast and acrylic denture base materials according to manufacturers' instructions and kept without finishing or polishing. C. albicans was isolated from patients with denture stomatitis. Fourteen specimens (7 of each material) were not coated with human saliva (control), deposited in yeast suspension (107 ) yeast cells/ml, incubated for 1hr at room temperature and washed with phosphate buffer saline and then stained with crystal violet. The remaining 14 specimens (7 of each material) were coated with saliva and treated as previously described. Adherent yeast cells in 84 fields of view (0.25mm2/field) of mate-rials were enumerated. The results were expressed as yeast cells/mm2 of material. Results: In compari-son between the two denture base materials, Candida adherence to acrylic resin (170 yeast cells/mm2) is greater than Valplast (126 yeast cells/mm2). Both saliva uncoated and coated acrylic samples have higher means of Candida adherence (208, 132 cells/mm2) than saliva uncoated and coated Valplast samples (175, 77 cells/mm2) respectively. High significant reduction in yeast counts was seen in both materials after saliva coating. Conclusions: Great reductions in yeast counts were determined in Val-plast material specially in saliva coated specimens when compared with acrylic resin.


Article
Evaluation of Transverse strength, Impact strength and Hardness of Thermosense denture base material and compare the result with heat cure acrylic denture base material (in vitro study)

Author: Dr. Hadeel Adnan Mohsin, B.D.S., M.Sc. * د. هديل عدنان
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2016 Volume: 13 Issue: 1 Pages: 64-69
Publisher: Al-Mustansyriah University الجامعة المستنصرية

Loading...
Loading...
Abstract

Background: Thermosense material is the innovative virtually unbreakable, newmonomer free rigid denture base material easy and quick to polish and availablein 10 colors, suitable to patients unable to accept denture made from materialsthat could result in allergic reactions or other sensitivity problems. This type issuitable for full and partial denture and can be used for rebase and reline jobs.Also suitable for overdenture on implant and for repair.Material and methods: sixty samples were prepared and divided in to two maingroups according to the type of material that used (thermosense denture basematerial and heat cure acrylic denture base material). Each main group weresubdivided in to three subgroups according to the type of test that has used(Hardness, impact strength, and transverse strength). Data were analyzed by onewayanalysis of t-test.Results: for this study the result for three tests; hardness, transverse strength andimpact strength show high significant difference.conclusion: This study showed Thermosense denture base material had higher impactstrength than Heat cure acrylic denture base material but this material had highertransverse strength and hardness than Thermosense denture base material.

Listing 1 - 4 of 4
Sort by
Narrow your search

Resource type

article (4)


Language

English (4)


Year
From To Submit

2016 (2)

2012 (1)

2011 (1)