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Article
Non-polar micro-coating on acrylic denture material for reducing the incidence of dental biofilm formation

Authors: Dr. Lateef Essa Aljorani د.لطيف عيسى الجوراني --- Dr. Arshad F. Jassem Al-Kaabi ارشد جاسم
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2018 Volume: 15 Issue: 1 Pages: 77-82
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Aim: Dental plaque formation is a major health risk associated with prolonged wornacrylic dentures. The dental biofilm usually develops when improper cleaning andsterilizing of dentures is achieved. The aim of this study was to improve theacrylic material surface properties for minimizing the incidence of dental plaqueformation on acrylic dentures by lowering the surface energy.Method: The acrylic (polymethylmethacryate) surface modification was achieved byapplying a non-polar micro-coating on acrylic samples which was the dentalbaseplate wax. Two experimental groups used in this study, the control and thecoated groups with 10 samples each. The surface analysis was conducted using thecontact angle's technique. All samples soaked in salivary solution for 5 days. Themethylene blue dye material used as an indicative for the dental plaque formation.Results and conclusion: The surface analysis showed a significant decrease in thesurface hydrophilicity of the coated group by increasing the water contact angledegree values (P-value<0.05). The microscopic analysis by visual inspectionshowed a reduced formation of the dental biofilm on the acrylic samples. Withinthe limitations of this study, the suggested coating material can possibly reducethe incidence of the dental biofilm formation on acrylic dentures.


Article
Incidence of different types of removable partial dentures in Sulaimania

Author: Faraidoon A. Miran
Journal: Journal of Oral and Dental Research مجلة طب الفم والاسنان ISSN: 23106417 Year: 2018 Volume: 5 Issue: 1 Pages: 70-77
Publisher: Iraqi Association for Oral Research الجمعية العراقية لبحوث طب الفم

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Abstract

Background: Removable partial prosthodontics is reversible treatment method for partially edentulous patients at any age. Even thought, recent reports have shown a consistent decline in the prevalence of tooth loss during the past few decades, the remain significant variation in tooth loss distribution Objectives The aim of the study is to detect the incidence of different classes of removable partial dentures according to Kennedy classification, age range and gender. Materials and methods the work authorization forms for 102 patients requiring RPDs from the clinics of the College of Dentistry, Sulaimania University. A one-year period was reviewed for this study. The Kennedy classification with the guidelines advocated by Applegate for each partially edentulous arch was recorded, and the data was collected for RPD regarding gender and age. Results Females (60.41%) have more RPDs restorations than males (39.58%) at the total of 144 RPD100% .Kennedy class II (51.38 %) RPDs more common than other classes and the female (27.77%) more than male (23.61%)in class II And the least common is Class IV(1.38%)only .in relation of distribution of RPD by age Most of the RPD are at the age of 45-54 of age (47.22%) and least common RPDs at age of 15-24 Years (1.38%) also it is only in the female group The upper P.D. (50.69%) is more common than lower (49.30%). Conclusion In the females, the upper class II RPD was the most common incidence at age between 45-54 years.


Article
Effects of Novel Polyetheretherketone (PEEK) Clasp Design on Retentive Force at Different Tooth Undercuts

Authors: Saja A. Muhsin --- Duncan J. Wood --- Anthony Johnson --- NunoSereno --- et al.
Journal: Journal of Oral and Dental Research مجلة طب الفم والاسنان ISSN: 23106417 Year: 2018 Volume: 5 Issue: 2 Pages: 13-25
Publisher: Iraqi Association for Oral Research الجمعية العراقية لبحوث طب الفم

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Abstract

Background The material characteristics of many thermoplastic materials, including PEEK, have been evaluated in vitro to investigate their mechanical and physical properties. However, all the manufacturers of thermoplastic materials and laboratories making non-metal clasp dentures still recommend the original denture design. Objectives To investigate the retentive force of a novel clasp design for PEEK thermoplastic material at 3 different undercut depths with fatigue cycling equivalent to 3 years of insertion/removal use. Materials and Methods Samples (n=10) were prepared for the test. A novel clasp designs for PEEK and conventional design for Co-Cr were created using 3D-RPD software (DWOS). PEEK-Juvora™ clasps were fabricated using a Roland 3D-milling machine; PEEK-Optima®NI1 were thermo-pressed at 200˚C mold temperature using thermopress 400 injecting unit; while Co-Cr alloy was used to cast the metal clasps. Samples were tested at tooth undercut depths of 0.25, 0.50, and 0.75 mm. They were investigated for the retentive force at the initial fabrication and after 1st, 2nd, and 3rd Year respectively of fatigue simulation. This was represented by clasp insertion and removal 3 times per day using fatigue chewing simulator machine. The data was statistically analyzed using ANOVA at p<0.05.Results There was a statistically significant difference (p<0.05) between the retentive force of the PEEK compared to Co-Cr clasps. PEEK-Juvora™ exhibited the highest retention at 3 different undercut depths over 3 years followed by PEEK-Optima®NI1 at 0.75, and 0.50mm (P<0.05). However, the initial retentive force required to dislodge the PEEK-Optima®NI1 clasp processed at 200 °C was statistically non-significant (p>0.05) as the Co-Cr at 0.25 mm tooth undercut depth. Conclusion Clasps made of machined PEEK-Juvora™ and thermo-pressed PEEK-Optima®NI1 at 200 ˚C mold temperatures showed the most promising retentive force with a non-fracture tendency at deeper tooth undercut. This novel PEEK clasp design may improve the clasp retention, bracing, additionally to increase its durability comparing to Co-Crclasp.


Article
Bacterial Contamination of Acrylic Resin Complete Denture/ in Vitro Study

Author: Cheman Abdulrahman Al-Jmoor
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2018 Volume: 30 Issue: 2 Pages: 1-4
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Cross contamination of dental appliances in the dental clinics and laboratories may potentially be a health hazard to the dental team and the patient. This study aimed to evaluate bacterial contamination of acrylic complete denture as received from dental laboratory before delivery to the patient, and then to evaluate the effectiveness of disinfection with 2% chlorhexidine and Kin denture cleaner tablet.Materials and methods: 45 newly made upper complete dentures undergone biaacterial examination for contamination before delivered to the patient. Samples were examined in two stages, first after finishing and polishing; when collected from the laboratory and before inserting to the patient mouth, second; after the samples were immersed in 2 different disinfectant materials, 2% chlorhexidine mouth wash and Kin denture cleaner tablet. After initial stage, the dentures were divided into 3 groups. Group 1 immersed in Kin denture cleaner tablet for 10 minutes, group 2 immersed in 2% chlorhexidine mouth wash for 10 minutes and group 3 immersed for 20 minutes in 2% chlorhexidine. Data were analyzed with a computer-run statistical program (IBM SPSS Version 23).Results: High score of bacterial contamination was found initially in the sample collected from dental laboratory. Significant reduction in the colonies number was noticed after immersing the dentures in 2% Chlorhexidine and Kin denture cleaner tablets for10 minutes. There was nearly no contamination found with samples immersed in 2% chlorhexidine for 20 minutes.Conclusion: Dental laboratory is a main source of microbial contamination. Immersion of the dental prosthesis in disinfectant materials is essential before inserting into the patient mouth. 2%chlorhexidine mouth wash was more effective as disinfection material as compared to Kin denture cleaner tablet.


Article
Influence of Coca-cola on Surface Roughness and Microhardness of Flexible Denture Base Material

Author: Noora Musadaq نورا مصدق قاسم
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2018 Volume: 6 Issue: 1 Pages: 19-27
Publisher: Tikrit University جامعة تكريت

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Abstract

Two potential problems commonly associated with flexible denture base material are surface roughness and the reduction of microhardness due to many reasons, rough surface can cause bacterial collection and the patient feels discomfort, and the possibility of the denture scratched when the surface hardness is reduced. The aim of this study was to evaluate the influence of Coca-cola on the surface quality of the flexible denture base material represented by the surface roughness and microhardness. A total of (10) samples were prepared for this study with the dimension of ( 40mm, 10mm, 3mm) length, width, and height respectively from thermo-plastic flexible resin (X-flexible capsules, color; K2 , size; LChina) by the conventional methods following the manufacturer instructions. The samples were immersed in Coca-cola drink for 12 days at room temperature. This period represents the average of one year of the beverage consumption, the drink has been changing daily.The samples were marked randomly and kept in special containers, and each sample has two rectangular surfaces used for the tests. One side is used for microhardness test and the other side used for the surface roughness test. The first tests were done before immersing the samples in coca-cola as control group. And after immersing the second tests were done as experimental group. In this study the data was analyzed using Independent samples (T- test). And results showed that there is no statistically significant difference in the surface roughness of the samples before and after immersing in Coca-cola (P-value > 0,05), while the microhardness test showed statistically a significant difference (P-value < 0,05) before and after immersing in Coca-cola. The surface roughness of flexible thermoplastic resin is not affected by coca-cola drink. While the levels of mirohardness showed decreasing after immersion in coca-cola drink. Therefore, the flexible thermoplastic material could be damaged if it is subjected to extra consumption of Coca-cola drink by the patient and this leads to lessen the amount of hardness by the time that could affect the efficiency of the prostheses, also could affect the mechanical


Article
Modified Processing Technique for Acrylic Resin Denture Base

Author: Ibrahim H. Alfahdawi ابراهيم حمد مخلف
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2018 Volume: 6 Issue: 1 Pages: 28-32
Publisher: Tikrit University جامعة تكريت

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Abstract

Modified flasking technique for acrylic resin denture base at sandy stage. The uniform denture base plate wax pattern was made on the stone casts with a thickness of 3 mm. For the flow of acrylic on ridge, the necks of teeth were slight grinded from palatal or lingual surfaces toward buccal surface to allow more space. The volume of the definitive casts must be reduced as much as possiblebefore flasked in the lower part of the traditional flasks and fill with dental plaster (class II) covering the buccal, labial, incisal and occlusal surfaces of the teeth to give more support and prevent teeth migration. After curing cycle, the denture bases are carefully deflasked, the excess trimmed and polished the surfaces of the denture. Dentures processed with this procedure provides good retention and esthetic, more hygienic and comfortable for the patient than those processed with the conventional method. Giving more support and prevent teeth migration, comfortable for patient, good esthetic, give fine details of the mold and decreasing of time required for processing and finishing the cured prostheses.


Article
Study Compression and Impact Properties of PMMA Reinforced by Natural Fibers Used in Denture

Authors: Jawad K. Oleiwi --- Sihama I. Salih --- Hwazen S. Fadhil
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 6 Part (A) Engineering Pages: 652-655
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The fracture in dentures prepared from acrylic resin occurs frequently during the accidental damage or service through heavy occlusal force [1]. Impact failures usually occur out of the mouth as a result of accidental dropping due to cleaning, coughing or sneezing or a sudden blow to the denture [2]. This paper is focused on the effect of natural fibers on the mechanical properties of PMMA by changing two parameters (content of fibers and length of fibers). Fibers were treated with alkaline solution to improve the interfacial adhesion. Composite specimens were prepared by using hand lay-up method. The results were showed that the increasing the weight fraction of both fibers lead to increase compression strength and decrease impact strength of composite specimens. While, increasing fiber length of both fibers lead to decrease compression strength and increase impact strength of the composite specimens. The largest value obtained for bamboo specimens at (2mm) fiber length and (9wt. %) and reach (530 MPa.). The main goal of this research is studying the impact and compression properties of PMMA reinforced by natural fibers (siwak and bamboo) by varying length and concentration of both kinds of fibers.


Article
STUDY THERMAL BEHAVIOR OF HEAT CURE POLY (METHYL METHACRYLATE) REINFORCED BY BAMBOO AND RICE HUSK POWDERS FOR DENTURE APPLICATIONS

Authors: Jawad K. Oleiwi --- Qahtan Adnan Hamad --- Hadil Jabbar Abdul Rahman
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2018 Volume: 11 Issue: 4 Pages: 417-425
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

The present research, studies the effect of adding two different types of reinforcing powders, which included: Bamboo (Ba) and Rice Husk (RH), that added with different weight fractions (2, 4, 6 and 8 wt. %), and with the selected size particles of (25µm and 75µm) on thermal behavior of heat Cure Poly (Methyl Methacrylate) such as thermal conductivity and thermal diffusivity in addition to the differential scanning calorimetry (DSC) analysis and these tests were accomplished at temperature of laboratory. The poly Methyl Methacrylate properties which reinforced by (Bamboo and Rice Husk) powders are mainly influenced by the interfacial adhesion strength between the powders and the matrix, and in order to get better correlation between the natural powder and PMMA matrix, so the powders were treated with alkali (sodium hydroxide NaoH) solution prior to use as reinforcement materials. The results showed that the values of the thermal conductivity and thermal diffusivity increased with increasing of the weight fraction for both particle sizes (25 µm and 75 µm) of natural powders.


Article
DETERMINATION OF RELATION BETWEEN THE VERTICAL DIMENSION OF OCCLUSION AND RIGHT HAND LITTLE FINGER

Author: Faraidoon A. Miran
Journal: Journal of Oral and Dental Research مجلة طب الفم والاسنان ISSN: 23106417 Year: 2018 Volume: 5 Issue: 1 Pages: 22-31
Publisher: Iraqi Association for Oral Research الجمعية العراقية لبحوث طب الفم

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Abstract

Background Determination of the VDO is one of the most important steps in making complete denture Objectives The present study evaluates the relation between vertical dimension of occlusion, and the length of the little fnger of right hand. Material and Methods a cross-sectional study was conducted on 200 dentate subjects selected both males and females were involved in the study. Measurements of the verticaldimension of occlusion were recorded clinically using modifed digital vernier caliper, with the person is seated correctly on the dental chair in an upright position; and instructed to close his teeth in centric occlusion. The length of the little fnger of the right hand was measured from tip of fnger to the farther most point on palmer digital crease. The measurements were taken with the hand straight, flat and supine position, Results showed that the vertical dimension of occlusion was signifcantly and positively correlated with the length of the little fngers, in females more compatible than males. Conclusion Since the variations between the vertical dimension of occlusion and the length of little fnger are within the range of 1mm for females and 2mm for males respectively. As a conclusion of the present study vertical dimension of occlusion prediction through this method is reliable, and reproducible. Also the method is simple, economic, and non-invasive; hence, it could be recommended for everyday practice.


Article
Enhancement of the Tensile and the Compression Properties for Heat- Cured Acrylic Resin Denture Base Materials
تحسين خاصيتي الشد والانضغاط لراتنج الاكريليك المبلمر حراريا لمادة طقم الاسنان

Authors: Mohammed Gh. Hammed محمد غازي حمد --- Ibrahim H. Al-Fahdawi ابراهيم حمد الفهداوي --- Moaaed Motlak مؤيد محمود مطلك
Journal: Baghdad Science Journal مجلة بغداد للعلوم ISSN: 20788665 24117986 Year: 2018 Volume: 15 Issue: 4 Pages: 449-454
Publisher: Baghdad University جامعة بغداد

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Abstract

This work aims to investigate the tensile and compression strengths of heat- cured acrylic resin denture base material by adding styrene-butadiene (S- B) to polymethyl methacrylate (PMMA). The most well- known issue in prosthodontic practice is fracture of a denture base. All samples were a blend of (90%, 80%) PMMA and (10%, 20%) S- B powder melted in Oxolane (Tetra hydro furan). These samples were chopped down into specimens of dimensions 100x10x2.5mm to carry out the requirements of tensile tests. The compression strength test specimens were shaped into a cylinder with dimensions of 12.7mm in diameter and 20mm in length. The experimental results show a significant increase in both tensile and compression strengths when compared to control (standard) results for the preparation material.

يهدف هذا البحث إلى التحقق من خصائص متانة الشد والانضغاط للمادة التي تدخل في صناعة طقوم الأسنان المعاملة حراريا عن طريق إضافة الستايرين - بيوتادين (S- B) إلى البولي مثيل ميثا أكريلايت (PMMA). إن الكسر الذي يحدث في طقوم الأسنان المصنعة من هذه المواد هي من احد المشاكل التي يجب معالجتها. ان جميع العينات المحضرة عبارة عن خليط من البولي ميثيل ميثا أكريلايت بنسبة (90 ٪ و 80 ٪) و (10 ٪ ، 20 ٪) من مسحوق S- B المذاب في أوكسولان (Tetra hydro furan). تم تقطع هذه العينات بالأبعاد 100x10x2.5 ملم لأجراء اختبارات الشد لها. اما عينات اختبار متانة الانضغاط فهي أسطوانية الشكل بأبعاد 12.7 ملم بالنسبة لقطر العينة و 20 ملم بالنسبة للطول. أظهرت النتائج التجريبية زيادة ملحوظة في كل من متانة الشد والانضغاط للعينات مقارنة بنتائج العينات القياسية لمواد التحضير.

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