Medicine and Health Sciences Commons^™

Synthesis And Characterization Of Poly(Allyl Methacrylate) Obtained By Free Radical Initiator., Selda Keskin

Allyl methacrylate was polymerized in CCl4 solution by a,a0-azoisobutyronitrile at 50, 60, and 708C. The kinetic curves were autoaccelarated types at 60 and 708C, but almost linear at 508C. Arrhenius activation energy was 77.5 kJ/mol. The polymer was insoluble in common organic solvents. It was characterized by FT-IR, NMR, DSC, TGA and XPS methods. About 98–99% of allyl side groups were remained as pendant even after completion of the polymerization. The spectroscopic and thermal results showed that polymerization is not a cyclopolymerization type, but may have end group cyclization. The high molecular weight is the main cause of a polymer …

The Evaluation Of Some Flexural Properties Of Denture Base Resin Reinforced With Various Aesthetic Fibers, Selda Keskin

No abstract provided.

Bolton Tooth-Size Discrepancies Among Unicersity Of Malaya's Dental Students, Othman S. A., Mookin H., Asbollah M.A., Hashim N.A.

Siti Adibah Othman

The objective of this retrospective study was to investigate what percentage of the dental students in the University of Malaya has a tooth size discrepancy. The sample comprised 40 good quality pre-treatment study models with fully erupted and complete permanent dentitions from first molar to first molar, which were selected from the dental students of the University of Malaya. The mesiodistal diameter tooth sizes were randomly measured manually from first molar to first molar using digital calliper (Mitutoyu) accurate to 0.01 mm, and the Bolton analyses for anterior and overall ratios were calculated by scientific calculator. Reproducibility analysis for intra- …

Validation Of Cone Beam Ct Scan For Measurement Of Palatal Depth In Study Casts, Radzi Z., Yahya N. A., Abu Kasim N. H., Abu Osman N. A., Yusof Z. Y. M., Mohd F. N., Noor N. H. M., Jamaludin M., Othman S. A., Obaidellah U. H., Mohamed N. H., Kadir R., Nambiar P.

Siti Adibah Othman

The purpose of this study was to validate the use of digital dental study casts obtained from Cone beam CT Scan (CBCT) against gold standard; that is traditional dental study cast measured with digital caliper. Thirty-four study casts of Malaysian Aborigines were selected from Centre of Malaysian Pribumi Studies Databank. Palatal depth of each study casts were measured using Mitutoyo digital caliper. Subsequently, all the study models were scanned using i-CAT CBCT and the palatal depth were measured using i-CAT software. Data were analysed using SPSS version 12.0 where Intraclass correlation and paired T-test were employed. There was no significant …

Evaluation Of Obturation Quality In Round And Irregular Root Canals, Ahmed A. Madfa

Ahmed A. Madfa

Objective: This study compared the quality of root canal obturation in round and irregular-shaped canals at two cross-sectional levels by evaluating the canal area filled by two core materials using two obturation techniques. Methods: Single canals in 60 mandibular premolars were instrumented, irrigated and divided into four equal groups. They were root filled as follows: lateral compaction/RealSeal™ (LC/R), lateral compaction/gutta-percha (LC/GP), warm vertical compaction/RealSeal™ (WC/R) and warm vertical compaction/gutta-percha (WC/GP). The teeth were sectioned horizontally at 3 mm (L3) and 6 mm (L6) intervals from the obturated canal terminus. Shapes of canals in all cross-sections were examined using a Leica …

Modification Of Pmma Dental Resin With Palm Oil Based Polyol, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Objectives: This study is an attempt to enhance the properties of conventional PMMA denture material by incorporation of a polyfunctional polyol derived from palm oil by copolymerization with methyl methacrylate monomer to overcome the low fatigue resistance property of PMMA. Methods: A series of copolymerizations of palm oil polyol with MMA was performed in solution. The polyol was added from 40-20 %, MMA from 20-40% , benzoyl peroxide as initiator was at 0.04% and toluene used as solvent was at 60 % of the total weight. The copolymerization was carried out in a 500ml-round-bottom reaction flask, equipped with a magnetic …

Conversion Of A New Monomer For Dental Resin Application, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Objective: The aim of this study was to investigate the degree of conversion and cross-linking of polyurethane dimethacrylate (PUDMA), derived from palm oil polyol, for dental resin application. Methods: Polyurethane dimethacrylate was synthesized by reacting excess amount of Methylene diphenyl diisocyanate (MDI) with palm oil polyol. The resulting isocyanate polyurethane prepolymer was then acrylated using hydroxymethacrylate (HEMA). Fourier transform infrared spectroscopy was used to ascertain the formation of PUDMA, and to determine the degree of conversion (DC) of: I) PUDMA, II) Bis-GMA, III)Bis-EMA,IV) Bis-GMA/TEGDMA (3:1), V) Bis-GMA/TEGDMA(3:1)/Bis-EMA (3:1), VI) PUDMA/Bis-EMA (3:1), VII) Bis-GMA/TEGDMA(3:1)/PUDMA (1:1), and VIII) Bis-GMA/TEGDMA(3:1)/PUDMA/Bis-EMA (1-1-1). The photo …

Flexural Strength Of Pmma Modified With Palm-Oil Based Polyol, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Objectives:Biocompatibility is an important desirable property for a dental polymer and it can be achieved by utilizing more materials from natural sources. The flexural strength of an experimental polymer prepared from MMA monomer modified with palm-oil polyol was compared to two commercial resins,namely the Lucitone 199® (Dentsply Trubyte, USA) and Impact (Ivoclar Vivadent, Liechtenstein). Methods: The experimental polymer was prepared by copolymerizing MMA monomer and palm oil polyol. The resulting polymer was cast into a plate form and sectioned using a precision diamond saw (Buhler, Germany) to form 10 specimens of dimension, 65mm x 11mm x 5mm. These specimens were …

Demineralization Potential Of Qat Extracts At Composite Restoration Interface, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Objective: To evaluate the demineralization potential of qat extracts at composite restoration interface. Methods: Class V cavities were prepared on the buccal surface of thirty extracted sound premolars and were restored with a nanohybrid composite (Grandio, VOCO, Germany). Specimens were subsequently coated with nail varnish exposing 2mm of enamel around the restoration margin. The specimens were divided into three equal groups of 10 and were then immersed in acid gel and qat extracts (10% and 20%) for 4 weeks. All specimens were removed and washed using deionized water and later examined by direct vision and stereomicroscope prior to sectioning. Specimens …

Finite Element Analysis Of An Automated Rapid Maxillary Expander (Arme), Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

An Automated Rapid Maxillary Expander (ARME), is a specially designed orthodontic appliance to overcome the shortcomings imposed by the traditional butterfly expansion appliance. It operates by automatically widening the maxilla (upper jaw) by expanding the midpalatal suture [1]. This procedure is not feasible after late teenage years due to more rigid facial skeleton features. According to the study by Cozzani [2], the activation of the device could produce 0.25 mm of expansion per day. Over the period of 2 weeks, the expansion produced is up to 7 mm in total [1]. For this study, we explored the mechanism involved in …

Acquiring Anatomical Representation Of Human Maxilla For Rapid Maxillary Expansion, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

The purpose of the study is to model and provide a better understanding of maxilla bone involved in the treatment for rapid maxillary expander (RME) for dento-facial applications. The treatment is recommended for patients presented with an arch width deficiency named cross bites. Cross bites often cause abnormal physical forces that disrupt the balance of the occlusal relationship. More commonly, the maxilla or the upper jaw appears to be narrow and contributes to significant degree of crowding in the mouth. Early investigators [1-4] discovered that rapid maxillary expansion resulted in a splitting of the median palatal suture. The expansion is …

The Effect Of Light Curing Tip Angulations On The Shear Bond Strength Of An Orthodontic Adhesive, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

The purpose of this study was to investigate the effect of light curing tip angulations on the shear bond strength of an orthodontic adhesive. Three groups of thirty premolar teeth had brackets attached in a standardized manner using Transbond XT. The orthodontic adhesive were cured with a Blue LED light curing unit for 40 seconds using three different angulations 0 degrees, 45 degrees and 9 degrees at a standardized 3 mm distance. The debonding force was measured using an Instron Universal Testing Machine. Data were computed and analysed using SPSS version 12.0. Kruskal-Wallis test was employed to compare the shear …

Validation Of Cone Beam Ct Scan For Measurement Of Palatal Depth In Study Casts, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

The purpose of this study was to validate the use of digital dental study casts obtained from Cone beam CT Scan (CBCT) against gold standard; that is traditional dental study cast measured with digital caliper. Thirty-four study casts of Malaysian Aborigines were selected from Centre of Malaysian Pribumi Studies Databank. Palatal depth of each study casts were measured using Mitutoyo digital caliper. Subsequently, all the study models were scanned using i-CAT CBCT and the palatal depth were measured using i-CAT software. Data were analysed using SPSS version 12.0 where Intraclass correlation and paired T-test were employed. There was no significant …