research centers


Search results: Found 6

Listing 1 - 6 of 6
Sort by

Article
An evaluation of the effect of retention means on increasing the debonding strength of the denture acrylic teeth attached to the denture base resin

Author: Abbas F. Al-Huwaizi عباس فيصل الحويزي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 1 Pages: 14-17
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Background: The debonding of acrylic teeth from the denture base is a challenging problem to the dentist and dental technician in which special means must be done to increase the debonding strength of the tooth.Material and method: Sixty specimens of acrylic central incisors were attached to acrylic rods and grouped into 5 groups according to the shape of the retention means placed at the tooth ridge lap. The specimens were strained under tension to examine their debonding strength.Results: The teeth with serrations (Group 2) have shown to be the most effective mean of increasing debonding strength, followed by the 2 longitudinal grooves (Group 4) where the difference between these groups was insignificant. Then followed by the teeth with 4 holes, and finally the difference between the teeth with a central groove and the control group were insignificant.Conclusions: It is recommended that the tooth ridge lap should be serrated with a fissure groove or placement of the 4 grooves to increase the debonding strength of the tooth.


Article
Evaluation of the stress concentration of different incisal ridge preparations of porcelain veneers (Finite element analysis)

Author: Abbas F. Al-Huwaizi عباس فيصل الحويزي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 4 Pages: 1-4
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Background: Porcelain veneers are under a great deal of stress which may lead to clinical failure as fracture ordettachment. This study examined whether different finishing lines and lingual shoulder preparations in the incisalarea of the maxillary central incisor affect the bond of the porcelain veneers.Materials and methods: A two- dimensional finite element model was made. Location and magnitude of maximumVon Mises stresses were calculated in porcelain veneer. Six types of preparations were drawn as:incisal overlap of0.5mm, 1mm and 1.5mm depth and lingual shoulder, and incisal overlap of 0.5mm, 1mm and 1.5mm depth withoutshoulder preparation.Results: Stress formation is maximum in the incisal edge region. All the lingual shoulder preparations presented betterstress distribution than the non shoulder preparationsConclusion: Stress is distributed more evenly when the tested preparation possesses a good thickness of porcelainand the more the surface area with incisal overlap the less possibility of bond failure


Article
Determination of the vertical dimension by cranio-facial measurement using clinical and cephalometric analysis (comparative study)

Authors: Abbas F. AL-Huwaizi --- Hadeel A. Al-Dhaher
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2009 Volume: 21 Issue: 4 Pages: 44-47
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

ABSTRACT
Background: Evaluating the maxillo-mandibular vertical dimension is of great importance in constructing successful
denture prosthesis, whoever it is a tedious process which may be misinterpreted leading to false readings. Hence with
the aid of cephalometric analysis a cephalogram may present a graphic representation of a problem to be met. This
study aimed to introduce a new mathematical method for determination the occlusal vertical dimension (O.V.D.).
Materials and methods: The first part was conducted to derive a clinical ratio between the O.V.D. and the ear-eye
distance, as well as to derive a radiographical ratio between the same distances using a computerized calibration
system on a lateral cephalometric view. The sample of this part consists of 34 dentate subjects (17 male and 17
female) of age range between 21-23 years old. The second part of this study aimed to evaluate the accuracy of
clinical and radiographical application of the ratios that were derived from the first part in estimating the O.V.D. from
the ear-eye distance measured in dentate subjects. The sample used in this part was 14 subjects (7 male and 7
female) of the same age range for the clinical and radiographical ratio.
Results: The clinical ratio of O.V.D./ear-eye distance is of significance in determination of O.V.D. for both dentulous
and edentulous subjects, while the radiographical ratio of O.V.D./ear-eye distance is of significance in determination
of O.V.D. in dentulous subjects only. There is a highly significant difference between the male and female ear-eye
distance (clinically) and significant difference between male and female ear-eye distance radiographically. As well
as, there is a non significant correlation between the clinical O.V.D. with ear-eye distance in male but significant in
female and total groups, and there is a significant correlation between them radiographically in female but of non
significant correlation in male and total groups.
Conclusion: the ratio of O.V.D./ear-eye distance could play a helpful role in the determination of O.V.D.
Keywords: Vertical dimension, cephalometric analysis. (J Bagh Coll Dentistry 2009; 21(4): 44-47).

Keywords


Article
Assessment of the properties of locally produced impression compound

Authors: Nameer H. Al-Hashimi نمير الهاشمي --- Abbas F. Al-Huwaizi عباس فيصل الحويزي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 3 Pages: 23-26
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Background: The goal of this study was the production of new type of impression compound that meets the ADA specifications along with being cheap and available in the local market.Materials and Methods: The basic ingredients were similar to those used by the commercially available products (Harvard, QD and Vevey). Specific properties were tested, like visual inspection, flow, reproduction of details, compatibility with stone, thermal expansion, and repeated use expiration.Results: The study proved that the new impression was within the limit of the American Dental Association specification No.3. (ADA No.3) (1), hence it could be used sufficiently.Conclusion: The use of the new impression compound for dental purpose is advised. Yet the reuse of the same product again and again is not advised because of the deterioration of the impression compound properties


Article
The Prevalence of Peg Shaped and Missing Permanent Maxillary Lateral Incisors in Najaf City
انتشار عدم وجود القاطع الجانبي العلوي الدائمي وجود القاطع الجانبي العلوي بشكل مخروطي في مدينة النجف الأشرف

Authors: Raed F. Al-Huwaizi --- Muhsin Hamza Khamis --- Anaam Sh. B. Al Hadad --- Abbas F. Al-Huwaizi
Journal: kufa Journal for Nursing sciences مجلة الكوفة لعلوم التمريض ISSN: 22234055 Year: 2013 Volume: 3 Issue: 3 Pages: 96-101
Publisher: University of Kufa جامعة الكوفة

Loading...
Loading...
Abstract

Background: The presence of a missing or peg shaped lateral incisor is a major concern for the subjects facial esthetics.Objectives: The objectives are to find the prevalence of peg shaped and missing permanent maxillary lateral incisors in Najaf City.Methodology: A cross sectional study was constructed and composed of 416 Iraqi students (215 males and 201 females) randomly chosen from 3 colleges of Kufa University in Najaf. Each subject was examined by visual inspection under day light looking for missing or peg shaped permanent maxillary lateral incisors.Results: The prevalence of missing maxillary lateral incisors was 3.8% (16 subjects) with an insignificant gender difference. There were two unilateral missing maxillary lateral incisor and 14 bilateral cases. Prevalence of peg shaped laterals was 4.3% (17 subjects) with an insignificant gender difference. Maxillary median diastema was found in 15.4% of the sample. Presence of missing lateral incisors showed a significant relationship with the presence of a maxillary median diastema.Conclusions: The presence of missing or peg shaped lateral incisors was found to be statistically significantly related to the presence of spacing and the presence of peg shaped lateral incisor showed a non-significant relationship with the presence of a maxillary median diastema

الخلفية: أن عدم وجود القاطع الجانبي العلوي الدائمي أو وجوده على شكل مخروطي يسبب مشاكل في الشكل الجمالي.الهدف: أن نجد نسبة عدم وجود القاطع الجانبي العلوي الدائمي و نسبة وجود القاطع الجانبي العلوي بشكل مخروطي في مدينة النجف الأشرف.المنهجية: تم إنشاء دراسة مقطعية تكونت من 416 طالب عراقي (215 ذكر و 201 أنثى) و بشكل عشوائي مختارة من ثلاثة كليات من جامعة الكوفة.تم فحص كل شخص تحت ضوء الشمس في النهار للبحث عن فقدان السن أو أذا كونه بشكل مخروطي.النتائج : أن نسبة عدم وجود القاطع الجانبي العلوي الدائمي كان 3.8% (16 شخصا) مع عدم وجود فروقات ذو أهمية بين الجنسين.كان هناك حالتان الفقدان موجود في جانب واحد من الفك و 14 حالة موجودة في كلا الجانبين.أن نسبة الشكل المخروطي للقاطع الجانبي العلوي الدائميكان 4.3% (17 شخص) مع عدم وجود فروقات ذو أهمية بين الجنسين.أن نسبة وجود فراغ بين القواطع الوسطية العلوية في العينة كان 15.4%. كما وجد علاقة ذو أهمية بين نسبة فقدان أو الشكل المخروطي للقاطع الجانبي العلوي الدائمي أحصائيا مع وجودالفراغ الوسطي للفك العلوي بين القواطع الوسطية. الاستنتاجات: كانت نسبة فقدان أو الشكل المخروطي للقاطع الجانبي العلوي الدائميأحصائيا ذو أهمية مع وجود فراغات بين الأسنان في الفك. بينما نسبة وجود القواطع العلوية الجانبية ليست ذو أهمية مع وجود الفراغ الوسطي للفك العلوي بين القواطع الوسطية.

Keywords

peg shape


Article
The Surface Hardness Measurement of Stone and Improved Die Stone After the Addition of a Mixture of Chemical Additives with Different Proportion

Loading...
Loading...
Abstract

Background: Incorporation of chemical additives has long been a technique used to improve properties of the gypsum products. The purpose of this work was to study the effects of adding a combination of gum Arabic and calcium hydroxide to a type III dental stone and type IV improved die stone with different proportion. The effect on water/powder ratio, and surface hardness was determined.Material and method: Both material stone and die stone were blended with two proportion of additives so that each material was mixed twice but with different proportion of gum Arabic (0.1% and 0.2%) and calcium hydroxide (0.5 % and 0.3%). Data for hardness were subjected to two-way analysis of variance.Results: The results revealed that the chemical additives were reduced the water requirements of gypsum products so that the reduction of water lead to increase the density of mixture that sets harder. For type III dental stone the additives significantly improved the surface hardness, while for type IV improved die stone the surface hardness was not enhanced except it was designed to be mixed at low water/powder ratio, and in some instances a reduction in hardness was observed, especially at the most reduced water / powder ratio (0.18)

Listing 1 - 6 of 6
Sort by
Narrow your search

Resource type

article (6)


Language

English (5)


Year
From To Submit

2018 (1)

2013 (2)

2009 (1)

2005 (2)