research centers


Search results: Found 3

Listing 1 - 3 of 3
Sort by

Article
Determination of the Effect of Conventional Elastomeric Ligature of Different Ligation techniques versus Nonconventional type on Canine Position using Frictional Mechanics (Typodont Study)

Author: Zaid S Tawfek
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2013 Volume: 13 Issue: 2 Pages: 358-365
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

Aims: To evaluate the effect of different ligature types and ligation techniques on the rate of space closure, tipping and rotation of canine after sliding. Materials and Methods: The total number of the samples were 50 sample classified under five groups according to the method and type of ligation; the first group: preformed stainless steel ligature wire (SL), the second group: preformed stainless steel kobayashi ligature wire (KL), the third group: elastomeric ligature in figure – O (EO), the fourth group: elastomeric ligature in figure – 8 (E8) and the fifth group: non-conventional Slide Leone elastomeric ligature (NE). A typodont used in this study with preadjusted Roth stainless steel brackets 0.022×0.030 inch and a stainless steel orthodontic arch wire 0.017×0.025 inch. A bite plane extension bar (BPB) and canine extension bar (CB) are constructed for the measurement of canine tipping and rotation. A 180 gm. of force applied by short continuous elastomeric power chain to retract the right canine. After immersion of the typodont in water bathe with 50-55 0C for 5 minutes, the rate of space closure were measured in millimeter using vernier (from the distal wings of canine bracket and the mesial wings of the second premolar), the tipping and rotation were measured by taking a photograph to the typodont using digital camera, with transvers projection (for tipping) and occlusal projection (for rotation) from right side (directly toward the right canine), then the angle between (BPB) and (CB) measured directly on the photograph using Protractor. Results: A statistical analysis (descriptive statistics, ANOVA and Duncan Multiple Analysis Range Test) used in this study, for the rate of space closure the results showed that there is a significant difference between the five groups at p ≤ 0.001, the NE group had the highest amount of tooth movement while KL group had the lowest level, for the tipping; the NE group had the highest level of tipping while SL, KL and E8 groups had the lowest level with a non-significant difference between them, for the rotation; the results showed that NE group had the highest level of rotation, while KL group had the lowest level. Conclusions: The higher rate of space closure, the higher rotational degree and the higher tipping degree were associated with NE group, while KL group had shown the lowest rate of space closure and the lowest rotational degree. The lowest degree of tipping was associated with the SL, KL and E8 groups.


Article
Evaluation of The Effect of Immersion Periods in The Artificial Saliva on The Surface Roughness of Three Types of orthodontic Arch Wires

Authors: Zaid S Tawfek --- Khudair A Al–Jumaili
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2008 Volume: 8 Issue: 1 Pages: 72-78
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

Aims: To evaluate the effect of immersion periods in artificial saliva on the surface roughness of an arch wire. Materials and Methods: The roughness of three types of orthodontic arch wires: stainless steel (SS), titanium molybdenum alloy (TMA) and composite coated wire (CC) were first measured at dry condition then incubated in artificial saliva at 37 o C with saliva pH (7.25) for different immersion periods (1, 14 and 28 days). Then the surface roughness was measured by using Taylor Hobson Profi-lometer (Talysurf type 10). Results: There was a significant increase in surface roughness of the three types of wires during the first day of immersion but as the immersion periods increased, it showed a non significant difference in the roughness of SS and TMA. The roughness of CC however, increased. Conclusions: It was concluded that the surface roughness of SS and TMA wires increased during the first day of immersion, such increase is not significant after that, while in case of CC, as the immersion periods increase the surface roughness significantly increased.


Article
Shear Bond Strength of Resin Modified Glass Ionomer Cement Using Different Enamel Conditions

Authors: Mohammed T Younis --- Zaid S Tawfek --- Mustafa M Hamed
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2010 Volume: 10 Issue: 1 Pages: 127-132
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

Aims: In an effort to improve the shear bond strength of resin modified glass ionomer cement on orthodontic brackets, various enamel conditioning have been evaluated for use with this cement. Materials and methods: A total of 100 freshly extracted human premolars were subjected to two steps of treatment. The first step of treatment involve dividing the teeth into 5 groups each of 20 teeth: (I) treated with 20 second acid etching with 37% phosphoric acid; (II), treated with micro–etching using 50 μ aluminum oxide; (III), treated with air polisher using 45 μ sodium bicarbonate; (IV), treated with coarse finishing disk for 10 second; (V), left the enamel clean without treatment. In the second step each group then subdivided into two subgroups, ten teeth subjected to wetting with tab water and ten left dry. Following, storage for 24 hours at 37°C in distilled water, shear debonding force was measured using a Universal Testing Machine with a cross–head speed of 10 mm/minute. Results: The result indicated that the highest shear bond strength was for acid etched enamel under wet condition with lowest mean for normal dry enamel. the Mann–Whitney analysis estimated a significant difference between wet and dry condition in general with high probability of bond failure for the dry than that of wet conditions. Conclusions: The suitable enamel conditions regarding the shear bond with the mode of bond failure had been shown to be the wet and dry situation of group III and wet situation of group IV. But, it could be concluded that the most suitable enamel condition may be that treated with a coarse finishing disk under wet condition.

Keywords

Listing 1 - 3 of 3
Sort by
Narrow your search

Resource type

article (3)


Language

English (3)


Year
From To Submit

2013 (1)

2010 (1)

2008 (1)