Background: preparation of root canals is an important step in root canal treatment. Mechanical instrumentation of root canals cause an irregular layer of debris, known as the smear layer. As a result, several studies reported that preferring the removal of the smear layer. Objective: To study the influence of the energy (100 mJ) of Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser at short pulse duration (60 μs) on smear layer removal of apical third after using Photon induced photoacoustic streaming technique. Materials and methods: Eighteen straight single-rooted mandibular premolars were used. The roots length were uniform to 14mm from the anatomic apex and instrumented using Protaper Gold Rotary NiTi file system to size 40 taper 0.06. Er,Cr:YSGG pulsed laser (waterlase iplus Biolase, CA, USA) 2780 nm was used at short pulse duration (60 μs, 5 Hz ,air and water off) delivered by MD/iplus Glass Tips (MZ6) 600 μm in diameter, length=6 mm, calibration factor= 1.00. Ultrasonic activator ENDO1 (Guilin Woodpecker Medical Instrument Co., Ltd.china) was used with Ultrasonic activator tip ED98 (25#, 2% taper, 18.5mm) (Guilin Woodpecker Medical Instrument Co., Ltd.china). The samples were arbitrarily divided into three groups (n=6) and used as follows: (A) conventional irrigation with 5 ml of 17 % EDTA, (B) passive ultrasonic irrigation with 5 ml of 17 % EDTA, (C) Er,Cr:YSGG induced photoacoustic streaming with 5 ml of 17 % EDTA. After final irrigation with normal saline and drying, the roots were painted with nail varnish externally, and 2% methylene blue dye injected into canal until the canal filled with dye. The tooth was splitted at the fourth millimeters from root apex with a diamond disc representing the apical third. Picture was taken by Professional Digital SLR camera (Nikon D7100, Nikon Corporation, Thailand) with 40X magnification. The dye penetration was measured by using analytical software (measure picture CAD-KAS Kessler Germany). ANOVA test was used to analyse repeated measure mean between tested concentration (5.25% NaOCL, 17% EDTA) and control. Data was expressed as mean±SD. LSD (Least Significant Difference) test was used to calculate the significant differences between tested mean. Results: The mean values of the percentage of dye penetration area in two experimental groups was higher than the control group, as the follow (20.79±1.15control, 34.5453±0.45 ultrasonic group, 85.9804±2.69 Er,Cr.YSGG+17%EDTA at 0.5 W). The Percentage of dye penetration in Er,Cr:YSGG laser induced photoacoustic streaming with 17% EDTA was significantly high (P value 0.001), followed by ultrasonic activated group, while control group result in less Percentage of dye penetration than both study groups. Conclusion: In this study, we concluded that Er,Cr:YSGG pulsed laser (0.5 W,5 Hz , air and water off) at short pulse duration (60 μs) with 17% EDTA using PIPS technique for activation of irrigant in endodontic treatment give better result than ultrasonic activation in smear layer removal
The settlement rate and pore water pressure dissipation rate are mainly controlled by the permeability of soil. Both laboratory and field tests show that the permeability is varied during the loading and consolidation process. It is known that consolidation process is accompanied by decrease in void ratio which leads to decrease in the coefficient of permeability. The importance of the decrease of the coefficient of permeability on the time rate of settlement and pore water pressure needs to be investigated.
This paper takes into account the change in coefficient of permeability during consolidation and studies its effect on consolidation characteristics of a clay layer. The finite element method is used in the analysis and the packag
(2)
Background: The marginal adaptation has a key role in the success and longevity of the fixed dental restoration, which is affected by the impression and the fabrication techniques .The objective of this in vitro study was to evaluate and compare the marginal fitness of lithium disilicate crowns using two different digital impression techniques (direct and indirect techniques) and two different fabrication techniques (CAD/CAM and Press techniques). Materials and Methods: Thirty two sound upper first premolar teeth of comparable size extracted for orthodontic reason were selected in this study .Standardized preparation of all teeth samples were carried out with modified dental surveyor to receive all ceramic crown restoration with 1 mm deep
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(3)
Background: Ceramic veneers represent the treatment of choice in minimally invasive esthetic dentistry; one of the critical factors in their long term success is marginal adaptation. The aim of the present study is to evaluate the marginal gap of ceramic veneers by using two different fabrication techniques and two different designs of preparation. Material and methods: A typodont maxillary central incisor used in the preparation from which metal dies were fabricated, which were in turn used to make forty stone dies. The dies divided into four experimental groups, each group had ten samples: A1: prepared with butt-joint incisal reduction and restored with IPS e.max CAD, A2: prepared with overlapped incisal reduction and restored with IPS e.
... Show MoreObjective: To evaluate and compare the effect of mechanical surface treatment (groove, aluminum oxide particles)
with 45 degree bevel type of joint on tensile bond strength of acrylic specimens repaired by two curing methods
(microwave and water both).
Methodology: Eighty specimens (80) were prepared from pink heat cure acrylic resin. They were divided into two
main groups (40 specimen repaired by microwave energy and 40 specimens repaired by water bath method).Each
group can be divided into four subgroups of ten according to the surface treatment. The control group A was left
intact, group B received no surface treatment, group C and D received surface treatment by (groove, 50 m aluminum
oxide particles). Specimens
The goals of endodontic preparation were to shape and clean the space of the root canal and remove microorganisms, affected dentin and pulp, the apical foramen and the canal curve should be protected from being transported during endodontic canal preparation. The aim of this study was to evaluate the curve straightening of curved root canals and apical transportation after preparation with four rotary systems. Forty mesial roots of the lower 1st molars teeth only the mesiobuccal canals were used, these roots were immersed into cold clear acrylic , the teeth roots divided into four groups according to rotary system used for preparation of the canals (ten roots for each group):. group I: ProTaper Next rotary system, group II: IRaCe Plus rotar
... Show MoreThis research deals with the use of a number of statistical methods, such as the kernel method, watershed, histogram, and cubic spline, to improve the contrast of digital images. The results obtained according to the RSME and NCC standards have proven that the spline method is the most accurate in the results compared to other statistical methods.
Objective(s): To assess the effect of removable partial dentures on the abutment teeth in comparison with that of the
remaining dentition, and to investigate the effect of regular check up on periodontal health for patients using this
type of prosthesis.
Methodology: One hundred patients wearing removable partial dentures for at least three years included in the
study. Teeth used as direct or in direct retainers for the removable partial denture were considered as the study
group, while the remaining dentition in the same jaw was considered as the control group. The following periodontal
parameters were registered for each tooth, plaque and gingival indices, clinical attachment level and tooth mobility.
Patients were
Background: Although methotrexate (MTX) is a frequently used chemotherapy drug, its effectiveness is sometimes hampered by the drug's toxic consequences. Omega 7 is a monounsaturated fatty acid, with different anti-inflammatory, anti-diabetic anti-obesity applications, and its possible protective effects against MTX-induced blood toxicity were investigated in this study. Objective: Evaluation of possible protective effects of omega7 against MTX-induced blood toxicity. Methods: 30 mice were divided into five groups, the First group take liquid paraffin orallyfor 7 days for served as negative control and the second group take methotrexate (20mg/kg) intraperitoneallyto serve as a positive control,the third group takes omega 7 (100mg/kg
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The objective of all planning research is to plan for human comfort and safety, and one of the most significant natural dangers to which humans are exposed is earthquake risk; therefore, earthquake risks must be anticipated, and with the advancement of global technology, it is possible to obtain information on earthquake hazards. GIS has been utilized extensively in the field of environmental assessment research due to its high potential, and GIS is a crucial application in seismic risk assessment. This paper examines the methodologies used in recent GIS-based seismic risk studies, their primary environmental impacts on urban areas, and the complexity of the relationship between the applied methodological approaches and the resulting env
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