Background: Esthetic correction represents one of the clinical conditions that required the use of laminate veneers in premolars region. Aim of the study: The purpose of this study was to evaluate the fracture strength of the laminate veneers in maxillary first premolars, fabricated from either composite (direct and indirect techniques) or ceramic CAD/CAM blocks. Materials and Methods: Fifty sound human maxillary premolar teeth were used in this in vitro study. Teeth were divided randomly into one control group and four experimental groups of ten teeth each; Group A: Restored with direct composite veneer (Filtek Z250 XT), Group B: Restored with indirect composite veneers (Filtek Z250 XT), Group C: Restored with lithium disilicate ceramic CAD/CAM blocks (IPS e. max CAD) and Group D: Restored with resin nano ceramic CAD/CAM blocks (Lava Ultimate Restorative). Standard preparations were done using Ceramic Veneer Set (Komet). Indirect laminate veneers were cemented with the Relyx Veneer Cement (3M ESPE) and all specimens were stored in distilled water at 37°C for 2 weeks. The load was applied on the occlusal part of the veneer at 45˚ to long axis of the tooth using universal testing machine. Results were analyzed with one-way ANOVA and LSD tests. Specimens were examined by stereomicroscope at a magnification of 20x to evaluate the mode of failure. Results: Control group showed higher mean of fracture strength with highly significant difference in comparison to the experimental groups (P<0.01). (Group A) showed higher mean of fracture strength with statistically significant difference in comparison to (Group B and Group D). On the other hand the difference between (Group A and Group C) was statistically highly significant. Statistically non-significant difference was found among the three indirectly restored groups. Conclusions: All veneers used in this study can be considered as acceptable treatment in the premolars region for patients with normal biting force. Direct composite veneer is the most favorable technique in term of fracture strength, while IPS e. max CAD laminate veneers were least likely to fracture and most likely to completely debond.
esearch Summary
Holidays and occasions in Islamic societies have a legal character and origin. Some of them are proven by the words and actions of the legislator, and some are within the scope of custom that is regulated by the honorable Sharia, and others are approved by scholars and people because of their connection, piety and charity. It has a kind of good.
One of the purposes of the noble Sharia is to glorify the honorable times associated with the blessed events, so that lessons and lessons may be recalled in them, and to activate the legitimate gifts in those events that develop in the individual, the family and the community the meanings of goodness and honor and all that is good and good. Accord
... Show Morestudy was conducted on a stretch of Tigris river crossing Baghdad city to determine the concentration of some chlorophenols pollutants. Aqueous samples were preliminary enriched about 500 times and the chlorophenols have determined using high performance liquid chromatography HPLC. Limits of detection LOD were (0.007–0.012 mg L-1), relative standard deviations RSD% were 2.4%–5.59% and relative recoveries were 51.06%– 104.07%. The existence of chlorophenols in Tigris river was in the range 0.023–4.596 mg L-1. The developed method suggested in this study can be applied for routine analysis and monitoring of chlorinated phenols in environmental aqueous samples.
Taliban has returned to the forefront since regaining control of Afghanistan in mid-August 2021, prompting the international community and researchers to speculate whether it has adopted a different political vision and ideology from its previous rule (1996-2001). The previous rule presented a distorted version of governance that lacked clear political and ideological foundations, characterized by impulsive and chaotic decisions, and the absence of a comprehensive theoretical and intellectual framework for governance.
Once again, Taliban returned to power on August 15, 2021, and took control of the country. This raised many questions about Taliban's return, the extent of its flexibility and adaptability that allowed the movement t
... Show MoreABSTRACTBackground: cochlear implants are electronic devices that convert sound energy into electrical signals to stimulate ganglion cells and cochlear nerve fibers. These devices are indicated for patients with severe to profound sensorineural hearing losses who receive little or no benefit from hearing aids. The implant basically takes over the function of the cochlear hair cells. The implant consists of external components (microphone, speech processor and transmitting coil) and internal components (receiver stimulator and electrode array). The implant is inserted via a trans mastoid facial recess approach to the round window and scala tympani.Objectives: to determine the effectiveness and safety of non fixation method in cochlear imp
... Show MoreThe most common cause of death is cardiovascular disease (CVD), with ischemic heart disease being the most notable type. There is a propensity to raise the sensitivity of methods in contemporary laboratory for diagnosing of CVD, and assessing key as CVD bio-indicators. The urgent task is to seek for different indicators as a hopeful tool for early detection and monitoring of myocardial infarction in blood samples only. This study comprised 117 Volunteers, recorded with both genders in the age range of 32-64 years old. The volunteers were categorized into two groups: 67patients of myocardial infarction, other group embraced 50 healthy individuals. The samples of blood were collected and directed for biochemical analysis to evaluate estr
... Show MoreThe parasite Alchammannia Aaúlan Ahdma backbone and the other for Avgari and moves them alternately Vafiqra is Alannsan and Allbaún and other either Allavgari is an insect Aharms or sand fly of the genus deployed in the ancient world is different form the parasite and installed Albayukimaaúa in each of the Family is so when transmitted from host to another passes stages growth
The present research focuses on the study of the effect of mass transfer resistance on the rate of heat transfer in pool boiling. The nucleate pool boiling heat transfer coefficients for binary mixtures (ethanol-n-butanol, acetone-n-butanol, acetone-ethanol, hexane-benzene, hexane-heptane, and methanol-water) were measured at different concentrations of the more volatile components. The systems chosen covered a wide range of mixture behaviors.
The experimental set up for the present investigation includes electric heating element submerged in the test liquid mounted vertically. Thermocouple and a digital indictor measured the temperature of the heater surface. The actual heat transfer rate being obtained by multiplying the voltme
... Show MoreIn this study four cheese samples were randomly collected from local markets. These cheese samples were Ishaqi, Danone, Arab white cheese and Agricultural college cheese.
Results obtained revealed that all these cheese samples were contaminated by fungi in addition to the presence of same heavy metals under study which were Fe, Pb, Ni and Cr. All fungal contaminat were identified which were contaminated them in winter (January). However, fungal pollution in summer was 100% while in winter was 50% Aspergillus niger was polluted chees samples100% in summer while it was 75% in winter. Aspergillus fumigatus was polled cheese samples under study 50% in summer and 0% in winter .Results for heavy metals determination revealed that Fe was con
The study tries to answer several questions posed by the subject, one of the important: How the Internet promotes rumor? And what are the most Internet applications that promote rumor? And the practical ways to reduce these negative? Using the process of in vestige and reading theoretical heritage available in this field, and inferred the numbers and statistics marked the uses of the Internet and its applications over recent years, and the characteristics of each these tools in the field of collection, processing, and dissemination of information
A simple, new, and sensitive spectrophotometric technique for the determination of methyldopa was presented in this research article. The suggested technique includes reacting metoclopramide with NaNO2 in the presence of hydrochloric acid to produce diazonium salt, and then the drug methyldopa reacts with the diazonium salt to produce a yellow azo dye. The maximum wavelength of the dye was 458 nm. This method is effectively used for the determination of methyldopa in different pharmaceutical formulations. It has been found that there are no significant interactions between common excipients and pure methyldopa. The results were processed statistically, and compared with those obtained from officially approved methods, they were found to be
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