Zuha Ayad Jaber Jedy

Peracetic acid (PAA) is widely used as a sterilizing/disinfecting agent, and, in endodontics, it has been introduced as a promising irrigant in root canal treatment. It has been used at different concentrations to achieve various functions. However, endodontic instruments in contact with PAA of a certain concentration may affect their fatigue resistance. Therefore, the aim of this study was to investigate the impact of PAA on the cyclic fatigue resistance of three commercial heat-treated nickel-titanium (NiTi) rotary files. Three types of heat-treated NiTi rotary files were selected: One Curve (OC), ProTaper Gold (PTG), and Wave One Gold (WOG). Each type was divided into three subgroups (n = 6 for each file type): (1) untreated instruments; (2) files immersed in 0.002% PAA; and (3) files immersed in 0.35% PAA. The performance of each file type was tested in a simulated canal. The number of cycles to fracture (NCF) was determined to assess cyclic fatigue resistance of the files. Independent sample t-test was applied to compare each treated file within a subgroup with its respective control group, and one-way ANOVA was used for comparison among the main groups. All types of tested files revealed a significant decline in the cyclic fatigue resistance after exposure to 0.002% PAA except the PTG (P=0.209). After exposure of the files to a higher concentration (0.35% PAA), a dramatic reduction was demonstrated by all the groups. Before and after exposure of the files to PAA, PTG displayed the highest cyclic fatigue resistance, followed by the WOG, while the OC showed the lowest resistance. Exposure of heated-treated NiTi files to PAA in a relatively high or low concentration adversely affects the cyclic fatigue resistance. The PTG files demonstrated the best performance among the tested types and can be disinfected with 0.002% PAA for clinical purpose.

Objectives: the cosmetic dentistry request to increase the duration of veneers and crowns to the tooth structure, which increase the cosmetic translucent zirconia duration. Aims: the research objective is to Contrast of shear bond strength of translucent zirconia veneers bond to the enamel among changed light intensity. Method: thirty upper-removed premolar was used. Thirty translucent zirconia discs were made according to manufacturing direction then randomly dived into two assemblies. Using bisco choice2 resin cement is light cured. The two assemblies dropped into I group and II group, Group I: low intensity light power has at 1000mW / cm² (10 Sec) used. Group II: high light intensity groups that is high intensity power at 1400 mW/cm² (4 Sec) used. Results: high significant difference (<0.001) Statistically among groups II and I in means for low intensity assemblies is 10.12 Mpa however the high light intensity assemblies mean 16.97 Mpa. Conclusions: Giving to this study the high intensity light more efficient bond force of translucent zirconia veneer to the enamel than low intensity light.

AbstractABSTRACT : The reciprocating file program was claimed the resistance be increased to fatigue in evaluation with the rotation file program.Newly 2 new kinds of NiTi files have been marketed one curve file and VDW blue. The purpose of this study was to comparison of cyclic fatigue resistance amongProTaper gold, one curve, WaveOne® Gold and VDW blue files. Cyclic fatigue testedfour files with the zirconia artificial canal curve 45 canal a simultaneouspecking motion hasobtain with (n = 6 each) instrument that (operataccording to recommended reciprocationmotion until the ProTaper gold, one curve, WaveOne® Gold and VDW blue filesfractured . ProTaper F2 and one curve were tested incontinuous rotation and WaveOne® Gold and VDW blue files tested in reciprocation movement. (NCF) represent number ofcycles to fracture which obtain by measuring the time spend to fracture. Using one-way statisticanalysis. The results revealed that VDW blue had higherNCF&then One-curve and then WaveOne gold and the ProTaper gold F2 had a lowest NCF. Reciprocating files VDW blue demonstratedsignificantly higher cyclic fatigue than others files (P <0.01). The 2 brands of NiTi file VDW blue and One-curve appear to have superior mechanical properties than WaveOne gold and ProTaper gold F2.

Background: Bonding of orthodontic brackets of fixed orthodontic appliance by using acid etch technique was first introduced in 1955. LED-based lightsources posses many benefits as minimal heat generation.There is a new generation of LED light cure corporate with three different intensities (standard, high power and extra power). Objective: this study was aimed to evaluate the effect of increasing intensity and decreasing duration of LED light on shear bond strength and adhesive remnant index of metal orthodontic brackets. Materials and Method: Sixty healthy extracted maxillary premolars were divided into three groups of twenty teeth for each, group (Ι) cure with a standard LED light curing (1000mW/cm2) for 10 seconds, group (ΙΙ) cured through a high-intensity LED curing light (1400mW/cm2) for 8 seconds, group (ΙΙΙ) cured with a extra high-intensity LED curing light (3200mW/cm2) for 6 seconds. The teeth mounted in acrylic resin, Shear bond strength test was done. Then, adhesive remnant index (ARI) was evaluated. Data were analyzed by one-way analysis of variance ANOVA test and LSD, and Fisher exact test. Results: The results showed that there were statistically significant differences among the study groups. The maximum value of shear bond strength was for group ΙΙΙ (17.834 ± 0.367) and the minimum shear bond strength value was for group Ι (8.888 ± 0.307). ARI scores showed a statistically significant differences among groups, with a high tendency toward score 1 and score 0 in all three groups. Conclusion: High intensity LED light with low curing duration has advantage of increasing bond strength in addition to reducing chair time taken for curing procedure and enamel cleaning following de-bonding procedure without any effect on the enamel integrity.

Abstract: To evaluation the effect of different surface treatment on shear bond strength between composite increments to determine the most effective procedure that increase bond strength between composite increments Methods: four groups used in this study and each group consist of 20 blocks of composite

She is a member of the Postgraduate Studies Committee at the College of Dentistry

member of the Central Educational Supervision Committee at the dentistry college.

Conference of root canal fillings in baghdad