Objective:The aim of the present study was to compare the canal transportation, centering ratio, debris and smear layer score after using 3 rotary Ni-Ti systems, Revo-S (RS; Micro-Mega, Besancon Cedex, France) and ProTaper Next (PTN; Dentsply Tulsa Dental Specialties, Tulsa, OK) and M-Pro system( Guangdong, China, Mainland). Material and methods: Thirty nine mesiobuccal root canals of extracted lower first molars with 20˚ to 45˚ angle of curvature and were divided randomly into 3 groups of 13 samples each: group RS, group M-Pro and group PTN. Root canal transportation and centering ratio were evaluated at 3, 6 and 9 mm from apex using i-CAT CBCT (Hatfield, pennsylvania ,USA) before and after preparation.Thirteen Roots from each group were split longitudinally using diamond disc, by making a groove on buccal and lingual side of root without reaching the lumen of the canal.The root halves were examined under Scan Electron Microscope (SEM) by magnification x 1000 and x 4000 for debris and smear layer respectively The significance level was set at P ≤ 0.05. Results: There was no statistically significant difference in canal transportation, canal centering ratio, debris and smear layer score between the three tested groups. Conclusion: From the obtained results and within the limitations of this study, the following could be concluded:M-Pro Nickel Titanium rotary system had a negligible effect on root canal transportation which was similar to the ProTaper Next and Revo-S systems and no system was able to clean the root canal system completely.

Aim: To compare strontium ranelate as a pulp capping agent to bisphosphonate and calcium hydroxide. Materials and methods: The pulps of 36 premolars from 4 dogs were exposed and capped with one of 3 test materials, namely strontium ranelate, bisphosphonate, and calcium hydroxide. Half of the specimens underwent histologic evaluation at 6 weeks and the remaining half were assessed at 12 weeks. Each slide was scored from 1 to 3 according to hard tissue formation, inflammation, and odontoblastic differentiation. The pH of the 3 materials was also measured. Data were inspected using SPSS software and the recorded scores were statistically analyzed at 6 and 12 weeks. Results: Calcium hydroxide was the only material that exhibited discontinuous dentin bridge at both evaluation periods. Strontium ranelate showed irregular hard tissue formation in few of the samples at 12 weeks; while bishphonate did not induce any hard tissue formation. All the materials exhibited severe to moderate inflammatory reaction at 6 weeks which subsided to mild inflammation at 12 weeks. Differentiation of odontoblasts was observed with all materials at both evaluation periods with no significant differences among them. The average pH obtained for Dycal base was 9, and 12 for the catalyst; for bisphosphonate the value was 6.8; and 8.6 for strontium ranelate. Conclusions: Strontium ranelate was not as effective as calcium hydroxide as a pulp capping agent, while bisphosphonate failed to show any potential for hard tissue formation up to 12 weeks. However, all the test materials allowed healing of the pulp tissues.

The objective of this study was to determine and compare the Push-out bond strength of AH Plus sealer of root canal following prior application of calcium hydroxide (Ca[OH]2) paste and Nano-silver gel as intracanal medication in single-rooted human extracted maxillary incisors. Methodology: Using of ProTaper System up till master apical file # F5 have been carried out to prepare root canals of 30 human extracted maxillary incisors. According to the intracanal medication applied, division of teeth were carried out in random manner into three groups. Group I: Control group (No intracanal medication), Group II: Nano-silver gel and Group III: Calcium hydroxide Ca(OH)2. Three weeks later, the elimination process of the intracanal medications were achieved by using passive ultrasonic irrigation of 5 mL 2.5% NaClO, in addition to that, a 17% EDTA was used in the step of final flush for duration of 60 seconds succeeded by 5 mL of distilled water. Using the master cone #F5 and AH plus sealer, the single cone approach was used to fill the canals. After 1 week, the universal testing machine was implemented to test the push out-bond strength of the samples, which was performed for a 2-mm-thick of coronal, middle and apical thirds of each root. Results: A remarkable difference was evident between the control group and the comparison groups (p<0.001). Within the control group, the greatest value was evident (4.85±1.65), followed by calcium hydroxide (2.11±1.17), meanwhile the lowest value was discovered in nano-silver (1.41±1.08). Post hoc pairwise comparisons demonstrated a remarkably higher value in the control group than the rest of groups (p<0.001) with no statistically remarkable difference between calcium hydroxide and Nano-silver group. Conclusion:Prior calcium hydroxide and nano-silver placement seemed to decrease the push-out bond strength of epoxy resin-based Ah plus sealer.

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Due to its capacity to carry out traditional human tasks at any time of day, digital transformation is essential to the hospitality sector since it reduces costs significantly, eradicates human mistake, and offers better customer service. With the use of artificial intelligence applications, the possibilities of improving customer service are the main goal of the organization. The main purpose of this paper is to examine the impact of digital transformation on guest loyalty at Marsa Alam hotels, which is considered as one of the main destinations in Egypt. The field study was conducted through a web-based survey of a sample of hotel guests in Marsa Alam, where 384 questionnaire forms were distributed and 323 were valid with a response rate of (83.8%). SPSS software version 22 was used to analyze the data. The study findings showed that there are a positive relationship between digital transformation and guest loyalty. Digitalizing hotel operations includes many benefits such as increased brand awareness, improved guest experience, and increased operational efficiencies. The recommendations included: The necessity of activating Egypt's Vision 2030, create a technological infrastructure for the digital economy, announce digital transformation initiatives through digital platforms.