one of the main factors that affect the success of the cast crown is the accuracy of the internal and marginal fit, a well-fitting crown reduces the chance for recurrent caries and periodontal disease, whereas the space between a poorly-fitting crown and tooth preparation enables accumulation of bacterial plaque, the use of paint- on die spacing technique to produce the cement gap and subsequently to improve the seating of the cast crowns has become quite popular in the recent years. The purpose of the study is to compare the marginal gap and the internal fit produced by two paint-on die spacing materials (Manicure and paint on die spacer ). Twenty four identical stone dies were made, 12 were coated with paint- on die spacer material, and 12 were coated with nail varnish material, the dies coated with die spacer were divided into three groups (DA,DB,DC), and the dies coated with nail varnish were also divided into three groups (VA,VB,VC), groups DA and VA were coated with one layer, DB and VB were coated with two layers, DC and VC were coated with three layers, for both groups wax patterns were made and casted using the lost waxing technique and all steps were standardized, impression replicas of the casted crowns were made and sectioned by means of the impression replica technique, measurements were taken using Scanning Electron Microscope, from 4 points (marginal gap, mid-axial, axio-occlusal and mid-occlusal). There was no statistical significant difference in accuracy between crowns fabricated on die spacer coated dies and crowns fabricated on nail varnish coated dies. with the crowns fabricated on die spacer coated dies being slightly more accurate.
ABDUSSALAM ELJABALI(12-2019)

INTRODUCTION: CAD/CAM denture base materials are milled from pre-polymerized pucks of resin that are highly condensed. So, they provide no polymerization shrinkage eliminating its subsequent disadvantages. This technology offered improved fit, strength properties and more bio-hygienic denture bases compared with conventional processing of the denture base material. OBJECTIVES: The aim of the study was to evaluate the physico-mechanical properties of CAD/CAM denture base material and the effect of thermo-cycling on it compared with the conventional one. MATERIALS AND METHODS: The study was conducted on two parallel groups, divided according to the denture material used. Group (1) conventional PMMA (control group), group (II) CAD/CAM PMMA (study group) of 40 specimens each (16 for impact strength, 16 for flexural strength, 8 for surface roughness and grinded powder form both materials for residual monomer test). Each group was divided into 2 sub-groups: (A) No thermo-cycling and (B) Thermo-cycling, then subjected to 4 different tests, impact strength, flexural strength, surface roughness and residual monomer tests. Data were collected, tabulated and statistically analyzed. Significance level was set at 5%. Bar charts were used for graphical presentations. RESULTS: Our study revealed a highly statistically significant decrease in residual monomer of CAD/CAM PMMA material in both conditions before and after thermo-cycling when compared to conventional PMMA material, which therefore leads to enhanced impact strength and significantly reduced surface roughness after heat treatment. On the other hand, also a highly significant reduction of its flexural strength after thermocycling has been observed. CONCLUSIONS: CAD/CAM dentures with lower amount of methacrylate monomer exhibit more favourable physico-mechanical properties and they have a long-term biocompatibility even with thermal changes making them a more satisfactory as a denture base material for edentulous patients.
Yusra Muftah Saad Elfaidy, Ahmed M. Abdelhamid, Sonia M. Elshabrawy(12-2018)

Background and Objectives: Compliance of community pharmacies with the proper practice of storage and dispensing of medicines is crucial for ensuring the quality and safety of medicines, particularly with the circumstance of recurrent electricity blackout in Libya. This study was aimed to assess the compliance of community pharmacies with the proper practice of drug storage in Tripoli city, Libya. Materials and Methods: A cross-sectional survey conducted in November 2020 targeting a total of 56 community pharmacies in Tripoli, Libya. The questionnaire was adapted from the WHO Checklist for Good Storage Practices and included 41 questions organized under five sections: socio-demographics, pharmacist’s attitude toward the quality of storage practices, queries on environmental storage conditions, the quality of facilities in the community pharmacy, and queries on storage and pharmacy practices. Data were presented as descriptive statistics. Results: Out of the total 56 visited pharmacies, a total of 46 (82.1%) pharmacists participated in the study with one pharmacist being interviewed in every pharmacy. Results showed that 15% of employees reported variety of cleanliness regulatory depending on cutting off running water circumstances in Tripoli and other reasons. About 78.8% participants observed dust in shelves and over the drugs packaging, and 22% of the participant pharmacies’ drugs exposure to direct sunlight. Additionally, 72% of employee experienced high temperatures in the pharmacy during electricity blackouts, whereas only 48% of them experienced humidity. In addition, 91.4% had alternative source of electricity, 44.3% had a power backup connected to the refrigerators. Conclusion: The compliance of majority of the community pharmacies operated in Tripoli is below standard. There is still need to improve the storage practices in the community pharmacies by obeying with the regulatory standards as specified by the Drug Regulatory Authority of Libya.
Ahmed Elbadri M Atia(5-2021)