Aim:The purpose of this study was to evaluate in an in-vitro model the antibacterial efficacy of manually agitated nano-chitosan and nano-propolis as root canal irrigation protocols in comparison to manually agitated sodium hypochlorite against Enterococcus Faecalis. Material and Methods:The root canals of 50 single rooted human premolars were flattened to a standard length of 18mm cleaned and shaped to a size F5 Protaper, apices closed with composite, fixed into an Eppendorf vial with silicon impression material, autoclaved, and randomly assigned to the test groups (n=10) . Negative control was autoclaved and microbial analyzed. The other 40 specimens were contaminated with freshly prepared suspension of E. Faecalis and incubated for 4 weeks and equally divided into 4 groups positive control group (n=10) was not subjected to any further treatments, group A final irrigation with 5.25% NaOCl, group B final irrigation with nanochitosan and group C final irrigation with nano-propolis ; all irrigation protocols were combined with manual agitation with well fitted gutta perch cone for 2 minutes under a laminar flow hood. Microbial samples were collected from all the root specimens and colony forming units were counted and transformed into log CFU. The collected data were statistically analyzed.Results: There was no statistical significant difference in log CFU count between group A (treated with NaOCl) and group B, C (treated with CNP and PNP) while groups A, B, C showed statistically significant difference from positive control group with (p > 0.05). Conclusion:With in the limitations of the present study it can be concluded that all irrigation protocols had efficient antibacterial effect against E. faecalis.Manually agitated (CNP or PNP) can be considered as a more safe, efficient, and simple alternative instead of sodium hypochlorite against E. faecalis.

Aim:To evaluate the effect of deep marginal elevation on the marginal adaptation and fracture resistance in endodontically treated teeth restored with endocrowns constructed by two CAD/CAM ceramics in an in-vitro model.Material and methods: twenty four human, intact freshly extracted mandibular first molars were endodontically treated and mounted in an upright position in a standard plastic ring filled with acrylic resin 4mm apical to the CEJ. A standard endocrowns preparation was performed with a butt-joint occlusal margin for all specimens and a proximal box preparation was done on the mesial surfaces. The specimens were then equally divided in to two groups (n=12) according to the material used in construction group (M) using IPS e.max CAD ceramic blocks and group (V) using Vita Enamic ceramic blocks; then further divided in to two subgroups (n=6) according to the application of a mesial marginal elevation or not into (ME, VE) with marginal elevation and groups (MN, VN) without marginal elevation. All endocrowns were cemented to the corresponding preparation using dual cured self-adhesive resin cement (RelyX, Unicem). All specimens were thermally aged with 10000 cycle in water bath between 5˚C-55˚C. The marginal adaptation was evaluated using stereomicroscope (40 ×) at 5 predetermined points on the mesial margin for each specimen and mean gap measurement was calculated. All specimens were then subjected to fracture resistance test via universal testing machine. The collected data was recorded, tabulated and transferred for statistical analysis.Results: Vita Enamic with deep marginal elevation (VE) recorded the lowest marginal gap measurements at (69.3 µm)which is significantly lower than all tested subgroups (P < 0.001), while IPS e.max CAD with deep marginal elevation (ME) subgroup showed significantly higher fracture resistance (1478.2N) than all tested subgroups (P< 0.001). Conclusion:Deep marginal elevation enhances both marginal adaptation and fracture resistance of IPS e.max CAD and Vita Enamic. IPS e.max CAD has higher fracture resistance while Vita Enamic has better marginal adaptation.

Aim: Evaluate the efficacy of the combined use of XP shaper and finisher in cleaning simulated internal root resorption defects in comparison to the conventional passive ultrasonic irrigation using stereomicroscope. Materials and methods: The root canals of 90 freshly extracted human mandibular premolars were prepared using Protaper up to F4 and the teeth were split longitudinally and semicircular cavities (simulated internal root resorption cavities) were prepared in the canal wall on each half of the roots, then randomly assigned into two experimental groups (n=40) according to the cleaning technique groups (A) cleaned using passive ultrasonic irrigation , group (B) cleaned using XP-endo shaper followed by XP-endo finisher , five specimens were assigned to serve as negative control and five more were assigned to serve as positive control. Colored gelatin material (CGM) was prepared and applied into the semicircular cavities except for the negative control which did not receive (CGM). The root halves were reassembled creating a circular simulated resorption cavity within the root canal. Specimens were cleaned according to the group they were assigned to except for the positive control which did not receive any further treatment. All the specimens were disassembled and the residual CGM was examined under a stereomicroscope at 10x magnification and calculated as percentage of residual CGM to total area of the IRR cavity by using image analysis software and the data were statistically analyzed with one-way ANOVA test and significance level was set at P > 0.05. Results: None of the tested methods could completely remove the CGM from the simulated IRR cavities. Group B showed lower mean percentage of residual CGM than did group A (P0.041 >). Concussion: within the limitations of this study XP-endo shaper followed by XP-endo finisher was more effective in cleaning inaccessible internal root resorption defects than PUI.

INTRODUCTION: The study aims as a pilot study to evaluate the effect of different treatment regimen and different types of endodontic sealers on pain and periapical radiographic changes was studied. MATERIALS AND METHODS: Forty patients in need of an endodontic root canal treatment on anterior teeth were selected and divided into two groups (20 patients each), according to the endodontic treatment protocol (single or multiple visits). Then, each group was subdivided into two subgroups according to sealer used 10 each (AH Plus Jet resin sealer, Total Fill Bioceramic Sealer). To record pain intensity of the patients at different intervals: 1, 2, 3, 7 days, a visual analog scale was used. Furthermore, patients were recalled after 1, 3, 6, 9 months to evaluate periapical radiographic changes. RESULTS: Showed that as regard pain assessment both tested endodontic sealers, as well as single or multiple visits have no statistically significant difference between pain values of patients during all the observation period from immediately post-operative, after 4, 12, 24, 48, 72 h as well as after 7 days (p > 0.05). As regard lamina dura thickness, results showed that with both tested endodontic sealers as well as single or multiple visits, there was no statistically significant difference between lamina dura thickness of patients after 1 month, 3, 6 as well as after 9 months. CONCLUSIONS: Neither number of visits of endodontic treatment nor type of sealer used for obturation affects post-operative pain and thickness of lamina dura.

Aim: To evaluate the efficacy of chitosan as a post-space irrigant on bond strength of glass fiber posts luted with self-adhesive resin cements. Methodology: thirty single rooted human mandibular premolars with similar dimensions were decoronated to a standard root length of 15mm, endodontically treated and subjected to post preparation to a 10mm length. Specimens were randomly divided in to 3 groups according to the post space irrigant (PSI) to be used in to group (Saline, EDTA, Chitosan) n=10 each. Following irrigation procedure glass fiber posts (GFP) (Glassix radiopaque, H Nordin, Chailly/Montyreux, Switzerlandand) were cemented using self-adhesive resin cement (RelyX U100). Specimens were sectioned perpendicular to the long axis into 1mm thick slices. Three slices (one representative of each root third) from each specimen were subjected to push-out test and bond strength in MPa was statistically analyzed. Results: the bond strength was significantly higher in both EDTA and Chitosan groups than saline group P < 0.001. Bond strength was significantly affected by the region of the root canal P< 0.001. Conclusion: PSI affects the bond strength of GFP luted with self-adhesive resin cements. Chitosan can serve as a safer alternative for EDTA as a chelating agent. Chitosan as a PSI has a positive influence on the bond strength of GFP luted with self-adhesive resin cements.