Purpose: This clinical study was performed to evaluate the clinical effect of Platelet Rich Fibrin (PRF) application on healing process of periapical bony defects after endodontic peri-radicular microsurgery. Material and methods: Twenty-eight teeth in 25 patients were included in this study. They were divided into 2 equal groups, each including fourteen teeth. After retrograde filling was completed, the bony crypt was grafted with Platelet Rich Fibrin in the study group (Group A, n=14) and no graft in the control group (Group B, n=14). Patients were recalled at 12 months postoperatively for examination. Results: After one year of clinical and radiographic follow up, Group A showed higher success rate (81.8%), While Group B showed the lower success rate (45.4%). Significant difference in results was found between the two groups (P < 0.05). Conclusions: Within the limitation of this study, application of PRF in bony crypt after endodontic peri-radicular microsurgery showed higher long-term success rate and hence it may be considered as an adjunct autologous material to endodontic peri-radicular microsurgery.

Objectives: The purpose of this study was to evaluate and compare the effect of endodontic irrigation protocols on the micro-tensile bond strength of total-etch and universal adhesives to coronal dentin. Materials and Methods: forty teeth were collected and their occlusal surfaces were flattened until middle dentin was exposed. They were divided into four groups according to surface treatment of dentin (untreated (control), NaOCl, EDTA and combination of the two irrigants). Two different adhesives were selected for the current study (total-etch adhesive and universal adhesive). Adhesives were applied according to manufacturers' instructions, then composite restoration was built up incrementally. Resin/dentin specimens were sectioned for micro-tensile bond strength (µTBS) testing. A specimen from each group was randomly selected and investigated under scanning electron microscope (SEM). Results: Regarding the total-etch adhesive; the control group showed the highest value of µTBS, followed by the group irrigated with NaOCl + EDTA, EDTA and NaOCl; respectively. Regarding the Universal adhesive; dentin irrigated with a combination of EDTA+NaOCL was found to give the highest value of µTBS. It was followed by that irrigated with EDTA and control group. Irrigation with NaOCl resulted in a dramatic decrease in the µTBS in comparison with the other groups (p < 0.001). Conclusions: the use of a combination of NaOCl and EDTA as a regular endodontic irrigants in dental clinics was found to highly improve the quality of bond strength between dentin and both the total-etch and universal adhesives used for bonding the coronal composite restoration.

Objectives: the aim of this study was to compare fracture resistance of endodontically treated premolars restored with fiber reinforced post and different resin composite restorative materials. Materials and Methods: Eighty sound extracted premolar teeth were divided in to 3 groups; A (10 teeth kept sound as +ve control), B (10 teeth prepared only as –ve control), C (60 teeth divided into subgroup a as prepared and restored without post, and subgroup b as prepared and restored with prefabricated fiber-reinforced post (Glassix plus, Harald Nordin SA, Switzerland)). Each subgroup was divided into 3 divisions (n=10); 1 (coronal restoration with Tetric EvoCeram), 2 (coronal restoration with Tetric N-ceram), and 3 (coronal restoration with Tetric N-ceram Bulk-fill). All the teeth in group C were prepared for MOD cavities, root canal cleaned, shaped and obturated. All the teeth were subjected to thermo-mechanical aging and the universal testing machine by applying vertical compressive force at a crosshead speed of 0.5 mm/ min. All the data were collected to be subjected to quantitative statistical analysis. Results: Group A showed the highest fracture resistance values, and Group B showed the lowest values. Two-way ANOVA showed a significant difference among all groups. Conclusions: Bulk-fill resin composite restorations supported with prefabricated fiber-reinforced post improved fracture resistance of endodontically treated maxillary premolars.

Objectives: Assessment of the cumulative impacts of endodontic procedures using novel BioAKT Endo root canal irrigant on Enterococcus faecalis in comparison with sodium hypochlorite irrigant. Materials and Methods: Eighty single-rooted premolar teeth were collected for this study. The crowns were sectioned and the length of the roots was standardized to 15 mm. The roots were then initially cleaned, shaped, and inoculated with E. faecalis. The excess broth was removed by sterile paper points and then sample 1 (S1) was taken. The roots were divided into eight groups, groups 1-4 were instrumented and irrigated with BioAKT Endo root canal irrigant then sample 2 (S2) was taken. Groups 5-8 were instrumented and irrigated with 5.25% NaOCl. Standard laboratory methods were followed to determine the number of CFU for the tested organism. Data were collected and analyzed. A specimen from each group was randomly selected and investigated under an (SEM) to evaluate the bacterial contamination on the root canal walls initially and after the endodontic procedures. Results: Marked bacterial reduction was detected in all groups after instrumentation and irrigation with BioAKT Endo or 5.25%NaOCl, however, NaOCl groups were superior to BioAKT Endo groups. The maximum bacterial reduction was achieved in group 5 followed by 7, 6, 8,1,3,2, and 4 in descending order. SEM evaluation confirmed the final microbial results. Conclusions: BioAKT Endo is considered a novel irrigant material for root canals with a marked and promising anti-bacterial activity. Further in-vivo and in-vitro studies are required to investigate this class of endodontic irrigants.

Background/Objectives: Non-surgical retreatment aims to remove infected filling material, prepare the canal for disinfection, and re-obturate. This ex vivo study evaluated the residual filling material and dentin volume removed after retreatment using a rotary or reciprocating system. Methods: Twenty mesial roots of mandibular molars with two independent, straight canals were decoronated to a 16 mm working length and obturated. Pre-operative nano-CT scans measured the initial dentin and filling material volumes. Specimens were randomly assigned to two groups: Solite RE Black system (RE1-30/0.08; RE2-20/0.06) and WaveOne Gold—small file (20/0.07). Post-operative nano-CT scans were superimposed to calculate the remaining filling material and dentin volume removed. Data are presented as the mean ± SD, and groups were compared using independent t-tests. Results: Neither system completely removed the intracanal filling material. The mean residual filling material volume was 1.42 ± 0.21 mm³ (Solite RE Black) vs. 1.56 ± 0.27 mm³ (WaveOne Gold), representing approximately 14% vs. 16% of the initial filling material, respectively (p < 0.05). Mean dentin volume removed was 0.95 ± 0.18 mm³ vs. 1.12 ± 0.22 mm³, with no significant difference (p > 0.05). Conclusions: In single-rooted, straight canals, Solite RE Black removed more filling material than WaveOne Gold, while dentin loss was similar. These findings are specific to straight canals, and further studies are required for curved or multi-rooted teeth.

Purpose: This experimental study was to evaluate and compare bone regeneration capacity of experimental bone defects filled with different autologous platelet concentrates (APCs) as a bone graft material in the rabbit’s tibiae. Material and methods: A total of forty-two adult rabbits were included in this study. After creation of bone defects, the animals were randomly assigned to three groups. In control group, no bone graft was used (Group A, n=14), in one test group Plasma Rich in Growth Factors (PRGF) was used as bone graft material (Group B, n=14), and in the other test group Injectable Platelet Rich Fibrin (i-PRF) was used as bone graft material (Group C, n=14). After implantation, each group was further divided into two subgroups, where rabbits were sacrificed 2 and 4 weeks postoperatively and the defects were evaluated with histologic and histomorphometric analysis. Results: Both test groups (Group B and Group C) treated with APCs (PRGF: 10.92±0.85 & 41.53±2.55and i-PRF: 13.13±0.68 &57.27±1.66 at 2 and 4 weeks respectively) demonstrated higher percentages of new bone formation than the control group (5.11±1.15 & 30.31±1.29 at 2 and 4 weeks respectively) (P < 0.001). Significant difference was found between the two test groups and control group (P < 0.001). On the other hand, significant difference was found between test groups (P < 0.001). Conclusions: Within the limitation of this animal study, the adjunct implication of either i-PRF or PRGF in endodontic surgery may be of great significance as it dramatically improves bone regeneration.