Abstract: Aims: The aim of this research was to determine the cytotoxic effect of different concentrations of iron oxide nanoparticles (IONPs) in combination with hydrogen peroxide ( H2O2) in vitro as a potential endodontic irrigating solution. Materials and Methods: Cytotoxicity of IONPs at concentrations (8, 4, 2, 1, 0.5, and 0.25 mg/ml) with 3% H2O2 were evaluated on cultured Human Dermal Fibroblast  (HDFn) cell line. Cytotoxicity was assessed after 10 minutes of exposure using the Mosmann’s Tetrazolium Toxicity (MTT) assay. Results: Tukey’s test indicated that no significant difference in cell viability was found at lower concentrations (0.2, 0.5, 1, and 2 mg/ml). While at a concentration of 4 and 8 mg/ml, the cell viability was not significantly different from each other whereas, significantly different from previous concentrations. Conclusion: From the gained data, it can be deduced that IONPs+H2O2 had almost no cytotoxic effect on HDFn cell viability at concentrations 0.2, 0.5, 1, and 2 mg/ml, while a moderate decrease of survival has been observed at concentrations 4 and 8  mg/ml.

Abstract: Aims: The aim of this research was to determine the cytotoxic effect of different concentrations of iron oxide nanoparticles (IONPs) in combination with hydrogen peroxide ( H2O2) in vitro as a potential endodontic irrigating solution. Materials and Methods: Cytotoxicity of IONPs at concentrations (8, 4, 2, 1, 0.5, and 0.25 mg/ml) with 3% H2O2 were evaluated on cultured Human Dermal Fibroblast  (HDFn) cell line. Cytotoxicity was assessed after 10 minutes of exposure using the Mosmann’s Tetrazolium Toxicity (MTT) assay. Results: Tukey’s test indicated that no significant difference in cell viability was found at lower concentrations (0.2, 0.5, 1, and 2 mg/ml). While at a concentration of 4 and 8 mg/ml, the cell viability was not significantly different from each other whereas, significantly different from previous concentrations. Conclusion: From the gained data, it can be deduced that IONPs+H2O2 had almost no cytotoxic effect on HDFn cell viability at concentrations 0.2, 0.5, 1, and 2 mg/ml, while a moderate decrease of survival has been observed at concentrations 4 and 8  mg/ml.

Abstract: Aims: For evaluation and comparison of the accuracy of different methods for virtual models obtaining techniques. Materials and methods: The reference cast was prepared for 3-unit fixed bridge. Four Groups with 8 samples in each group. Stone models were poured from conventional impressions. Digital impressions of the reference cast were created using two types of intraoral scanner defers in scanning technology and direct impression digitization. Reference cast, stone casts and scannable impressions were subsequently scanned using a laboratory optical scanner; files were exported in a stereolithography file format. All datasets were superimposed using 3D analysis software to evaluate the accuracy (trueness and precession). An independent-samples median test summary was performed to compare trueness among the four impression groups. The independent-samples Kruskal-Wallis test was performed to evaluate the precession of each group of impression techniques. Results: with regard to trueness, the Trios Group and Medit i500 Group had the highest trueness of all groups, with no significant differences between them, followed by the conventional impression group, then the scannable impression group which had the largest deviation from the reference model. None of the groups showed significant differences in precession. Conclusions: Intraoral scanners have a high accuracy level for both trueness and precession. Scannable impression direct digitization showed significantly higher deviation than conventional impression stone casts with clinically acceptable levels of accuracy.

Abstract: Aims: For evaluation and comparison of the accuracy of different methods for virtual models obtaining techniques. Materials and methods: The reference cast was prepared for 3-unit fixed bridge. Four Groups with 8 samples in each group. Stone models were poured from conventional impressions. Digital impressions of the reference cast were created using two types of intraoral scanner defers in scanning technology and direct impression digitization. Reference cast, stone casts and scannable impressions were subsequently scanned using a laboratory optical scanner; files were exported in a stereolithography file format. All datasets were superimposed using 3D analysis software to evaluate the accuracy (trueness and precession). An independent-samples median test summary was performed to compare trueness among the four impression groups. The independent-samples Kruskal-Wallis test was performed to evaluate the precession of each group of impression techniques. Results: with regard to trueness, the Trios Group and Medit i500 Group had the highest trueness of all groups, with no significant differences between them, followed by the conventional impression group, then the scannable impression group which had the largest deviation from the reference model. None of the groups showed significant differences in precession. Conclusions: Intraoral scanners have a high accuracy level for both trueness and precession. Scannable impression direct digitization showed significantly higher deviation than conventional impression stone casts with clinically acceptable levels of accuracy.

Abstract: Aims: Evaluate and compare the accuracy of virtual models and their three dimensionally printed (3D) models. Materials and methods: Reference models were prepared with four types of prostheses: 3-unit fixed bridge (FXD), single crown (SC), Cl I Kennedy classification (Cl I) and Cl III Kennedy classification (Cl III). Digital impressions of the reference model were created using the Trios intraoral scanner. Reference and 3D printed models were subsequently scanned using a laboratory optical scanner, and files were exported in a stereolithography file format. All datasets were superimposed using 3D analysis software to evaluate the accuracy. The Wilcoxon signed-rank test weas performed to compare the virtual and 3D printed groups in each type of preparation model. Results: The 3D printed casts showed a higher deviation from the reference cast (in all types of preparations) than the virtual cast of Trios IOS. There were significant differences between virtual and 3D printed cast samples in the Fixed bridge, Single Crown and Class I Kennedy Classification groups, while for the comparison between the virtual and 3D printed cast samples in the Class III Kennedy Classification group, we found that there were no significant differences. Conclusions: Intraoral scanners have a high accuracy level. The 3D printed models showed a significantly higher deviation than the digital impression with a clinically acceptable level of accuracy.

Abstract: Aims: Evaluate and compare the accuracy of virtual models and their three dimensionally printed (3D) models. Materials and methods: Reference models were prepared with four types of prostheses: 3-unit fixed bridge (FXD), single crown (SC), Cl I Kennedy classification (Cl I) and Cl III Kennedy classification (Cl III). Digital impressions of the reference model were created using the Trios intraoral scanner. Reference and 3D printed models were subsequently scanned using a laboratory optical scanner, and files were exported in a stereolithography file format. All datasets were superimposed using 3D analysis software to evaluate the accuracy. The Wilcoxon signed-rank test weas performed to compare the virtual and 3D printed groups in each type of preparation model. Results: The 3D printed casts showed a higher deviation from the reference cast (in all types of preparations) than the virtual cast of Trios IOS. There were significant differences between virtual and 3D printed cast samples in the Fixed bridge, Single Crown and Class I Kennedy Classification groups, while for the comparison between the virtual and 3D printed cast samples in the Class III Kennedy Classification group, we found that there were no significant differences. Conclusions: Intraoral scanners have a high accuracy level. The 3D printed models showed a significantly higher deviation than the digital impression with a clinically acceptable level of accuracy.

Abstract: Aims: The purpose of this study is to provide a complete overview of the current scientific information on the use of nanoparticles in endodontic irrigation. The complicated structure of the root canals makes thorough cleaning and disinfection difficult. The removal of infection from the root canal system is the primary goal of root canal treatment. Irrigation is the only way to sterilize inaccessible anatomic irregularities. Because of the nanoparticles ultra-small sizes, big surface area/mass ratio, and enhanced chemical reactivity, applying them with irrigants improve disinfection efficiency. Conclusion: The use of nanoparticles in irrigation can improve the antibiofilm efficacy of endodontic treatment particularly against chronic endodontic infections like E. faecalis. Many more researches are required to identify the best nanoparticles for use in root canal irrigation, which is still in the works.

Abstract: Aims: The purpose of this study is to provide a complete overview of the current scientific information on the use of nanoparticles in endodontic irrigation. The complicated structure of the root canals makes thorough cleaning and disinfection difficult. The removal of infection from the root canal system is the primary goal of root canal treatment. Irrigation is the only way to sterilize inaccessible anatomic irregularities. Because of the nanoparticles ultra-small sizes, big surface area/mass ratio, and enhanced chemical reactivity, applying them with irrigants improve disinfection efficiency. Conclusion: The use of nanoparticles in irrigation can improve the antibiofilm efficacy of endodontic treatment particularly against chronic endodontic infections like E. faecalis. Many more researches are required to identify the best nanoparticles for use in root canal irrigation, which is still in the works.

Abstract: Purpose: This review’s aim is to prove whether derotation can correct minimal class II. Materials and Methods: The systematic search included Medline (PubMed, Ovid MEDLINE and EBSCO, Science Direct, and Cochrane Library (Cochrane Review, Trails), and additional studies were searched in the reference lists of all articles. The date of the last search was December 13th, 2022. The methodological quality of the retrospective studies were graded by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP), and prospective studies by means of the Newcastle–Ottawa Scale. Results: Totally, 1342 studies were identified for screening, and 5 studies were eligible. The Quality Assessment Tool for Quantitative Studies rated 2, of the included retrospective clinical studies as high risk and 1 as moderate risk. The Newcastle–Ottawa Scale rated all 2 included studies as high risk. The mean molar derotation values varied from 1 mm to 2 mm. Conclusion: Through this systematic review, we have highlighted that; the derotation can correct the minimal class II. It is possible thanks to several devices like traspalatin arch, clear aligner, headgear, and some distalizers especially those with vestibular action. The mean molar derotation values varied from 1 mm to 2 mm, conditionally to not lose the space obtained by the effect of medialization.

Abstract: Purpose: This review’s aim is to prove whether derotation can correct minimal class II. Materials and Methods: The systematic search included Medline (PubMed, Ovid MEDLINE and EBSCO, Science Direct, and Cochrane Library (Cochrane Review, Trails), and additional studies were searched in the reference lists of all articles. The date of the last search was December 13th, 2022. The methodological quality of the retrospective studies were graded by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP), and prospective studies by means of the Newcastle–Ottawa Scale. Results: Totally, 1342 studies were identified for screening, and 5 studies were eligible. The Quality Assessment Tool for Quantitative Studies rated 2, of the included retrospective clinical studies as high risk and 1 as moderate risk. The Newcastle–Ottawa Scale rated all 2 included studies as high risk. The mean molar derotation values varied from 1 mm to 2 mm. Conclusion: Through this systematic review, we have highlighted that; the derotation can correct the minimal class II. It is possible thanks to several devices like traspalatin arch, clear aligner, headgear, and some distalizers especially those with vestibular action. The mean molar derotation values varied from 1 mm to 2 mm, conditionally to not lose the space obtained by the effect of medialization.

Abstract:  Aims: This study aims to assess the apical microleakage of root canals after irrigation by NaOCl, EDTA, and MTAD.Materials and methods: 36 lower premolars were used in this study. Preparation of the samples was done by files of ProTaper to size F3. Samples were distributed into three experimenting groups; each one contained ten samples as follows: Group 1- samples were finally washed for five minutes with five ml of 5.25% NaOCl. Group 2- samples were finally washed for five minutes with five ml of 17% EDTA. Group 3- samples were finally washed for five minutes with five ml of MTAD. Six samples were utilized as positive and negative control groups, each one contained three samples. The samples were obturated by single cone technique except for the samples of the positive control group, which were not obturated. All the samples were incubated at 37 OC for 7 days in 100% humidity. The dye penetration method was used to assess apical leakage. Finally, data were collected and statistically analyzed. Results: MTAD group revealed the least leakage supervened by the EDTA group and the NaOCl group revealed the highest leakage. The MTAD group did not differ significantly from the EDTA group, while the NaOCl group differed significantly from MTAD and EDTA groups. A positive control group revealed a dye leak through the whole length of the root, while a negative control group did not reveal any dye leak. Conclusions: Under the conditions of this study, the final irrigation with MTAD or EDTA is better than the final irrigation with 5.25 % NaOCl in terms of less apical microleakage. 

Abstract:  Aims: This study aims to assess the apical microleakage of root canals after irrigation by NaOCl, EDTA, and MTAD.Materials and methods: 36 lower premolars were used in this study. Preparation of the samples was done by files of ProTaper to size F3. Samples were distributed into three experimenting groups; each one contained ten samples as follows: Group 1- samples were finally washed for five minutes with five ml of 5.25% NaOCl. Group 2- samples were finally washed for five minutes with five ml of 17% EDTA. Group 3- samples were finally washed for five minutes with five ml of MTAD. Six samples were utilized as positive and negative control groups, each one contained three samples. The samples were obturated by single cone technique except for the samples of the positive control group, which were not obturated. All the samples were incubated at 37 OC for 7 days in 100% humidity. The dye penetration method was used to assess apical leakage. Finally, data were collected and statistically analyzed. Results: MTAD group revealed the least leakage supervened by the EDTA group and the NaOCl group revealed the highest leakage. The MTAD group did not differ significantly from the EDTA group, while the NaOCl group differed significantly from MTAD and EDTA groups. A positive control group revealed a dye leak through the whole length of the root, while a negative control group did not reveal any dye leak. Conclusions: Under the conditions of this study, the final irrigation with MTAD or EDTA is better than the final irrigation with 5.25 % NaOCl in terms of less apical microleakage. 

Abstract:  Aims: The study aims to evaluate the effect of different surface treatments on the shear bond strength between flowable composite and glass ionomer cement. Materials and Methods: 40 samples of glass ionomer cement were prepared by mixing the GIC under manufacturer instructions and applied inside a transparent ring measured 3mm in diameter and 2 mm in height. Then the samples were segmented into 4 groups, Group (1) as a control negative group without surface treatment, Group (2) with surface treated by 37% phosphoric acid, Group (3) surface treated by air abrasion with aluminum oxide particles, and Group (4) surface treated by polishing discs. Then Adper single bond 2 was placed over samples of groups (2,3,4) and light cured, then another transparent ring measured 3 mm in diameter and 6 mm in height was applied over each GIC disc, and flow the flowable composite incrementally into two layers, each layer as 3mm and cured by light cure. Then remove the transparent rings to obtain the two bonded materials, GIC, and flowable composite as one sample, then measure the bond strength between the two materials for all groups by using the universal testing machine. Data were analyzed by using One-Way Analysis of Variance and Tukey’s test. Results: A significant difference is observed in shear bond strength (SBS) of the groups (P<0.05). Group (3) showed the high SBS and Group (1) showed the lowest SBS and there is a significant difference between all the groups in relation to SBS. The high difference between Gp(3) and Gps(1,4) whereas the lowest difference is between Gp(2) and Gp(4). Conclusions: Within the limitation of this study, the treatments of surface increase the shear bond strength between GIC and flowable composite, and high bond strength is obtained by air abrasion technique then followed by acid etching and polishing disc respectively.

Abstract:  Aims: The study aims to evaluate the effect of different surface treatments on the shear bond strength between flowable composite and glass ionomer cement. Materials and Methods: 40 samples of glass ionomer cement were prepared by mixing the GIC under manufacturer instructions and applied inside a transparent ring measured 3mm in diameter and 2 mm in height. Then the samples were segmented into 4 groups, Group (1) as a control negative group without surface treatment, Group (2) with surface treated by 37% phosphoric acid, Group (3) surface treated by air abrasion with aluminum oxide particles, and Group (4) surface treated by polishing discs. Then Adper single bond 2 was placed over samples of groups (2,3,4) and light cured, then another transparent ring measured 3 mm in diameter and 6 mm in height was applied over each GIC disc, and flow the flowable composite incrementally into two layers, each layer as 3mm and cured by light cure. Then remove the transparent rings to obtain the two bonded materials, GIC, and flowable composite as one sample, then measure the bond strength between the two materials for all groups by using the universal testing machine. Data were analyzed by using One-Way Analysis of Variance and Tukey’s test. Results: A significant difference is observed in shear bond strength (SBS) of the groups (P<0.05). Group (3) showed the high SBS and Group (1) showed the lowest SBS and there is a significant difference between all the groups in relation to SBS. The high difference between Gp(3) and Gps(1,4) whereas the lowest difference is between Gp(2) and Gp(4). Conclusions: Within the limitation of this study, the treatments of surface increase the shear bond strength between GIC and flowable composite, and high bond strength is obtained by air abrasion technique then followed by acid etching and polishing disc respectively.

Abstract: Aims: The study aims to appraise the clinical efficiency of 2% ethanolic thuja orientalis extract in comparison to the effect of kenalog in orabase in patients with recurrent aphthous stomatitis RAS. Materials and methods: This clinical research included eighty patients with active lesions, twenty patients were treated with ethanolic thuja extract, twenty patients were treated with kenalog in orabase, twenty patients were treated with orabase as a control positive, and twenty without treatment as a control negative. Results: The results showed a good effective response of topical ethanolic thuja extract compared with the effect of kenalog in orabase in patients with recurrent aphthous stomatitis. Conclusion:  conclude that herbal medicine can be employed as an alternative RAS therapy.

Abstract: Aims: The study aims to appraise the clinical efficiency of 2% ethanolic thuja orientalis extract in comparison to the effect of kenalog in orabase in patients with recurrent aphthous stomatitis RAS. Materials and methods: This clinical research included eighty patients with active lesions, twenty patients were treated with ethanolic thuja extract, twenty patients were treated with kenalog in orabase, twenty patients were treated with orabase as a control positive, and twenty without treatment as a control negative. Results: The results showed a good effective response of topical ethanolic thuja extract compared with the effect of kenalog in orabase in patients with recurrent aphthous stomatitis. Conclusion:  conclude that herbal medicine can be employed as an alternative RAS therapy.

Abstract:  Aims: The aim of the current study is to evaluate the effect of Aloe Vera gel on the healing process of surgically made maxillary alveolar bone defects and new bone tissue formation in rabbits. Materials and Methods: Twenty albino rabbits were randomly chosen to conduct the study, all selected rabbits were inhabited under the same circumstances involving ventilation, temperature, and diet. Each rabbit received the anesthetic solution separately and underwent a surgical procedure in both sides of the maxillary alveolar bone which involved a longitudinal oral mucosal incision followed by circular bone defect creation and further placement of Aloe Vera gel and a tiny gel foam piece in the left side of the animal's jaw bone, while right side bone hole was left empty for control. According to euthanization date, rabbits were divided into five groups and euthanized at the 3rd, 7th, 14th,28th, and 42 days post-surgery, the histomorphometric assessment included evaluation of the amount of granulation tissue formed and calculation of the surface area of newly formed bone tissue in relation to the microscopical field using special image analysis software. Results: Histomorphometric analysis results revealed a statistically significant difference in the amount of granulation tissue and new bone tissue surface area between control and Aloe Vera groups at all-time intervals of the study favoring Aloe Vera groups. Conclusions: Aloe Vera gel has a beneficial effect on bone healing process with its enhancement effect on new bone tissue formation.

Abstract:  Aims: The aim of the current study is to evaluate the effect of Aloe Vera gel on the healing process of surgically made maxillary alveolar bone defects and new bone tissue formation in rabbits. Materials and Methods: Twenty albino rabbits were randomly chosen to conduct the study, all selected rabbits were inhabited under the same circumstances involving ventilation, temperature, and diet. Each rabbit received the anesthetic solution separately and underwent a surgical procedure in both sides of the maxillary alveolar bone which involved a longitudinal oral mucosal incision followed by circular bone defect creation and further placement of Aloe Vera gel and a tiny gel foam piece in the left side of the animal's jaw bone, while right side bone hole was left empty for control. According to euthanization date, rabbits were divided into five groups and euthanized at the 3rd, 7th, 14th,28th, and 42 days post-surgery, the histomorphometric assessment included evaluation of the amount of granulation tissue formed and calculation of the surface area of newly formed bone tissue in relation to the microscopical field using special image analysis software. Results: Histomorphometric analysis results revealed a statistically significant difference in the amount of granulation tissue and new bone tissue surface area between control and Aloe Vera groups at all-time intervals of the study favoring Aloe Vera groups. Conclusions: Aloe Vera gel has a beneficial effect on bone healing process with its enhancement effect on new bone tissue formation.

Abstract:  Aims: This study aims to evaluate the shear bond strength of three types of dual-cure self-adhesive resin cement (SARCs) bonded to three different substrates with detection types of failure, EDX analysis for substrates, control substrate, and after three resin cement applications. Materials and methods: Thirty specimens from enamel and the same number from dentin and zirconia are prepared. Zirconia discs prepared by CAD-CAM system. Dental specimens prepared from intact surface 3rd molar for enamel and premolar for dentin. After teeth sectioning, all specimens are embedded in auto-cure acrylic resin in a plastic tube. All specimens were polished with sandpaper and zirconia sandblasting, rubber mold was fixed on the surface of the specimen. Three types of dual-cures (SARCs) were applied on the surface of the specimens and after curing the specimens were kept in distilled water at 37 ºC inside the incubator for 24 hours. Then specimens subjected to shear bond strength on a universal test machine after the failure occurs specimens examined under a stereomicroscope to detect the mode of failure.  Three control specimens enamel, dentin, and zirconia without any treatment, and nine were from failure specimens send to EDX analysis. Results: The results of this study analyzed with SPSS 25 edition, results showed no significant difference in shear bond strength (SBS) between the three (SARCs) bonds to enamel substrate, while in dentin and zirconia, there was a significant difference in SBS between self-adhesive resin cement. Failure mode detected under the stereomicroscope examination shows no significant difference between the three substrates in failure mode when the bond to BisCem® and TheraCem®Ca, but RelyX™U200 showed a significant difference. EDX analysis shows the presence of Calcium, Phosphorus ions on the zirconia surface when TheraCem®Ca was applied while not present when using the other two types of cement. The amount of calcium and phosphorus ions different from one specimen to another related to the type of substrate and the cement when compare with the control group. Conclusion: TheraCem ®Ca showed improvement in SBS to zirconia due to its composition such as acidic monomer MDP and calcium and phosphorus ions. BisCem and RelyXU200 show better performance with tooth structure and comparable results with zirconia.    

Abstract:  Aims: This study aims to evaluate the shear bond strength of three types of dual-cure self-adhesive resin cement (SARCs) bonded to three different substrates with detection types of failure, EDX analysis for substrates, control substrate, and after three resin cement applications. Materials and methods: Thirty specimens from enamel and the same number from dentin and zirconia are prepared. Zirconia discs prepared by CAD-CAM system. Dental specimens prepared from intact surface 3rd molar for enamel and premolar for dentin. After teeth sectioning, all specimens are embedded in auto-cure acrylic resin in a plastic tube. All specimens were polished with sandpaper and zirconia sandblasting, rubber mold was fixed on the surface of the specimen. Three types of dual-cures (SARCs) were applied on the surface of the specimens and after curing the specimens were kept in distilled water at 37 ºC inside the incubator for 24 hours. Then specimens subjected to shear bond strength on a universal test machine after the failure occurs specimens examined under a stereomicroscope to detect the mode of failure.  Three control specimens enamel, dentin, and zirconia without any treatment, and nine were from failure specimens send to EDX analysis. Results: The results of this study analyzed with SPSS 25 edition, results showed no significant difference in shear bond strength (SBS) between the three (SARCs) bonds to enamel substrate, while in dentin and zirconia, there was a significant difference in SBS between self-adhesive resin cement. Failure mode detected under the stereomicroscope examination shows no significant difference between the three substrates in failure mode when the bond to BisCem® and TheraCem®Ca, but RelyX™U200 showed a significant difference. EDX analysis shows the presence of Calcium, Phosphorus ions on the zirconia surface when TheraCem®Ca was applied while not present when using the other two types of cement. The amount of calcium and phosphorus ions different from one specimen to another related to the type of substrate and the cement when compare with the control group. Conclusion: TheraCem ®Ca showed improvement in SBS to zirconia due to its composition such as acidic monomer MDP and calcium and phosphorus ions. BisCem and RelyXU200 show better performance with tooth structure and comparable results with zirconia.    

Abstract: Aims: The aim of this research was to study the effect of artificial aging on the translucency of four different veneering restorations. Materials and methods: Twenty laminate veneers were prepared on prefabricated metal dies of upper right central incisors with incisal lap preparation design using CAD-CAM system from four different materials (Zircad Prime "ZP", DD cubeX2 ML "DD", CopraSupreme Symphony "WP", IPS E.max CAD), with 0.5 mm thicknesses. The samples were divided into four equal groups with five samples from each material, aging was done in the steam autoclave at (134c) and (0.2 Mpa) for five hours according to (ISO 13356). TP was tested using a (3nh) colorimeter. Statistical analysis was done using ANOVA at a level of significant 5%. Results: The mean of translucency parameter (TP) between the examined groups shows that lithium disilicate and Zircad prime (ZP) groups showed significant differences, while White Peak (WP) and Direct Dental (DD) showed no significant difference. Conclusions: lithium disilicate material and ZP were affected by aging, while other types of zirconia including WP and DD were not affected by aging due to their structural composition.

Abstract: Aims: The aim of this research was to study the effect of artificial aging on the translucency of four different veneering restorations. Materials and methods: Twenty laminate veneers were prepared on prefabricated metal dies of upper right central incisors with incisal lap preparation design using CAD-CAM system from four different materials (Zircad Prime "ZP", DD cubeX2 ML "DD", CopraSupreme Symphony "WP", IPS E.max CAD), with 0.5 mm thicknesses. The samples were divided into four equal groups with five samples from each material, aging was done in the steam autoclave at (134c) and (0.2 Mpa) for five hours according to (ISO 13356). TP was tested using a (3nh) colorimeter. Statistical analysis was done using ANOVA at a level of significant 5%. Results: The mean of translucency parameter (TP) between the examined groups shows that lithium disilicate and Zircad prime (ZP) groups showed significant differences, while White Peak (WP) and Direct Dental (DD) showed no significant difference. Conclusions: lithium disilicate material and ZP were affected by aging, while other types of zirconia including WP and DD were not affected by aging due to their structural composition.

Abstract: Aims: To investigate the effect of adding nanoparticles on the compressive strength of alginate impression material. Materials and Methods: In this study, two types of nanoparticles were added to alginate impression materials: silver and zirconium oxide at four concentrations: 0.5 %, 1%, 2%, and 5% by weight. Compressive strength was tested for 45 samples made according to American Dental specification no.18 for the alginate impression material. Results: The addition of silver nanoparticles did not alter the compressive strength of alginate impression material, whereas the addition of zirconium oxide significantly decreased its compressive strength. Conclusions: The incorporation of silver nanoparticles into alginate impression materials as antimicrobial agents had no negative effect on its compressive strength, whereas adding antimicrobial zirconium oxide nanoparticles significantly reduced the compressive strength of alginate impression material

Abstract: Aims: To investigate the effect of adding nanoparticles on the compressive strength of alginate impression material. Materials and Methods: In this study, two types of nanoparticles were added to alginate impression materials: silver and zirconium oxide at four concentrations: 0.5 %, 1%, 2%, and 5% by weight. Compressive strength was tested for 45 samples made according to American Dental specification no.18 for the alginate impression material. Results: The addition of silver nanoparticles did not alter the compressive strength of alginate impression material, whereas the addition of zirconium oxide significantly decreased its compressive strength. Conclusions: The incorporation of silver nanoparticles into alginate impression materials as antimicrobial agents had no negative effect on its compressive strength, whereas adding antimicrobial zirconium oxide nanoparticles significantly reduced the compressive strength of alginate impression material

Abstract: Aims: The study aims to estimate the carriage of Staphylococci spp on nares and hands among dental staff and their antibiotic resistance pattern. Materials and Methods: 100 samples were collected from the nose and hands of dental workers (dentists and assistants) in the teaching hospital of the College of Dentistry, University of Mosul from the period 17th Dec. 2020 to 9th Feb.2021. The isolates were diagnosed based on phenotypic traits, microscopy, biochemical test, and the use of the vitek – 2compact device to confirm the species, 66 isolates showed that they were able to ferment mannitol, 32 isolates from the hands, and 34 isolates from the nose while the other isolates showed an inability to ferment mannitol sugar. All Staphylococcus isolates were Gram-positive, catalase 100%, coagulase (18.75%) for hand isolates, and (52.9%) for nosal isolates. Using the vitek 2-compact (40) isolates of fermented mannitol were diagnosed and the results were as follows (20) isolates Staph.aureus 14; (70%) from nose and 6(30%) from hand, 5 isolates of Staph. lugdunensis  ;4 (80%) from nose ,1 (20%) from hand .4 isolates Staph. Saprophyticus; 2 (50%) from nose, 2(50%) from hand,2 isolates of Staph. hominis; (100%) from hand,3 isolates of Staph. warneri 2;(66.67%) from nose, 1(33.33%) from hand and one isolate of Staph.sciuri 1,(100) from hand and one isolate of Leuconostoc mesenteroides from hand, four isolates the device couldn't diagnose. The sensitivity of the different isolates to oxacillin was determined with minimum inhibitory concentration (MIC) using vitek2-compact device as oxacillin indicates methicillin in the device. The isolates differed in their resistance to the antibiotic oxacillin where the highest resistance was the percentage to each of Staph.lugdunensis   and Staph.sciuri the resistance rate reached 100% followed by  Staph.aureus  were the resistance rate reached 80% then Staph.warneri 66.67% , Staph.hominis 50% and  Staph. Saprophyticus 25% . The sensitivity of different isolates to antibiotics was determined by using Kirby –Bauer method using seven types of antibiotics Staphylococcus isolates showed resistance to both oxacillin and methicillin at percentage 100% except for Staph. Saprophyticus where the resistance was 50%.

Abstract: Aims: The study aims to estimate the carriage of Staphylococci spp on nares and hands among dental staff and their antibiotic resistance pattern. Materials and Methods: 100 samples were collected from the nose and hands of dental workers (dentists and assistants) in the teaching hospital of the College of Dentistry, University of Mosul from the period 17th Dec. 2020 to 9th Feb.2021. The isolates were diagnosed based on phenotypic traits, microscopy, biochemical test, and the use of the vitek – 2compact device to confirm the species, 66 isolates showed that they were able to ferment mannitol, 32 isolates from the hands, and 34 isolates from the nose while the other isolates showed an inability to ferment mannitol sugar. All Staphylococcus isolates were Gram-positive, catalase 100%, coagulase (18.75%) for hand isolates, and (52.9%) for nosal isolates. Using the vitek 2-compact (40) isolates of fermented mannitol were diagnosed and the results were as follows (20) isolates Staph.aureus 14; (70%) from nose and 6(30%) from hand, 5 isolates of Staph. lugdunensis  ;4 (80%) from nose ,1 (20%) from hand .4 isolates Staph. Saprophyticus; 2 (50%) from nose, 2(50%) from hand,2 isolates of Staph. hominis; (100%) from hand,3 isolates of Staph. warneri 2;(66.67%) from nose, 1(33.33%) from hand and one isolate of Staph.sciuri 1,(100) from hand and one isolate of Leuconostoc mesenteroides from hand, four isolates the device couldn't diagnose. The sensitivity of the different isolates to oxacillin was determined with minimum inhibitory concentration (MIC) using vitek2-compact device as oxacillin indicates methicillin in the device. The isolates differed in their resistance to the antibiotic oxacillin where the highest resistance was the percentage to each of Staph.lugdunensis   and Staph.sciuri the resistance rate reached 100% followed by  Staph.aureus  were the resistance rate reached 80% then Staph.warneri 66.67% , Staph.hominis 50% and  Staph. Saprophyticus 25% . The sensitivity of different isolates to antibiotics was determined by using Kirby –Bauer method using seven types of antibiotics Staphylococcus isolates showed resistance to both oxacillin and methicillin at percentage 100% except for Staph. Saprophyticus where the resistance was 50%.

Abstract: Aims: This clinical study is aimed at evaluating the effectiveness of exercise therapy in patients with the temporomandibular joint disorder and comparing them with patients who take medications. Materials and Methods: 44 patients with temporomandibular joint disorder were divided into 2 groups, 22 patients were instructed to perform jaw exercises and the other 22 patients were given a non-steroidal anti-inflammatory drug and muscle relaxant. Clinical examination of joints and muscles, including pain, spasm, interincisal distance, and presence of locked joint. These were done pre and post-treatment within three visits. Results: clinically, there was no actual evidence in the exercise group, and medication group, except for locked jaw relief in the exercise group. Statistically, it showed no significant differences in variance after two visits between the two groups. Conclusion: there was not providing definite evidence of treatment efficacy in short-time trials in patients with temporomandibular joint disorder. However, exercises are an effective treatment for a locked jaw than medical agents.

Abstract: Aims: This clinical study is aimed at evaluating the effectiveness of exercise therapy in patients with the temporomandibular joint disorder and comparing them with patients who take medications. Materials and Methods: 44 patients with temporomandibular joint disorder were divided into 2 groups, 22 patients were instructed to perform jaw exercises and the other 22 patients were given a non-steroidal anti-inflammatory drug and muscle relaxant. Clinical examination of joints and muscles, including pain, spasm, interincisal distance, and presence of locked joint. These were done pre and post-treatment within three visits. Results: clinically, there was no actual evidence in the exercise group, and medication group, except for locked jaw relief in the exercise group. Statistically, it showed no significant differences in variance after two visits between the two groups. Conclusion: there was not providing definite evidence of treatment efficacy in short-time trials in patients with temporomandibular joint disorder. However, exercises are an effective treatment for a locked jaw than medical agents.

Abstract: Aims: The objective of this study is to compare the wound healing potential between two different biomaterials after induced surgical intraoral incisions. Materials and methods: The study was conducted on (12) male New Zealand rabbits, randomly divided into two groups (6 animals per group) according to the healing periods (3rd,7th, and 14th) days. Two incisions were made on the buccal mucosa of each rabbit bilaterally. For the first group, the defects were filled with (PerioKIN Hyaluronic 1%) gel, O3OHEAL-M gel for the second group, applied three times daily, two rabbits were randomly selected each group at the (3rd, 7th, and 14th) days, and biopsies were taken. The biopsy specimens were subjected to histological evaluation to assess the physiological parameters of the wound-healing process. Results: median results of Inflammatory Cells Infiltration grading in which day 3 group II was the highest and day 14 was lowest and Granulation tissue formation in which day 7 was highest and re-epithelization scoring showed highest at day 14, according to the time period and their were no significant differences of Group versus group (within the same day). So, there is very close activity of the two materials in relation to their use in wounds with tissue loss. Conclusions: use of PerioKIN Hyaluronic 1% gel and O3OHEAL-M gel application three times daily for bare wounds give a satisfactory result for better healing and isolation to get rid of the infection in the appropriate time.

Abstract: Aims: The objective of this study is to compare the wound healing potential between two different biomaterials after induced surgical intraoral incisions. Materials and methods: The study was conducted on (12) male New Zealand rabbits, randomly divided into two groups (6 animals per group) according to the healing periods (3rd,7th, and 14th) days. Two incisions were made on the buccal mucosa of each rabbit bilaterally. For the first group, the defects were filled with (PerioKIN Hyaluronic 1%) gel, O3OHEAL-M gel for the second group, applied three times daily, two rabbits were randomly selected each group at the (3rd, 7th, and 14th) days, and biopsies were taken. The biopsy specimens were subjected to histological evaluation to assess the physiological parameters of the wound-healing process. Results: median results of Inflammatory Cells Infiltration grading in which day 3 group II was the highest and day 14 was lowest and Granulation tissue formation in which day 7 was highest and re-epithelization scoring showed highest at day 14, according to the time period and their were no significant differences of Group versus group (within the same day). So, there is very close activity of the two materials in relation to their use in wounds with tissue loss. Conclusions: use of PerioKIN Hyaluronic 1% gel and O3OHEAL-M gel application three times daily for bare wounds give a satisfactory result for better healing and isolation to get rid of the infection in the appropriate time.

Abstract: Aims: To compare the effects of Hyaluronic acid (PerioKIN Hyaluronic 1%)® and ozonated oil (O3OHEAL-M) ® on healing after induced wounds in rabbits oral mucosa and to detect the presence of interleukin-6 (IL-6) as a biomarker using immunohistochemistry. Materials and methods: The study was conducted on (12) male New Zealand rabbits, randomly divided into two groups (6 animals per group) according to the healing periods (3rd,7th, and 14th) days. Two incisions were made on the buccal mucosa of each rabbit bilaterally. For the first group, the defects were filled with (PerioKIN Hyaluronic 1%) gel, (O3OHEAL-M) gel was applied for the second group, applied three times daily, two rabbits were randomly selected of each group at the (3rd, 7th, and 14th) days, and biopsies were taken. The biopsy specimens were subjected to Immunohistochemical evaluation to assess wound healing potential utilizing IL-6 as a marker. Results: Median scores of IL-6 expression for oral mucosa showed that at day three perioKIN group showed higher expression of the marker but at day seven there was equal and finally at day fourteen there is no expression of IL-6 marker in Ozoheal group, there was a statistically significant difference at all periods for Ozoheal group which means that Ozoheal has less reaction to local tissue response.   Conclusion:  Ozoheal drug is better than perioKIN gel as an anti-inflammatory action and thus could reduce the sequelae related to the inflammatory process.

Abstract: Aims: To compare the effects of Hyaluronic acid (PerioKIN Hyaluronic 1%)® and ozonated oil (O3OHEAL-M) ® on healing after induced wounds in rabbits oral mucosa and to detect the presence of interleukin-6 (IL-6) as a biomarker using immunohistochemistry. Materials and methods: The study was conducted on (12) male New Zealand rabbits, randomly divided into two groups (6 animals per group) according to the healing periods (3rd,7th, and 14th) days. Two incisions were made on the buccal mucosa of each rabbit bilaterally. For the first group, the defects were filled with (PerioKIN Hyaluronic 1%) gel, (O3OHEAL-M) gel was applied for the second group, applied three times daily, two rabbits were randomly selected of each group at the (3rd, 7th, and 14th) days, and biopsies were taken. The biopsy specimens were subjected to Immunohistochemical evaluation to assess wound healing potential utilizing IL-6 as a marker. Results: Median scores of IL-6 expression for oral mucosa showed that at day three perioKIN group showed higher expression of the marker but at day seven there was equal and finally at day fourteen there is no expression of IL-6 marker in Ozoheal group, there was a statistically significant difference at all periods for Ozoheal group which means that Ozoheal has less reaction to local tissue response.   Conclusion:  Ozoheal drug is better than perioKIN gel as an anti-inflammatory action and thus could reduce the sequelae related to the inflammatory process.

Abstract: Aims: To compare the retention of copings produced by Direct Metal Laser Sintering (DMLS), Hard metal CAM (Computer Assisted Milling) and conventional casting techniques. Materials and Methods: An implant abutment was used as an ideal model which was scanned by 3D scanner and 8 copings of each group were fabricated from a single STL file. Each specimen was seated, luted, and mounted on a vertical column universal testing machine for a pull-off test. Dislodgement readings were recorded and statistically analyzed with ANOVA test and Duncan’s multiple range test. Results: Significant difference was found between the studied groups in retention. The laser-sintered group showed the highest force required for dislodgement followed by conventional casting group then by the hard metal milling group. Conclusions: within the limitations of this study, Laser sintered group has the superior retention above the other two groups

Abstract: Aims: To compare the retention of copings produced by Direct Metal Laser Sintering (DMLS), Hard metal CAM (Computer Assisted Milling) and conventional casting techniques. Materials and Methods: An implant abutment was used as an ideal model which was scanned by 3D scanner and 8 copings of each group were fabricated from a single STL file. Each specimen was seated, luted, and mounted on a vertical column universal testing machine for a pull-off test. Dislodgement readings were recorded and statistically analyzed with ANOVA test and Duncan’s multiple range test. Results: Significant difference was found between the studied groups in retention. The laser-sintered group showed the highest force required for dislodgement followed by conventional casting group then by the hard metal milling group. Conclusions: within the limitations of this study, Laser sintered group has the superior retention above the other two groups

Abstract: AbstractAims: To evaluate the efficiency of an Er Cr: YSGG laser in debonding of veneers made of lithium disilicate (E-max®) as measured with the shear bond strength (SBS); determine the effect of two laser powers on the SBS required to debonding veneers, and finally determining the mode of failure for all groups. Materials and methods: Thirty ceramic discs (1mm in thickness and 5mm in diameter) were prepared according to the manufacturer’s instructions. The outer surfaces of enamel for thirty bovine teeth were made flat and the discs cemented onto these prepared surfaces through using luting agent (choice 2 light cure) (Bisco, Inc, Schaumburg IL, USA). Samples were stored   in distilled water for 24hours, after which they were divided randomly into three equal groups (n=10) according to the laser power used as follows: Cont.: for the control group that wasn't subjected to laser irradiation; L3: For group irradiated at 3 watt (60 sec.); L5: For group irradiated at 5 watt (60 sec.).  SBS was measured by Instron universal testing machine and the failure modes were evaluated by using stereomicroscope. Results: Both lasers irradiated groups (3 and 5 watts) showed significant reduction in SBS required to debonding veneers as compared to the control group (a=.000). However, there was no significant difference between the two laser powers. Conclusion: Er,Cr:YSGG could be a safe, effective, fast and harmless method for the removal of E-.max® laminate veneers, as it caused significant reduction in SBS required for debonding of cemented veneers. Since there was no significant difference between the two laser powers therefore three watts may be advocated.

Abstract: AbstractAims: To evaluate the efficiency of an Er Cr: YSGG laser in debonding of veneers made of lithium disilicate (E-max®) as measured with the shear bond strength (SBS); determine the effect of two laser powers on the SBS required to debonding veneers, and finally determining the mode of failure for all groups. Materials and methods: Thirty ceramic discs (1mm in thickness and 5mm in diameter) were prepared according to the manufacturer’s instructions. The outer surfaces of enamel for thirty bovine teeth were made flat and the discs cemented onto these prepared surfaces through using luting agent (choice 2 light cure) (Bisco, Inc, Schaumburg IL, USA). Samples were stored   in distilled water for 24hours, after which they were divided randomly into three equal groups (n=10) according to the laser power used as follows: Cont.: for the control group that wasn't subjected to laser irradiation; L3: For group irradiated at 3 watt (60 sec.); L5: For group irradiated at 5 watt (60 sec.).  SBS was measured by Instron universal testing machine and the failure modes were evaluated by using stereomicroscope. Results: Both lasers irradiated groups (3 and 5 watts) showed significant reduction in SBS required to debonding veneers as compared to the control group (a=.000). However, there was no significant difference between the two laser powers. Conclusion: Er,Cr:YSGG could be a safe, effective, fast and harmless method for the removal of E-.max® laminate veneers, as it caused significant reduction in SBS required for debonding of cemented veneers. Since there was no significant difference between the two laser powers therefore three watts may be advocated.

Abstract: Aims: The present study aims to compare and evaluate transportation of three different single endodontic files (EdgeOne Fire, One curve file and Wave One Gold file) by using CBCT. Materials and Methods: Thirty freshly extracted human mandibular first molars with mature apices and intact mesial root randomly distributed into three groups (n=10) only Mesiobuccal canals (MB) with curvatures of 25–35 were prepared by using Edge One Fire (group A), MicroMega One curve file (group B) and Wave One Gold file (group C)  and 3-dimensional, high-resolution CBCT images were obtained using  CS8100 3D equipment (Carestream Health, Rochester, NY) at three cross-section levels that corresponded to 3-mm, 5-mm, and 7-mm distance from the apical end of the root before and after root canal preparation with 87 KV, 2.00 mA and 150 µm voxel size to determine the degree of canal transportation of the three file systems. Results: the highest degree of root canal transportation appeared with One Curve file while Edge One Fire showed the lowest degree of root canal transportation and there was a statistically significant difference between all three files. Conclusions: Within the limitations in this study, it can be  concluded tha all tested Ni-Ti file systems resulted in root canal transportation, and Edge One Fire file is safer during preparation of curved canals than One Curve file.

Abstract: Aims: The present study aims to compare and evaluate transportation of three different single endodontic files (EdgeOne Fire, One curve file and Wave One Gold file) by using CBCT. Materials and Methods: Thirty freshly extracted human mandibular first molars with mature apices and intact mesial root randomly distributed into three groups (n=10) only Mesiobuccal canals (MB) with curvatures of 25–35 were prepared by using Edge One Fire (group A), MicroMega One curve file (group B) and Wave One Gold file (group C)  and 3-dimensional, high-resolution CBCT images were obtained using  CS8100 3D equipment (Carestream Health, Rochester, NY) at three cross-section levels that corresponded to 3-mm, 5-mm, and 7-mm distance from the apical end of the root before and after root canal preparation with 87 KV, 2.00 mA and 150 µm voxel size to determine the degree of canal transportation of the three file systems. Results: the highest degree of root canal transportation appeared with One Curve file while Edge One Fire showed the lowest degree of root canal transportation and there was a statistically significant difference between all three files. Conclusions: Within the limitations in this study, it can be  concluded tha all tested Ni-Ti file systems resulted in root canal transportation, and Edge One Fire file is safer during preparation of curved canals than One Curve file.

Abstract: Aims: To assess and report the microhardness incidence in fissure system of the human dental enamel next Er,Cr:YSGG laser and Diode laser applications in order to examine anti-cariogenic impact and to compare the obtained results between the two laser types. Materials and Methods: Forty extracted impacted lower third molars teeth used in the experiment that should have an obvious occlusal fissure. Intact lower third molar were collected, which were free from caries. Teeth roots separated from crowns ,then the crowns were separated  bucco-lingually  into two equal parts which were applied in 4 test groups included  control group without any treatment, acid group only immersed in demineralizing solution, Diode laser group in which samples subjected to Diode laser (at wavelength 980nm, power 5 watt, mode P3, the time was 30 second) then immersed in demineralizing solution PH 4.4 for 96 hr., and Er,Cr:YSGG laser group in which samples  subjected to Er,Cr:YSGG laser (wave length 2780nm, pulse energy 20 Hz with pulse mode (H-mode), time 10 second) then immersed in demineralizing solution pH 4.4 for 96 hr. Results: The mean microhardness was significantly different from each other at p≤ 0.01. And Er,Cr:YSGG laser had mean surface microhardness significantly higher than other groups then Diode laser group. Conclusions: Both types of lasers increased microhardness of enamel at fissure area, and Er,Cr:YSGG had better effect than Diode laser..

Abstract: Aims: To assess and report the microhardness incidence in fissure system of the human dental enamel next Er,Cr:YSGG laser and Diode laser applications in order to examine anti-cariogenic impact and to compare the obtained results between the two laser types. Materials and Methods: Forty extracted impacted lower third molars teeth used in the experiment that should have an obvious occlusal fissure. Intact lower third molar were collected, which were free from caries. Teeth roots separated from crowns ,then the crowns were separated  bucco-lingually  into two equal parts which were applied in 4 test groups included  control group without any treatment, acid group only immersed in demineralizing solution, Diode laser group in which samples subjected to Diode laser (at wavelength 980nm, power 5 watt, mode P3, the time was 30 second) then immersed in demineralizing solution PH 4.4 for 96 hr., and Er,Cr:YSGG laser group in which samples  subjected to Er,Cr:YSGG laser (wave length 2780nm, pulse energy 20 Hz with pulse mode (H-mode), time 10 second) then immersed in demineralizing solution pH 4.4 for 96 hr. Results: The mean microhardness was significantly different from each other at p≤ 0.01. And Er,Cr:YSGG laser had mean surface microhardness significantly higher than other groups then Diode laser group. Conclusions: Both types of lasers increased microhardness of enamel at fissure area, and Er,Cr:YSGG had better effect than Diode laser..