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Objectives: To assess the capability of different orthodontic arch-wires to retain oral biofilm and to correlate the adhesion to surface roughness of the wires. Methods: Four types of orthodontic arch-wires were used for the study, Nickel-titanium (NiTi), Copper nickel-titanium (Cu-NiTi) , Beta Titanium (TMA) & Beta III Titanium (CNA) new arch wires and 4 weeks after intraoral usage, were examined for Surface roughness (SR) using an atomic force microscope (AFM). Adhesion of Streptococcus mutans (MS), Staphylococcus aureus (SA), and Candida albicans (CA) were performed using colony count method. Statistically, the following tests were done: analysis of variance, Pearson correlation coefficient test, post hoc Tukey test. Results: The four wire types showed significant increases in SR (P< 0.05) after 4 weeks of intra-oral usage, TMA wires recorded the highest roughness values while the lowest ones were for NiTi wires. Bacterial adhesion was detected on all wires, ANOVA showed significant differences between the wires concerning MS, SA and CA adhesion. A significant positive correlation (P=.001) was observed between bacterial adhesion and surface roughness after intra-oral exposure. Conclusions: SR of the wires increased after intra-oral use and there was a positive correlation with the biofilm adhesion.

Introduction: Implant-supported orthodontic treatment has gained an expanded interest by researchers and orthodontists in the recent years. Therefore, different methods were tried to achieve the best results in this kind of treatment. Aim of the study:The current research was conducted to compare the effect of 2 different treatment methods on the surface of orthodontic titanium mini-screws and on bone response to the treated implants.Materials and methods: Forty-eight titanium mini-screw implants were distributed under 3 equal groups; as received, sandblasted, and laser-treated, respectively. After application of the surface-treatment methods, half of the selected screws were tested for surface morphology, using a scanning electron microscope (SEM) and a digital profilometer. To evaluate the biological effects of surface treatment methods, the other screws were implanted in rabbits' tibias which were subjected to histological examination at the end of the experimental periods of 4 and 8 weeks. The surgical procedures and euthanasia were conducted according to the limitations of Research Committee of Mansoura University.Results: Sandblasted implants showed the highest surface roughness and the most pronounced bone response. Conclusion:Sandblasting surface treatment provide more favorable conditions for implant osseointegration, in comparison to laser-treatment.

Background: With the current mass international roll out of several vaccines against SARS-Cov-2, several reports of unheeded complications have made headlines. One of which involves myocarditis with the now FDA fully approved vaccine, Pfizer, and others. We hypothesize through this study that a dysregulated micro-RNA response resulting from such type of vaccines can be involved in triggering myocarditis. Methodology: Embase, Medline and the Cochrane Central Register were used to search for specific keywords such as “mRNA COVID-19 vaccines” AND “Myocarditis” for relevant publications up to 1st of September 2021. The systematic review was performed using PRISMA protocolResults:Literature review has identified 26 cases series and reports involving the development of myocarditis from mRNA vaccines, a total of 89 patients were included. Age range was clearly identified in 66 patients. Among those 66 patients, 94% were below 50 years of age, also out of 89 patients, 94% were males. Myocarditis developed, after a median time of 72 hours of the 2nd dose. 90 of cases of myocarditis developed myocarditis after the 2nd dose, the few patients developing myocarditis after the first dose were either predisposed by a history of myocarditis or a history of previous COVID-19 infection. Conclusion:In conclusion, interpretation of the results in view of the suggested hypothesis, reveals that the micro-RNAs implicated in myocarditis in general are as well implicated in the pathogenesis of severe COVID-19, this can explain why patients having a first dose with a history of COVID-19 can develop myocarditis from mRNA vaccines, also the relatively higher likelihood of this complication in males and younger aged individuals can be explained by the upregulation of key myocarditis related miRNAs in those two strata, due to higher muscle mass and suggests performing a sarcopenia index in recipients of the vaccine to correlate it with the likelihood of this complication. This could later set a cut-off of this easy bed-side index to stratify cases a higher risk of this rare complication.

Introduction:Resin infiltration technique is a promising option for treatment of incipient enamel lesions, especially for patients with history of fixed orthodontic appliances. However, its ability to resist aging under thermal influences in the oral cavity is still questionable. Aim of the study: The present research aimed to inspect the ability of resin-infiltrated initial enamel lesions, to resist aging under thermal challenge. Materials and methods:Fifty extracted non-carious premolars were included in the present study. Specimens were equally distributed into 5 groups, where group 1 included teeth with sound enamel (control), while group 2 included teeth with decalcified untreated lesions. Specimens of group 3 were subjected to Icon® resin infiltration after decalcification. For groups 4 and 5, decalcified resin-infiltrated specimens were subjected to thermocycling (TC) at 5,000 or 10,000 cycles respectively. Surface evaluation parameters included surface microhardness and roughness. Surface morphology was further evaluated using scanning electron microscope (SEM). For statistical analysis, ANOVA and LSD tests were used.Results: Resin-infiltrated enamel was more resistant to surface changes, under thermal stresses, than the non-resin-infiltrated enamel. The resin surface showed high resistance to surface degradation at thermal stress of 5000 cycles, while more deterioration started to appear at 10,000 cycles. Conclusion:Resin infiltration has the ability to provide adequate protection to the demineralized enamel against thermal attack of 5,000 thermal cycles. However, surface microcracks generated at 10,000 thermal cycles indicate that the material might further deteriorate on aging for more than one clinical service year.

Background Deterioration in shear bond strength has been reported after immediate bracket bonding following hydrogen peroxide bleaching. This study compared the effectiveness of three antioxidant agents, namely, alpha-tocopherol, green tea extract, and sodium ascorbate, in reversing the bleaching effect and as possible alternatives to delayed bonding. Methods A total of 105 extracted human premolars were arbitrarily assigned to 7 groups (n = 15 each), including group 1 as the unbleached control group and six experimental groups, which were bleached with 40% hydrogen peroxide in three sessions of 15 min each. In experimental group 2, bonding was performed immediately after bleaching, whereas in groups 3 and 4, bonding was delayed for 1 and 2 weeks, respectively; meanwhile, the specimens were immersed in artificial saliva at 37 °C. Groups 5, 6, and 7 were treated immediately after bleaching with 10% of alpha-tocopherol, green tea extract, and sodium ascorbate solutions, respectively, for 15 min. Specimens were processed using 500 thermal cycles between 5 and 55 °C, with a dwell time of 30 s after 24 h of bracket bonding, and then tested for shear bond strength. The adhesive remnant index was examined to evaluate fracture mode. One-way analysis of variance, Kruskal–Wallis H, and post hoc Tukey’s honestly significant difference tests were used to compare the data. Significant results were subjected to pairwise comparisons with Bonferroni’s correction-adjusted of p values ≤ 0.050. Results Shear bond strength was significantly lower (p < 0.001) in the immediate bonding and 1-week delay groups than in the control group. However, no significant difference was detected among the 2-week delay, antioxidant-treated, and control groups (p > 0.05). Conclusions Application of 10% alpha-tocopherol, green tea extract, or sodium ascorbate for 15 min could restore shear bond strength after 40% hydrogen peroxide bleaching as an alternative to delay in bracket bonding.

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Introduction: Fixed orthodontic appliances usually provide a shelter for plaque and stain deposition on teeth, stimulating patients to seek teeth bleaching before finishing their orthodontic treatment course. The influence of the whitening agents on the bonded brackets has not been investigated yet. Aim of the study:The current study was conducted to investigate the effect of bleaching techniques on surface roughness of three different types of esthetic orthodontic brackets.Materials and methods: Forty five healthy premolars were selected and classified into 3 groups according to the technique of bleaching. Group A was the control un-bleached group, while groups B and C were either subjected to "in-office" or "at-home" bleaching, respectively. For each group, 3 types of brackets were tested; Transcend ® (polycrystalline ceramic), Inspire Ice ® (Monocrystalline ceramic) and Spirit ® (Resin bracket). Brackets were bonded and bleached according to manufacturers' instructions and surface roughness was evaluated using environmental scanning electron microscope (ESEM). For statistical analysis, ANOVA and LSD tests were used. Results:Brackets subjected to at-home bleaching showed lower Ra values than those subjected to in-office bleaching. Ice ® brackets showed the lowest Ra values, in comparison to the other tested types of brackets. Conclusion:At-home bleaching had lower roughening effect on orthodontic brackets, as compared to in-office technique. Ice brackets were most resistant to the roughening effect of the investigated bleaching agents.