Cone-beam computed tomography analysis of curved root canals after mechanical preparation with three nickel-titanium rotary instruments

Cone beam computed tomography is a 3-dimensional high resolution imaging method. The purpose of this study was to compare the effects of 3 different NiTi rotary instruments used to prepare curved root canals on the final shape of the curved canals and total amount of root canal transportation by using cone-beam computed tomography. A total of 81 mesial root canals from 42 extracted human mandibular molars, with a curvature ranging from 15 to 45 degrees, were selected. Canals were randomly divided into 3 groups of 27 each. After preparation with Protaper, Revo-S and Hero Shaper, the amount of transportation and centering ability that occurred were assessed by using cone beam computed tomography. Utilizing preand post-instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Canals were metrically assessed for changes （surface area, changes in curvature and transportation） during canal preparation by using software SimPlant; instrument failures were also recorded. Mean total widths and outer and inner width measurements were determined on each central canal path and differences were statistically analyzed. The results showed that all instruments maintained the original canal curvature well with no significant differences between the different files （P=0.226）. During preparation there was failure of only one file （the protaper group）. In conclusion, under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. Areas of uninstrumented root canal wall were left in all regions using the various systems.

Calcitonin and vitamin D3 have high therapeutic potential for improving diabetic mandibular growth

The goal of this study was to assess the effect of the intermittent combination of an antiresorptive agent （calcitonin） and an anabolic agent （vitamin D3） on treating the detrimental effects of Type 1 diabetes mellitus （DM） on mandibular bone formation and growth. Forty 3-week-old male Wistar rats were divided into four groups： the control group （normal rats）, the control C＋D group （normal rats injected with calcitonin and vitamin D3）, the diabetic C＋D group （diabetic rats injected with calcitonin and vitamin D3） and the diabetic group （uncontrolled diabetic rats）. An experimental DM condition was induced in the male Wistar rats in the diabetic and diabetic C＋ D groups using a single dose of 60 mg.kg-1 body weight of streptozotocin. Calcitonin and vitamin D3 were simultaneously injected in the rats of the control C＋D and diabetic C＋D groups. All rats were killed after 4 weeks, and the right mandibles were evaluated by micro-computed tomography and histomorphometric analysis. Diabetic rats showed a significant deterioration in bone quality and bone formation （diabetic group）. By contrast, with the injection of calcitonin and vitamin D3, both bone parameters and bone formation significantly improved （diabetic C＋ D group） （P 〈 0.05）. These findings suggest that these two hormones might potentially improve various bone properties.

Side Effects of Pfizer-BioNTech COVID-19 Vaccine among Libyan Young Adults: Observational Study

Purpose: Since the mRNA technology used to manufacture Pfizer-BioNTech COVID-19 Vaccine is new, it is still difficult to predict its consequences. However, many young people, especially in developing countries, think that they are less susceptible to severe infection with the Coronavirus 2 (SARS-CoV-2), Therefore, they do not prefer to take the COVID-19 vaccines. Accordingly, studies in this aspect are necessary to increase people’s awareness of the acceptance of vaccination, especially for the youth. Patients and Methods: This study was conducted on healthy young adults of both sexes. Participants (n = 81) were received two doses of the Pfizer-BioNTech COVID-19 Vaccine. A paper questionnaire was prepared, the survey asks about the side effects related to receiving the Vaccine. All participants completed the questionnaire twice, once after the first dose and again after the second dose. Data were collected and statistically analyzed. Results: The most common side effects were Muscle pain, Tiredness, Headache, and Fever. Less common side effects were Chills, Fainted, Breathlessness, and Coughing. Rare side effects include nausea and vomiting, Diarrhea, Anaphylactic Reaction, and Swollen Lymph Nodes. Side effects that are strongly associated with females are Headache, and Joint pain, for males, Anaphylactic reaction. The study revealed a significant difference between the number of females (96.5%) and males (85%) who suffered from the side effects of the Pfizer-BioNTech COVID-19 Vaccine (P = 0.033). Conclusion: Most of the side effects reported in our study were consistent with Pfizer’s fact sheet for recipients and caregivers. Through our follow-up to the participants in the study, we noticed that the reported side effects were not too bad, and they were able to carry out their daily activities, so we recommend taking the vaccine, especially for young people.

Autologous platelet-rich-fibrin-induced revascularization sequelae:Two case reports Autologous platelet-rich-fibrin-induced revascularization sequelae:Two case reports

BACKGROUND A key requirement for biomimetic regeneration of tissues is a 3D scaffold.The gold standard scaffold for revascularization is the blood clot,however,an adequate blood clot cannot always be achieved in narrow canals or mature roots.Hereby,we document the effects of platelet-rich fibrin(PRF)for the regenerative endodontic treatment(RET)of two immature permanent teeth with necrotic pulps for up to 48 mo.CASES SUMMARY The first patient was a 22-year-old female with history of trauma in tooth#9 with a sinus tract and a large periapical lesion.The second was a 9-year-old male presenting with a badly decayed tooth#14.Both cases were treated with RET and PRF prepared from the patients’blood.PRF and its extract were used as a scaffold for RET.Patients were followed-up to 9 and 48 mo(4 years),respectively.Both patients,were asymptomatic after treatment.At the 9-mo-follow-up of case#1,there was radiographic evidence of periapical bone healing,however,the root apex was still open.In case#2,the roots exhibited apical closure and normal periapical bone architecture at 12-mo follow-up,while no root lengthening was observed.After 48 mo,case#2 showed extensive intracanal calcification in all root canals that complicated conventional root canal treatment.CONCLUSION RET with PRF and its extract could be used in revascularization of immature permanent teeth.However,proper case selection to comply with long-term follow-up is necessary and adverse events such as calcification and canal obliteration should be planned for.