Objective To evaluate the apical sealing ability of iRoot SP root canal sealer in oval-root canal. Methods After root canals were instrumented by Mtwo, 28 premolars with oval-root canal were randomly divided into 2 groups, 14 teeth in each. The root canals were obturated with AH Plus (group A) and iRoot SP (group B) by modified continuous wave condensation technique. The apical leakage was evaluated by dye penetration method and transparent teeth technique. Results Mean depth of leakage was (0.92 ± 0.26) mm for group A and (0.84 ± 0.40) mm for group B. There was no significant difference between the two groups (t=0.506, P > 0.05). Conclusion The apical sealing ability of iRoot SP is equivalent to AH Plus in oval-root canal.

MTA is rarely applied in the repair of root fractured section. A case of maxillary second premolar which fractured ten years ago had been connected with MTA in this article and the cone beam CT was used to evaluate the treatment effect.
Bicuspid ; Cone-Beam Computed Tomography ; Glutamates ; Guanine ; analogs & derivatives ; Humans ; Pemetrexed ; Tooth Root

Objective: To evaluate the efficacy of Mtwo rotary instruments during root canal retreatment. Methods : Thirty mandibular premolars with oval root canal were prepared with ProTaper rotary instruments and obturated with lateral condensation method. The samples were divided into 2 groups. In Mtwo group, the filling materials were removed with Mtwo retreatment system and Mtwo basic instruments. Inmanual stainless group, the filling material were removed with manual instruments. The percentage of residual filling material was measured with image proplus software and the operating time was recorded. Results: The percentage of residual filling material in Mtwo group was significantly lower than manual group in middle third, but the opposite result can be found in the coronal third. In the whole canal, no significant difference was found between the two groups. The mean operating time in Mtwo group was significantly shorter than manual group. Conclusion Mtwo rotary instruments can shorten the time of retreatment, neither of the groups can remove the filling material in oval root canal completely.

Tooth avulsion is one of the most serious case of all traumatic injuries, frequently found in the immature permanent teeth. The common treatment for avulsed permanent tooth is replantation and splint fixation. However it usually results in root inflammation, root absorption and ankylosis, eventually lead to extraction. The present report describes a 8-year-old boy with two immature mandibular central incisors avulsed three hours after the accident. Replantation was performed, and the teeth were splinted. Radiographic and clinical examinations were performed during 15 months follow-up. At present, the avulsed teeth have a favorable prognosis, and remained in a stable functional position and did not reveal root inflammation, root absorption and ankylosis.

When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.
Female ; Humans ; Adult ; Tooth Replantation ; Root Canal Therapy ; Dental Pulp Cavity ; Gutta-Percha/therapeutic use* ; Tooth Root ; Molar/surgery* ; Retreatment

Objective To analyze the prevalence and genetic characteristics of influenza A(H3N2) viruses in the city of Xiangyang in 2022-2023, and to provide a scientific basis for predicting the epidemic and mutation of influenza virus. Methods Throat swab specimens of the influenza like cases were collected from national influenza monitoring sentinel hospitals in Xiangyang every week. RNA was extracted from the specimens for influenza diagnosing using real-time RT-PCR．Viruses were isolated from H3N2 positive specimens, and HA and NA genes were amplified and sequenced．3D modeling analyses were conducted. Results The gene phylogenetic tree showed that the H3N2 isolates in 2022-2023 belonged to 3C.2a1b.2a1 and 3C.2a1b.2a2 branches, respectively. The A(H3N2) influenza virus strains all had amino acid point mutation sites on important antigenic determinants of HA protein. The epitope mutations of the 2022 A(H3N2) strain mainly occurred in regions B, C, and D. The epitope mutations of the A(H3N2) strain in 2023 mainly occurred in regions C and D. Different glycosylation sites of HA gene were found in 2022-2023 strains. No variation was found in key amino acid sites associated with neuraminidase inhibitor resistance. The difference of overall structure was not obvious in the three-dimensional simulation structure diagram. Conclusion The A(H3N2) influenza strains isolated in this study have shown antigenic drift, especially the mutation of HA, which may affect the protective effect of the vaccine on the local population and lead to influenza epidemic. The variations of HA and NA suggest that close attention should be paid to the epidemic and genetic variation of H3N2 subtype influenza virus, to provide a scientific basis for the selection of influenza virus vaccine strains and the prevention and control of influenza.