Acquisition of the arginine deiminase system benefits epiparasitic Saccharibacteria and their host bacteria in a mammalian niche environment.

Saccharibacteria are a group of widespread and genetically diverse ultrasmall bacteria with highly reduced genomes that belong to the Candidate Phyla Radiation. Comparative genomic analyses suggest convergent evolution of key functions enabling the adaptation of environmental Saccharibacteria to mammalian microbiomes. Currently, our understanding of this environment-to-mammal niche transition within Saccharibacteria and their obligate episymbiotic association with host bacteria is limited. Here, we identified a complete arginine deiminase system (ADS), found in further genome streamlined mammal-associated Saccharibacteria but missing in their environmental counterparts, suggesting acquisition during environment-to-mammal niche transition. Using TM7x, the first cultured Saccharibacteria strain from the human oral microbiome and its host bacterium Actinomyces odontolyticus, we experimentally tested the function and impact of the ADS. We demonstrated that by catabolizing arginine and generating adenosine triphosphate, the ADS allows metabolically restrained TM7x to maintain higher viability and infectivity when disassociated from the host bacterium. Furthermore, the ADS protects TM7x and its host bacterium from acid stress, a condition frequently encountered within the human oral cavity due to bacterial metabolism of dietary carbohydrates. Intriguingly, with a restricted host range, TM7x forms obligate associations with Actinomyces spp. lacking the ADS but not those carrying the ADS, suggesting the acquired ADS may also contribute to partner selection for cooperative episymbiosis within a mammalian microbiome. These data present experimental characterization of a mutualistic interaction between TM7x and their host bacteria, and illustrate the benefits of acquiring a novel pathway in the transition of Saccharibacteria to mammalian microbiomes.

Digenic inheritance accounts for phenotypic variability in amelogenesis imperfecta.

Amelogenesis imperfecta (AI) represents a group of clinically and genetically heterogeneous disorders that affect enamel formation and mineralization. Although AI is commonly considered a monogenic disorder, digenic inheritance is rarely reported. In this study, we recruited two nonconsanguineous Chinese families exhibiting diverse phenotypes of enamel defects among affected family members. Digenic variants were discovered in both probands. In family 1, the proband inherited a paternal frameshift variant in LAMA3 (NM_198129.4:c.3712dup) and a maternal deletion encompassing the entire AMELX gene. This resulted in a combined hypoplastic and hypomineralized AI phenotype, which was distinct from the parents' manifestations. In family 2, whole-exome sequencing analysis revealed the proband carried a maternal heterozygous splicing variant in COL17A1 (NC_000010.11 (NM_000494.3): c.4156 + 2dup) and compound heterozygous variants in RELT (paternal: NM_032871.4:c.260A > T; maternal: NM_032871.4:c.521 T > G). These genetic changes caused the abundant irregular enamel defects observed in the proband, whereas other affected family members carrying heterozygous variants in both COL17A1 and RELT displayed only horizontal grooves as their phenotype. The pathogenicity of the novel COL17A1 splice site variant was confirmed through RT-PCR and minigene assay. This study enhances our understanding by highlighting the potential association between the co-occurrence of variants in two genes and variable phenotypes observed in AI patients.

The short-term impact of comprehensive caries treatment on the supragingival microbiome of severe early childhood caries.

BACKGROUND: Children affected by severe early childhood caries (S-ECC) usually need comprehensive caries treatment due to the extensive of caries. How the oral microbiome changes after caries therapy within the short-term warrant further study. AIM: This study aimed to investigate the short-term impact of comprehensive caries treatment on the supragingival plaque microbiome of S-ECC children. DESIGN: Thirty-three children aged 2-4 years with severe caries (dt > 7) were recruited. Comprehensive caries treatment was performed under general anesthesia in one session and included restoration, pulp treatment, extraction, and fluoride application. Supragingival plaque was sampled pre- and 1-month posttreatment. The genomic DNA of the supragingival plaque was extracted, and bacterial 16S ribosomal RNA gene sequencing was performed. RESULTS: Our data showed that the microbial community evenness significantly decreased posttreatment. Furthermore, comprehensive caries treatment led to more diverse microbial structures among the subjects. The interbacterial interactions reflected by the microbial community's co-occurrence network tended to be less complex posttreatment. Caries treatment increased the relative abundance of Corynebacterium matruchotii, Corynebacterium durum, Actinomyces naeslundii, and Saccharibacteria HMT-347, as well as Aggregatibacter HMT-458 and Haemophilus influenzae. Meanwhile, the relative abundance of Streptococcus mutans, three species from Leptotrichia, Neisseria bacilliformis, and Provotella pallens significantly decreased posttreatment. CONCLUSION: Our results suggested that comprehensive caries treatment may contribute to the reconstruction of a healthier supragingival microbiome.

Danggui Shaoyaosan attenuates doxorubicin induced Nephrotic Syndrome through regulating on PI3K/Akt Pathway.

The study aimed to explore the role and the underlying mechanism of Danggui Shaoyaosan (DSS) in nephrotic syndrome (NS). NS rat model was induced by doxorubicin injection twice. After DSS treatment, inflammation and oxidative stress index were detected via ELISA. Western blot was used for the protein detection. Go and KEGG analysis was applied to evaluate target gene and signaling of DSS. MCP-5 cell was applied for the cell rescue experiments and mechanism exploration. The 24 h urine protein levels of NS rats increased significantly, which was reduced by DSS treatment in a concentration-dependent manner. After DSS treatment, levels of BUN, SCr, TG and TC were also decreased, and serum ALB and TP levels were increased in rats. GO and KEGG pathway enrichment identified PI3K-Akt to be the candidate signaling of DSS in the treatment of NS, which was activated in NS rats. The recuse experiments in MCP-5 demonstrated that IGF-1, the agonist of PI3K/AKT, abolished the beneficial role of DSS in podocyte cell viability, apoptosis, inflammation and oxidative stress. In conclusion, DSS exerts a protective role against the development of NS. The mechanism is related to the improvement of podocyte injury and the inhibition of PI3K/Akt pathway-related proteins.

Enamel defects of Axenfeld-Rieger syndrome and the role of PITX2 in its pathogenesis.

OBJECTIVES: To investigate the detailed ultrastructural patterns of dental abnormalities affected by Axenfeld-Rieger syndrome (ARS) with a heterozygous microdeletion involving paired-like homeodomain 2 (PITX2) and explored the underlying molecular mechanisms driving enamel defects. SUBJECTS AND METHODS: Sanger sequencing, genomic quantitative PCR analysis, and chromosomal microarray analysis (CMA) were used to screen the disease-causing mutation in one ARS proband. An exfoliated tooth from an ARS patient was analyzed with scanning electron microscopy and micro-computerized tomography. A stable Pitx2 knockdown cell line was generated to simulate PITX2 haploinsufficiency. Cell proliferation and ameloblast differentiation were analyzed, and the role of the Wnt/ß-catenin pathway in proliferation of ameloblast precursor cells was investigated. RESULTS: An approximately 0.216 Mb novel deletion encompassing PITX2 was identified. The affected tooth displayed a thinner and broken layer of enamel and abnormal enamel biomineralization. PITX2 downregulation inhibited the proliferation and differentiation of inner enamel epithelial cells, and LiCl stifmulation partially reversed the proliferation ability after Pitx2 knockdown. CONCLUSIONS: Enamel formation is disturbed in some patients with ARS. Pitx2 knockdown can influence the proliferation and ameloblast differentiation of inner enamel epithelial cells, and PITX2 may regulate cell proliferation via Wnt/ß-catenin signaling pathway.

Phylosymbiosis: The Eco-Evolutionary Pattern of Insect-Symbiont Interactions.

Insects harbor diverse assemblages of bacterial and fungal symbionts, which play crucial roles in host life history. Insects and their various symbionts represent a good model for studying host-microbe interactions. Phylosymbiosis is used to describe an eco-evolutionary pattern, providing a new cross-system trend in the research of host-associated microbiota. The phylosymbiosis pattern is characterized by a significant positive correlation between the host phylogeny and microbial community dissimilarities. Although host-symbiont interactions have been demonstrated in many insect groups, our knowledge of the prevalence and mechanisms of phylosymbiosis in insects is still limited. Here, we provide an order-by-order summary of the phylosymbiosis patterns in insects, including Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera. Then, we highlight the potential contributions of stochastic effects, evolutionary processes, and ecological filtering in shaping phylosymbiotic microbiota. Phylosymbiosis in insects can arise from a combination of stochastic and deterministic mechanisms, such as the dispersal limitations of microbes, codiversification between symbionts and hosts, and the filtering of phylogenetically conserved host traits (incl., host immune system, diet, and physiological characteristics).

Phylosymbiotic Structures of the Microbiota in Mollitrichosiphum tenuicorpus (Hemiptera: Aphididae: Greenideinae).

Aphids harbor an array of symbionts that provide hosts with ecological benefits. Microbial community assembly generally varies with respect to aphid species, geography, and host plants. However, the influence of host genetics and ecological factors on shaping intraspecific microbial community structures has not been fully understood. In the present study, using Illumina sequencing of the V3 - V4 hypervariable region of the 16S rRNA gene, we characterized the microbial compositions associated with Mollitrichosiphum tenuicorpus from different regions and plants in China. The primary symbiont Buchnera aphidicola and the secondary symbiont Arsenophonus dominated the microbial flora in M. tenuicorpus. Ordination analyses and statistical tests suggested that geography and aphid genetics primarily contributed to the variation in the microbiota of M. tenuicorpus. We further confirmed the combined effect of aphid genetics and geography on shaping the structures of symbiont and secondary symbiont communities. Moreover, the significant correlation between aphid genetic divergence and symbiont community dissimilarity provides evidence for intraspecific phylosymbiosis in natural systems. Our study helped to elucidate the eco-evolutionary relationship between symbiont communities and aphids within one given species.

Microbiota associated with Mollitrichosiphum aphids (Hemiptera: Aphididae: Greenideinae): diversity, host species specificity and phylosymbiosis.

Symbiotic association is universal in nature, and an array of symbionts play a crucial part in host life history. Aphids and their diverse symbionts have become a good model system to study insect-symbiont interactions. Previous symbiotic diversity surveys have mainly focused on a few aphid clades, and the relative importance of different factors regulating microbial community structure is not well understood. In this study, we collected 65 colonies representing eight species of the aphid genus Mollitrichosiphum from different regions and plants in southern China and Nepal and characterized their microbial compositions using Illumina sequencing of the V3 - V4 hypervariable region of the 16S rRNA gene. We evaluated how microbiota varied across aphid species, geography and host plants and the correlation between microbial community structure and host aphid phylogeny. Heritable symbionts dominated the microbiota associated with Mollitrichosiphum, and multiple infections of secondary symbionts were prevalent. Ordination analyses and statistical tests highlighted the contribution of aphid species in shaping the structures of bacterial, symbiont and secondary symbiont communities. Moreover, we observed a significant correlation between Mollitrichosiphum aphid phylogeny and microbial community composition, providing evidence for a pattern of phylosymbiosis between natural aphid populations and their microbial associates.

Effects of Rose Bengal- and Methylene Blue-Mediated Potassium Iodide-Potentiated Photodynamic Therapy on Enterococcus faecalis: A Comparative Study.

BACKGROUND AND OBJECTIVES: This study was performed to compare the use of methylene blue (MB) and rose bengal (RB) in antimicrobial photodynamic therapy (PDT) targeting Enterococcus faecalis (E. faecalis) bacteria in planktonic and biofilm forms with potassium iodide (KI) potentiation. STUDY DESIGN/MATERIALS AND METHODS: E. faecalis bacteria in planktonic form were exposed to antimicrobial PDT protocols activating MB and RB, with or without KI potentiation, following laser irradiation with different exposure times, 60 mW/cm2 laser power, and different photosensitizer agent (PS)/potentiator concentrations to observe relationships among the variables. Two continuous-wave diode lasers were used for irradiation (red light: λ = 660 nm and green light: λ = 565 nm). The pre-irradiation time was 10 minutes. The vitality of E. faecalis biofilm was assessed by confocal laser scanning microscopy, and the morphology was determined by scanning electron microscopy. The effects on the proliferation of stem cells from the apical papilla (SCAPs) were analyzed by cell counting kit-8 assay. The staining effect of antimicrobial PDT on dentin slices was investigated. Statistical analysis using a one-way analysis of variance was done. RESULTS: KI-potentiated RB and MB antimicrobial PDT both effectively eradicated E. faecalis bacteria in planktonic and biofilm forms. The minimum bactericidal concentrations of PSs (±100 mM KI) were obtained through PDT on planktonic E. faecalis, and the optimal light parameters were 60 mW/cm2 , 6 J/cm2 for 100 seconds. KI-potentiated PDT effectively strengthened the ability to inhibit E. faecalis biofilm with 86.50 ± 5.78% for MB (P = 0.0015 < 0.01) and 91.50 ± 1.75% for RB (P = 0.0418 < 0.05) of bactericidal rate, with less toxicity for SCAPs (P < 0.001) and less staining. KI could reduce the staining induced by antimicrobial PDT on dentin slices. CONCLUSION: A combination of KI and antimicrobial PDT may be a useful alternative to conventional disinfection methods in endodontic treatment. MB and RB antimicrobial PDT at much lower concentrations with KI could hopefully achieve disinfection effects comparable with those of 1.5% NaClO while causing few adverse effects on SCAPs. KI helps to avoid staining problems associated with high concentrations of photosensitizer agents. Lasers Surg. Med. © 2020 Wiley Periodicals, LLC.

A retrospective study of survival of 196 replanted permanent teeth in children.

BACKGROUND/AIM: The extra-alveolar period and storage medium are important for the survival of replanted teeth. The aim of this study was to evaluate factors affecting the survival of replanted teeth in children. MATERIAL AND METHODS: Complete dental records of avulsed teeth including age, gender, extra-alveolar time, storage type and period, stage of root development, crown fracture, gingival laceration, alveolar fracture, antibiotics, and splint type and period were obtained. Kaplan-Meier, Cox regression and chi-square tests were used to analyse the risk factors affecting survival (P < 0.05). RESULTS: The study included 196 replanted teeth with a mean follow-up period of 4.0 years. Forty-two (21.4%), 45 (23.0%), and 109 teeth (55.6%) showed functional healing, inflammatory resorption and replacement resorption. The root resorption incidence of teeth with extra-alveolar time longer than 30 minutes was higher vs teeth with a time of less than 30 minutes (P = 0.010). Physiologically stored replanted teeth showed lower incidence of root resorption (19/31, 61.3%) than those stored in non-physiologic media (94/114, 82.5%) (P = 0.025). Root resorption incidence of teeth stored non-physiologically within 30 minutes and then transferred to physiologic media (25/33, 75.8%) was similar to that of teeth stored physiologically (P = 0.127). Teeth stored non-physiologically for longer than 30 minutes had a significantly higher root resorption incidence (99/113, 87.6%) than teeth stored non-physiologically within 30 minutes (55/83, 66.3%) (odds ratio = 1.726, P = 0.001). Pulp canal obliteration occurred in five of the 56 immature teeth (8.9%) but two of them were later extracted because of replacement resorption. The survival of mature teeth (111/140, 79.3%) was significantly higher than that of immature teeth (39/56, 69.6%) (P = 0.007). CONCLUSIONS: This study suggested that non-physiologic storage within 30 minutes was critical for the periodontal healing of replanted teeth. Replanted immature teeth had lower survival rates than mature teeth.

Lack of association between LTF gene polymorphisms and different caries status in primary dentition.

OBJECTIVE: Dental caries is related to cariogenic bacteria, salivary components, oral hygiene and host susceptibility. Lactoferrin is an important antimicrobial glycoprotein in saliva; however, the role of the LTF gene in caries susceptibility is unclear. We investigated the association between LTF polymorphisms and the severity of caries. DESIGN: Our study included 910 healthy paediatric subjects (aged 24-48 months) categorised into three groups: 403 with no caries or white-spot lesions; 230 with moderate caries (8 ≤ dmft ≤ 12); and 277 with severe caries (13 ≤ dmft ≤ 20). Information regarding the subjects' oral habits was gathered using questionnaires. The LTF rs1126477 and rs1126478 polymorphism alleles were genotyped by Sanger sequencing. RESULTS: The three groups showed no significant differences in LTF polymorphisms alleles, genotypes or haplotypes distribution. Multifactor dimensionality reduction analysis showed that the interactions between breastfeeding for a duration >24 months, night feeding >24 months and high frequency of sweet food intake increased the risk of caries (p = 0.0014); however, we detected no interaction effect between the LTF polymorphisms and oral habits on caries susceptibility. CONCLUSIONS: The LTF rs1126477 and rs1126478 polymorphisms showed no association with the different levels of caries risk in our Chinese paediatric cohort.

A novel 4q25 microdeletion encompassing PITX2 associated with Rieger syndrome.

OBJECTIVE: Rieger syndrome (RS) is a genetic disorder characterized by abnormal development of the eyes, teeth, and umbilicus, and the paired-like homeodomain 2 (PITX2) gene is often implicated in its pathogenesis. This study aimed to identify the underlying genetic defect in a Chinese patient with RS. SUBJECTS AND METHODS: DNA samples were screened for PITX2 gene mutations and copy number variations (CNVs) using Sanger sequencing and genomic quantitative PCR analysis (qPCR). Chromosomal microarray analysis (CMA) was performed to fine-map the CNVs. RESULTS: The proband suffered from severe hypodontia and conical teeth in her permanent dentition. No PITX2 point mutations were found in this Chinese family, but a heterozygous deletion involving PITX2 was suspected and verified by the SNPs analysis and qPCR in the proband. An approximately 0.47 Mb (chr4: 111, 334, 313-111, 799, 327, GRCh37/hg19) deletion including PITX2 was finally determined by CMA. CONCLUSIONS: To our knowledge, this is the first reported case of RS caused by a CNV of the PITX2 gene in a Chinese patient. CNV screening must be considered if point mutation screens yield negative results in these patients. The distribution of SNP genotypes among family members may also provide clues about gene deletion.

Pulp prognosis following conservative pulp treatment in teeth with complicated crown fractures-A retrospective study.

BACKGROUND/AIM: Complicated crown fractures are relatively common in children where the maintenance of the pulp is especially important in young permanent teeth. The aim of this study was to analyze the pulp prognosis of permanent teeth with complicated crown fractures treated with conservative pulp treatment in adolescents. MATERIAL AND METHODS: Complete dental records of teeth with complicated crown fractures treated with conservative pulp treatment were obtained. The risk of pulp necrosis and infection was evaluated by the Kaplan-Meier method and Cox regression (P<.05). Risk factors included gender, age, time interval between dental injury and treatment, stage of root development, type of pulp treatment, and coronal restoration. RESULTS: The study involved 375 teeth treated with direct pulp capping, partial or coronal pulpotomy, and direct pulp capping retreated by pulpotomy (partial or coronal). The frequency of pulp necrosis and infection was 10.1% (11/109) for partial pulpotomy and 9.8% (22/205) for coronal pulpotomy. There was no difference between partial and coronal pulpotomy (P=.673). The risk of pulp necrosis and infection was not significantly different between pulpotomy (partial and coronal; 33/314, 10.5%) and retreatment by pulpotomy (partial or coronal) after direct pulp capping (2/33, 6.1%; P=.436). However, the frequency of pulp necrosis and infection after direct pulp capping (16/28, 57.1%) was significantly higher than that with pulpotomy (partial or coronal; odds ratio=8.216, P<.001). The time interval between dental injury and treatment did not significantly influence pulp survival after pulpotomy (partial or coronal; P=.312), but the stage of root development had a significant impact (P<.001). CONCLUSIONS: Partial or coronal pulpotomy, employed either as a primary pulp treatment or secondary to emergency pulp capping, had similarly satisfactory pulp survival rates.

Long-term treatment outcomes in immature permanent teeth by revascularisation using MTA and GIC as canal-sealing materials: a retrospective study.

BACKGROUND: Pulp revascularisation with MTA sealing has been accepted as an alternative treatment for non-vital immature permanent teeth. Successful revascularisation cases with GIC sealing were also reported, but lack of long-term researches. AIM: To evaluate long-term outcomes of revascularisation using MTA and GIC as canal-sealing materials in non-vital immature permanent teeth. DESIGN: Clinical and radiographic data of 60 non-vital immature permanent teeth treated with revascularisation (36.8 ± 12.4 months of follow-up) were reviewed. Of these, 28 teeth were sealed with MTA, and 32 with GIC. Tooth survival, success rate, and increases in root length and dentine wall thickness were evaluated. RESULTS: Teeth in MTA group showed a similar survival rate (96%) to GIC group (100%). The success rate in MTA group (93%) was greater than that in GIC group (59%). Eight of fourteen failed teeth due to recurrent apical disease (seven teeth in GIC group and one in MTA group) achieved complete root development. There was no statistically significant difference in root length or dentine wall thickness increase between the groups. CONCLUSIONS: Long-term outcome of revascularisation in non-vital immature permanent teeth sealed with GIC was not as good as that with MTA. Although more recurrent apical disease developed, results on root development were acceptable in GIC sealed cases.

Microbiome interaction with sugar plays an important role in relapse of childhood caries.

Childhood caries have a high relapse rate after full mouth therapy. This study aimed to elucidate the relationship between the microbiome, sugar, and the relapse of childhood caries after therapy. A total of 24 children aged 2-4 years who underwent one caries treatment session participated in this study. Supragingival plaque was collected before therapy and 1 and 7 months after therapy, then sequenced using the 16S rRNA high-throughput approach. We found 11 phyla, 140 genera, and 444 species in 72 samples. The children were divided into relapse-free (n = 13) and relapse (n = 11) groups according to whether they relapsed 7 months after therapy. The bacterial community richness, diversity, structure, and relative abundance of bacterial taxa were significantly different between the two groups 7 months after therapy. The two groups also differed in the relative abundance of bacterial taxa, both before and 1 month after therapy. Bacterial community richness and diversity were lower in the relapse-free group 1 month after therapy. Using different operational taxonomic units between the relapse-free and relapse groups 1 month after therapy, a relapse-risk assessment model was built with 75% accuracy, 0.1905 out-of-bag error, and 66.67% validation accuracy. Patients in the relapse group had higher sugar intake frequencies than those in the relapse-free group during follow-up. Interactions between the microbiome and sugar intake frequency were found through co-occurrence networks. We conclude that the microbiome is significantly different between the relapse-free and relapse groups at the time of relapse. Supragingival plaque collected immediately after therapy can be used to predict the risk of relapse. Furthermore, the correlation between sugar intake frequency and microbiome is associated with the relapse.

Changes in dental plaque microbial richness and oral behavioral habits during caries development in young Chinese children.

OBJECTIVE: To detect changes in the microbial richness of dental plaque and oral behaviors during caries development in young Chinese children. METHODS: Supragingival plaque samples and a survey of oral behaviors of 130 children aged 3 at baseline were analyzed at 6 months and 12 months. Total DNA was isolated from all samples and PCR-denaturing gradient gel electrophoresis analysis was conducted. RESULTS: In the follow-up, 44 children had caries or cavity fillings at 6 months, a further 28 children had caries or cavity fillings at 12 months. The other 58 children remained caries-free at 12 months. According to the changes in caries status at the 12-month follow-up, all participants were divided into three groups: caries-free, caries at 6 months and caries at 12 months. The changes in oral behaviors during the 12-month follow-up were not significantly different in the three groups. The frequency of eating sweets and eating sweets before sleeping was significantly different among the three groups at baseline. At baseline, the average detectable bands of caries in the 12-month caries group were similar to those of the caries-free group; both of them were higher than that of the 6-month caries group. At 6 months, the average detectable bands of the 12-month caries group were significantly lower than that of the caries-free group although the children of the 12-month caries group were caries-free at that time. CONCLUSIONS: For young Chinese children, the high frequency of eating sweets and eating sweets before sleeping are risk factors of caries onset, and the decrease in microbial richness could occur 6 months before the onset of caries.

[A retrospective study on pulpal tissue prognosis of avulsed permanent teeth in children].

OBJECTIVE: To analyze the pulpal prognosis of replanted permanent teeth in children and to examine the associated factors. METHODS: The samples consisted of 67 children with 81 avulsed permanent teeth treated in Peking University Hospital of Stomatology from 2000 to 2012. Their clinical data of the replanted teeth were collected, and the follow-up period was no less than 12 months. The pulpal prognosis was classified as pulp necrosis and pulp non-necrosis. RESULTS: The replantation within 30 minutes after avulsion led to the most significant increase in pulpal healing (P<0.05). The dental pulp of 80% (4/5) young permanent teeth replanted within 30 minutes remained vital, while all the teeth replanted after 30 minutes developed pulp necrosis within 60 days after replantation. CONCLUSION: The extra-alveolar period significantly affects the prognosis of pulp in immature permanent teeth after replantation. When the extra-alveolar period is more than 30 minutes, the chance of pulp revascularization after replantation is very low, therefore pulp extirpation should be performed.

Analysis of pulp prognosis in 603 permanent teeth with uncomplicated crown fracture with or without luxation.

AIM: To analyze the pulp prognosis of uncomplicated crown-fractured teeth with or without concurrent luxation injury in adolescent. MATERIAL AND METHODS: Complete dental records of traumatized permanent teeth were obtained, including the patient's name, gender and age, position of the traumatized tooth, its stage of root development, time elapsed between dental injury and treatment, diagnosis, clinical procedures, and follow-up period. Pulp prognosis was evaluated over a period of at least 6 months using Andreasen's classification. Kaplan-Meier method and Cox regression were used to examine the risk factors inherent to the prognosis of pulp healing, with P < 0.05 accepted as statistically significant. RESULTS: The study involved 603 teeth with uncomplicated crown fractures followed up for 6 months or longer, of which 104 suffered luxation at the same time. The frequency of pulp necrosis in teeth with complete root development was higher than those with incomplete root development. For uncomplicated crown fracture with luxation, crown-fractured teeth with intrusion had a higher incidence of pulp necrosis than other types of concurrent luxation (OR: 33.613). The incidence of pulp necrosis within 3 months was significantly higher than in other time periods (P = 0.021), and the median survival time was 53 days (95% confidence interval: 34-67 days). CONCLUSIONS: Existence of concurrent luxation injury and complete root development are important risk factors of pulp necrosis in teeth with uncomplicated crown fractures in adolescent.

[Evaluation of therapeutic effect of children's dental treatment under general anesthesia: 111 cases report].

OBJECTIVE: To retrospectively evaluate the efficiency of dental treatment under general anesthesia (GA) in child patients, and analyze the related factors. METHODS: The records of patients treated under GA in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, between Aug 2008 and Jun 2012 were collected and analyzed. Two hundred and twenty eight records were found, of which 111 patients under 18 years old who were recalled more than 3 months after GA were selected randomly. The unplanned treatments including caries, failed restoration, root canal treatment and space maintenance fall-off etc. were recorded and analyzed. The survival rate and median survival time of the teeth were calculated, and a multivariate analysis was performed by Cox proportional hazard model. RESULTS: Totally, there were 1 415 teeth treated under GA. The median survival time was 825 days, 77.0% of the teeth were present during their recall period. The median time of the first unplanned treatment was 215 days, and the failed restoration was the main reason for the unplanned treatment. Other factors such as the age at treatment, gender, total number of decayed teeth, reason for GA, and living place were found unassociated with the survival rate. CONCLUSION: The effect of dental treatment under GA is satisfied. Regular dental visit after GA is very important for children's dental health.

Impact of marine ranching demonstration areas on regional ecological efficiency - Trial evidence based on the SCM.

The establishment of marine ranching demonstration areas is crucial for restoring offshore fishery resources, fostering ecosystem harmony, and creating blue "carbon sinks" in China. While their ecological benefits are evident, their impact on surrounding areas remains uncertain. This study takes the first batch of national marine ranching demonstration areas established in 2015 as a quasi-natural experiment and uses synthetic control methods to empirically evaluate the effects and mechanisms of their construction on regional ecological efficiency. Results show heterogeneous impacts, with positive effects in Jiangsu and Liaoning but negligible elsewhere. Mechanism analysis reveals that marine ranching demonstration areas enhance ecological efficiency through economic growth, and industrial structure optimization. Differences in marine ranching types and regulations influence their impact, with public welfare-oriented marine ranching showing greater positive effects compared to aquaculture-oriented ones. Overall, these findings hold theoretical and practical implications for advancing modern marine ranching construction.