Oral health status in Sichuan Province: findings from the oral health survey of Sichuan, 2015–2016

To investigate oral health status in the residents of Sichuan Province, southwest China, a cross-sectional study was performed using the latest Oral Health Survey Basic Methods recommended by the World Health Organization. A multistage stratified random cluster-sampling method was used to enroll participants from the following three groups： children aged 3-5 years, adolescents aged 12 years, and people aged 65-74 years. In these three groups, the mean numbers of teeth that were affected by caries were 3.28, 0.86 and 5.13, respectively, resulting in a prevalence of 63.47%, 37.20% and 83.20%, respectively. Relative to the high rate of decayed teeth, the prevalence of fillings was very low in all age groups （0.97%, 7.24% and 5.43%, respectively）, In the 12-year-old adolescent group, only 3.61% had good pit and fissure sealing. In addition, the rate of dental fluorosis was 24.80%, and the Community Fluorosis Index value was 0.39. In the elder group, the community periodontal index was 2.92. The prevalence in the elderly of having lost at least one tooth was 75.54%. Additionally, 4.44% of these participants were edentulous. The incidence of dental prosthesis was 51.75%, the proportion with a removable partial denture, a fixed denture, full dentures, dental implants and an informal fixed bridge was 21.59%, 11.45%, 4.64%, 0 and 16.67%, respectively. In this study, 8.2% of the elderly participants were affected by different types of oral mucosal lesions. Among such lesions, recurrent aphthous ulcers were most prevalent （2.69%） and oral lichen planuses were second （1.6%）. The conclusion presented in this survey is that oral diseases, especially dental caries and periodontal disease, are frequent and common in Sichuan province, China. Moreover, the treatment rate is very low, and primary prevention and treatment options are therefore urgently needed in this population.

An in vitro study on the efficacy of removing calcium hydroxide from curved root canal systems in root canal therapy

To compare the efficacy of various irrigants(citric acid, ethylenediaminetetraacetic acid(EDTA) and Na OCl) and techniques in removing Ca(OH)2in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or2.5% Na OCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH)2from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2removal in the canals.In simulated root canals, we found that 10% citric acid removed more Ca(OH)2than 2.5% NaOCl in the 0–1 mm group from the apex level(Po0.05). Ultrasonic and Endo Activator activation significantly removed more Ca(OH)2than a size 30 K file in the apical third(Po0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17%EDTA in removing Ca(OH)2in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2using the decalcifying solution with Endo Activator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2removal was provided based on the conclusions of this study and the methods recommended in previous studies.

Development of a 50K SNP Array for Japanese Flounder and Its Application in Genomic Selection for Disease Resistance

Single nucleotide polymorphism(SNP)armays are a powerful genotyping tool used in genetic research and genomic breeding programs.Japanese flounder(Paralichthys olivaceus)is an economically-important aquaculture flatfish in many countries.However,the lack of high-efficient genotyping tools has impeded the genomic breeding programs for Japanese flounder.We developed a 50K Japanese flounder SNP array,"Yuxin No.1,"and report its utility in genomic selection(GS)for disease resistance to bacterial pathogens.We screened more than 42,.2 million SNPs from the whole-genome resequencing data of 1099 individuals and selected 48697 SNPs that were evenly distributed across the genome to anchor the array with Affymetrix Axiom genotyping technology.Evaluation of the array performance with 168 fishs howed that 74.7%of the loci were successfully genotyped with high call rates(>98%)and that the poly-morphic SNPs had good cluster separations.More than 85%of the SNPs were concordant with SNPs obtained from the whole-genome resequencing data.To validate"Yuxin No.1"for GS,the arrayed geno-typing data of 27 individuals from a candidate population and 931 individuals from a reference popula-tion were used to calculate the genomic estimated breeding values(GEBVs)for disease resistance toEdwardsiella tarda.There was a 21.2%relative increase in the accuracy of GEBV using the weighted geno-mic best linear unpiased prediction(wGBLUJP),compared to traditional pedigree-based best linear unbi-ased prediction(ABLUP),suggesting good performance of the'Yuxin No.1"SNP array for GS.In summary,we developed the"Yuxin No.1"50K SNP array,which provides a useful platform for high-quality geno-typing that may be beneficial to the genomic selective breeding of Japanese flounder.