To evaluate the clinical success of the treatment of maxillary anterior primary incisors caries with composite resin strip crowns.Children who presented with severe early childhood caries and were treated comprehensive caries under general anesthesia from January to December 2016 were enrolled in this study. Composite crowns using preformed celluloid crown (3M ESPE, USA) called as "strip crown technique" were applied to treat vital primary incisors with two or multiple surface cavities. Selective etchings of enamel, Universal Bond adhesive and 3M Z350 resin were used to make strip crowns. The patients returned at the end of 6, 12 and 18 months and received clinical and radiologic examinations. Dentists who did not attend the treatment evaluated the strip crowns clinically by modified United States Public Health Service (USPHS) criteria.Four hundred eighteen restorations, placed in 127 children aged 1.17-5.75 years (average of 3.22), were evaluated. The overall retention rate was 97.8% at the end of 6 months, 93.6% at 12 months and 89.2% at 18 months. After 18 months, 28 restorations (6.7%) were totally lost and 4.1% were rated as having lost some resin material. Only four teeth (1.0%) had secondary caries at the end of 18 months and 1.4% teeth had pulpal pathology requiring root canal treatment. Composite crowns had good performance in contour and adjacent contact and improved aesthetics significantly. Twenty-nine teeth (6.9%) showed mild gingivitis and 93.1% showed healthy gingival. 11.2% of the teeth demonstrated color change because plaque accumulation and the polish could remove the stains. The complete loss of strip crowns was mainly related to eating bites.Strip crowns performed well for restoring primary incisors with large or multisurface caries for periods of over 18 months. The strip crowns can be a durable and aesthetic restoration for vital carious primary incisors with adequate tooth structure after caries removal. Functional movement is an important cause of complete loss. Because of the high technical sensitivity and its requirement of the cooperation of children, strip crowns are more suitable for older and cooperative children as well as children receiving dental treatment under sedation or general anesthesia.
To evaluate the clinical effect of fluoride releasing flowable resin used in treatment of early enamel caries of children compared with conventional sealant.Seventy-six patients, including fifty-two couples of permanent first molars and thirty couples of premolars were selected for this trial. Both sides of all the molars and premolars were diagnosed as early enamel caries based on International Caries Detection and Assessment System (ICDAS) dental caries diagnostic criteria. Using the contralateral control, the teeth were randomly divided into two groups. Molars/premolars in the experimental group were sealed with a fluoride releasing flowable resin; the contralateral molars/premolars were sealed with a conventional fissure sealant as a control group. The retention rate and progress of caries were evaluated at the end of 3, 6, 12 and 24 months.There was no fissure sealant loss or caries progression in both groups 3 and 6 months after sealing the premolars by fluoride releasing flowable resin or conventional fissure sealants. At the end of 12 and 24 months, only one case of fissure sealant loss was observed in conventional fissure sealant group. There was no statistical significance between the two premolar groups. In the first molar group, fluoride releasing flowable resin showed 100%, 98.08%, 90.38% and 88.46% complete retention at the end of 3, 6, 12 and 24 months, respectively. The conventional fissure sealant retention rates were 96.15%, 92.31%, 76.92% and 73.08% at the corresponding time points. The data at the end of 24 months showed that fluoride releasing flowable resin had significantly higher retention rate than the conventional fissure sealant group (P<0.05). The incidence of caries progression at the end of 6, 12 and 24 months were 1.92%, 5.77% and 7.69%, respectively, in the fluoride releasing flowable resin group. In the conventional fissure sealant group, the incidence was 5.77%, 19.23% and 25.00%, respectively. At the end of 12 and 24 months, more significant decrease of caries progress incidence was observed in the fluoride releasing flowable resin group than in the control group, and there was statistical difference between the two groups (P<0.05).Compared with conventional fissure sealant, using fluoride releasing flowable resin as a fissure sealant in children enamel caries of permanent molars can improve the sealant preservation rate and effectively prevent enamel caries progress.
To assess the effects of breast-feeding duration, bottle-feeding duration and oral habits on the occlusal characteristics of primary dentition in 3-6-year-old children in Beijing.This cross sectional study was conducted via an examination of the occlusal characteristics of 734 children combined with a questionnaire completed by their parents/guardians. The examination was performed by a single, previously calibrated examiner and the following variables were evaluated: presence or absence of deep overbite, open bite, anterior cross bite, posterior cross bite, deep overjet, terminal plane relationship of the second primary molar, primary canine relationship, crowding and spacing. Univariate analysis and multiple Logistic regressions were applied to analyze the associations.It was found that a short duration of breast-feeding (never or ≤6 months) was directly associated with posterior cross bite (OR=3.13, 95%CI=1.11-8.82, P=0.031) and no maxillary space (OR=1.63, 95%CI=1.23-2.98, P=0.038). In children breast-fed for ≤6 months, the probability of developing pacifier-sucking habits was 4 times that for those breast-fed for >6 months (OR=4.21, 95%CI=1.85-9.60, P=0.000 2). The children who were bottle-fed for over 18 months had a 1.45-fold higher risk of nonmesial step occlusion and a 1.43-fold higher risk of class II canine relationship compared with those who were bottle-fed for 6-18 months. Non-nutritive sucking habits were also found to affect occlusion: a prolonged digit-sucking habit increased the probability of an anterior open bite, while a pacifier-sucking habit was associated with excessive overjet and absence of lower arch developmental space. Tongue-thrust habit was associated with anterior open bite (OR=4.21, 95%CI=1.85-9.60, P=0.000 2) and posterior cross bite (OR=7.24, 95%CI=1.30-40.13, P=0.024). Lower lip sucking habit was associated with deep overjet and had a negative association with class III canine relationship. Unilateral chewing was associated with spacing in mandibular (OR=1.57, 95%CI=1.03-2.41, P=0.037). Mouth breathing was associated with chronic rhinitis and adenoidal hypertrophy and had an association with spacing in maxillary. The chi-square test did not indicate a statistically significant association between upper lip sucking habit and any occlusal characteristics.Breast-feeding duration was shown to be associated with the prevalence of posterior crossbite, or no maxillary space in the deciduous dentition and development of a pacifier-sucking habit. Children who had a longer duration of bottle-feeding were more likely to develop class II canine relationship. Children who had an oral habit were more likely to develop abnormal occlusal characteristics.
Abstract Background The preparation of the middle mesial (MM) canal of mandibular molars represents a challenge because it is often curved, narrow, and close to the root concave. The purpose of this study was to evaluate the ex vivo shaping ability of 3 nickel-titanium (NiTi) rotary systems in the MM canal using 3D printed resin tooth replicas. Methods A permanent mandibular first molar with a MM canal was acquired from a pool of extracted teeth and reproduced by a 3D printer. The resin tooth replicas ( n = 18) were equally assigned to 3 groups for the evaluation of the shaping abilities of 3 NiTi rotary systems (OneShape [OS], Twisted Files [TF], and ProTaper Gold [PTG]) according to the manufacturer’s recommendations. The tooth replicas were scanned by micro-computed tomography (micro-CT) twice before and after instrumentation of the mesiobuccal (MB), mesiolingual (ML), and MM root canals. After 3D reconstruction, the canal straightening, change of root canal volume and surface area, the mesial and distal canal wall thickness and canal transportation at the levels of 1, 2, and 3 mm below furcation were assessed. One-way variance analysis and Turkey’s post hoc test were used for comparisons of the means among different groups, and paired- t test was used to compare the mesial and distal sides of the mesial roots. Results As compared with OS and TF, the use of PTG in preparation of MM canals resulted in significantly more straightening of canal curvature ( p < 0.05), greater post-instrumentation canal volume and surface area, and thinner mesial and distal remaining canal wall thickness at 1, 2 and 3 mm below furcation (all p < 0.05). Regarding the root canal transportation in the mesiodistal direction, there was no significant difference among the 3 instruments (all p > 0.05) after the preparation of the MB and ML canals. However, in the MM canal, more pronounced transportation was detected in the PTG group at 2 mm below furcation, and in the TF group at 3 mm below furcation as compared with the other 2 systems (both p < 0.05). Conclusions 3D printed tooth replicas have the advantages of consistency and can be an ideal model to evaluate the shaping ability of different instruments in the MM canal. OS and TF files performed similarly and both are appropriate for shaping the MM canal, while PTG may cause excessive and uneven resin removal, especially near the furcation, and may lead to root fragility and procedural errors.
Objective: Single-cell RNA sequencing (scRNA-seq) was used to analyze the developing mouse molars, in order to construct a spatiotemporal development atlas of pulp cells, and further to reveal the developmental process and regulatory mechanism of tooth development. Methods: Ten mandibular first molars from C57BL/6 mice in postnatal day (PN) 0 and 3 were respectively dissected and digested to obtain single-cell suspensions. scRNA-seq was performed on 10× Genomics platform. PN 7 mouse molar scRNA-seq data were obtained from our previous study. PN 0, 3, and 7 scRNA-seq data were integrated for following analysis. The initial quality control, mapping and single cell expression matrix construction were performed by Cell Ranger. Quality control, standardization, dimensional reduction and cluster analysis were performed by using Seurat. Monocle was used to generate the pseudotime trajectory. Scillus was used to perform gene ontology analysis. In order to detect the spatiotemporal change of different population of pulp cells, the marker genes of each cluster were demonstrated by RNAscope in situ hybridization. Results: There were twenty-six cell clusters within mouse molars, which were identified as eight different cell types, including dental pulp cells, dental follicle cells, epithelial cells, immune cells, endothelial cells, perivascular cells, glial cells and erythrocytes. We further re-clustered and analyzed dental pulp cells. Cluster 0 were mature pulp cells, which located at the upper portion of crown. The main functions of cluster 0 were osteogenesis and extracellular structure organization. Cluster 1 were apical papilla cells, which located at the apical part of roots, whose main functions were extracellular structure organization and organ development. Cluster 2 were cycling cells, which were actively proliferated, resided in the lower portion of the crown. Cluster 3 and 4 were preodontoblasts and odontoblasts, respectively. Their functions were closely related to biomineralization. The proportion of mature pulp cells increased with the development process, while the proportion of cycling cells and odontoblast lineage decreased. According to the expression pattern of marker genes of each cluster, we constructed a cell atlas of dental pulp. Pseudotime trajectory analysis found there were two development trajectories within dental pulp. They both started from SPARC related modular calcium binding 2 (Smoc2)+ dental papilla cells, then went through DNA topoisomerase Ⅱ alpha (Top2a)+ cycling cells, and finally divided into coxsackie virus and adenovirus receptor (Cxadr)+ mature pulp cells or dentin sialophosphoprotein (Dspp)+ odontoblasts two lineages. Conclusions: scRNA-seq could fully discover the intercellular heterogeneity of cells on transcriptome level, which provides a powerful tool to study the process and regulatory mechanism of organ development.目的: 通过在单细胞水平分析小鼠磨牙细胞间异质性,构建牙髓细胞发育的时空图谱,进一步揭示牙齿发育的过程和调控机制。 方法: 分别收集出生后0、3 d的C57BL/6小鼠下颌第一磨牙各10颗,制备单细胞悬液,采用单细胞转录组测序(single-cell RNA sequencing,scRNA-seq)技术进行测序。从本课题组前期研究中提取7 d小鼠磨牙scRNA-seq数据,与0、3 d数据进行合并分析。使用Seurat程序对测序数据进行质控、标准化、降维和聚类分析;Monocle程序进行拟时序分析,预测发育轨迹;Scillus程序进行基因本体分析,对细胞功能进行注释。使用原位杂交技术对标记基因进行体内定位,明确不同亚群细胞的体内分布和时空变化。 结果: Seurat分析显示小鼠磨牙细胞具有26个细胞亚群,可分为牙髓细胞、牙囊细胞、上皮细胞、免疫细胞、内皮细胞、管周细胞、胶质细胞和红细胞等八大类细胞,其中牙髓细胞包含5个亚群:成熟牙髓细胞,标记基因为柯萨奇病毒腺病毒受体(coxsackie virus and adenovirus receptor,Cxadr);牙乳头细胞,标记基因为SPARC相关模块化钙结合蛋白2(SPARC related modular calcium binding 2,Smoc2);周期细胞,标记基因为Ⅱ型DNA拓扑异构酶(DNA topoisomerase Ⅱ alpha,Top2a);前成牙本质细胞,标记基因为棕榈酰蛋白羧酸酯酶(notum palmitoleoyl-protein carboxylesterase,Notum);成牙本质细胞,标记基因为牙本质涎磷蛋白(dentin sialophosphoprotein,Dspp)。随着牙胚发育,成熟牙髓细胞的比例逐渐增加,周期细胞和成牙本质细胞比例逐渐降低。原位杂交染色和基因本体分析结果显示,Cxadr+成熟牙髓细胞定位于牙冠上部,主要功能为成骨和“细胞外结构组织”;Smoc2+牙乳头细胞位于根尖,主要功能与“细胞外结构组织”和器官发育相关;Top2a+周期细胞位于牙冠下部,进行有丝分裂;Notum+前成牙本质细胞邻近上皮根鞘,和Dspp+成牙本质细胞的主要功能同为生物矿化。Monocle分析显示牙髓细胞有2条发育轨迹,从Smoc2+牙乳头细胞起始,经过Top2a+周期细胞,再分化为Cxadr+成熟牙髓细胞或成牙本质细胞。 结论: scRNA-seq技术能在转录组水平充分揭示细胞间的异质性,为研究器官发育过程和调控机制提供了有力工具。.
Pediatric dentistry treats patients aged 0-18 years, encompassing the characteristics of general dentistry. The clinical techniques are closely related to restorative dentistry, endodontics, orthodontics, and maxillofacial surgery, while also possessing unique aspects. It particularly focuses on the growth and development patterns of children's dentition and maxillofacial structures. Currently, digital technology has deeply integrated with various clinical disciplines of dentistry, and pediatric dentistry has made significant progress with pediatric-specific digital applications. On one hand, the introduction of mature digital technologies is enabling the digital transformation of pediatric dental treatment models; on the other hand, there is innovative development of new digital technologies tailored to the specific needs of pediatric dental care, filling gaps in the field. Based on years of research in digital technology for pediatric dentistry, our team details the current innovative applications and scientific explorations in this area from these two perspectives. Additionally, we anticipate the potential expansion of digital technologies not yet applied in pediatric dentistry, providing a reference for clinical scholars in the field to conduct exploratory research.
Objective: To investigate the protective role of alprostadil on aortic dissection. Methods: 26 C57BL6 male mice were divided into control group (normal drinking water, n=13) and model group (1 g·kg-1·d-1 BAPN via drinking water, n=13). On day 14, mRNA expression of inflammatory-related genes as well as EP receptor families were detected by RT-PCR (n=6 each) and EP4 protein levels were determined by Western blot (n=7 each). Another 88 mice were divided into 3 groups: control group (n=22), model group (n=33) and treatment group (n=33). The mice in model group and treatment group were applied with BAPN (1 g·kg-1·d-1) via drinking water. The mice in treatment group received additional intraperitoneal injection with alprostadil (80 μg·kg-1·d-1) for 28 days. The mice in the control and model group received equal volume intraperitoneal injection with 0.9% saline respectively. The body weight and systolic blood pressure, the mortality and morbidity were monitored from the beginning until the designed end of the study. On day 28, the mice were sacrificed and aorta were fixed, embedded and sliced, followed by staining with HE and Victoria Blue. The distribution of EP4 was determined by immunohistochemistry in control (n=6) and model group (n=6). Furthermore, the concentration of PGE1 were tested among model (n=3) and treatment group (n=4). EP4 protein expression was determined in model group (n=7) and treatment group (n=6). Results: On day 14, mRNA expression level of MCP-1 ((2.74±1.55) vs. (1.00±0.49),<0.05) and MMP2((1.38±0.42) vs. (1.00±0.27), P<0.05) was significantly upregulated in model group compared with control group. Protein expression of EP4 receptor also increased in aorta in model group compared with control group (1.48±0.51 vs. 1.00±0.19, P<0.05). In the dissection area, the EP4 expression was also enriched compared with non-dissection area, particularly in endothelial cells and inflammatory cells on day 28. BAPN applied in drinking water (model and treatment groups) successfully induced the aortic dissection in mice, some mice died of the rupture. The elastic fibers were fractured, and the infiltrated immune cells were visible in dissected tissue. False lumen was formed. There was no dissection and death in the control group. Compared with control group, the morbidity and mortality rates were significantly increased in the model group (60.6%, 20/33, 30.3%, 10/33) and the treatment group (72.7%, 24/33, 24.2%, 8/33). The mortality and morbidity rates were similar between model and treatment groups. There is no difference in terms of SBP among three groups (P>0.05). Further study showed that after alprostadil injection, the blood concentration of PGE1 was increased in treatment group ((0.540±0.041 vs. 0.436±0.012)μmol/L, P<0.05). Besides, the EP4 receptor expression was downregulated in the treatment group compared to model group (0.60±0.30 vs. 1.00±0.20, P<0.05). Conclusion: EP4 expression is upregulated in BAPN induced aortic dissection mouse model. No protective effects are observed post alprostadil treatment in this model probably due to the reduced expression of EP4.目的: 探讨前列地尔注射液对β-氨基丙腈(BAPN)诱导的主动脉夹层的作用及其机制。 方法: 选取3周龄雄性C57BL/6小鼠26只随机分成对照组(普通饮水,n=13)和模型组(1 g·kg-1·d-1 BAPN饮水,n=13),14 d时提取主动脉组织RNA和总蛋白,采用实时定量聚合酶链式反应和蛋白质免疫印迹检测对照组和模型组主动脉炎症相关基因、EP基因mRNA(每组各6只)和前列地尔受体4 (EP4)蛋白(每组各7只)表达。选取3周龄雄性C57BL/6小鼠88只,按随机区组设计法分为3组:对照组(普通饮水+生理盐水80 μg·kg-1·d-1,n=22)、模型组(1 g·kg-1·d-1 BAPN饮水+生理盐水80 μg·kg-1·d-1,n=33)和治疗组(1 g·kg-1·d-1 BAPN饮水+80 μg·kg-1·d-1 前列地尔注射液,n=33)。BAPN饮水前1 d开始每日腹腔注射给药,连续给药28 d。记录每组小鼠体重、血压变化及因主动脉夹层破裂死亡情况。28 d时,大体解剖观察主动脉夹层发生情况;取主动脉组织进行固定、包埋和切片,苏木素-伊红和维多利亚蓝-核固红染色观察主动脉的形态结构变化,同时,免疫组化染色观察对照组(6只)和模型组(6只)EP4蛋白的表达分布情况。并对模型组(3只)和治疗组(4只)血浆PGE1进行ELISA检测。选取3周龄雄性C57BL/6小鼠13只,随机分为模型组(1 g·kg-1·d-1 BAPN饮水+生理盐水,n=7)和治疗组(1 g·kg-1·d-1 BAPN饮水+80 μg·kg-1·d-1 前列地尔注射液,n=6),14 d时对主动脉EP4蛋白表达进行定量分析。 结果: 模型组小鼠BAPN诱导14 d时主动脉单核细胞趋化因子1 [(2.74±1.55)比(1.00±0.49)]和基质金属蛋白酶2[(1.38±0.42)比(1.00±0.27)]的mRNA表达及EP4蛋白(1.48±0.51比1.00±0.19)表达高于对照组(P均<0.05)。免疫组化结果显示EP4可在模型组的内皮细胞、炎症细胞中表达。小鼠主动脉解剖观察可见模型组和治疗组均有明显的夹层,苏木素-伊红和维多利亚蓝-核固红染色显示模型组和治疗组主动脉夹层血管可见弹力板断裂、充满红细胞的假腔形成和炎症细胞浸润。对照组无主动脉夹层和死亡发生,与对照组相比,模型组主动脉夹层发生率(60.6%,20/33)、破裂死亡率(30.3%,10/33),以及治疗组的主动脉夹层发生率(72.7%,24/33)、死亡率(24.2%,8/33)均明显升高,体重明显降低(P均<0.05),但模型组与治疗组间比较差异无统计学意义(P>0.05)。3组间血压无明显差异(P>0.05)。相较于模型组,治疗组在给药后血药浓度高[(0.540±0.041)μmol/L比(0.436±0.012)μmol/L,t=4.10,P<0.05],EP4蛋白表达低[(0.60±0.30)比(1.00±0.20),P<0.05]。 结论: 在BAPN诱导的小鼠主动脉夹层模型中EP4表达增高,但使用前列地尔注射液腹腔给药对该模型中主动脉夹层的破裂无保护作用,其可能原因是前列地尔反馈抑制了EP4的表达。.