The capability of regenerative endodontics to promote the complete root formation in immature permanent teeth with different initial pre-operative conditions.

OBJECTIVES: To describe the potential possibility of complete root formation after regenerative endodontic procedures (REPs) in immature permanent teeth with different initial pre-operative conditions. MATERIALS AND METHODS: Children who underwent REPs in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China, from January 2013 to December 2022 were enrolled. Whether the tooth achieved complete root formation was determined using post-operative periapical radiography. The potential possibility of complete root formation after REPs in immature permanent teeth with different initial conditions is discussed. RESULTS: A total of 428 teeth from 401 patients were included, of which 258 (60.2%) achieved complete root formation. In cases that achieved complete root formation, the most serious type of trauma was avulsion, the teeth with the worst initial root development were less than one-third of the development (stages 6-7), and the longest duration of the presence of apical lesions in the tooth before the first visit was more than 180 days. There is a significant difference in the root formation of teeth with different initial developmental stages and diagnoses. CONCLUSIONS: The active period of continued root formation was 5-21 months post-operatively. The higher the initial stage of root development and the shorter the duration of the presence of apical lesions in the tooth before the first visit, the greater the possibility of root formation. However, complete root formation may still be expected after REPs in severely injured immature permanent teeth and teeth with poor initial pre-operative root development conditions (less than stage 7) at the first visit. This is also true for teeth with long-term and large-scale apical lesions.

Analysis of the achievement of primary and secondary goals and influencing factors in single-rooted immature permanent teeth after regenerative endodontic procedures: a retrospective study.

OBJECTIVE: This study explored the achievement of primary and secondary goals and factors influencing their achievement in regenerative endodontic procedures (REPs) for immature permanent teeth. METHODS: Dental records of all patients who received REPs for immature permanent teeth at the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology between January 2012 and January 2023 were retrieved. The evaluation of the primary goal was based on medical and radiographic records. The achievement of the primary goal was defined as the absence of clinical signs and symptoms, such as pain, swelling, or sinus tract and the absence of periapical radiolucency, as assessed on postoperative periapical radiographs. The achievement of secondary goal represented increased root wall thickness and/or increased root length, that is, continued root development. Periapical radiographs before and after treatment were used to evaluate the achievement of the secondary goal. The secondary goal was required to be achieved alongside the achievement of primary goal. RESULTS: A total of 436 teeth (136 anterior and 300 posterior teeth) were included in this study, 96.1% of which demonstrated achievement of the primary goal. Signs of failure (17 teeth) included crown fracture and uncontrolled and recurrent periapical lesions. In addition, 77.8% of teeth demonstrated achievement of the secondary goal, and more than half of the teeth exhibited a complete root development. Evaluation factors included patients' age, sex, tooth type, etiology, preoperative periapical lesion, duration of clinical signs and symptoms, follow-up period, and stage of root development. The achievement of the primary and secondary goals were significantly related to age and tooth type (p < 0.05). CONCLUSIONS: Children with a younger initial visit age are more likely to achieve primary and secondary goals. Additionally, posterior teeth had an advantage over anterior teeth in achieving primary and secondary goals.

Dielectric modulation strategy of carbon nanotube field effect transistors based pressure sensor: towards precise monitoring of human pulse.

Continuous monitoring of arterial pulse has great significance for detecting the early onset of cardiovascular disease and assessing health status, while needs pressure sensors with high sensitivity and signal-to-noise ratio (SNR) to accurately capture more health information concealed in pulse waves. Field effect transistors (FETs) combined with the piezoelectric film is an ultrahigh sensitive pressure sensor category, especially when the FET works in the subthreshold regime, where the signal enhancement effect on the piezoelectric response is the most effective. However, controlling the work regime of FET needs extra external bias assistance which will interfere with the piezoelectric response signal and complicate the test system thus making the scheme difficult to implement. Here, we described a gate dielectric modulation strategy to match the subthreshold region of the FET with the piezoelectric output voltage without external gate bias, finally enhancing the sensitivity of the pressure sensor. A carbon nanotube field effect transistor and polyvinylidene fluoride (PVDF) together form the pressure sensor with a high sensitivity of 7 × 10-1kPa-1for a pressure range of 0.038-0.467 kPa and 6.86 × 10-2kPa-1for a pressure range of 0.467-15.5 kPa, SNR, and the ability to continuously monitor pulse in real-time. Additionally, the sensor enables high-resolution detection of weak pulse signals under large static pressure.

Evaluation of the characteristics of root canal calcification after regenerative endodontic procedures: A retrospective cohort study over 3 years.

AIM: This study aimed to evaluate the characteristics of root canal calcification after regenerative endodontic procedures (REPs) during long-term follow-up. DESIGN: Data of children who underwent REPs and were followed up for >3 years in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China, from January 2013 to January 2019, were collected. All the patients were treated by the protocol of REPs based on the American Association of Endodontists (AAE) protocol. A total of 91 teeth of 54 boys and 37 girls (average age 10.4 ± 1.9 years) with follow-up duration >3 years were included. The follow-up duration ranged from 36 to 92 months (average, 53.2 ± 13.4 months). The prevalence, contributing factors, and long-term prognoses of root canal calcification after REPs are discussed. Independent t-test and χ2 test were used for statistical analysis. RESULTS: The incidence of root canal calcification was 78% (71/91). The use of calcium hydroxide paste was significantly correlated with the occurrence of root canal calcification (p < .05). Some teeth showed aggravation of calcification with time; however, not all teeth showed calcification after longer follow-up duration. CONCLUSIONS: Teeth treated with REPs had a relatively high probability of root canal calcification detection during the long-term follow-up. The occurrence of calcification is related to the use of calcium hydroxide paste but does not affect the long-term prognosis of teeth.

Continued root development of immature permanent teeth after regenerative endodontics with or without a collagen membrane: A randomized, controlled clinical trial.

BACKGROUND: Recent studies evaluated the efficacy of a collagen membrane (Bio-Gide) to promote root development in regenerative endodontics (REPs). However, the influence of etiology and tooth type on the results was not assessed. AIMS: To evaluate the quantitative and qualitative effect of a collagen membrane (Bio-Gide), with and without the effect of etiology and tooth type, in promoting root development in immature teeth after REPs. DESIGN: Eighty nonvital immature teeth were divided randomly into two groups (40 teeth in each group). REPs were performed with (experimental group) and without (control group) a collagen membrane. All teeth were subjected to regular clinical and radiographical follow-up. RESULTS: Seventy-six teeth were included in the final analyses. The average follow-up periods were 33.1 ± 21.8 months for the control group and 28.1± 18.6 months for the experimental group. Quantitative analysis of root development in the experimental group showed a greater increase in dentin wall thickness in the middle one-third of the root compared to the control group, with or without the effect of etiology and tooth type. Six types of root development were observed. There was no significant difference in the type of tooth development between the two groups. CONCLUSION: The use of a collagen membrane could promote an increase in dentin wall thickness in the middle one-third of the root, and it had no significant effect in terms of the type of subsequent root development.

A Flexible Integrated Bending Strain and Pressure Sensor System for Motion Monitoring.

Flexible sensors have attracted increasing research interest due to their broad application potential in the fields of human-computer interaction, medical care, sports monitoring, etc. Constructing an integrated sensor system with high performance and being capable of discriminating different stimuli remains a challenge. Here, we proposed a flexible integrated sensor system for motion monitoring that can measure bending strain and pressure independently with a low-cost and simple fabrication process. The resistive bending strain sensor in the system is fabricated by sintering polyimide (PI), demonstrating a gauge factor of 9.54 and good mechanical stability, while the resistive pressure sensor is constructed based on a composite structure of silver nanowires (AgNWs) and polydimethylsiloxane (PDMS)-expandable microspheres with a tunable sensitivity and working range. Action recognition is demonstrated by attaching the flexible integrated sensor system on the wrist with independent strain and pressure information recorded from corresponding sensors. It shows a great application potential in motion monitoring and intelligent human-machine interfaces.

A Flexible Two-Sensor System for Temperature and Bending Angle Monitoring.

A wearable electronic system constructed with multiple sensors with different functions to obtain multidimensional information is essential for making accurate assessments of a person's condition, which is especially beneficial for applications in the areas of health monitoring, clinical diagnosis, and therapy. In this work, using polyimide films as substrates and Pt as the constituent material of serpentine structures, flexible temperature and angle sensors were designed that can be attached to the surface of an object or the human body for monitoring purposes. In these sensors, changes in temperature and bending angle are converted into variations in resistance through thermal resistance and strain effects with a sensitivity of 0.00204/°C for temperatures in the range of 25 to 100 °C and a sensitivity of 0.00015/° for bending angles in the range of 0° to 150°. With an appropriate layout design, two sensors were integrated to measure temperature and bending angles simultaneously in order to obtain decoupled, compensated, and more accurate information of temperature and angle. Finally, the system was tested by being attached to the surface of a knee joint, demonstrating its application potential in disease diagnosis, such as in arthritis assessment.

Clinical and Radiographic Assessment of the Efficacy of a Collagen Membrane in Regenerative Endodontics: A Randomized, Controlled Clinical Trial.

INTRODUCTION: Recent reviews confirm a general lack of randomized, controlled clinical studies on the efficacy of regenerative endodontics in immature teeth affected by pulp and periapical diseases. Moreover, we have no evidence of the curative efficacy of collagen membranes used as scaffolds in regenerative endodontics. Here, we evaluated whether a Bio-Gide collagen membrane (Geistlich Pharma AG, Wolhusen, Switzerland) has efficacy in promoting dentin formation in regenerative endodontics. METHODS: Forty-three patients yielding a total of 46 nonvital immature teeth were divided randomly into 2 groups. Subsequent to chemomechanical preparation, regenerative endodontics with (the experimental group) and without (the control group) Bio-Gide were performed. All cases were followed up clinically and radiographically every 3 months for at least 6 months. Quantitative analyses using an imaging program yielded percentage changes in root dimensions based on a comparison between preoperative and recall radiographs. RESULTS: The results of 40 patients (43 teeth) were included in the final analyses. All patients from both groups showed clinical success with complete resolution of signs and symptoms. Radiographically, the thickness of the dentin wall at the middle third of the root was higher for the experimental group than the control group. However, other indicators were comparable between both groups. CONCLUSIONS: The use of the Bio-Gide collagen membrane promoted the development of the dentin wall in the middle third of the root in patients undergoing regenerative endodontic procedures. The convenience of operation and the assured positioning of the sealing material make the Bio-Gide collagen membrane especially suitable for handling wide root canals.

[Epidemiological analysis on malaria prevalence in Shanghai from 2003 to 2012].

OBJECTIVE: To understand the epidemiological characteristics of malaria in Shanghai. METHODS: Data related to malaria cases during 2003 to 2012 year in Shanghai was collected and analyzed according to the 3 stages as malaria pre-elimination (2003-2008), pilot malaria elimination (2009-2010) and malaria elimination (2011-2012), respectively. RESULTS: A total number of 936 malaria cases were collected, including 616 cases of Plasmodium (P.) vivax, 110 cases of P. falciparum and 210 cases of unidentified plasmodium. The overall annual incidence rate of malaria was lower than 1 per one hundred thousand and showing a gradual downward trend after 2008. P. vivax was mostly seen during 2003-2008 while the proportion of P. falciparum increased gradually during 2009-2010 and the case of P. falciparum occupied the most during 2011-2012. During 2003-2008, most malaria cases were infected in other provinces but diagnosed in Shanghai. However, between 2008 and 2012, malaria cases were mainly imported from overseas which accounted for 82.80% of the total identified cases, particularly in 2012 that all the malaria cases were imported from Africa and South-East Asia. No indigenous malaria case had been identified since 2009. CONCLUSION: The annual incidence rate of malaria in Shanghai showed a gradual downward trend. Not a single indigenous malaria case had been found for the last 4 years. However, the fact that the situation of importation called for special attention.