Detection of periodontal pathogens in oral mucous membranes of edentulous individuals

BACKGROUND: The purpose of this study was to investigate the colonization of Campylobacter rectus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Prevotella intermedia, and Tannerella forsythia (previously T. forsythensis) in the tongue and cheek of newborns and elderly individuals with no teeth. METHODS: Seventy-four edentulous subjects were included in this cross-sectional study. Microbiologic samples were taken from the dorsum of the tongue and cheek mucosa of all individuals and analyzed using a bacterial DNA-specific polymerase chain reaction. RESULTS: C. rectus was the most prevalent species in both groups (20.9% in the cheek of newborns, and 77.4% in the tongue of elderly subjects). P. gingivalis and P. intermedia were not detected in any of the 43 newborns; however, P. gingivalis was recovered from the tongue and cheek (3.2%) of elderly individuals, whereas P. intermedia was detected in the tongue (9.6%) and cheek (3.2%) of elderly individuals. T. forsythia was detected in newborns as well as elderly individuals, although the highest prevalence was observed in the tongue of newborns (6.9%) and elderly (9.6%) individuals. A. actinomycetemcomitans was not found in the tongue of newborns, but we observed A. actinomycetemcomitans in the cheek (2.3%) of newborns and in the tongue (12.9%) and cheek (6.4%) of elderly patients. CONCLUSIONS: Although we did not detect P. gingivalis and P. intermedia in newborns, periodontal pathogens could be detected from the oral mucous membranes of edentulous individuals. Our results suggest that major attention should be paid to edentulous individuals as an important measure in the prevention of the initial colonization of natural teeth and dental implants by periodontal pathogens.     

Radiographic measurement of residual root thickness in premolars with post preparation

A minimum thickness of 1 mm has been suggested for the residual root wall in post preparation. The objective of this paper is to evaluate the reliability of radiography when used to measure root thickness. In 106 upper first premolars with one and two root canals, post preparations were made with Peeso reamers to a depth in the root equal to the crown length. Bucco-palatal radiographs were taken of each tooth. The films were processed and projected with a magnification of x20. The smallest thickness of the mesial and distal walls of each root at the apical end of the preparation was measured and recorded. The teeth were then cut at the level of the measurement, and the smallest thickness of the proximal walls was measured using a microscope with a micrometric eyepiece. Fourteen percent of the teeth with one root canal and 27% of the teeth with two root canals could not be measured due to blurred radiographic contours. Variance analysis showed a highly significant difference (p < 0.001) when radiographic and anatomical measurements were compared. The radiograph showed greater thicknesses than were actually present and should not therefore be considered to be a reliable method for measuring residual thickness of tooth walls after post preparation.     

Evaluation of rat alveolar bone response to Angelus MTA or experimental light-cured mineral trioxide aggregate using fluorochromes

Introduction

The aim of this study was to evaluate the rat alveolar bone response after the implantation of experimental light-cured mineral trioxide aggregate (MTA) or Angelus MTA (Angelus, Londrina, Paraná, Brazil) by histological and fluorescence analysis.

Methods

Thirty Wistar Albino rats were divided into three groups. In the control group, empty polyethylene tubes were inserted into the rat alveolar sockets immediately after extraction. In the other groups, the tubes were filled with light-cured MTA or Angelus MTA. Five animals from each group were injected with calcein on day 7, alizarin on day 14, and oxytetracycline on day 21. On day 30, these animals were killed, and the right hemimaxillas were removed and histologically processed. Half of the maxillas were processed and stained with hematoxylin and eosin. The remaining maxillas were processed for fluorescence analysis and stained with Stevenel blue and alizarin red. New bone was histomorphometrically evaluated using a Merz grid.

Results

The light-cured MTA presented a similar response when compared with Angelus MTA; it was characterized by a mild inflammatory response and complete bone healing. In the light-cured MTA group, the fluorescence areas were more evident at 21 days, showing an increase in bone formation. However, dystrophic mineralization was observed only with Angelus MTA.

Conclusions

It was concluded that both materials present a similar inflammatory response and bone healing, but dystrophic mineralization was observed only with Angelus MTA.     

A rationale method for evaluating unscrewing torque values of prosthetic screws in dental implants

Objectives

Previous studies that evaluated the torque needed for removing dental implant screws have not considered the manner of transfer of the occlusal loads in clinical settings. Instead, the torque used for removal was applied directly to the screw, and most of them omitted the possibility that the hexagon could limit the action of the occlusal load in the loosening of the screws. The present study proposes a method for evaluating the screw removal torque in an anti-rotational device independent way, creating an unscrewing load transfer to the entire assembly, not only to the screw.

Material and methods

Twenty hexagonal abutments without the hexagon in their bases were fixed with a screw to 20 dental implants. They were divided into two groups: Group 1 used titanium screws and Group 2 used titanium screws covered with a solid lubricant. A torque of 32 Ncm was applied to the screw and then a custom-made wrench was used for rotating the abutment counterclockwise, to loosen the screw. A digital torque meter recorded the torque required to loosen the abutment.

Results

There was a significant difference between the means of Group 1 (38.62±6.43 Ncm) and Group 2 (48.47±5.04 Ncm), with p=0.001.

Conclusion

This methodology was effective in comparing unscrewing torque values of the implant-abutment junction even with a limited sample size. It confirmed a previously shown significant difference between two types of screws.     

青年心肌致密化不全合并心力衰竭1例并文献复习

目的 系统回顾心肌致密化不全(NVM)的疾病特点及诊治要点,并总结该病的治疗经验.方法 回顾性分析2020年4月2—18日及9月2—7日该院心内科入院收治的1例NVM合并心律失常、心力衰竭及血栓栓塞等多种并发症的青年患者的诊治经过,并系统随访11个月,观察患者预后.结果 积极控制并纠正心律失常后患者心脏结构及功能呈现可逆性改善.结论 NVM是临床较为罕见的先天性心肌病.其临床表现多样而不典型,可出现包括心律失常、心力衰竭、血栓栓塞等多种不良事件,甚至可出现心源性猝死等恶性后果.临床医师需加强对该病的认识,为及时确诊并合理治疗提供可能.     

急性ST段抬高型心肌梗死患者PCI术后无复流现象的研究进展

冠状动脉粥样硬化性心脏病是全球范围内心血管疾病患者死亡的主要原因,其中以急性ST段抬高型心肌梗死(STEMI)最为凶险。及时经皮冠状动脉介入治疗(PCI)是目前急性STEMI患者最主流的再灌注策略。而部分患者在PCI术后仍不能得到充分的血液灌注,即出现无复流现象(NRP),与随后的不良临床预后密切相关。因此,为了有效恢复再灌注后冠状动脉微循环的血流,防治冠状动脉NRP的发生就显得尤为重要。本文回顾NRP的定义、诊断和临床表现,以病理生理机制为桥梁,提出通过相关预测因子来选择防治策略从而提高PCI疗效。     

Investigation of IL4 gene polymorphism in individuals with different levels of chronic periodontitis in a Brazilian population

BACKGROUND: Cytokines are key factors that mediate the inflammatory process during periodontal disease. Recent works have shown that the levels of cytokine expression are regulated by genetic polymorphisms, and that these variations can interfere with the progression of disease. The-590 (C-->T) polymorphism of the IL4 gene is associated with high levels of IgE in asthmatic families, and the frequency of the T allele was increased in asthmatic children. The concentration of IgE in gingival tissue was found to be elevated in patients with periodontitis. OBJECTIVE: In this study the relationship between the-590 (C-->T) polymorphism in the IL4 gene and different levels of chronic periodontal disease was investigated. MATERIAL AND METHODS: DNA was extracted from buccal epithelial cells of 113 unrelated adult individuals with different levels of periodontitis. The PCR-RFLP technique was used to investigate the polymorphism in the promoter of IL4 gene. RESULTS: No significant differences in the allele and genotype frequencies of the polymorphism were found between control and groups with periodontal disease. CONCLUSION: : We conclude that the-590 (C-->T) polymorphism in the IL4 gene is not associated with the susceptibility to chronic periodontal disease.     

Inverted U-Shaped Associations between Glycemic Indices and Serum Uric Acid Levels in the General Chinese Population: Findings from the China Cardiometabolic Disease and Cancer Cohort (4C) Study

Objective The relationship between serum uric acid(SUA)levels and glycemic indices,including plasma glucose(FPG),2-hour postload glucose(2 h-PG),and glycated hemoglobin(HbA1 c),remains inconclusive.We aimed to explore the associations between glycemic indices and SUA levels in the general Chinese population.Methods The current study was a cross-sectional analysis using the first follow-up survey data from The China Cardiometabolic Disease and Cancer Cohort Study.A total of 105,922 community-dwelling adults aged≥40 years underwent the oral glucose tolerance test and uric acid assessment.The nonlinear relationships between glycemic indices and SUA levels were explored using generalized additive models.Results A total of 30,941 men and 62,361 women were eligible for the current analysis.Generalized additive models verified the inverted U-shaped association between glycemic indices and SUA levels,but with different inflection points in men and women.The thresholds for FPG,2 h-PG,and HbA1 c for men and women were 6.5/8.0 mmol/L,11.0/14.0 mmol/L,and 6.1/6.5,respectively(SUA levels increased with increasing glycemic indices before the inflection points and then eventually decreased with further increases in the glycemic indices).Conclusion An inverted U-shaped association was observed between major glycemic indices and uric acid levels in both sexes,while the inflection points were reached earlier in men than in women.     

National Nutrition and Health Systematic Survey for Children 0-17 Years of Age in China

The main purpose of the National Nutrition and Health Systematic Survey for children 0-17 years of age in China (CNHSC) was to collect basic data on the nutrition, development, and health status for children in different regions across China using evidence-based, reliable, and cost-effective approaches. Children and their parents or guardians from seven regions (south, southwest, north, northwest, eastern, central, and northeast China) in China were recruited. A multi-stage stratified randomized sampling method was used. Two provinces were randomly sampled from each of the seven regions, from which one urban district and one rural country were also randomly sampled, resulting in a total of 28 survey counties/districts. Dietary surveys, health examinations, laboratory testing, and questionnaires were used to collect dietary intake, nutritional status, child development, and health status information. Nutrition, health, and lifestyle assessment of children and their parents was determined using the Knowledge Attitude Practice (KAP) survey. Greater than 100,000 children (38,000 children < 6 years of age and 66,000 children 6-17 years of age) completed the survey. The survey provided comprehensive data on child nutrition and health status for future studies and will serve as the basis for an integrated nutrition and health improvement strategies proposal for children in China.