Application of apical negative pressure irrigation in the nonsurgical treatment of radicular cysts:A case report

BACKGROUND Radicular cysts are one of the most common odontogenic cystic lesions found in the jaw.Nonsurgical treatment of large radicular cysts is a topic of ongoing debate,and there is still no clear consensus on the most effective therapies.The apical negative pressure irrigation system aspirates the cystic fluid and releases the static pressure in the radicular cyst,representing a minimally invasive approach for decompression.In this case,the radicular cyst was in close proximity to the mandibular nerve canal.We used nonsurgical endodontic treatment with a homemade apical negative pressure irrigation system and the prognosis was good.CASE SUMMARY A 27-year-old male presented to our Department of General Dentistry with complaints of pain in the mandibular right molar when chewing.The patient had no history of drug allergies or systemic disease.A multidisciplinary management approach was designed and included root canal retreatment with a homemade apical negative pressure irrigation system,deep margin elevation and prosthodontic treatment.According to a 1-year follow-up period,the patient showed a favorable outcome.CONCLUSION This report reveals that nonsurgical treatment with an apical negative pressure irrigation system may provide new insights into the treatment of radicular cysts.

Design of a modern automatic control system for the activated sludge process in wastewater treatment

The Activated Sludge Process(ASP) exhibits highly nonlinear properties. The design of an automatic control system that is robust against disturbance of inlet wastewater flow rate and has short process settling times is a challenging matter. The proposed control method is an I-P modi fied controller automatic control system with state variable feedback and control canonical form simulation diagram for the process. A more stable response is achieved with this type of modern control. Settling times of 0.48 days are achieved for the concentration of microorganisms,(reference value step increase of 50 mg·L-1) and 0.01 days for the concentration of oxygen(reference value step increase of 0.1 mg·L-1). Fluctuations of concentrations of oxygen and microorganisms after an inlet disturbance of5 × 103m3·d-1are small. Changes in the reference values of oxygen and microorganisms(increases by 10%, 20% and 30%) show satisfactory response of the system in all cases. Changes in the value of inlet wastewater flow rate disturbance(increases by 10%, 25%, 50% and 100%) are stabilized by the control system in short time. Maximum percent overshoot is also taken in consideration in all cases and the largest value is 25% which is acceptable. The proposed method with I-P controller is better for disturbance rejection and process settling times compared to the same method using PI controller. This method can substitute optimal control systems in ASP.

Root Canal Treatment of Mandibular First Molar with Radix Entomolaris

Aim: To confirm the effect of root canal treatment on radix entomolaris. Case: Radix entomolaris was an additional root that located on the distolingual of mandibular first molars. In this case, the radix entomolaris was detected clinically and radiographically with root canal configuration such as curves. An awareness and understanding of this unusual root and root canal morphology could contribute to the successful outcome of endodontic treatment. Conclusion: Root canal treatment on this case shows the lack of symptoms and normal radiographic presentation for two months follow-up.

Non-Surgical Endodontic Retreatment of Anterior Tooth with a Large Periapical Lesion and Extruded Guta Percha with 36 Months Follow-Up: A Case Report

Root canal treatment failure depends on many factors. Overfillings, insufficient fillings, missing canals, failure to provide a complete apical plug, and impermeability of coronal restoration are some of them. Failed root canal treatment may not always manifest itself immediately after treatment. Sometimes, root canal treatments, which have not been done well, can manifest themselves with extensive lesions and severe pain in the apical after a long time. Apical resection may be considered as a solution in lesions that are too large to be treated, but retreatment without surgery should be attempted beforehand. Thus, the patient may have recovered from unnecessary surgical procedures and treated with a more conservative method. This case presents the non-surgical retreatment of a left lateral tooth with a large periapical lesion with extruded gutta percha followed by a 36-month follow-up.

Tooth anatomy risk factors influencing root canal working length accessibility

The aim of this study was to analyze the specific influence of root canal anatomy on the accessibility of working length during root canal therapy. Four hundred seventy-six root canal therapy cases （amounting to a total of 1 005 root canals） were examined. The anatomy risk factors assessed in each case included： tooth type （tooth location）, root canal curvature, and root canal calcification, as well as endodontic retreatment. The investigation examined the correlation between each of these anatomic factors and the working length, with statistical analysis consisting of Chi-square tests and multiple logistic regression analysis. In an independent factor analysis, tooth type （tooth iocation）, root canal curvature, canal calcification, and endodontic retreatment were determined to be the primary risk factors. In a multiple-factor regression model, root curvature and canal calcification were found to most significantly influence root canal working length accessibility （P〈0.05）. Root canal anatomy increases the difficulty of root canal preparation. Appropriate consideration of tooth anatomy will assist in accurate determination of preparation difficulty before instrumentation. This study alerts clinical therapists to anatomical factors influencing the working length accessibility, and allows for a direct estimate of success rate given in situ measurements of tooth factors during the root canal treatment procedure.

Calcium Hydroxide in Endodontics: An Overview

Background: Calcium hydroxide has been used in dentistry since several decades. It has been used in a number of applications in the field of endodontics such as root resorption, intracanal medicament, and root canal sealers. Although this material exhibits several advantages, it also has some limitations. Objectives: To review the role of calcium hydroxide in the field of endodontics, focusing on its mechanism of action, antimicrobial effects, different applications, cytotoxicity or biocompatibility, and its removal from the root canals. Materials and Methods: An electronic search was done using different databases. Out of 2,664 articles, only 33 articles have been selected to be included in this review because they are directly related to the topic and matched the inclusion criteria of this review: “Language: English” and “Year: 2000-2016”. Results: The antimicrobial effect of calcium hydroxide is controversial. Although some studies supported the effectiveness of calcium hydroxide against some bacteria others reported its limitation against fungal infection. Calcium hydroxide can be used effectively as intracanal medicament, root canal sealer, in weeping canals, for perforation management and root resorption. Conclusions: Despite the limitation of antimicrobial activity of calcium hydroxide, it is used effectively in a number of treatment modalities in endodontics. Due to its biological and therapeutical properties, calcium hydroxide is the material of choice for all pulp therapy. However, when using calcium hydroxide as a dressing material in root canal treatment caution should be taken to prevent the overextension of the paste beyond the tooth apex and avoid the harmful side effects.

Successful management of a tooth with endodontic-periodontal lesion:A case report

BACKGROUND Endodontic-periodontal lesion is a commonly encountered dental condition.However,the prognosis of the condition varies from good to poor.Some cases are associated with a poor prognosis that requires tooth extraction.This report presents a case of an endodontic-periodontal lesion in a tooth that was successfully treated by root canal treatment.CASE SUMMARY A 51-year-old female patient with no medical history complained about persistent pain and discomfort in her left mandibular first molar.Clinical examination showed the left mandibular first molar with poor restoration.It was also associated with underlying necrotic pulp and periodontal involvement.Radiographic examination revealed visible bone defects in the apical and periodontal areas.Based on the findings,the patient was diagnosed with a primary endodontic lesion.A root canal treatment for the endodontic lesion was performed.The patient received a coronal all-ceramic endocrown restoration.A follow-up was arranged to check the prognosis.At the 3 mo follow-up,the clinical and radiography evaluations showed complete disappearance of signs and symptoms and an increase in the radiopacity of the root area.CONCLUSION Despite the poor prognosis associated with many endodontic lesions,this case report highlights that a good prognosis is still possible for an endodontic lesion with apical and periodontal bone loss.In this case,it was achieved via successful root canal treatment without the need for periodontal or surgical intervention.

CLINICAL STUDY ON THE TIME OF TREATING CHEMOTHERAPY INDUCED TOXIC AND SIDE EFFECTS IN MALIGNANT TUMOR PATIENTS BY ACUPOINT INJECTION OF ASTRAGALUS ROOT INJECTION

Objective: To investigate the suitable time of treating virulent and side effects of chemotherapy for malignant tumor by acupoint injection of Astragalus Root injection. Methods: Sixty three patients with malignant tumor were divided into three groups: prevention treatment (PT) group (n=23 cases),post chemotherapy treatment (PCT) group( n=22 cases), Western medicine (WM) group ( n=18 cases). The patients in PT, PCT and WM groups were treated respectively from the fifth day on before chemotherapy and from the first day on after chemotherapy, 18 days in all. The patients in WM group were administered Batilol and Leucogen from the first day on after chemotherapy. Changes of leukocytes and immunoglobulin before and after treatment were observed. Results: 1) Acupoint injection of Astragalus Root injectio could increase the number of leukocytes and immunoglobulin content and its effect was better than that of Western medicine (P<0.05); 2) The effect of PT group was better than that of PCT group in preventing and treating virulent and side effects of chemotherapy (P<0.05). Conclusion: It should be stressed on prevention of malignant tumor by using acupoint injection of Astragalus Root for relieving virulent and side effects of chemotherapy.

Exploring the practice of common oral diseases among the patients visiting in the selected dental college and hospital in Bangladesh

Background:Having the ability to identify potential health risk factors such as lifestyle,ethnicity,health status,and social determinants associated with oral health status risk,health care providers can take an active role in health screening to discover any need for clinical preventive services,including dental preventive services,and can detect health problems.Methods:A descriptive type of cross-sectional study was conducted to explore the practice of common oral diseases among the patients visiting in the selected dental college and hospital in Bangladesh from October 2019 to December 2019.About 100 patients were interviewed through a semi-structured questionnaire,followed by an oral examination through a checklist and a face-to-face interview.A systematically random sampling technique was employed to select the study population.Results:Among them,the(21-30)year age group shows a maximum 20%,whereas the(71-80)year age group represents the minority with only 2%.Among them,56%were male and 44%were female.Students represent the majority of 26%,whereas others(day laborers)represent only 4%.Decayed teeth remained in 72%of cases,teeth were missing in 31%of cases,and filled teeth were present in 24%of cases.A majority of 71%clean teeth once daily,whereas only 29%clean teeth twice daily.Again,only 30%brush teeth at night and a maximum of 95%brush teeth in the morning.Moreover,a maximum of 68%use toothpaste and brushes,while only 4%use meswak for cleaning their teeth.About 4%of cases with no debris,51%of cases with less than 1/3rd of the tooth with debris,32%of cases with 1/3rd-2/3rd of the tooth with debris,and 13%of cases with more than 2/3rd of the tooth with debris were present.Again,about 30%had no calculus,52%less than 1/3rd of tooth,16%in between 1/3rd and 2/3rd of tooth,and 2%more than 2/3rd of the calculus was present.About 47%of mild,22%of moderate,6%of severe and 25%had no inflammation.Furthermore,for treatment purposes,20.69%was advised for scaling,19.66%for filling,16.90%for root canal treatment,17.59%for extraction,17.24%for prosthodontic treatment,1.03%for orthodontic treatment,2.07%for pulpotomy,2.41%for pulpectomy,and 2.41%for minor surgery.Overall,about 72%of the respondents,mostly the students,are suffering from decayed teeth,which may be due to a lack of frequency of brushing,indicating 95%that it is once daily.In addition,the most alarming situation among them is about 20.69%required scaling,which may be due to improper and inadequate brushing maintenance.Conclusion:to some extent,the above scenario may reflect the negative hallmark for our country’s younger generation in terms of oral health practice.Therefore,the establishment of a preventive oral health policy by our policymakers for the general population,mostly school-going students,on an emergency basis.

Identification of WRKY Transcription Factors Related to Saikosaponin Biosynthesis in Adventitious Roots of Bupleurum chinense

Objective To identify the genes of WRKY transcription factors（TFs） from roots of Bupleurum chinense and genes that potentially regulate saikosaponin（SS） biosynthesis.Methods Firstly,the subfamily cluster analysis was mainly based on Arabidopsis thaliana WRKYs for 27 putative WRKY TFs selected from previous transcriptome sequencing data.Secondly,qPCR was used to screen such genes of WRKY TFs that could be induced by NaCI and PEG6000 in adventitious roots of B.chinense.Meanwhile,saikosaponins（SSs） in treated adventitious roots were determined by HPLC.The roots were collected at 0,2,4,8,12,24,48,and 72 h after treatments,and 120 h only for PEG.Finally,the tissue-specific expression was analyzed on screened genes by qPCR.Results The 27 genes were grouped into three categories：There were nine in Group Ⅰ,15 in Group Ⅱ,and two in Group Ⅲ.Four genes of WRKYTFs,BCWRKY6,BCWRKY16,BCWRKY32,and BCWRKY35 were obviously induced by NaCI in adventitious roots of B.chinense,while only BCWRKY32 was induced by PEG.The content of SSs increased at different levels in NaCI and PEG6000 treatment.Three genes including BCWRKY6,BCWRKY32,and BCWRKY35,expressed most in roots,were similar to the accumulation pattern of SS.Conclusion The three WRKY genes,BCWRKY6,BCWRKY32,and BCWRKY35,may be involved in the biosynthesis of SS.