Elka Radeva - Academia.edu (original) (raw)

Papers by Elka Radeva

Journal of International Society of Preventive and Community Dentistry

Aims and Objectives: This in vitro study aimed to compare the efficacy of three different irrigat... more Aims and Objectives: This in vitro study aimed to compare the efficacy of three different irrigation methods in removing calcium hydroxide from curved root canals and to estimate the amount of residual medicament using microcomputed tomography. Materials and Methods: Thirty extracted molars with curved mesial root canals, ranging from 25° to 30°, were prepared with ProTaper Next using X2 to full working length and were filled with calcium hydroxide. Teeth also were randomly divided into four groups: group 1 (n = 8)— Erbium: Yttrium-Aluminum-Garnet (Er:YAG) laser; group 2 (n = 8)—EndoActivator; group 3 (n = 8)—EndoVac; and a control group (n = 6)—negative control with no calcium hydroxide. Microcomputed tomography was used to evaluate the residual amount of filling material. Statistical analysis was performed using IBM SPSS Statistics 26, with a significance level of 0.05. Descriptive statistics, student t test, and Chi-square test were applied for data analysis. Results: The greates...

Journal of IMAB, May 30, 2024

Introduction. One of the commonly encountered pathologies in the oral cavity when using removable... more Introduction. One of the commonly encountered pathologies in the oral cavity when using removable dentures is denture stomatitis, attributed to Candida spp. colonization on the denture surface. Aim. Determination of the type and quantity of Candida spp. on the mucosal and denture surfaces in patients treated with "ThermoSens" partial dentures before and after treatment. Materials and Methods. Thirty patients were prosthetically treated and divided into 2 groups. In the first group (n=20), treatment was performed with "ThermoSens" partial dentures, while in the second (control) group, patients were treated with conventional dentures (n=10). Swabs were taken from the mucosal and denture surfaces. The samples were tested for quantitative and qualitative differentiation of Candida spp. before prosthetic treatment, at the first and third month after prosthetic treatment. The data was statistically processed using SPSS Statistics 26. Results. No statistically significant difference was observed regarding the quantitative accumulation of Candida spp. on the denture and mucosal surfaces between the two groups of patients (p>5%), measured at 1 month and 3 months after prosthetic treatment. It was found that the predominant Candida spp. in both groups of patients was Candida albicans. Conclusion. Although no statistically significant difference was observed in the two test groups regarding the number of colonies of Candida spp., the main group showed a tendency for a more significant increase in their number (up to 10 5 CFU/ml) on the denture surfaces at the third month after prosthetic treatment, which may be a presumption for the development of denture stomatitis.

Journal of IMAB, Apr 2, 2020

Introduction: Knowledge of endodontic microbiology and microbial organization in the root canal s... more Introduction: Knowledge of endodontic microbiology and microbial organization in the root canal system is important for understanding the disease process and for establishing effective antimicrobial therapeutic strategies. The purpose of this survey is to summarize the knowledge of 5-year Bulgarian dental students about endodontic infections and their treatment. Materials and Methods: The survey includes students from FDM-Sofia who were asked to answer 11 questions online. The questions relate to species characteristics and microbial count of microorganisms in infected root canals in primary and persistent infections, apical periodontitis and overtreatment. Additional information on the respondents' age and gender has been collected and the data has been analyzed using descriptive statistic. Results: Ninety-three students participated in the survey, 31.52% of whom reported that over 300 microbial strains could be isolated from infected root canals. In apical periodontitis 8.7% reported 20-40 strains. 47.83% indicated that the microbial count in an infected root canal in a primary endodontic infection is 10 5. Streptococcus spp. is indicated as the main reason for persistent infections by 53.26% and Enterococcus faecalis by 25%. 40.22% have chosen Streptococcus spp. as the primary species associated with overtreatment, 27.17% have chosen Peptpstreptococcus and 19.57%-Enterococcus faecalis. 85.87% associate pain with Peptpstreptococcus and Prevotela spp. 68.48% consider plating onto agars as the main method for isolating and identifying microorganisms. The results are presented graphically and represent the percentage distribution of the answers. Conclusion: Students' knowledge of species characteristics of microorganisms in various nosological units associated with infected root canals should be increased.

Irreversible pulpitis is characterized by acute and intense pain that is difficult to control wit... more Irreversible pulpitis is characterized by acute and intense pain that is difficult to control with painkillers; hence the patient needs urgent endodontic help The aim of this study has been to determine the minimum set of interventions needed in order to reduce the pain and prevent further complications when treating emergency cases of irreversible pulpitis. The study encompassed 102 endodontic cases. After being diagnosed as advanced irreversible pulpitis, the cases were divided into 3 groups depending on the manipulations. The results show that the minimum set of interventions leading to a satisfactory clinical result, to a lower percentage of bleeding in the root canal and pain at percussion, was the one in Group 2. The best clinical results were achieved by Group 3, but frequently, due to the lack of time within a single appointment, it is impossible to implement all manipulations in this group.

Journal of US-China Medical Science, Jun 28, 2014

The complete preparation of the root canal space is one of the most important stages in endodonti... more The complete preparation of the root canal space is one of the most important stages in endodontic treatment. While the root canal space is being prepared, debris, irrigant, necrotic tissue or bacteria may be extruded into the periapical region, leading to periapical inflammation and postoperative flare-ups. The aim of this study is to compare in vitro the amount of debris and irrigant extruded apically after a root canal preparation, using two instrumentation techniques-the conventional hand "step back" technique with SS K-files and the engine-driven "crown down" technique with Ni-Ti K3 files. Two groups of 20 extracted teeth with single canals were used. In group 1 (10 teeth), the root canals were instrumented using a "step back" technique and stainless steel K-files. In group 2 (10 teeth), the root canals were instrumented using a "crown-down" technique and nickel-titanium K3 rotary instruments. Debris and irrigant extruded from the apical foramen during instrumentation were collected into vials and the amounts were measured. The debris extruded through the apical foramen in group 1 (K-files) was 0.400 mg and in group 2 (K3 files)-0.225 mg. The volume of the extruded irrigant was 0.443 mL in group 1 and 0.247 mL in group 2. The time taken for instrumentation was 13 min for the step back technique and 8.7 min for the crown-down technique. There is a significant difference in the amount of debris and irrigant produced between the two groups. During biomechanical preparation of the root canal space, debris and irrigant were extruded through the apical foramen by both instrumentation techniques.

Journal of IMAB, Nov 29, 2022

Introduction: The endodontic therapy is performed with appropriate preparation techniques, irriga... more Introduction: The endodontic therapy is performed with appropriate preparation techniques, irrigation solutions and intracanal medications, with the aim of eliminating residual microorganisms. The purpose of the survey is to evaluate the level of awareness and clinical use of intracanal medicaments, and ways to remove them among dentists. Material and methods: The subject of the survey is the opinion of 249 dentists with different work experience and work orientations. Questions to identify the most commonly used intracanal medicaments in the course of endodontic treatment by general dentists are included. Identify the clinical situations in which they are most commonly used, as well as the preferred techniques and solutions for their elimination. The data were processed with the statistical software IBM SPSS Statistics 26. The results of the survey show that most of the respondents practice general dentistry and 98% of the respondents use intracanal medications in their practice. The most commonly used intracanal medicament is calcium hydroxide in single and combined form, 49% and 75%, respectively. According to 96.7%, medications affect the healing process. Syringe and needle irrigation with 2-5.25% NaOCI is one of the most commonly used methods for removing intracanal medicaments (96.3%). 74% of the respondents have difficulties in removing intracanal medicaments. Conclusion: Based on their clinical experience, respondents indicated that they have difficulty in the complete removal of intracanal medicaments, and half of them believe that not all methods for their removal are available. At the same time, the respondents point out that the incomplete removal of intracanal drugs affects the adhesion of the canal filling material to the walls of the root canal.

Journal of IMAB, Dec 19, 2017

The aim of this study is to investigate the temperature changes of the external root surface whic... more The aim of this study is to investigate the temperature changes of the external root surface which occur during post space preparation with Peeso reamers at two different speeds. Materials and methods: Twenty nine extracted single rooted human teeth were used. The tooth crown was removed and the length of the roots was standardized at 15 mm. Then each root canal was prepared with Revo-S Ni-Ti rotary system and filled with sealer and gutta-percha by cold lateral condensation technique. The teeth were divided into three groups: Group 1 (n=12)-post space preparation was performed at 2800 rpm. Group 2 (n=12)-post space preparation was performed at 4700rpm. Control group (n=5)-without post space preparation. Two thermocouples were connected to the outer surface of the root at 4 mm and 8 mm from the coronal part. During post space preparation, the temperature rises were measured using two digital thermometers which registered the temperature changes at 10s, 20s and 30s. Statistical analysis was performed. Results: In the first 10 seconds of the preparation a slight increase of the temperature (1-2°C) was observed in the two points of the root surface where the thermocouples were attached to the roots of both groups. In the period from start to 20s the temperature of the teeth prepared with higher speed increased by 4.9°C compared to the teeth prepared at lower speed-the temperature increased by 3.6°C. Between the beginning point and the 30s the increasing of the temperature was higher-9.1°C in group 2. Conclusion: In both groups, the temperature on the external root surface increased during post space preparation. The higher speed of the Peeso reamers might reach a critical level of 10 degrees on the external root surface which might lessen the possibility of a successful outcome of the endodontically treated teeth.

Balkan Journal of Dental Medicine, 2018

Background/Aim: The aim of the present study was to describe the use of irrigants by dentists in ... more Background/Aim: The aim of the present study was to describe the use of irrigants by dentists in Bulgaria in relation to their years of professional experience. Material and Methods: The data were collected with the help of a questionnaire. The survey included questions concerning frequency of irrigants applied, their respective concentrations, as well as spectrum of disinfectants used in endodontics. In addition, information about respondents' age, years of professional experience, gender, and main areas of continuing education was collected. The statistical analysis was performed with the help of IBM SPSS Statistics 22.0. Results: 219 replies were analysed (response rate 27,3%). The majority of the respondents (31.1%) had 21 to 30 years of professional experience. 18.7% had over 30 years. Most of the practitioners reported their continuing education to be in the area of general dentistry-52%, while about 1.2 % had specialised in endodontics. Dentists with long-standing professional experience use predominantly H 2 O 2-78%. Dentists with least experience use 17% EDTA-53.6%. No significant differences were established for the use of sodium hypochlorite and 2% chlorhexidine. 82% of the respondents use conventional needle 27G for intracanal irrigation; 60% never use ultrasonic irrigation. Conclusions: The analysis of the usage of irrigants shows that many general dental practitioners do not follow the quality recommended protocols for endodontic irrigation protocols.

Acta Medica Bulgarica, Oct 1, 2016

Hermetic sealing of the apical area after root end resection is essential to the success of endod... more Hermetic sealing of the apical area after root end resection is essential to the success of endodontic surgery. To compare microleakage after root end resection of the two bioceramic sealers without retrograde fi lling-Total Fill BC Sealer and MTA Fillapex, and two materials for retrograde fi lling-MTA and Biodentine, using the method of penetration of dye-2% methylene blue. Forty eight extracted single-rooted human teeth were used in this study. The resection was made at 3 mm from the root tip at an angle of 90 degree to the long axis of the tooth. The teeth were divided into 4 groups: 1st group (n = 9)-root canal obturation with Total Fill BC Sealer without retrograde fi lling; 2nd group (n = 8)-root canal obturation with MTA Fillapex without retrograde fi lling. 3rd group (n = 10)retrograde ultrasonic cavity preparation and fi lling with MTA. 4th group (n = 8)-retrograde ultrasonic cavity preparation and fi lling with Biodentine. The outer surface of the root was covered with two layers of varnish, with the exception of the apical 3 mm and then immersed in 2% methylene blue for 72 h. The degree of penetration of the dye is measured in millimeters. The data was entered and processed with the statistical package IBM SPSS Statistics 22.0. We reject the null hypothesis when p < 0.05. With signifi cantly higher value is the arithmetic mean of the group with the root canal obturation with Total Fill BC Sealer without retrograde fi lling-2,01 mm; versus a retrograde fi lling with MTA-0,68 mm and Biodentin-0,51 mm; and no statistically signifi cant difference with the group root canal obturation with MTA Fillapex-1,76 mm. In the four material microleakage dye was observed, but to varying degrees.

Folia Medica, Apr 30, 2023

Introduction: Successful periapical surgery requires appropriate root resection, preparation, and... more Introduction: Successful periapical surgery requires appropriate root resection, preparation, and adequate sealing. Aim: The aim of the present study was to assess the marginal adaptation of MTA and Biodentine after apical resection with an Er:YAG laser and a diamond turbine bur using a scanning electron microscope (SEM). Materials and methods: The crown part of forty-eight extracted single-root human teeth was removed, and the root canal length of 15 mm was standardized. The root canals were prepared using rotary Ni-Ti Revo-S files up to an apical stop-AS40 and filled with MTA Fillapex and gutta-percha points (cold lateral condensation). The teeth are divided into 2 main groups: group 1 (n=24) after apical resection with a turbine bur, ultrasonic preparation of the retrograde cavity at 3 mm depth and retrograde obturation with Biodentine and MTA; group 2 (n=24) after apical resection with an Er:YAG laser, ultrasonic preparation of the retrograde cavity at a depth of 3 mm and retrograde obturation with MTA and Biodentine. A SEM was used for assessment of the marginal adaptation of the material to the root dentin. The data was entered into and analyzed with IBM SPSS Statistics 22.0. Results: In the group with apical resection with a turbine bur, a statistically significant difference in the gap size between the material and dentin was found in both materials we studied (MTA and Biodentine). The higher mean value was in MTA (1.72 µm), in Biodentine it was 1.08 µm. In the group with apical resection with Er:YAG laser, no statistically significant difference in the gap size between the material and dentin was found in both studied materials: MTA-1.88 µm, Biodentine-1.32 µm. Conclusions: In the present study, MTA and Biodentine showed good sealing capabilities after apical resection. Biodentine displayed better marginal adaptation when resecting the root tip using a turbine bur. The Er:YAG laser-assisted apical resection shows sealing of the open dentinal tubules around the resected root surface.

Biotechnology & Biotechnological Equipment, Jul 14, 2023

The aim of the current literature review shows the reasons for endodontic-surgery treatment and i... more The aim of the current literature review shows the reasons for endodontic-surgery treatment and its techniques (methods) for its realization. When conservative treatment is not possible because of post with crowns, bridges and consideration of the possibility of weakening of the remaining dental hard tissues, there are reasons for undertaking apical surgery. This can be defined as endodontic-surgery procedures that include apical resection, curettage and retrograde filling. The aim is sealing the root canal in order to eliminate microleakage of periapical tissues. In relation to this literature discusses issues related to the sealing of the root canal and updating of various cements for root canal filling. The access to the apical portion may be provided by a low-speed handpiece with fissure burs or high-energy lasers, supported by microsurgical mirror and microscope. Different ultrasonic tips are an alternative for retrograde root canal preparation. Materials that might be used are: MTA, Biodentin, IRM, EBA, I Root SP, MTA Fillapex, ProRoot Endo Sealer, EndoSequence Bioceramic Root Repair Material. Conclusion: in appropriately selected clinical cases, endodontic-surgical approach gives good and reliable results and should be preferred over the decision for extraction of the tooth and its subsequent replacement by implant therapy.

Introduction. Frequently isolated pathogens from teeth with necrotic pulp include various enteric... more Introduction. Frequently isolated pathogens from teeth with necrotic pulp include various enteric bacteria (Klebsiella, Enterobacter), fungi (especially Candida spp.) and enterococci (Enterococcus faecalis). Candida albicans is the most often isolated species. Fungi can be found both in primarily infected teeth and in teeth where the endodontic treatment has failed. The aim of the current study has been to evaluate the in vitro effectiveness of some of the intracanal irrigants used in eliminating Candida albicans. Materials and Methods. The study used clinical isolates of Candida albicans from infected root canals. The effectiveness of the following endodontic irrigants were studied: 17% EDTA, 2% CHX (chlorhexidine), 6% NaOCl (sodium hypochlorite), 3% NaOCl 8 3% H2O2 (hydrogen peroxide). The study used an agar-diffusion method: cavities were made in the agar and then filled with the studied medicaments. The data were input and processed using the statistical package SPSS 15.0.1. The level of significance for rejecting the null hypothesis was fixed at p<0,05. Results. The largest observed zone of inhibition of bacterial growth was achieved with 6% NaOCl-25.88mm and 17% EDTA-24.50mm. The 2% chlorhexidine solution came third in effectiveness compared to the other solutions-the zone of inhibition of the bacterial growth was 17.75mm. 3% NaOCl was less effective than 6%NaOCl, with an inhibition zone of 14.00mm. The lowest effectiveness was registered in the case of 3% H2O2-5.38mm. Conclusions. In infected root canals there are some microorganisms (Candida albicans, E. Faecalis) that are more resistant to chemical and mechanical procedures and this must be taken into account when using various endodontic irrigants and intracanal medicaments. With the reduction of concentration, the effectiveness of NaOCl against Candida albicans is reduced significantly. The 2% chlorhexidine solution is more effective than 3% NaOCl in eliminating Candida albicans.

International journal of scientific and research publications, Aug 12, 2020

Introduction: Novel coronavirus disease was announced on January 30, 2020, by the World Health Or... more Introduction: Novel coronavirus disease was announced on January 30, 2020, by the World Health Organization (WHO). On March 13, 2020 many dental offices closed due to the impending danger. Patients were discharged from the schedules without a clear idea of when normal dental activity would resume. Under such circumstances, a lot of patients with pain, caries or fracture restoration had to wait for dental care during these two months. The aim of the current study is to analyze the character of the dental complains and treatment immediately after 2 months of quarantine due to COVID-19; and to consider proposals and strategies for infection control in the new situation. Materials and methods: The study included patients who visited general dental practice in the period of May 14-June 14, 2020. Patient information about gender, age and diagnosis were analyzed. The obtained body temperatures and the questionnaires for the epidemiological study of COVID-19 were reviewed. The data are compared with those for the same period-May 14-June 14, 2019. The results of the conducted study are presented graphically and represent the percentage distribution of gender, age and diagnosis. Results: For both periods of time the percentage of female who visited dental practice is higher-53% for 2020 and 57% for 2019, than male percentage-47% for 2020 and 43% for 2019, respectively. The highest percentage (47%) of patients who visited the dental practice in two months' quarantine were aged 41-50, compared to the year of 2019 when the highest percentage (31%) of patients were aged 61-70 and 24%-51-60. The highest percentage (41%) of patients in two months' quarantine in the year of 2020 were with fracture of restoration or tooth fracture and 20% turned out to be with irreversible pulpitis. Within the same period of time in 2019, treatment of apical periodontitis-39% and restorations/caries treatment-33% were most prevalent. Prosthetic reasons for the study period of one month in 2020 were 15%, while for 2019-6%. Periodontal reasons-18% cases were registered for 2020, and 9%-for 2019. Conclusions: In two months' quarantine the patients look for dental care only in case of pain (irreversible pulpitis, symptomatic periodontitis) or tooth/restoration/crown fracture. In pandemic situation during COVID-19 outbreak, personal protective equipment and patient screening are considered to be of great importance in protecting dental staff and patients.

Proceedings of the Bulgarian Academy of Sciences

This study aims to investigate the relationship between dental erosion and frequency of non-alcoh... more This study aims to investigate the relationship between dental erosion and frequency of non-alcoholic beverage intake in normal-weight, overweight, and obese individuals. The study involved 264 subjects aged 18–60 years with normal weight (control group), overweight and obesity. The frequency of non-alcoholic beverage intake has been assessed. The grade of erosive tooth wear has been measured using the BEWE index (Basic Erosive Wear Examination). When comparing the control and overweight groups, a statistically significant difference has been found between the group with no erosive wear, score 0, and the one with initial enamel surface loss, score 1, (χ2 = 18.633, p < 0.05). When comparing the control and obese groups, a significant difference has been found between the groups with score 0 (χ2 = 19.179, p < 0.05), score 2 (χ2 = 0.160, p < 0.05) and score 3 (χ2 = 0.160, p < 0.05), as well as when comparing the subjects in the control group with score 0 by sex (χ2 = 3.360,...

Folia Medica

Journal of IMAB - Annual Proceeding (Scientific Papers)

Acta Medica Bulgarica, 2020

Introduction: Determination of the curvature of root canals at present is accomplished by complic... more Introduction: Determination of the curvature of root canals at present is accomplished by complicated or expensive methods. Therefore, there is a need to develop a new digital method by which this curvature can be determined quickly, easily and accurately. The aim of this in-vitro study is to determine the angles of curvature of the root canals of extracted teeth by comparing a new digital method of measurement with an established digital method. Material and Methods: Forty-eight (48) root canals of extracted teeth were studied to achieve the goal. In all roots, curvature is measured by three methods: Method 1 – new digital photographic method and special Software (Screen Protractor); Method 2 – a new digital radiography method and special software (Screen Protractor); Method 3 – approved method, digital by X-ray and special Software (Durr dental). Results: The mean degrees of the measured curvature of the root canals in all three groups are similar and are about 22°. There are no s...

International Journal of Scientific and Research Publications (IJSRP), 2021

Introduction: The presence of a curve limits the preparation of the root canal and can lead to pr... more Introduction: The presence of a curve limits the preparation of the root canal and can lead to procedural errors related with the formation of ledges, fracture of instruments, canal transportation or perforation of the apical foramen. Nickel-Titanium instruments are recommended to use in such cases due to their superior flexibility and resistance to cyclic fatigue. Aim: To assess the shaping ability of ProTaper Gold in preparation of moderate curved canals (25º-30º) on extracted human teeth, using x-ray. Materials and methods: The experimental study was performed on extracted human teeth (canines, premolars and lower molars, n=24 canals). Diagnostic radiographs were done in order to determine the root canal curvature beforehand. The teeth that were used had moderate curvature of 25º-30º. The coronal part of the teeth was removed using diamond burrs and the root length was standardized at 15 mm (using visual method). The root canals were prepared using ProTaper Gold up to F3. After preparation diagnostic radiographs were made to evaluate the resultsreduction of working length, fracture of instruments, ledges and perforations. The data obtained was statistically processed. Results: Reduction of working length by 0.27±0.05 mm was observed. During the preparation stage of the root canals using ProTaper Gold no breakage of any instrument was observed. No ledges or perforations were formed. Conclusions: Following the results of this in vitro study it can be concluded that the use of ProTaper Gold instruments facilitates the preparation of moderately curved root canals. This can be attributed to their superior physical properties which allow better preservation of the original shape of the root canal.