Introduction: Key stages in the treatment of chronic apical periodontitis (CAP) are the assessment of the status of periapical zone, effective decontamination and subsequent sealing of the root canal space. Purpose: The aim of this article is to analyze histologic and electron microscopic results from periapical tissue examination in teeth with chronic apical periodontitis. Material and Methods: The apices of 43 teeth (n = 43) were examined, allocated in two groups. The teeth were stored in saline solution (9% NaCl) supplemented with thymol, at 4°C. The apical portions of the roots were resected at 5 mm coronary. After resection, the apices were fixed to stands for SEM-examination. The periapical lesions (n = 24) were carefully removed with a curette from the root or the apical portion of the alveolar socket and were kept in 10% formalin solution to the preparation of histological samples. Results and Discussion: The results of the performed SEM-examinations of the apical zones showed that in 97.6% of the teeth with radiographically diagnosed CAP, there were external resorption around the apical foramen and associated apertures of varying degrees – from the initial to the advanced stage of apical resorption. Despite the limited number of examined cases, the results obtained confirm the histology and the inaccuracy of diagnostic assumptions in some of the cases, resultant from the radiographic examination only Conclusion: Based on the analysis of results, the following conclusions can be drawn: that external resorption around the apical foramen is established in 97.6% of cases in the teeth with radiographically diagnosed CAP.

Introduction: The pathogenesis of internal and external resorptive processes in the dental tissues and those of the periapical zone is not fully understood, but the main purpose, either in teeth with internal resorption or in teeth with periapical lesions, is decontamination of the endodontic space and subsequent three-dimensional obturation in order to isolate periapical and oral tissues and prevent reinfection. Purpose: The aim of this article is to analyze in vivo some key characteristics of the apical zone in teeth with chronic apical periodontitis. Material and Methods: To facilitate the clinical protocol after the radiographic analysis and assessment of patency, the working lengths of 153 root canals (n = 153) in 106 teeth were determined. The clinical widths of the apical narrowing were measured by using the last instrument (ISO 0.02 tapered file), which can move freely through the apical narrowing after electrometric determination of the working length (Raypex 5 /VDW, Germany/). Results and Discussion: Determination of working width and working length is important for realizing the first stage of decontamination – maximum instrumentation of the endodontic space and choice of a clinical protocol. The classification of root canals in a particular group according to the relative patency or lysed apical opening is important for the selection of obturation technique, which is essential for reducing the microleakage in the zone. Conclusion: Since the target of this work were teeth with CAP, in the majority of the cases with clinical findings of root canals with preexisting filling, radicular pins, obliteration, separated canal instruments, perforations at different levels, via falsa or thresholds, the access to the apical zone was not subjected to a closely observed instrumental clinical protocol. In the treatment of each case, however, the clinical principles of modern endodontic treatment were closely observed.

Purpose. The purpose of this study is to follow-up the biometrical and skeletal vertical changes in patients with deep overbite in mixed dentition after a functional orthodontic treatment with Trainer System™ is conducted. Material and Methods. 32 patients (20 girls and 12 boys) with deep overbite in mixed dentition were followed-up. An orthodontic treatment with Trainer System™, including Trainer for kids (T4K)-blue, T4K-red and Myobrace was conducted. The recommended time for wearing the appliances was 8–12 hours, mostly at the night and 1–2 hours total time during the day. All the patients were photo-documented. Impressions, panoramic radiographs and lateral cephalograms were taken before the beginning of the treatment and at the end of every single step in relation with every change of appliances. Comparative biometrical and cephalometric analyses were made. The data was statistically processed. Results. The comparative biometrical analyses showed reduction of overbite with 2.5–3.5 mm after the end of the orthodontic treatment. 62% of cases showed relapse from 0.5 to 1mm. After the end of the orthodontic treatment an inclination of upper and lower incisors and changes with M/SN, М/F, ANB, SNA, SNB values were established. Conclusions. If untreated during the growing period, deep overbite leads to serious functional disorders, pathologic abrasion and myo-articular problems. Myofunctional Trainer System™ is successfully applied in the management of deep overbite in growing kids with early mixed dentition. The design of appliances helps the right positioning of tongue and jaws, removes bad habits, harmonizes tooth arches, corrects the vertical problems.

Aim: To be analyzed common features of occlusal relationships in patients with bruxism and bruxomania at maximum intercuspation (MIP) and eccentric jaw movements. Materials and Methods: 30 patients (22 women and 8 men, mean aged of 42,8 ± 13,3) with bruxism and/or bruxomania are examined with the system T-Scan III. Sequence of records is - at maximum intercuspation (MIP); in manual leading to central relation and in eccentric jaw movements. In the same sequence is investigated control group - 30 people (15 women and 15 men) aged between 21 and 45 who didn’t have bruxism and/or bruxomania and dentition is preserved. Results: In the control group 85% of cases there is a balance of forces in both halves of the dental arch. In patients with bruxism is established uneven distribution of forces in MIP and articulation blockages (95%). There are three major reasons that impede spontaneous bilateral closing - force outliers (93% of cases); low force outliers (82%) and presence of interceptive contacts and sliding occurring in the beginning of occlusion time until MIP (in all patients). Conclusions: In order to achieve a balanced occlusion in patients with bruxism and/or bruxomania required are correct diagnosis, registration and removal of preliminary contacts, articulation blockages and infraocclusion. Occlusal analysis is objective and an indicator of subsequent treatment only when it is a combination of clinical, instrumental and computerized occlusal analysis.

Introduction: Children with disabilities are a unique group with impaired ability to cater for their own oral health and are in greater need of procedures for the prevention of oral diseases, due to the higher risk of their occurrence than in their non-disabled peers. Treating such children is difficult, it requires specific conditions and is time-consuming. Objective: The aim of our study was to evaluate the competence of dentists concerning the oral health and the specific treatment in children with disabilities. Material and methods: The study included 150 randomly selected dentists from the Sofia region of Bulgarian Dental Association. Their knowledge was assessed via anonymous questionnaire consisting of 18 items. Results: The results of the questionnaire revealed low level of competence on matters of children with disabilities, their special features and behavioral problems. These results raise the need of undertaking of emergency measures in creating step-by-step instruction programs aimed at all practicing dental medicine who have not undergone special training during their education.

INTRODUCTION: Oral hygiene is an essential element of health education programs for schoolchildren. AIM: The study aims to assess the skills when conducting oral hygiene of a group of schoolchildren and to conduct training in its rules. MATERIAL AND METHODS: The study covers 30 children aged 6-12 years. The training was conducted by the methods of the visual pedagogy and implementation of the technique “Say, show, do”. The assessment of the oral-hygiene status was held by the simplified oral hygiene index-Greene & Vermillion. RESULTS AND CONCLUSION: The children do not have proper oral hygiene habits. The daily oral care is inadequate. The number of cleaned tooth surfaces during oral hygiene practice is small. Children have no developed proper oral hygiene skills, and brush only the vestibular surfaces of the teeth (80%), 13.3% the vestibular and the occlusal, and 6.7% only cover lingual surfaces too. The unsatisfactory oral hygiene status is also a result of using only one type of toothbrush movements. The improvement of children's health knowledge should play key role in correcting their oral hygiene technique.

For many years the oral infection, especially periodontitis, is considered as a potential contributing factor to a variety of clinically important systemic diseases. Alopecia areata (AA) is an autoimmune disease with unclear etiology and pathogenesis, rarely associated with dental foci. This disease has a strong psychological impact on the patient, because it presents with hair loss and can affect any hair-bearing area, but usually involves the face and scalp, where esthetic considerations play an important role in self perception. In this article is presented a case of alopecia areata resulting from dental foci that was effectively resolved by eliminating a focalized dental infection via dental extraction. In this sense, patients with AA should be subjected to careful exploration of the oral cavity in search of possible dental infections. Close collaboration between dentist, dermatologist, endocrinologist and other medical specialists in the interdisciplinary approach of diagnosis and treatment is needed.

The aim of the study was to compare the effectiveness of eight endodontic ultrasonic tips in removing stainless steel fragments from the curve of simulated root canals. Methods: Each of the instruments – K-files 25 (EMS), ET25 (Satelec), Redo2 (VDW), RT3 (EMS), CPR8 (Obtura Spartan), Proultra8 (Maillefer), E7 (NSK) and ENDO E3 (W&H) was used to remove 10 stainless steel fragments from the curve of simulated root canals (Dentsply-Maillefer) under magnification 10x and 16x with a dental microscope (OPMI Pico, Carl Zeiss). Success rate, working time and root canal enlargement were recorded and compared. Results: Success rates were as follows: K-files – 80%, ET25 – 90%, Redo 2 – 80%, CPR8 – 70%, Proultra8 – 80%, RT3 – 70%, Endo E3 – 60%, E7 – 50%. The differences were not statistically significant. Working time – mean values: K-files - 8,44 min, ET25 – 9,28 min, Redo 2 - 9,53, CPR8 – 11,01 min, Proultra8 – 10,31 min, RT3 – 11,57 min, Endo E3 – 15,34 min, E7 – 21,45 min. Endo E3 and E7 showed significantly longer working time, the differences between the other tips were not significant. Mean values of canal diameters were - K-files – 1,11 mm, ЕТ25 – 1,29 mm, Redo 2 – 1,31 mm, CPR8 – 1,54 mm, Proultra8 – 1,51 mm, RT3 – 1,61 mm Endo Е3 – 1,68 mm and Е7 – 1,72 mm. The differences in canal enlargement between CPR8, Proultra8, RT3, Endo E3 and E7 were not statistically significant. Conclusion: Endodontic ultrasonic tips with smaller diameters and sharp working points worked faster and preserved root canal better.

Introduction: Root resorption is a biological phenomenon, characterized by processes of cement and/or dentine depletion, resulting from the physiological or pathological activity of resorptive cells. Purpose: The aim of this article is to review of the literature on the peculiarities of the periapical resorptive processes. Conclusion: The absence of a physiological narrowing is challenging to the achievement of satisfactory early and late therapeutic results. It makes probable either the overpressing of necrotic, infected material when preparing the endodontic space or the overpressing of the sealer when sealing the root canal.

INTRODUCTION: The periodontal pathology is of great social importance due to the vast distribution in the human population. The adjunctive antibiotic administration could improve the healing in such cases but the latest data of the continuingly growing antibiotic resistance requires more precise approaches of antibiotic selection. The contemporary molecular diagnostic methods could offer the required precision for the microbiological identification in order to achieve better control of the periodontitis. OBJECTIVE: The aim of this study is to compare the microbiological effectiveness of adjunctive antibiotic administration with the mechanical periodontal therapy. METHODS: 30 patients with severe chronic periodontitis were enrolled in this study and were divided in 3 groups: Control group – with mechanical debridement only. Test group 1 – with combined adjunctive antibiotic administration using Amoxicillin+ Metronidazole. Test group 2 – with target antibiotic administration according to the resuts from the Real Time PCR identification. RESULTS: A considerable improvement of the periodontal status was reported in all treatment groups. The most positive results were in the group with target antibiotic administration were all tested clinical parameters showed the best improvement with statistically significant changes in sites with PD<3mm, PD 5-7mm, PD>7mm and CAL>5mm. CONCLUSION: The adjunctive antibiotic administration demonstrates better clinical effectiveness concerning the reduction of the severely affected sites in cases with severe generalized chronic periodontitis compared to the mechanical therapy alone. From all examined groups the target approach has statistically significant better results. These results suggest that this approach is recommended in cases with high prevalence of deep pockets.

Purpose: The aim of the research is to investigate the change in pulp vitality of teeth with periodontal disease using electric pulp tester (EPT). Methods: Subjected to observation were 108 patients with chronic periodontitis. Vitality of 805 teeth with periodontal pocket depth greater than 4 mm was studied by EPT. The research was conducted with EPT "Yonovit ". Results: The highest percentage of surveyed teeth (68.4%) respond to the norm when they are tested with EPT – values between 3 μA and 10 μA . Teeth that respond to EPT with values ​​below 3 μA and between 35-100 μA are relatively equal - respectively 4.3% and 3.3%. With increased threshold of irritation – 10-35 μA react 23.4% of teeth. Small number of teeth have threshold of irritation over 100 μA - 0.6%. Conclusion: The value of EPT among periodontal damaged teeth depends on many factors - patient's age, extent of periodontal affect, group affiliation of teeth, etc.

INTRODUCTION: Antibiotic use in chronic periodontitis may result in improvement in periodontal status, although many questions regarding the indications for this therapy remain unanswered. The polymicrobial etiology of the periodontal infection hinders the choice of the proper antibiotic agent. Furthermore the indiscriminate use of antibiotics could lead to high levels of resistance and to various adverse reactions. In the recent years a various molecular diagnostics protocols were proposed in order to facilitate the decision for adjunctive antibiotic administration. OBJECTIVE: The aim of this study is to compare the microbiological effectiveness of adjunctive antibiotic administration with the mechanical periodontal therapy. METHODS: 30 patients with severe chronic periodontitis were enrolled in this study and were divided in 3 groups: Control group – with mechanical debridement only. Test group 1 – with combined adjunctive antibiotic administration using Amoxicillin+ Metronidazole. Test group 2 – with target antibiotic administration according to the resuts from the Real Time PCR identification. RESULTS: The prevalence of all the isolated microorganisms (exept. E.nodatum and C.gingivalis) in Test Group 2 demonstrates statistically significant reduction compared with the other treatment approaches. Almost complete elimination was registered for the consensus pathogens from the red and orange complexes (above 99% and 100% for P.intemedia). CONCLUSION: The adjunct antibiotic treatment targeted with Real-Time PCR identification demonstrates almost complete elimination of the putative periodontal pathogens in the deep periodontal pockets in patients with severe chronic periodontitis. This result suggests slower recolonisation of these habitats thus limiting the risk for progression of the periodontal destruction.

The aim of the study was to determine the compatibility of 6 piezoelectric scalers - Mini Piezon (EMS), Pyon 2 LED (W&H), Woodpecker HW-3H (GWMI), Varios 550 (NSK), P5 Newtron (Satelec-Acteon) and DTE HD-7H (GWMI) with 8 types of endosonic tips for separated instruments removal - K-files # 20 and 25 (EMS), ET25 (Satelec), Redo 2 (VDW), CPR-tips 6,7,8 (Obtura Spartan), Proultra Endo tips 6,7,8 (Dentsply-Maillefer), RT3 (EMS), Endo E3 (W&H), E7 (NSK). Methods: Examined and measured was the change in the tips’ displacement amplitude with the power increase of the scalers under total magnification 80x with an optical microscope (Leica MZ6) and an image-measuring software (Klonk Image Measurement). Results: Ultrasonic devices’ compatibility with the examined tips was as follows: Woodpecker – 76,9%, Mini Piezon – 61,5%, Pyon 2 LED - 30,7%, Varios 550 – 83,3%, P5 Newtron – 83,3%, DTE – 33,3%. Lack of compatibility was found in 40,35% of all cases. In 29,82% of the cases of lack of compatibility it was demonstrated as a non-effective vibration, and in the rest of the cases – 10,53% - uncontrolled over-powerful vibration, which was dangerous to use. Conclusion: Endosonic tips should be carefully chosen in accordance with the ultrasonic scaler used.

Aim: To apply and follow up in clinical conditions the success rate of microinvasive technique of infiltration with low viscosity resin ICON® (DMG) of non cavitated approximal caries lesions of permanent children's teeth for a period of one year. Material and methods: The study included 18 children aged 7-16 years. They were divided into two groups - children with medium and high caries risk. The survey include 20 teeth with approximal non-cavitated enamel lesions up to the outer third of dentin (E1, E2, D1 – according to the manufacturer’s instructions of ICON®). The size of the lesions was determined using bitewing radiographs and the activity - by Papilla Bleeding Index. The clinical application of the infiltr+ant (ICON® Caries Infiltrant Proximal, DMG) was conducted according to the manufacturer's instructions. Bitewing radiographs were made at 6 and 12 months after infiltration in order to evaluate the success of the method. A test of the difference between two relative proportions and alternative test for analysis of the results were used. Results: Our study confirm the hypothesis that this method of infiltration is equally successful for permanent teeth in patients with moderate caries risk as well as those at high caries risk. Conclusion: This study is the first survey regarding the success of the application of ICON® for treatment of non-cavitated approximal carious lesions in permanent dentition of children in the country. Research in this direction should continue in order to increase the conviction that caries can be controlled and arrested in its earliest stages.

Aim: The aim of the present study is to evaluate and compare the subjective acceptance in children during hard dental tissue therapy using Er:YAG laser 2940nm and conventional rotary instruments. Methods and materials: The study included ninety 6-12-years-old children with matched carious lesions (D3 threshold, WHO system), divided into two equal treatment groups. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in the control group with conventional rotary instruments, without anaesthesia. After cavity preparation patient’s subjective acceptance was assessed by a questionnaire concerning primary stress triggers. Results: The annoyance factor (vibration) was found as a stress trigger in the majority of control children (86.7%), while in the intervention group it was found in 2.2% of cases. The most anxiety provoking items in the intervention group were smell (67.7%) and taste (42.2%). The sound was found to be a stress trigger in more than half of control children (62.2%) and less than one-fifth of the children in the intervention group (15.6%). The study results showed significant difference in these items between two groups (p< 0.001). Conclusions: The Erbium:YAG lasers reduce three of four stress triggers in `4S` principle - vibration, sight and sound. They are a good treatment option for fearful children since they have acceptable efficiency in treatment of pediatric anxiety disorders compared to the mechanical preparation.

Aim: The aim of the present study is to evaluate and compare the pain perception of pediatric patients during cavity preparation with the use of Erbium:YAG laser 2940 nm and conventional rotary instruments. Methods and materials: A group of ninety 6-12-years-old patients with matched carious lesions (D3 threshold, WHO system) was divided into two equal treatment groups and treated without anaesthesia. In the intervention group the cavities were prepared with Erbium:YAG laser 2940nm and in the control group with conventional rotary instruments. At the end of the treatment each patient was asked to point the degree of its pain on the universal pain assessment tool. Results: Participants in the laser treatment group reported significantly lower pain scores compared to participants in the control group (p<0.005). The analysis of pain indicated that in the intervention group the scores obtained from the majority of cases (71.1%) were low and only one patient reported severe pain perception. In the conventional treatment group the results showed approximately equal frequency for low (40%) and moderate (42.2%) pain level. Conclusions: The Erbium:YAG lasers produce less pain compared to the conventional mechanical preparation. They offer new and useful possibilities in restorative dentistry in pediatric dentistry and are good treatment options.