Search

nema

nema

Glide path is a procedure that precedes mechanical instrumentation of the root canals. It is defined as a procedure used to expand or create a smooth tunnel from the coronal part of the root canal to its physiological terminus. It is performed using small-size hand files or specially designed mechanical NiTi instruments. An adequately created glide path extends the life of rotary NiTi instruments, enables better mechanical and chemical debridement and easier preservation of original morphology of endodontic space during further mechanical instrumentation. Frequent use of mechanical instrumentation in daily practice requires better understanding of the glide path, its significance, and instruments and techniques used for its creation.

Background/Aim. There is no standard protocol for cleaning and disinfection of used endodontic instruments before their sterilization and reuse. The aim of this study was to determine the efficiency of the different methods of removing biological debris from different types of used hand stainless steel endodontic instruments. Methods. A total of 120 hand stainless steel endodontic instruments: KerrTM reamers, KerrTM files, and HedströmTM files, each forty ISO 25, used for root canal treatment on extracted teeth, were analyzed. The used instruments were divided into four groups based on different decontamination protocols. The evaluation of the efficiency of the cleaning methods was based on the evaluation of the amount of stained organic residues on the instruments (Van Gieson staining). Samples were analyzed by stereomicroscopy (x40). Statistical analysis was performed using the Mann-Whitney U test for the KerrTM reamers and HedströmTM files, while the One-Way ANOVA/Bonferroni test was used for the KerrTM files, at a significance level of 5 % ( α = 0 .05). Results. Residual biological debris was observed on 93.3% of all the samples taken. The thermal disinfectant cleaning method showed the lowest contamination values for all types of instruments. The method of mechanical cleaning showed that the mean value of maximum biologic contamination (MBC) was 58.5% for the KerrTM reamers and 56.2% for KerrTM files, while for HedströmTM files, the highest MBC (50.2%) was shown by the ultrasonic method of cleaning. Conclusion. The use of a thermal disinfectant was the most efficient cleaning method for all three types of hand endodontic instruments.

Introduction: Preparation of glide path is an important precondition for the safe use of rotary NiTi instruments during endodontic treatment. Aim: The aim of this study was to examine the duration of glide path preparation as well as all the changes in canal morphology and canal diameter after the use of hand K-files and NiTi rotary PathFiles. Material and methods: This research was performed on a total of twenty Endo Training Blocks (Dentsply, Maillefer, Switzerland). The glide path was prepared using hand stainless steel K-files ISO #10-15-20 (Dentsply, Sirona, USA) (n = 10) and NiTi rotary PathFiles ISO #13, #16 and #19 (Dentsply, Sirona, Switzerland) (n = 10). The time required to establish the glide path was measured with an iPhone stopwatch (Apple Inc. Cupertino, California). The images of the apical segment of canals before and after glide path preparation were taken under the stereomicroscope (Boeco BSZ-405, Germany), and then images were analyzed and processed with Scopeimage 9.0 (Teleskop, Austria). Statistical analysis was performed with the Mann-Whitney test at the level of significance 5% (a = 0.05). Results: A statistically significant difference was observed in terms of the time required for glide path preparation. The mean total time for glide path preparation was significantly longer with K-files (382 ± 62 s) than with PathFile (200 ± 11 s) (p < 0.05). A statistically significant difference in terms of changing the morphology of the apical part of the canal (p > 0.05) was not observed. The difference in the diameter of the root canal was at the limit of statistical significance (p ≈ 0.05). Conclusion: Instrumentation with NiTi rotary PathFiles reduces the time required for glide path preparation. Preparing endodontic space for rotary instrumentation with hand K-Files and rotary PathFiles leads to similar changes in the morphology of the apical segment. A slightly larger diameter of the root canal was measured after preparation with the hand K-files.

nema

Introduction/Objective. of this study is to use scanning electron microscopy (SEM) analysis to examine surfaces of new and same sets of Ni-Ti instruments after canal preparations, to check their suspectability to corrosion. Methods. In this study, we used five different endodontic Ni-Ti instruments: K3, Mtwo, ProTaper Universal, HyFlex and BioRaCe. Instruments were analyzed before and after preparation of canals of different curvature, using SEM (150–2000 ×). Results. Corrosion of the working part was observed in 5.5% of new Ni-Ti instruments of the K3 system (apical and middle segment), in 5.5% of Mtwo instruments (apical third), and in 11.1% of ProTaper Universal systems (apical and middle third). Corrosion was not observed on the new instruments of the HyFlex and BioRaCe kits. After instrumentation, disinfection, and sterilization, corrosion was observed in all sets of K3 and ProTaper Universal systems and in all HyFlex instruments of the first group. Corrosion was observed in the HyFlex system in the second group in 16.7% of instruments (apical and middle third) and in the third 83.3% in the apical and 66.7% in the middle segment. In the Mtwo set, corrosion was observed in 16.7% of instruments in the first (apical and middle third), in the second group in 33.3% of instruments in the apical part and 50% in the middle third, while in the third group, corrosion was observed in 16.7% of instruments in the middle third of instruments. Conclusion. Rotary Ni-Ti instruments K3 and ProTaper Universal are susceptible to corrosion in a very high percentage. Ni-Ti systems with post-heat treatment of the working part (HyFlex) are somewhat more resistant to corrosion, while in Ni-Ti systems with electropolished surface (BioRaCe), corrosion is not observed.

More certain therapeutic and significantly facilitated solution of everyday endodontic problems are provided by the introduction of NiTi rotary files in endodontic practice and their proper application. However, their widespread use has caused more and more frequent fractures and has become a significant frustrating factor that diminishes their numerous benefits. Torsional stress and cyclic fatigue are the main reasons for the occurrence of a fracture, and the frequency of NiTi file fractures is exactly proportional to the degree of bending of the canal, knowledge of the features of the file, ie. the skill and expertise of the therapist. The most dominant factor for the occurrence of fractures is the dentist who, in addition to manual dexterity, must have a good knowledge of the anatomy of various canal systems and file design in order to make the best choice for each individual case. Properly formed access cavity and knowledge of the working part of NiTi files enable maximum realization of endodontic skills, increased efficiency of intervention and reduced possibility of error during canal instrumentation. The special treatment of NiTi alloy and new solutions related to the design of the working part have significantly increased file flexibility and resistance to cyclic fatigue. Specific design (reduced number of threads, change of conicity, interruption of blade continuity), reduced engagement of file, ie. change of dynamics of movement in the canal (full rotation, reciprocal, eccentric, transaxial), as well as reduced number of processing files, have also significantly influenced the reduction of fracture risks. The aim of this paper was to analyze the most common reasons for the fracture of NiTi files and emphasize measures and factors that can increase their safe use and reduce complications during canal instrumentation.

Introduction Deformations and fractures of Ni-Ti instruments during chemomechanical instrumentation of root canals occur due to the action of cyclic and torsional forces. The aim of this research was to analyze the surfaces of the working parts of Mtwo instruments after preparation of root canals with different curvatures using SEM and determine possible changes and deformations after instrumentation. Materials and methods The study included 3 sets of Mtwo (VDW, Munich, Germany) instruments. Each set was used to instrument 10 canals in three experimental groups (straight, slightly curved, and highly curved canals). Instrumentation was carried out using crown-down technique with the following irrigation solutions, 2% NaOCl (CHLORAXID 2%, Cerkamed, Polska) and Distilled water (Iva, Serbia) in the amount of 5 cm³. The apical and middle third of the instruments were scanned in two directions using SEM at different magnifications (150-2000X). The SEM images were analyzed using qualitative analysis for the presence of different irregularities according to Eggert et al. Statistical analysis of obtained data was performed using Fisher test at a confidence level of 5% ( a = 0.05). Results Most defects (37.3%) were observed in instruments used in highly curved canals, followed by the instruments of the second group (35.6%), and the least defects were (27.1%) observed in the group with straight canals. Higher prevalence of defects was observed in the apical thirds of instruments (54.2%), especially in the experimental group of curved canals where the highest presence was observed (20.3%). The presence of production grooves was observed in all instruments, and the most common types of defects after instrumentation were the appearance of corrosion and changes in the cutting edges. In the group with extremely curved canals fractures were observed in two instruments (10/0.04 and 15/0.05). Conclusion Root canal curvature significantly affects the occurrence of deformations and fractures of Ni-Ti rotating instruments. The most common types of defects were grooves, corrosion and changes in the blade edges. Mtwo instruments showed deformations in terms of thread changes, microfractures and two complete fractures.

Introduction Modern endodontic procedure implies the use of rotary Ni-Ti instruments during chemomechanical treatment of root canals. The aim of this study is to analyze the surfaces of new (unused) rotary endodontic instruments using the SEM-EDS method and determine how frequently manufacture defects or impurities appear on their working surfaces. Material and method Five new different sets of rotary endodontic Ni-Ti instruments were included in this study: K3, Mtwo, ProTaper Universal, HyFlex and BioRaCe. The working part of endodontic instrument was analyzed using SEMEDS method (magnifications ×150 to ×2000), which determined the morphological characteristics of the instrument surface and chemical composition of the found impurities. Statistical analysis was performed using the Fisher's test (p < 0.05). Results The results of SEM-EDS analysis showed that there is no new instrument without defects on its surface. The most common defects were observed in K3 (27.43%) and ProTaper Universal group (27.21%) and the least were in BioRaCe instruments (7.67%). The most common type of defect in tested instruments was fretting. In addition, the presence of debris and metal strips was found on all instruments, while corrosion of the working part was observed only in K3, ProTaper Universal and Mtwo systems in a small percentage. Conclusion Based on the results of this research, it can be concluded that manufacturing defects were noticed in all examined instruments. The most common defect is pitting. Impurities such as debris and metal strips have also been registered. No organic debris was observed on electropolished surface of BioRaCe instruments, but a small percentage of other types of defects were registered.

Introduction The aim of this study was to analyze working surfaces of new hand endodontic instruments and to check possible existence of dirt or defects on working surface that resulted from manufacturing process using SEM. Material and methods Three sets of new hand instruments: K-File (KF), (18 instruments) (Dentsply Maillefer, Switzerland) and Hedstorm Files (HF), (18 instruments) (SybronEndo Co, USA) were used. Instruments were analyzed by SEM method at 170× magnification while semi-quantitative EDS analysis was used to determine chemical composition of dirt particles. Fisher test (p < 0.05) was applied in statistical analysis. Results Results showed that none of the instruments was defect-free. The most common defects were metal strips and fretting noticed at the surface of all tested instruments. Debris was present on all KF (100% in apical and middle third) and HF (56% in apical and 56% in middle third) instruments. Pitting was noticed in KF (33% in apical and 39% in middle third) and HF (11% in apical and 6% in middle third) instruments. Corrosion of working surface, metal flash and disruption of cutting edge were marked only in KF group. Conclusion Manufacturing defects were noticed in all instruments and the most common type of irregularity were metal strips and fretting.

Introduction/Objective. The objective of this study is to use scanning electron microscopy (SEM) to analyze working surfaces of new manual and rotary endodontic instruments and to check possible existence of manufacture dirt particles or defects on the working surface. Methods. In this study, we used three sets of new manual instruments: K-File, KF (Dentsply Maillefer, Switzerland) and Hedstorm Files, HF (SybronEndo Co, USA) and three sets of mechanical Ni-Ti instruments – type K3 (SybronEndo Co, USA) and BioRaCe (FKG DENTAIRE Swiss Dental Products, Switzerland). The instruments were analyzed using SEM method at 170 × magnification while semi-quantitative energy dispersive x-ray analysis was used to determine chemical composition of dirt particles. Fisher test (p < 0.05) was applied in statistical analysis. Results. Results showed that none of the instruments were defect-free. The most common defect type was the presence of metal strips, which were noticed at the surface of all tested instruments. Debris was present on all manual and only one type of mechanical instruments, K3 (39% in the apical and 33% in the middle third). Fretting was noticed in all manual KF and all mechanical instruments of the K3 group. Pitting was common in all manual instruments, KF (33% in the apical and 39% in the middle third) and HF (11% in the apical and 6% in the middle third). Corrosion of the working surface, metal flash, and disruption of the cutting edge were marked only in the KF group. Conclusion. Manufacture defects were noticed in all instruments and the most common type of irregularity were metal strips. Electropolished surface of BioRaCe instruments showed no debris of organic origin.

Introduction/Objective. Irrigation has an important role in root canal cleaning and its efficiency depends on the type of irrigants, the amount, the technique and the irrigation protocol. The aim of this work was to estimate the efficiency of cleaning of the canal walls by using scanning electron microscope analysis after the instrumentation by rotary NiTi instruments with the use of three different irrigation solutions and two final irrigation protocols. Methods. Sixty extracted human incisors were divided into two groups after the rotary instrumentation with the iRace instruments. In both groups, the same amount (1.5 ml) of three solutions (2% sodium hypochlorite solution, 2% chlorhexidine solution, and 10% citric acid solution) and total final irrigation time (90 seconds) was the same. The final irrigation in the first group was accomplished using the technique of continuous irrigation and in the second group it was done using the intermittent protocol. The roots were cut longitudinally and analyzed by thirds (coronal, middle, and apical) on a scanning electron microscope (JSM 6460LV, JEOL Ltd., Tokyo, Japan) with 1,000× magnification. Results. The most efficient cleaning of the root canal walls in both groups was seen after the use of citric acid with the intermittent protocol of the final irrigation (90.7% clean walls), while the least efficient was the final irrigation by chlorhexidine with continuous irrigation (80.3%). The most efficient cleaning of the canal walls in both groups was observed in the coronal third and the largest amount of the smear layer in the apical third. Conclusion. The most efficient cleaning of the canal was achieved by the use of citric acid and the intermittent protocol of the final irrigation. In all tested solutions, the intermittent protocol of irrigation was more efficient than continuous irrigation.

Introduction Efficient cleaning and canal design present a basic precondition for successful endodontic treatment. The aim of this study was to evaluate, using SEM analysis, the efficacy of cleaning the apical third of the canal with one instrument in both reciprocating motion and full rotation systems. Materials and methods Thirty (30) single-rooted teeth (upper incisors), extracted due to periodontal problems, were used and selected in 2 groups. In the group 1, instrumentation was done with a single instrument UNICONE with reciprocal movements (MEDIN, Czech Republic), while in the group 2, a single instrument XPS endo SHAPER (XPS) (FKG, Dentaire, Swiss) with full rotation was used. 2% solution of NaOCl and 17% EDTA solution were used as irrigation agents in both groups. SEM analysis of the smear layer in the apical third was done at standard magnification of 1000x and presented on a scale of 1-5. Results showed mostly clean canal walls and no smear layer in the apical region in both tested groups. Canal walls were somewhat cleaner after using UNICONE with reciprocal movements (80%) compared to the canals instrumented with XPS ENDO SHAPER (76%), but this difference was not statistically significant. Conclusion Single-file NiTi systems did not remove smear layer completely, but provided efficient cleaning in the api-cal part of the canal. UNICONE file with reciprocal movements was somewhat more efficient in removing the smear layer compared to the full rotation XPS ENDO SHAPER file.

Introduction the main objective of endodontic treatment is to eliminate infection from root canal and prevent re-infection by three-dimensional hermetic obturation of the canal system. Endodontic failure can occur due to inability of complete control and elimination of infection from the root canal. The aim of this study is to investigate, by PCR technique, microbiological status of previously endodontically unsuccessfully treated teeth immediately after the removal of obturation material. Material and Methods the analysis included 30 teeth indicated for endodontic retreatment. After removing previous root canal filling material, the bacteriological sample was taken by sterile instrument (# 15) and paper points. Standard PCR technique was used to analyze the incidence of E.faecalis, P.micros, P.intermedia, P. endodontalis and a.actinomycetemcomitans. Results Positive bacteriological findings were registered in 80% of cases, while bacteria were not identified in 20% of all samples (all taken from the root canals without significant changes in periapical tissue). From 24 canals with identified bacteria, 17 had affected apical periodontium. The most dominant microbe in root canals with positive bacteriological finding was E.faecalis (83.3% of the canals) and P.intermedia (75%). In case of teeth with chronic periapical changes, the most common was E. faecalis (94%) and P.intermedia (82.3%). Conclusion the presence of periapical lesions significantly affects microbiological status of endodontically treated teeth. The presence of bacteria was confirmed in most teeth with periapical lesions, while the most frequently identified bacteria were E. faecalis, P.intermedia and P.micros.

Introduction Development of inflammatory lesions or their persistence after primary treatment is considered endodontic failure. The reason for failure can be complex anatomy of the canal system and numerous iatrogenic factors. The objective of this study was to analyze, clinically and radiographically, the causes of primary endodontic treatment failure and assess possibilities for retreatment of teeth with failed endodontic treatment. Method The study included 79 teeth (36 multirooted and 43 singlerooted tooth) indicated for repeated endodontic treatment. Based on the radiographic assessment of the status of periapical structures, teeth were divided into two groups. The first group included teeth without periapical lesions, i.e. the healthy periodontal tissues (PAI score of 1 and 2) in which retreatment was required for prosthodontic reason due to the poor quality of obturation (28 teeth), and the second group included teeth with visible signs of periapical tissue damage (PAI scores 3, 4 and 5) (51 teeth). In both groups, quality of obturation, coronal sealing and the presence or absence of clinical symptoms was analyzed. Results The most common radiographic finding of definitive obturation was short filling (65.8% of cases); “forgotten” canals (25.3%); non-homogeneous obturation with correct length (5.1%) and fractured instrument (3.8%). There was significant difference between healthy periodontal ligament and adequate restoration (P < 0.001). In 95% of patients with symptoms, changes in the periapical tissue were observed. Also, there was significant difference in the presence of symptoms after primary treatments, between the teeth with healthy apical periodontal tissue and teeth with periapical lesions (P = 0.019). Conclusion The outcome of the root canal treatment is significantly affected by the quality (density) of obturation and the presence and quality of coronal restoration. In patients with symptoms there were changes in the periapical tissue.

Introduction The aim of this study was to evaluate the efficacy of new rotary NiTi instrument XP endo SHAPER (XPS) used with conventional irrigation protocol on the root canal cleaning in the apical area. Material and methods The research was conducted in vitro on 40 extracted single-rooted teeth divided into the four groups. Instrumentation in the first group was performed using iRa Ce NiTi rotary instruments, in the second group the same instruments were used plus XP endo FINISHER (XPF) for smear layer removal. In the third group, canal instrumentation was done using new instrument XPS, and in the fourth XPS instruments plus XPF was used. During the instrumentation 2% NaOCl solution was used for rinsing canals. The SEM analysis of the cleaning quality in the apical third of the canal was performed on longitudinal root cross-sections and standardized microphotography with a 2000x magnification. Results The thickest smear layer in the apical third was recorded in the first group (iRa Ce) NiTi instruments (2.12), and somewhat less in the group with the new XPS instrument (1.95). An identical and somewhat smaller amount of smear layer was registered in the second and fourth groups where XPF was used with the final irrigant (1.64) (p

Root canal (endodontic) treatment is demanding and complex procedure. A variety of difficulties can occur in different phases of endodontic procedure. Complex anatomorphological tooth structure, curved canals, close proximity of lower molars and premolars to inferior alveolar nerve make endodontic treatment even more challenging. During endodontic treatment, an inferior alveolar nerve may become traumatized and symptoms may vary from mild neurosensory dysfunction to a complete loss of sensation in the innervation area of damaged nerve. The aim of this paper is to present a clinical case of endodontic treatment of lower second molar with C-shaped root canal in a patient with paraesthesia of inferior alveolar nerve due to endodontic origin.

Dental fear represents a significant social concern. Therefore, an individual approach to each patient and timely recognition and elimination of dental stress are necessary in order to provide adequate and successful treatment. The aim of this paper was to present possible application of music therapy in dentistry and its role in reducing dental fear. Music has shown great prospective as an alternative therapy method in various fields of medicine. Music therapy is painless and noninvasive anxiolytic method that reduces dental anxiety as it provides relaxation and distraction. Music in dental office creates positive atmosphere among patients and their company as well as dental staff.

Introduction. Endodontic retreatment is a complex intervention that requires detailed analysis of possible reasons for failure, and flawless practical execution of the procedure. Objective. The aim of the study was to assess the outcome of endodontic retreatment based on clinical and radiographic criteria after a two-year observation period. Methods. Clinical study included 49 teeth indicated for endodontic retreatment based on periapical index (PAI). All teeth were divided into two groups. Group I comprised teeth without any periapical lesion (PAI score of 1 and 2) while Group II consisted of teeth with visible periapical radiolucency (PAI score of 3, 4, and 5). Endodontic retreatment was completed in two visits with inter-appointment medication of 2% chlorhexidine and calcium hydroxide for two weeks. Outcome of endodontic retreatment was evaluated 12-24 months after final obturation. Results. Endodontic retreatment was successful in 93.3% in Group I after 24 months. In Group II, successful treatment and complete healing was found in 52.9% of teeth, whereas 14.7% of teeth showed only partial healing. However, clinical symptomatology was not present in any of the cases. Considering the absence of clinical signs and subjective symptoms, retreatment was successful in 67.6% of cases where chronic periapical inflammation was present. Conclusion. Endodontic retreatment was successful in high percentage in teeth with and without periapical lesions.

Introduction The aim of this study was to evaluate using SEM analysis the effectiveness of a new instrument XP-endo Finisher in cleaning root canal walls after instrumentation with BioRaCe NiTi rotary instruments. Material and Methods This in vitro study was conducted on 30 extracted single rooted teeth divided in two groups. Instrumentation of all canals was done using basic BioRaCe NiTi rotary instruments with copious irrigation of 2% NaOCl. In the first group, after complete instrumentation smear layer was removed using XP-endo Finisher, while the other group served as negative control. The roots were then after longitudinally cut and SEM analysis was performed. The presence of smear layer in the coronal, middle and apical third was assessed. The data were statistically analyzed using Mann-Whitney U-test (p

Dental anxiety might be the cause of serious health problems. Avoiding dental visits can lead to complications with functional, esthetic and sociological consequences. In order to have a simple and efficient dental procedure, it is very important to diagnose dental anxiety and to react adequately. The aim of this paper is using available literature to present most frequent causes, consequences as well as treatment options for dental anxiety. Treating dental anxiety and choosing the right treatment is not always easy, however, it is important for dental practitioners to be able to assess patient's behavior, possible causes of such behavior and select adequate therapy methods. Individual approach is very important as well as timely recognition and gradation of dental anxiety in order to apply adequate and successful dental treatment.

Implantology has become an important therapeutic procedure that allows complete aesthetic and functional rehabilitation of the oro-facial system in edentulous patients. Implant supported prosthetic restorations can be fixed in two ways, by cement or screws. Both techniques have advantages and disadvantages and their selection depend on situation in patient’s mouth. The aim of this study was to describe complete process of prosthetic rehabilitation in an edentulous patient, from pre-implant preparation, through implant placement and fixation of final restoration on implants. In this case report, one ceramo-metal bridge was fixed by screws in the lower jaw while the other one was fixed using glass-ionomer cement in the upper jaw. After bone augmentation and time necessary for its osseointegration (6 to 8 months), 16 implants were placed in both jaws. Eight weeks after the implant placement, final prosthetic rehabilitation was achieved by cementation of one ceramo-metal bridge in the upper jaw using glass ionomer cement and fixation of the second bridge with screws in the lower jaw. To achieve successful implant supported prosthetic rehabilitation, the treatment protocol must be followed from the beginning to the end of the therapy.

Introduction. Dental status of most people with special needs is not satisfactory. Many of them are edentulous or toothless, with acute extensive caries lesions present, high DMFT index and severe periodontal disease. The objective of this study was to examine the dental status of mentally impaired persons who live in the special institution “Srce u jabuci” in Pancevo. Material and Methods. Clinical examination was performed on 114 institutionalized patients (68 male and 46 female), age 22 to 71 years. Patients were divided in two groups; the first group consisted of 71 persons who had a moderate mental disorder (F71), while the second group included 43 respondents with severe mental retardation (F72). Oral examination revealed: the number of present teeth, caries lesions, the presence of restorations, the number of extracted teeth, the presence of residual roots, fractures and the presence and number of fixed restorations. Results. The mean DMFT of total examined teeth was 20.33±7.63. The greatest percentage found for extracted teeth (63.76%): in the first group 63.23%, and in the second 64.06%. The percentage of teeth that had caries lesions of all examined teeth was 33.48%, while the lowest percentage was for restored teeth (2.76%). In majority of examined people, initial caries, deep caries, or tooth with the exposed pulp (K1 - 51.74% K2 - 40.35%, K3 - 51.75%) were not found. A high percentage of examined people had more than 10 extracted teeth (52.63%). Most of them did not have any restoration in the mouth (81%) and only three persons had fixed denture. Conclusion. Dental status of institutionalized mentally impaired persons showed high prevalence of extracted teeth, significant presence of carious lesions and small percentage of restored teeth with inadequate oral hygiene.

Introduction Knowledge of the complexity of the root canal system in lower first molars and particularly the apical part of the root affects significantly the realization and success of the endodontic procedure. Aim The aim of this paper was to determine the thickness of the primary and secondary dentine around the main foramen of the mesial and distal root of the lower first permanent molar in teeth of various ages. Material and Method Fifty extracted lower first molars of both male and female patients extracted for various reasons were used in the study. All teeth were allocated to three age groups: under 25 years old (15 teeth), between 26 and 50 (20 teeth) and over 51 years old (15 teeth). After access cavity preparation, canal orifices were enlarged and root canals were explored using hand K-files #10. Using a diamond disc, the root tip was then cut off in the area of the apical foramen. Dentine thickness was determined using a complex configuration comprising of several devices which were interconnected by software. These included a polarised microscope (Leica DMLSP), a digital camera (Leica DC300) and a scanner. Results The results showed that the greatest mean thickness of the primary dentine was in the mesial root of the first lower molar in the first age group (0.177 mm), followed by the third (0.145 mm) whilst the least mean thickness was observed in the second age group (0.141 mm). In the distal root, the mean thickness of the primary dentine was in the second (0.175 mm), then the first (0.138 mm) and finally the third group (0.100 mm). The mean thickness of the secondary dentine in the mesial root was observed in the second group (1.25 mm), followed by the third (1.11 mm) whilst the least mean thickness was found in the first age group (0.95 mm). The mean thickness of the secondary dentine in the distal root was observed in the second group (1.26 mm), then the third (1.18 mm) whilst the least mean thickness was found in the first age group (0.99 mm). Conclusion The obtained results suggested that the mean thickness of the primary dentine in the mesial and distal roots was comparable. For both mesial and distal roots, the greatest mean thickness of the secondary dentine was observed in the second age group.

The main prerequisite for a successful treatment of pulp disease in apex periodontium is knowledge of morphological characteristics of root canal system, especially one third of his apex. The aim of this work was to define the exact distance of the main and auxiliary openings from the top of medial and distal roots of the first lower permanent molars. Methods: as a research material it was used a hundred extracted first lower molars of the patients of both gender, divided into three age groups. The analysis of the one third of apex was done with the help of binocular magnifying glass and digital roentgenography analysis half of the samples, which were filed with capillary contrast. Results: The results obtained showed that the longest average distance of the main opening from the top of medial root was 0.84mm, and the shortest was 0.61mm; while for the distal root the longest average distance was 0.89mm, and the shortest was 0.62mm. Maximum distance of the auxiliary openings from the top of medial root in the first group was 3.5mm, and the maximum distance of the auxiliary openings from the top of distal root was 2, 5 mm. The results obtained with digital rentgenography showed that the longest average distance of the main opening from the top of medial root was the one noticed in the second age group (0.91mm) then the one from the first group (0,83), and the shortest one in the third age group (0,71mm); as for the distal root: the longest average distance of the main opening from the top of the root was noticed in the third age group (0,95mm) then in the first (0,90mm) and than shortest in the second age group (0,89mm). Conclusion: The distance of the main and auxiliary openings from the top of medial and distal root of the first lower molar varies in the range from 0 to 3,5mm and it depends on the tooth age. .

Introduction. Understanding the morphology of the root canal system, and especially its apical third, represents the basic precondition for the successful treatment of diseased pulp and the apical endodontium. Aim. The aim of this study was to precisely locate the main and ancillary foramina in the mesial and distal first lower molars. Method. One hundred extracted first lower molars, originating from persons of both sexes and three different age groups, were used in the study. Results. The analysis of the sampled molars’ apical third was carried out using a binocular magnifier and a digital X-ray scanner (Trophy). The results showed that the main mesial and distal root foramina were located mostly on the distal surface. The ancillary mesial and distal root foramina were located at the lingual end, in most cases. Statistical analysis demonstrated the congruence of results achieved using the binocular magnifier and digital x-ray in 100% of cases if the main foramen is located on the very top of the mesial root (χ2 =17.23; p

Modern methods of root canal cleaning and filing are causing formation of the smear layer on treated surfaces. The aim of this paper was to review clinical aspect of smear layer in endodontics. Smear layer is the consequence of instrumentation of root canal walls and is consisted of organic and inorganic particles of cut dentine, necrotic and/or vital pulp fragments, microorganisms and their products. Existence of smear layer is affecting permeability of the radicular dentine, thus decreasing effects of canal medicaments and impairing adhesion of obturation materials in root canal. Removal of the smear layer from canal walls is possible with use of various chemical agents, ultrasonic or laser techniques. Regardless to contradictory attitudes and opinions, removing the smear layer is required for possible bacterial contamination, compromised effects of root canal medication and in order to obtain better obturation of canals 'system. .

Copyright of Serbian Dental Journal / Stomatološki Glasnik Srbije is the property of National Library of Serbia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Serbian Dental Journal / Stomatološki Glasnik Srbije is the property of National Library of Serbia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)