[Analysis of antimicrobial effect of MTAD solution in infected root canal system using PCR technique].

INTRODUCTION: Clinically acceptable antiseptic should possess organolithic-mineralolithic properties and antimicrobial efficacy, and should be non-toxic. OBJECTIVE: The aim of the paper was to assess the presence of genomes of the most common microorganisms (Porphyromonas gingivalis, Agregatibacter actinomycetemcomitans, Tanerella forsythensis, Prevotella intermedia, Treponema denticola and Enterococcus faecalis) in infected tooth root canals before and after rinsing with solution of doxycycline, citric acid and detergent Tween-80 (MTAD) in patients with clinically diagnosed primary apex periodontitis. METHODS: The content of primarily infected canals before and after using the MTAD solution was used as a biological material in which the presence of microorganisms DNA was proved. For the detection of bacterial genome the multiplex PCR technique was applied. RESULTS: The percentage of positive samples before canal treatment was 100%. In infected root canals E. faecalis was most dominant (37%). In a relatively high percentage we detected P. intermedia (25%), A. actinomycetemcomitans (20%), T. denticola (17%), T. forsythensis (15%) and P. gingivalis (10%). After rinsing the canal system using MTAD solution, there was a statistically significant decrease in E. faecalis (12%), P. intermedia (0%), T forsythensis (0%) and P. gingivalis (0%). The presence of other bacteria was also diminished but not statistically significantly. CONCLUSION: With the application of multiplex PCR technique which provided a simultaneous amplification of various genomic sequences, using several pairs of primers, the most dominant in infected root canals were E. faecalis. P. intermedia, A. actinomycetemcomitans, T. denticola, T. forsythensis and P. gingivalis. After mechanic treatment and irrigation of root canals with MTAD solution, P. intermedia, P. gingivalis and T forsythensis were not found. The presence of E. faecalis, A. actinomycetemcomitans and T. denticola was diminished, however, not statistically significantly.

[Incidence of lip and palate clefts in children in Nis from 1990 to 2007].

INTRODUCTION: Cleft lip and palate is a complex congenital anomaly of the orofacial system in children. OBJECTIVE: The aim of this study was to determine the incidence of live-born children with cleft lip and/or palate compared to the total number of children born in the period from January 1, 1990 to December 31, 2007. METHODS: Epidemiological investigation was based on the records of live-born children at the Hospital of Gynaecology and Obstetrics of the Clinical Centre Nis. The study included 61,116 live-born children, i.e. 56,905 full-term babies. RESULTS: The total number of registered clefts during the investigation period was 43 (22 boys and 21 girls). The most frequent were the secondary palate clefts (44.2%); combined cleft were present in 34.9%, while primary palate clefts were reported in 20.9%. In respect to the season and order of birth, there was no statistically significant difference in the frequency of the primary, secondary and complete palate clefts. The age of mothers was not identified as a risk factor for the occurrence of cleft lip and palate. CONCLUSION: In the studied period, 43 children were born with the cleft lip and/or palate, equally in boys as in girls. The secondary palate clefts were most frequent. The season and order of birth had no statistical influence on the occurrence of this anomaly.

[Tooth macromorphological and ultrastructural analysis of osteological material from the medieval locality of St. Panteleimon Church in Nis].

INTRODUCTION: Analysis of macromorphological and ultrastructural tooth characteristics of osteological material from the medieval site of St. Pantaleimon Church in Nis provides us with insight on the life, nutrition and habits of medieval population, as well as the structure and composition of their teeth. OBJECTIVE: The aim of this research, based on the tooth inspection of skeletal remains from the medieval site of St. Pantaleimon Church in Nis, was to analyze macromorphological characteristics, ultrastructure of the dental tissue of maxillary and mandibular molars, canines and incisors, as well as their chemical composition. METHODS: Macromorphological and ultrastructural analysis of the dental tissue of osteological material dating from the 12th century included 1312 teeth with advanced abrasion. Macromorphological changes were detected by using a dental mirror, probe and radiography. After irrigation, the teeth were prepared using the standard procedure and analyzed by scanning electronic microscopy (JEOL-JSM-5300). Chemical analysis was done by expanded downscaling (EDS) method for Mg, P, Ca. RESULTS: The analysis detected second degree abrasions of all teeth in individuals aged 20-25 years. Third and fourth degree abrasions of teeth were detected in individuals aged over 40 years. Ultrastructural analysis showed a complete obliteration of dentin tubules and pulp of the lower incisors, the apposition of intratubular dentin inside the tubules, as well as extensive deformity and loss of dentin structure on molars with preserved pulp volume and nerve fiber calcification. The calcification of nerve fibers showed that the formation of intratubular dentin was proportional with the biological potential of pulp and the degree of abrasion, and inversely proportional with the size of dentin surface. Chemical analysis showed that in the analyzed teeth Ca composition was slightly lower than that in the control group, P composition was almost identical, while Mg composition was multiply increased in comparison to the control group consisting of today's persons of matching age and examined teeth as the medieval individuals. CONCLUSION: Different ultrastructural tooth characteristics as a part of the complex masticatory system of the medieval man are the result of individual and the whole community adaptation to actual living conditions. Nerve fibers calcification of the pulp can explain the absence of pain despite the high level of dental abrasion.

[Efficiency of final irrigation of root canal in removal of smear layer].

INTRODUCTION: A smear layer forms on the root canal walls as the consequence of root instrumentation. The smear layer formed in such a way considerably influences the quality of root obturation and endodontic treatment outcome. OBJECTIVE: The aim of this study was to ultrastructurally analyse the surface of intracanal dentine after removal of the smear layer by the solution of doxycycline, citric acid and detergent Tween-80 (MTAD). METHODS: The study involved 60 single-rooted, extracted, human teeth divided into four groups. All samples were instrumented by a step-back technique and manual K-files, and rinsed during instrumentation by 2% CHX and H2O2. The first group of samples was exclusively rinsed by CHX and H2O2; in the second group, besides using CHX and H2O2, MTAD solution was used for the final irrigation. The samples which were rinsed by distilled water (+ control) and the samples rinsed by 5.25% NaOCI and 17% Na EDTA (-control) served as control groups. All samples were observed under the scanning electronic microscope JEOL-JSM-5300. The coronary, middle and apex thirds of the radix region were analysed. RESULTS: The obtained results of the SEM analysis showed that the application of 2% chlorhexidine and hydrogen peroxide did not give clear dentine walls, and the smear layer could not be removed completely. The application of the same combination (CHX and H2O2), added by the final MTAD irrigation solution, led to the efficient removal of the smear layer, while the morphological structure of dentine surface remained unchanged. Statistical analysis showed that canal walls in the experimental group with MTAD as the final irrigation were significantly clearer compared to the control group (p < 0.001). CONCLUSION: Based on the obtained results, it can be concluded that MTAD is an efficient solution for the final irrigation of the canal system.

[Tooth pathology analysis of osteological material from the Medieval locality of Saint Pantelejmon church in Nis].

INTRODUCTION: Medieval necropolis at the porch of St. Panteleimon church in Nis, from 12th century represents a typical Serbian necropolis, which has its analogies in several areas in Serbia. Preservation of the skeletal remains belongs to category of good and medium preservation. OBJECTIVE: The aim of the work was to study the skeletal remains for the prevalence of tooth caries, localization of caries lesions, presence of abrasion, supragingival tartar and resorption of alveolar bone as the indicator of periodontal disease. METHOD: The analyses included 42 skeletal remains. The anthropological analyses involved paleopathological findings on 954 teeth of 22 men and 20 women. The pathological changes of teeth were determined by inspection, dental probe, dental mirror and x-ray examination. Epidemiological research was done using average caries index. RESULTS: The antropological tooth pathology research of osteological material from the medieval localization of St. Pantaleimon Church in Nis showed the presence of caries in 7.86% cases, 9.93% women and 6.07% men. In 76% caries were localized on the approximal surfaces of teeth. Abrasion of the second and third degree was registered on the side and front teeth with transformation of contact points into contact surfaces and the creation of approximal, interstitial, scolded surfaces. A large quantity of supragingival tartar was found in all individuals aged over 25 years. Expressed alveolar bone resorption is the indicator of generalized periodontal disease. CONCLUSION: The prevalence of caries in the studied medieval population from the 12th century was sporadic, with localization on secondary predilection places. The abrasion of the second and third degree was present, and the resorption of the alveolar bone was registered in all the examined skeletal remains, which was the indicator of spread periodontal disease in this period.

[Ultrastructural investigation of root canal dentine surface after application of active ultrasonic method].

INTRODUCTION: The basic work principle of all ultrasonic techniques is the piezoelectric effect of producing high frequency ultrasounds of small length, which are transmitted over the endodontic extensions or canal instruments into the root canal. When in contact with the tissue, ultrasonic vibrations are converted into mechanical oscillations. Ultrasonic waves and the obtained oscillations along with the synergic effect of irrigation bring about the elimination of smear layer from the root canal walls. OBJECTIVE: The aim of the study was to ultrastucturally examine the effect of smear layer removal from the walls of canals by the application of the active ultrasonic method without irrigation, that is by the application of ultrasound and irrigation using distilled water and 2.5% NaOCl. METHOD: The investigation comprised 35 single-canal, extracted human teeth. After removal of the root canal content, experimental samples were divided into three groups. According to the procedure required, the first group was treated by ultrasound without irrigation; the second one by ultrasound with irrigation using distilled water; and the third group was treated by ultrasound and irrigation using 2.5% NaOCl solution. The control samples were treated by machine rotating instruments (Pro-File) and were rinsed by distilled water. RESULTS: The obtained results showed that the ultrasonic treatment of the root canal without irrigation did not remove the smear layer. The dentine canals are masked, and big dentine particles are scattered on the intertubular dentine. The ultrasonic treatment by using irrigation with distilled water provides cleaner dentine walls and open dentine tubules but with smaller particles on the intertubular dentine. The ultrasound treatment by using irrigation with 2.5% NaOCl solution provides a clean intertubular dentine surface without a smear layer and clearly open dentine tubules. CONCLUSION: Instrumentation of the root canal by application of ultrasound by using NaOCl as irrigation provides a clean dentine surface of the root canal without a smear layer.