Introduction/Objective. Development of materials which could be used as biological bone substitutes is one of the most valuable and active fields of biomaterial research. The goal of the study was to research the reaction of tissue on calcium silicate- (CS) and hydroxyapatitebased (CS-HA) newly synthesized nanomaterials, after being implanted into the subcutaneous tissue of a rats and direct pulp capping of rabbit teeth. Methods. The tested materials were implanted in 40 Wistar male rats, sacrificed after seven, 15, 30, and 60 days. The direct pulp capping was performed on the teeth of rabbits. Cavities were prepared on the vestibular surface of the incisors. The animals were sacrificed after 10 and 15 days. The control material was mineral trioxide aggregate (MTA). Histological analysis covered the tracking of inflammatory reaction cellular components, presence of gigantic cells, and necrosis of the tissue. Results. Seven days after the implantation, the strongest inflammatory response was given by the MTA (3.3 ?} 0.48), while CS and CS-HA scored 3 ? 0.71. After 60 days, the rate of inflammatory reactions dropped, which was the least visible with CS-HA (0.2 ? 0.45). The least visible inflammatory reaction of the rabbits? pulp tissue was spotted with the CS (1.83 ? 0.75), than with the MTA and CS-HA (2.67 ? 1.53, 3 ? 0.63). Conclusion. The newly synthesized materials caused a slight reaction of the subcutaneous tissue. CS-HA showed the best tissue tolerance. Nanostructural biomaterials caused a slight to moderate inflammatory reaction of the rabbits? pulp tissue only in the immediate vicinity of the implanted material.

Root resorptions present a significant problem in endodontic therapy of the affected teeth and in dentistry in general. The objective of this study was to analyze, based on epidemiological and statistical research, the frequency of clinical incidence of pathological root resorptions in everyday practice related to localization, type of tooth, age and sex of patients. Radiographie documentation of patients treated from 1997 till 2002 at the Department of Conservative Dentistry and Endodontics, Faculty of Stomatology in Belgrade, was used as baseline for this study. Retroalveolar radiographs of teeth with visible signs of resorptions were singled out from 15654 patients' clinical records used for this study. The external resorptions were shown as radiolucent areas localized on various outer root surfaces, followed by significant or less significant resorption of lamina dura and alveolar bone. Out of all teeth analyzed in this study, 594 (3.79%) showed some kind of resorption. The external resorptions were found to be more present in the upper jaw (55.10%) and molars (50.30%) than in the lower jaw (44.90%) and single root teeth (49.70%), but in both cases without significant statistical differences. The most frequent localization of resorptions was root apex (82.44%). In regard to age, the most frequent resorptions were recorded in patients aged between 21 and 30 years (28.40%), and the lowest incidence was found in the youngest population (5.51%). The results also showed that resorptions were more frequent among the female population (59.04%) than among the male population (40.96%). Based on these results, we may conclude that the external root resorptions are not a frequent clinical phenomenon. Proper and early diagnostics of such tissue pathology is one of the basic prerequisites for successful endodontic therapy of the affected root.

Introduction. Postoperative pain may develop after chemomechanical preparation during endodontic treatment or retreatment. It is associated with acute apical periodontitis caused by bacteria penetrated from the root canal into the periapical tissue. The purpose of this study was to evaluate the incidence of postoperative pain during endodontic treatment after intracanal medication performed with calcium hydroxide (CH) paste or 1% chlorhexidine gel (CHX). Material and Methods. The study included 22 asymptomatic teeth in both male and female patients. Fourteen teeth had the diagnosis of pulp necrosis and the other eight were retreatment cases. The root canals were prepared by crown-down technique using K files and copious irrigation with 0.5% sodium hypochlorite (NaOCl). Intracanal dressing was performed using either calcium hydroxide paste or 1% CHX gel. Each medicament was placed in the root canals of eleven randomly selected teeth. The teeth were restored with temporary filling. Postoperative pain was registered during the seven day period between two appointments. The level of pain was rated as follows: no pain, mild pain, moderate pain and severe pain (flare-up). The obtained data was analyzed using Fisher exact test. The level of significance was ?=0.05. Results. Postoperative pain was absent in 77.3% of total number of treated teeth. Severe pain (flare-up) was registered in 2 cases (9%). There was no significant difference in pain incidence between the CH paste and CHX gel group (p=0.610). Conclusion. Endodontic procedure used in this study which considered root canal instrumentation and irrigation followed by intracanal medication with CH and CHX resulted in low incidence of postoperative pain.

Introduction. The aim of this study was to investigate the solubility of gutta-percha points and various endodontic sealants in essential oils. Materials and method. Ninety-six gutta-percha points were divided into the four groups of 24 samples for every essential oil and subsequently divided into the three subgroups corresponding to the immersion times (2,10 and 15 min). The post-immersion amount was obtained for each. Endodontic sealers AHplus, Acroseal, Endomethasone N were included in the research. Samples were treated with corresponding oil for 10 min. Each sample was measured and the amount was obtained. Results. Orange oil was the most effective in dissolving gutta-percha compared to other tested essential oils (p < 0.05). Eucalyptol was more effective in dissolving gutta-percha than tea tree after 10 min (p < 0.05). There was no statistical significance in the effectiveness of essential oils in relation to the time of action (10 or 15 minutes) (p > 0.05). Most weight loss was recorded with Endomethasone for all solvents, but the highest in orange oil and tea tree, followed by eucalyptus and clove oil. Tea tree dissolved AH Plus more efficiently compared to Acroseal. Conclusion. Essential oils showed promising results in dissolving gutta-percha and sealers.

Introduction. Adequate radiopacity of endodontic sealers allows radiographic visualization, assessment of root canal filling quality and its clinical follow-up after obturation. The aim of our study was to evaluate the radiopacity of Bio-Root RCS, MTA Fillapex, Bioceramic Root Canal Sealer, GuttaFlow Bioseal in comparison to AH Plus sealer, as a gold standard in clinical practice. Material and methods. Sealer specimens, 2 mm thick and 5 mm in diameter, were radiographed with an aluminum stepwedge using digital imaging system. Radiographic densities of the specimens were shown as mean greyscale values (Adobe Photoshop CS4 software) and expressed as mmAl/mm of the material. ANOVA with a post hoc Tukey test was used, significance was set at 0.05. Results. Differences in radiopacity between tested endodontic sealers were statistically significant except the difference between BioRoot RCS and GuttaFlow Bioseal. Conclusion. Radiopacities of all evaluated calcium silicate-based sealers were higher than minimal values recommended by standards. AH Plus sealer had the highest radiopacity, while calcium silicate-based sealers showed lower values, from BioRoot RCS, followed by GuttaFlow Bioseal, to MTA Fillapex, in descending order, and Bioceramic Root Canal Sealer with the lowest values.