Microorganisms are the possible source of endodontic lesions. The polymicrobial infection makes the sterilization of the root canal difficult. The following case report describes the non-surgical endodontic treatment of teeth with a large periradicular lesion. First, an intracanal dressing of calcium hydroxide was given. Since the symptoms did not subside, the treatment protocol was changed. A triple antibiotic paste was used instead for 3 months. On follow up, teeth were clinically asymptomatic and radiographically showed healing of the periradicular lesion. The result of the case show that when most commonly-used medicaments fail in eliminating the symptoms, then a triple antibiotic paste (metronidazole, ciprofloxacin, and minocycline) can be used clinically in the treatment of teeth with large periradicular lesions.

Objectives:The objective of this in vitro study was to assess the effect of different chelating agents on the calcium loss and its subsequent effect on the microhardness of the root dentin.Materials and Methods:Ten single rooted lower premolars were selected. The teeth were decoronated and thick transverse sections of 2 mm were obtained from the coronal third of the root. Each section was then divided into four quarters, each part constituting a sample specimen from the same tooth for each group. The treatment groups were: Group 1 (Control): 5% Sodium hypochlorite (NaOCl) for 5 min + distilled water for 5 min; Group 2: 5% NaOCl for 5 min + 17% ethylenediaminetetraacetic acid (EDTA) for 5 min; Group 3: 5% NaOCl for 5 min + 2.25% Peracetic acid (PAA) for 5 min and Group 4: 5% NaOCl for 5 min + QMix for 5 min respectively. The calcium loss of the samples was evaluated using the Atomic Absorption Spectrophotometer followed by determination of their microhardness using Vickers Hardness Tester. Data was analyzed using one-way ANOVA, Post hoc Tukey test and Pearson correlation.Results:The maximum calcium loss and minimum microhardness was observed in Group 3 followed by Group 2, Group 4 and Group 1. There was a statistically significant difference between all the groups except between Groups 2 and 4.Conclusions:Irrigation with NaOCl + 2.25% PAA caused the maximum calcium loss from root dentin and reduced microhardness. A negative correlation existed between the calcium loss and reduction in the microhardness of root dentin.

The infection of the root canal system is considered to be a polymicrobial infection, consisting of both aerobic and anaerobic bacteria. Because of the complexity of the root canal infection, it is unlikely that any single antibiotic could result in effective sterilization of the canal. A combination of antibiotic drugs (metronidazole, ciprofloxacin, and minocycline) is used to eliminate target bacteria, which are possible sources of endodontic lesions. Three case reports describe the nonsurgical endodontic treatment of teeth with large periradicular lesions. A triple antibiotic paste was used for 3 months. After 3 months, teeth were asymptomatic and were obturated. The follow-up radiograph of all the three cases showed progressive healing of periradicular lesions. The results of these cases show that when most commonly used medicaments fail in eliminating the symptoms then a triple antibiotic paste can be used clinically in the treatment of teeth with large periradicular lesions.

Aim:The purpose of this in vitro study was to evaluate the cleaning efficacy of NaviTip, Max-i-Probe and Endovac in removal of debris from the root canal at 1.5 and 3.5 mm from the apex.Materials and Methods:Forty single-rooted teeth were divided into four groups according to the root canal irrigation system (EndoVac, NaviTip, Max-i-Probe, and control). Instrumentation was done using ProFile 0.06 taper series to MAF #40. Root canals were irrigated after each file size with 1 ml of 5% NaOCl. For final irrigation 5 ml of 5% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA) was used. Each group was irrigated with a different irrigation device. Four micron thick serial sections were prepared at 1.5 and 3.5 mm from the apical level and photographs were taken for the analysis. The influence of the irrigation system was evaluated using a one-way analysis of variance (ANOVA) test and unpaired t-test (P < 0.05).Results:Endovac showed significantly least amount of mean percentage debris followed by Max-i-probe and NaviTip at both levels (P < 0.05). In all the experimental groups, significantly less amount of mean percentage debris was seen at 3.5 mm level than at 1.5 mm level (P < 0.05). However, the difference was statistically insignificant in case of Endovac irrigation system group.Conclusions:Amongst all the experimental groups, Endovac removed significantly more debris followed by Max-i-probe and NaviTip at both levels.

Aim:The aim of the study is to evaluate the effect of ceramic type, thickness, and time of irradiation on degree of polymerization of dual-cure resin cement.Materials and Methods:Dual-cure resin cement (SoloCem) was used to prepare disk-shaped samples (0.5 mm thick × 5 mm diameter). Study group samples (n = 5) were light-cured for 40, 60, and 80 s through all ceramic leucite-reinforced (Cergo Kiss), lithium disilicate-reinforced (IPS e.max), and monolithic zirconia-reinforced (Ziecon) of three thicknesses (2, 3, and 4 mm). Negative control group samples were cured through metal disks and positive control samples were cured without the presence of ceramic. The degree of conversion (DC) was evaluated by Fourier transform infrared spectrometer. The recorded data were subjected to one-way analysis of variance, followed by post hoc analysis (Tukey HSD).Results and Conclusion:Greatest light transmission and DC were seen through Cergo Kiss, followed by IPS e.max Press and Ziecon, with insignificant difference between the latter two. The attenuation of light irradiance increased with increasing thickness of ceramic disks, with statistically significant values between 3 and 4 mm. Increasing time of irradiation to cure dual-cure resin cement did not always result in greater degree of polymerization.

Introduction:Irrigation plays an indispensable role in removal of tissue remnants and debris from the complicated root canal system. This study compared the human pulp tissue dissolution by different concentrations of chlorine dioxide, calcium hypochlorite and sodium hypochlorite.Materials and Methods:Pulp tissue was standardized to a weight of 9 mg for each sample. In all,60 samples obtained were divided into 6 groups according to the irrigating solution used- 2.5% sodium hypochlorite (NaOCl), 5.25% NaOCl, 5% calcium hypochlorite (Ca(OCl)2), 10% Ca(OCl)2, 5%chlorine dioxide (ClO2) and 13% ClO2. Pulp tissue was placed in each test tube carrying irrigants of measured volume (5ml) according to their specified subgroup time interval: 30 minutes (Subgroup A) and 60 minutes (Subgroup B). The solution from each sample test tube was filtered and was left for drying overnight. The residual weight was calculated by filtration method.Results:Mean tissue dissolution increases with increase in time period. Results showed 5.25% NaOCl to be most effective at both time intervals followed by 2.5% NaOCl at 60 minutes, 10%Ca(OCl)2 and 13% ClO2 at 60 minutes. Least amount of tissue dissolving ability was demonstrated by 5% Ca(OCl)2 and 5% ClO2 at 30 minutes. Distilled water showed no pulp tissue dissolution.Conclusion:Withinthe limitations of the study, NaOCl most efficiently dissolved the pulp tissue at both concentrations and at both time intervals. Mean tissue dissolution by Ca(OCl)2 and ClO2 gradually increased with time and with their increase in concentration.

Objective:To evaluate the depth of penetration of three resin-based root canal sealers into the dentinal tubules at the cervical, middle and apical third of the root canal.Materials and Methods:Root canals of 32 extracted human mandibular premolar teeth were prepared and obturated using EndoREZ + resin-coated gutta-percha points (group A), Epiphany + Resilon points (group B), or AH Plus + gutta-percha (group C). The teeth were split longitudinally in bucco-lingual direction and viewed under scanning electron microscope. Photographs were taken at cervical, middle and apical levels for all samples and corresponding measurements were made. The data obtained was statistically analyzed using one-way ANOVA and the post-hoc Bonferroni test for inter-group comparison.Results:The results showed that the greatest penetration into dentinal tubules was by EndoREZ sealer (525.2 μ, 327.802 μ and 198.36 μ at cervical, middle and apical third), followed by Epiphany sealer (479.7 μ, 297.212 μ, and 182.22 μ), and the least penetration was seen with AH Plus sealer (224.2 μ, 65.419 μ, and 40.7 μ). The penetration of sealer into the dentinal tubules was statistically significant between each group at each level and between different levels within each group (P<.05).Conclusion:The penetration depth of EndoREZ and Epiphany into the dentinal tubules is significantly greater than that of AH Plus.

This study evaluated the influence of fiber inserts, type of composites, and location of the gingival seat on microleakage in Class II resin composite restorations. Fifty noncarious human third molars were selected for the study. Standardized Class II box type cavities were prepared on the mesial and distal side of 45 teeth. The gingival margin was placed above the cementoenamel junction (CEJ) on the mesial side and below the CEJ on the distal side. The remaining five teeth received no cavity preparations. The prepared samples were divided randomly on the basis of type of composite and presence or absence of fiber inserts, into four experimental groups of 10 teeth each and two control groups of five teeth each. The groups were defined as follows: group I (n=10) - Z350 XT; group II (n=10) - Z350 XT with fibers; group III (n=10) - P90; group IV (n=10) - P90 with fibers; and group V (n=5) - positive controls, cavities were not restored; group VI (n=5) - negative controls, no cavities were prepared. The samples were stored in distilled water in incubator at 37°C for 24 hours and then subjected to 500 cycles of thermocycling (5°C and 55°C) with a dwell time of 15 seconds. They were then placed in a 2% methylene blue dye solution for 24 hours at 37°C. Samples were sectioned longitudinally and evaluated for microleakage at the occlusal and gingival margin under a stereomicroscope at 20× magnification. Kruskal-Wallis and Mann-Whitney U-tests were used to compare the mean leakage scores. Restorations with gingival margins in enamel showed significantly less microleakage. Significant reduction in microleakage was observed in groups restored with P90 composite than those restored with Z350 XT. No improvement in microleakage was observed with the use of fiber inserts (p>0.05).