The Efficacy of Different Antibiotic Compounds in Regenerative Treatment of Immature Necrotic Teeth.

Objectives: Endodontic treatment of immature teeth poses a significant challenge, especially in achieving a proper seal using traditional obturation methods. Revascularization presents itself as an alternative approach to this problem, and the application of triple antibiotic paste (TAP) has been suggested as a means to achieve disinfection during the procedure. This study aims to compare the antibacterial properties of three different antibiotic combinations to assess their effectiveness on root canal disinfection. Materials and Methods: Eighty samples were employed to assess the impact of three antibiotic combinations on Enterococcus faecalis, Escherichia coli, Streptococcus mutans, and a combination thereof. The antibiotics included metronidazole, ciprofloxacin, and cefaclor (CCM), the commonly used TAP, and a double antibiotic paste (DAP) composed of metronidazole and ciprofloxacin. Dentin shavings collected using Gates-Glidden drills were placed in microtubes containing a 2ml standard bacterial suspension. Microtube contents were diluted and cultured on BHI agar plates, with colony counts calculated based on dentine shavings' weight in CFU/mg. Kruskal-Wallis and Dunn's post-hoc tests were used for statistical analysis and P<0.05 was considered significant. Results: A significant difference in mean CFU was observed among all bacterial groups (P<0.05). Dunn's post-hoc analysis showed a significant difference only between the control group (methylcellulose) and the other antibiotic groups. There was no significant difference between the other antibiotic groups in two-by-two comparisons. Conclusion: There was no significant difference in the antimicrobial properties of DAP, TAP and CCM. Therefore, DAP and CCM may be used during regenerative treatment.

Post-treatment Flare-up Incidence after Using Nano Zinc Oxide Eugenol Sealer in Mandibular First Molars with Irreversible Pulpitis.

STATEMENT OF THE PROBLEM: Some patients may report moderate-to-severe pain and/or swelling following root canal treatment, which is undesirable for both the patient and dentist and may require an unscheduled emergency visit by patients to relieve their symptoms. PURPOSE: The aim of this study was to evaluate the post-treatment flare-up incidence following application of nano zinc oxide-eugenol (NZOE) sealer in mandibular first molars with irreversible pulpitis. MATERIALS AND METHOD: This single-blinded study was performed on 60 patients having mandibular first molars with irreversible pulpitis. After signing the written consent form, the patients were randomly divided into two groups considering their age range (20-34 and 35-50 years). Individuals without systemic diseases and with a first mandibular molar diagnosed with irreversible pulpitis due to caries, no sinus track and abscess, normal periapical radiographic appearance, no spontaneous pre-treatment pain, not taken any medication for at least 8 hours before the treatment visit were included in this study. Patients of both sexes with age range of 20 to 50 years were selected. In order to obturate the root canal space, AH26 sealer was used in the one group and the synthesized NZOE was applied in another group. The patients were then given questionnaires to report the severity of pain and presence of swelling during 6, 18, 24, and 48 hours of follow-up. The data was analyzed using SPSS v.19 software applying repeated measures ANOVA. The significance level was set at 0.05. RESULTS: The severity of pain was significantly lower in NZOE group at 24 hours post-treatment (p= 0.003). Patients reported no symptoms of swelling in any group. CONCLUSION: NZOE sealer manifested satisfactory results and could be regarded as a promising substitute to routine sealers since patients may experience less pain during the first hours after receiving root canal therapy.

Experimental Evaluation of the Effect of Zinc Salt on Inhibition of Streptococcus mutans.

STATEMENT OF THE PROBLEM: The rate of antibiotic resistance in bacteria and side effects of antibiotics and oral and teeth health care products are increasing. Therefore, researchers aim at finding new alternatives to control bacteria of dental caries. PURPOSE: The objective of this study was to investigate the inhibitory and bactericidal effects of different concentrations of zinc sulfate and zinc acetate solutions on the main recognized agent of dental caries, Streptococcus mutans. MATERIALS AND METHOD: In this experimental study, different concentrations of aqueous zinc sulfate and zinc acetate solutions were prepared and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these salts for Streptococcus mutans were determined in compare with penicillin, chlorhexidine by micro-serial dilution method. In addition, the diameters of zone of inhibition for these salt solutions in four concentrations along with chlorhexidine, as the control, were detected by the disc diffusion method. RESULTS: MIC and MBC of zinc sulfate solution were higher than penicillin and chlorhexidine. There were not statistically significant differences between the MIC and MBC of zinc acetate solution, penicillin, and chlorhexidine. In 25 and 50 µg/mL concentrations, the diameters of inhibition zone for zinc sulfate were more than zinc ac. CONCLUSION: Zinc sulfate and zinc acetate salts with 37.19 and 31.25 µgr/mL concentration had inhibitory effect on Streptococcus mutans growth respectively, although, no priority in antibacterial activity of the studied zinc salts was determined in comparison with penicillin and chlorhexidine.

In Vitro Cytotoxicity of a New Nano Root Canal Sealer on Human Gingival Fibroblasts.

INTRODUCTION: The aim of this in vitro study was to evaluate the cytotoxicity of a new nano zinc-oxide eugenol (NZOE) sealer on human gingival fibroblasts (HGFs) compared with Pulpdent (micro-sized ZOE sealer) and AH-26 (resin-based sealer). METHODS AND MATERIALS: The Pulpdent, AH-26, and NZOE sealers were prepared and exposed to cell culture media immediately after setting, and 24 h and one week after setting. Then, the primary cultured HGFs were incubated for 24 h with different dilutions (1:1 to 1:32) of each sealer extract. Cell viability was evaluated by methyl thiazolyl diphenyl tetrazolium bromide (MTT) assay. The results were compared using two-way analysis of variance followed by Tukey's post hoc test. The level of significance was set at 0.05. RESULTS: All sealer extracts, up to 32 times dilutions, showed cytotoxicity when exposed to HGF immediately after setting. The extracts obtained 24 h or one week after setting showed lower cytotoxicity than extracts obtained immediately after setting. At all setting times, NZOE showed lower cytotoxicity than Pulpdent and AH-26. While one-week extracts of NZOE had no significant effect on the viability of HGF at dilutions 1:4 to 1:32, both Pulpdent and AH-26 decreased the cell viability at dilutions of 1:4 and 1:8. CONCLUSION: NZOE exhibited lower cytotoxicity compared to Pulpdent and AH-26 on HGF and has the potential to be considered as a new root canal filling material.

Evaluation of the expression of VIII factor and VEGF in the regeneration of non-vital teeth in dogs using propolis.

OBJECTIVES: The purpose of the present study was the immunohistochemical evaluation of VEGF and VII factors in dog's teeth pulp revascularized with MTA and propolis. MATERIALS AND METHODS: 144 mature and immature two rooted dog's premolar canals were selected. Pulp necrosis and infection were established after 2 weeks and the disinfection of the canals was done with copious NaOCl irrigation and triantibiotic mixture (ciprofloxacin, metronidazole, and minocycline) for 3 weeks. Subsequently, the blood clot was evoked in the canal by periapical tissue irritation with a k-file. The samples were randomly divided into 6 experimental groups: propolis (groups 1, 2), MTA (groups 3, 4), and parafilm (groups 5, 6) in immature and mature teeth. The animals were sacrificed and samples were prepared for immunohistochemical evaluation of VEGF and the VIII factor. RESULTS: Tissue regeneration was seen in 64.5% of MTA, 38% of propolis, and 0% of parafilm group samples. Expression of VEGF and VIII factor in the propolis group was more than the MTA group and it showed a reduction after 3 months in comparison to 1 month. VEGF and VIII factor were seen in stromal cells in addition to endothelial vessel cells. Overall, expression of angiogenic factors was more in the open apex teeth compared to close apex ones. CONCLUSION: According to the results of this study, propolis can induce the expression of VEGF and VIII factor in infected mature and immature dog's teeth and is a suitable biomaterial for the revascularization technique.

Subcutaneous Connective Tissue Reaction to a New Nano Zinc-Oxide Eugenol Sealer in Rat Model.

INTRODUCTION: The aim of this animal study was to evaluate the histological response of the new nano zinc-oxide eugenol (NZOE) sealer in comparison with Pulp Canal Sealer (ZOE based) and AH-26 (epoxy resin sealer). METHODS AND MATERIALS: A total of 27 Wistar rats were used. Four polyethylene tubes were implanted in the back of each rat (three tubes containing the test materials and an empty tube as a control). Then, 9 animals were sacrificed at each interval of 15, 30 and 60 days, and the implants were removed with the surrounding tissues.Samples were evaluated for the presence of inflammatory cell (mononuclear cell), vascular changes, fibrous tissue formation and present of giant cell. Comparisons between groups and time-periods were performed using the Kruskal-Wallis and Mann-Whitney U non-parametric tests. The level of significance was set at 0.05. RESULTS: No significant difference was observed in tissue reactions and biocompatibility pattern of three sealers during 3 experimental periods (P<0.05). In all groups the tissue behavior showed tendency to decrease the irritation effect over time. Conclusion: The new nano zinc-oxide eugenol sealer has histocompatibility properties comparable to conventional commercial sealers.

Tooth Discoloration Resulting from a Nano Zinc Oxide-Eugenol Sealer.

INTRODUCTION: A desirable quality of any endodontic sealer is its ability to be tooth color friendly. Therefore the aim of the present study was to evaluate the tooth discoloration potential of a nano zinc oxide-eugenol (NZOE) sealer. METHODS AND MATERIALS: In order to evaluate tooth discoloration, the pulp chamber of 60 human maxillary central and lateral incisors were filled with one of the sealers, naming AH-26 (resin-based sealer), Pulpdent sealer (ZOE-based) and a NZOE experimental sealer. Color measurements was assessed at the baseline (before placement of sealers) (T0), 24 h (T1) and 72 h (T2) h, 1-week (T3), and 1-month (T4) after the placement of sealers using the Easy Shade spectrophotometer. Data were analyzed in SPSS software using one-way ANOVA, and repeated measured ANOVA. RESULTS: No significant differences were observed when the paired comparison test was performed (P>0.05). CONCLUSION: The tested NZOE sealer had similar tooth discoloration potential in comparison with AH-26 and ZOE sealer.

Tissue Reaction to Different Types of Calcium Hydroxide Paste in Rat.

The purpose of this study was to compare the biocompatibility of two types of calcium hydroxide paste in subcutaneous tissue in rat. Twenty-two Wistar rats were divided into 4 experimental (n=5 each) and one control (n=2) group. A polyethylene tube filled with either Dentsply or Sure-Paste was implanted in each rat in the experimental groups, while an empty polyethylene tube was used in the control group. After 15 or 60 days, the animals were sacrificed and histopathological examination carried out. Tissue reaction was assessed by inflammatory cell infiltration using a 4-point scoring system, ranging from 0 to 3. Data were analyzed with the Kruskal-Wallis, Wilcoxon, and McNemar tests. Both types of paste induced an inflammatory response at each time point, although the intensity varied. A significant reduction in the number of inflammatory cells was observed at 60 days. Dentsply appeared to induce a more marked inflammatory response at both time points, although the difference was not significant. These results suggest that both types of paste are biocompatible with subcutaneous tissue in rat.

Influence of Root Canal Tapering on Smear Layer Removal.

The purpose of the study presented here was to compare the influence of root canal taper on the efficacy of irrigants and chelating agents in smear layer removal. Eighty mesial roots of molar teeth were selected and prepared with rotary instruments. In group A, file 30/0.02 and in group B, file 30/0.4 were placed at working length and the smear layer was removed. In groups C and D, root canal preparation was the same as in groups A and B, respectively, except that the smear layer was not removed. The amount of the smear layer was quantified using a scanning electron microscope. Greater smear layer was detected in the apical portion of each group, whereas no significant difference was detected between groups in other portions. No statistical difference was found between canals with different tapers.

Cytotoxicity of a New Nano Zinc-Oxide Eugenol Sealer on Murine Fibroblasts.

INTRODUCTION: The aim of this study was to evaluate the cytotoxicity of a new nano zinc-oxide eugenol (NZOE) sealer in comparison with AH-26 and Pulpdent root canal sealers. METHODS AND MATERIALS: The L929 mouse fibroblast cells were cultivated and incubated for 24, 48 or 72 h with different dilutions (1/1, 1/2, 1/4, 1/8, 1/16 and 1/32) of culture media previously exposed to either of the test sealers naming NZOE, AH-26 or Pulpdent. At the end of incubation period, the effect of sealers on cell viability was evaluated using Mosmann's Tetrazolium Toxicity (MTT) colorimetric assay. The data was compared using the one-way analysis of variance (ANOVA) followed by the Tukey's post hoc test for multiple comparisons. RESULTS: After 24, 48 or 72 h, both NZOE and Pulpdent sealers inhibited cell viability at 1/1, 1/2 and 1/8 dilutions. Within the 24 and 48 h, the AH-26 sealer reduced the cell viability at all dilutions except the 1/32 solution; however after 72 h even the 1/32 dilution was cytotoxic. CONCLUSION: The biocompatibility of the nano zinc-oxide eugenol sealer was comparable to Pulpdent sealer and lower than AH-26.

In Vitro Evaluation of Apical Sealing Ability of HEROfill® Obturator Versus Cold Lateral Condensation in Curved Root Canals.

OBJECTIVES: This study aimed to assess and compare the apical sealing ability of HEROfill® Soft-Core system and lateral condensation technique in fine curved canals using the fluid filtration method. MATERIALS AND METHODS: Forty human mesiobuccal root canals of mandibular first molars with 25° to 40° curvatures were instrumented to an apical size 30/0.04. Roots were randomly assigned to two experimental groups of 15, designated as groups A and B. Two control groups, each containing five teeth, served as positive and negative controls. Group A was obturated using lateral condensation technique and group B with the HEROfill® Soft-Core system. The groups were tested for microleakage using an in vitro fluid filtration apparatus with 0.5 atm pressure at zero, two, four, six, eight and 10 minutes. Independent t-test was used to analyze the microleakage data. RESULTS: The mean and standard deviation (SD) values for fluid microleakage in the lateral condensation group were 0.58±0.49 µL/min, 0.68±0.35 µL/min, 0.74±0.22 µL/min, 0.71±0.29 µL/min and 0.60± 0.29 µL/min at two, four, six, eight and 10 minutes, respectively. The mean and SD values for fluid microleakage in the HEROfill® group were 0.53±0.42 µL/min, 0.67±0.34 µL/min, 0.69±0.26 µL/min, 0.73±0.33 µL/min and 0.63±0.26 µL/min at two, four, six, eight and 10 minutes, respectively. The difference between the lateral condensation and HEROfill® groups was not statistically significant at two (P=0.776), four (P=0.909), six (P=0.562), eight (P=0.861) or 10 (P=0.765) minutes. CONCLUSION: The HEROfill® system and cold lateral condensation technique were equally effective for apical sealing of curved canals.

Efficacy of a combined nanoparticulate/calcium hydroxide root canal medication on elimination of Enterococcus faecalis.

The purpose of this study was to evaluate the efficacy of Ca(OH)2 with or without a silver nanoparticle suspension to eliminate Enterococcus faecalis from root canals. A total of 66 extracted human single-rooted teeth contaminated with E. faecalis were treated with 10% Ca(OH)2 alone, Ca(OH)2 with nanosilver or sterile water (as a negative control). Samples were obtained with paper points and Gates-Glidden burs at 1 and 7 days after root canal preparation and the number of colony-forming units (CFU) was determined. The number of CFUs observed after dressing with Ca(OH)2 + nanosilver was significantly less than the number observed with Ca(OH)2 alone after 1 or 7 days (P < 0.001, P < 0.001). No differences in antimicrobial properties were observed between the two time points in the Ca(OH)2 + nanosilver group (P > 0.05). Higher antimicrobial efficacy was observed in the Ca(OH)2 group after 7 days than 1 day (P < 0.001). This study highlighted the potential advantage of using a mixture of Ca(OH)2 and nanosilver for intracanal medicament.

Zinc oxide nano-particles as sealer in endodontics and its sealing ability.

AIMS: The aim of this study was to evaluate the sealing ability of new experimental nano-ZOE-based sealer. SETTINGS AND DESIGN: Three types of nano-ZOE-based sealer (calcined at different temperatures of 500, 600 and 700°C) with two other commercially available sealers (AH26 and micro-sized zinc oxide eugenol sealer) were used. MATERIALS AND METHODS: Zinc oxide nano-particles were synthesized by a modified sol-gel method. The structure and morphology of the prepared powders were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The instrumented canals of 60 single-rooted teeth were divided into five groups (n = 10), with the remaining ten used as controls. The canals were filled with gutta-percha using one of the materials mentioned above as sealer. After 3, 45 and 90 days, the samples were connected to a fluid filtration system. STATISTICAL ANALYSIS USED: The data were analyzed using Student's t-test. RESULTS: The XRD patterns and TEM images revealed that all the synthesized powders had hexagonal wurtzite structures with an average particle size of about 30-60 nm at different calcination temperatures. Microleakage in AH26 groups was significantly more than that in three groups of ZnO nano-particles at all the three evaluation intervals. Apical microleakage of ZnO micro-powders was significantly more than that of all the materials, but the sealing ability of ZnO nano-powder sealers did not differ significantly. CONCLUSION: The results of this study showed that the synthesized ZnO nano-powder sealers are suitable for use as a nano-sealer in root canal therapy to prevent leakage; however, further studies should be carried out to verify their safety.

Comparison of air-driven vs electric torque control motors on canal centering ability by ProTaper NiTi rotary instruments.

AIM: Cleaning and shaping is one of the most important phases in root canal therapy. Various rotary NiTi systems minimize accidents and facilitate the shaping process. Todays NiTi files are used with air-driven and electric handpieces. This study compared the canal centering after instrumentation using the ProTaper system using Endo IT, electric torque-control motor, and NSK air-driven handpiece. MATERIALS AND METHODS: This ex vivo randomized controlled trial study involved 26 mesial mandibular root canals with 10 to 35° curvature. The roots were randomly divided into 2 groups of 13 canals each. The roots were mounted in an endodontic cube with acrylic resin, sectioned horizontally at 2, 6 and 10 mm from the apex and then reassembled. The canals were instrumented according to the manufacturer's instructions using ProTaper rotary files and electric torque-control motors (group 1) or air-driven handpieces (group 2). Photographs of the cross-sections included shots before and after instrumentation, and image analysis was performed using Photoshop software. The centering ability and canal transportation was also evaluated. Repeated measurement and independent t-test provided statistical analysis of canal transportation. RESULTS: The comparison of the rate of transportation toward internal or external walls between the two groups was not statistically significant (p = 0.62). Comparison of the rate of transportation of sections within one group was not significant (p = 0.28). CONCLUSION: Use of rotary NiTi file with either electric torquecontrol motor or air-driven handpiece had no effect on canal centering. CLINICAL SIGNIFICANCE: NiTi rotary instruments can be used with air-driven motors without any considerable changes in root canal anatomy, however it needs the clinician to be expert.

An in vitro evaluation of environmental pH changes after root canal therapy with three different types of calcium hydroxide.

OBJECTIVE: This study determined environmental pH changes after root canal dressing using 3 types of commercial calcium hydroxide pastes. METHODS: Thirty-two extracted single-rooted human premolars with 1 straight root canal were selected. Standard cavities were prepared on root surfaces. All root surfaces, excluding the cavities, were covered with nail polish. Root canals were prepared using the Easy RaCe rotary system. The teeth were randomly divided into 3 experimental groups filled with calcium hydroxide pastes: (Group 1) Sure-Paste, (Group 2) Meta-Paste, and (Group 3) Multi-Cal. The control group had 2 samples. Teeth were then placed in 10 mL of normal saline. Environmental pH values were measured at 1 h, 24 h, 48 h, and 1 week. Statistical evaluations of the results were performed via the ANOVA and Tukey tests. RESULTS: Results demonstrated that groups 3 and 1 showed a significant statistical difference (P<.001) with the pH being greater in group 3. There was no significant difference between groups 2 and 3 (P>.05). Intracanal placement of Multi-Cal compared with that of Sure-Paste and Meta-Paste resulted in a higher pH in simulated root resorption defects. CONCLUSION: In cases, like apexification, that need longer pH changes and higher disinfecting qualities, it might be better to use Multi-Cal, and for short-time use as disinfectant medicament Multi-Cal and Meta-Paste are equally effective.

Immunohistochemical expression of fibronectin and tenascin in human tooth pulp capped with mineral trioxide aggregate and a novel endodontic cement.

INTRODUCTION: The purpose of the present study was the immunohistochemical study of fibronectin (FN) and tenascin (TN) in human tooth pulp capped with mineral trioxide aggregate (MTA) and novel endodontic cement (NEC) (calcium enriched mixture cement) after 2 and 8 weeks. METHODS: Thirty-two premolar teeth that were scheduled for extraction for orthodontic reasons were exposed and capped with either MTA or NEC. The teeth were randomly divided into 4 groups: group 1 (NEC for 2 weeks), group 2 (NEC for 8 weeks), group 3 (MTA for 2 weeks), and group 4 (MTA for 8 weeks). After capping the exposed pulps with either NEC (groups 1 and 2) or MTA (groups 3 and 4), half of the specimens underwent extraction and were prepared for histologic and immunohistochemical evaluation for FN and TN after 2 weeks, and the remaining half were assessed after 8 weeks. FN and TN expression was scored by a blinded pathologist on a scale of I-IV, and the results were analyzed by the Wilcoxon and Mann-Whitney U statistical tests. RESULTS: FN and TN staining was observed in all 4 experimental groups, and there was no significant difference between expression of FN and TN in any groups. FN and TN staining was observed in the dentinal bridge matrix after 2 weeks under MTA. Expression of both markers reduced significantly after 8 weeks under MTA, and staining was observed only in unmineralized parts of dentinal bridge. FN and TN expression was observed in the matrix of the dentinal bridge after 2 weeks under NEC, and staining of both markers was reduced after 8 weeks compared with 2 weeks. The staining pattern of TN in NEC groups was higher than in MTA groups in both time intervals. However, the difference was not significant. CONCLUSIONS: The present study demonstrated that both MTA and NEC are suitable biomaterials for direct pulp capping and are able to stimulate dentinal bridge formation. Moreover, the role of FN and TN as 2 major components of the matrix of a reparative dentinal bridge was observed.

In-vitro evaluation of the effect of canal curvature on adaptation of gutta-percha in canals obturated with HEROfill system by CBCT.

A hermetic seal of the root canal space following canal preparation is important in endodontics. This study evaluated the effect of canal curve on adaptation of gutta-percha to dentinal walls of canals obturated using the Herofill system. For this in vitro study, 80 mesial roots of mature human first molars with length of 16 mm, curve between 5° and 45°, and no caries or resorption of the root surface were selected. A cone beam computed tomography system was used to evaluate the presence or absence of a gap in the samples. Photographs were taken in three sections: 2 mm above the curve, at the curve and 2 mm below the curve. The gap area was identified using Photoshop and AutoCAD software. Kruskal Wallis and Mann-Whitney tests were used to analyze the data mounted in a castcurve. There were significant differences between the two lateral condensation groups with various curves; roots with more curve had more gaps. When the Herofill and lateral condensation groups were compared without considering the sections and curve, there was a significant difference between these groups and the Herofill group had less gaps. The Herofill system is an alternative to the lateral condensation technique in severely curved canals.

Antibacterial effect of calcium hydroxide on intraluminal and intratubular enterococcus faecalis.

INTRODUCTION: Root canal treatment involves the elimination of intraradicular microorganisms. Calcium hydroxide [Ca(OH)(2)] is the most widely used canal dressing material. Enterococcus faecalis (E. faecalis) has been reported to be resistant to Ca(OH)(2) in-vivo. The purpose of this study was to evaluate the efficacy of Ca(OH)(2) on the elimination of intraluminal and intratubular E. faecalis. MATERIALS AND METHODS: Thirty six human single-rooted teeth were contaminated with E. faecalis. Thirty specimens in the experimental group were treated with 10% Ca(OH)(2); six specimens were treated with normal saline as the positive control (n=6). Specimens from experimental group were randomly divided into two subgroups of 15 each. In subgroup A, specimens were incubated and sampled after one day and in subgroup B, they were tested at day seven. Paper points and Gates Glidden burs were used to obtain the intraluminal and intratubular E. faecalis respectively. Samples obtained from these root canal preparations were analyzed for bacterial load by counting the number of colony forming units (CFUs). Mann-Whitney and t-test were used for analysis. RESULTS: Group B had significant decrease in CFUs compared with group A with both sampling methods (P<0.001). No differences were observed between the antimicrobial properties of Ca(OH)(2) against intraluminal and intratubular E. faecalis. After 1 week, there was a significant reduction in CFU load with Ca(OH)(2) intra canal medication. CONCLUSION: Ca(OH)(2) showed the same antimicrobial efficacy on intraluminal and intratubular E. faecalis.

The Effect of Blood on Apical Microleakage of Epiphany and AH26: An In Vitro Study.

UNLABELLED:   INTRODUCTION: Blood contamination of the canal during preparation can be a major problem in endodontics; this may result in apical microleakage. The aim of this in vitro study was to evaluate the effect of blood on apical microleakage of a resin-based root canal sealer (AH26) and a polymer-based root canal sealer (Epiphany). MATERIALS AND METHODS: In this experimental study, 50 decoronated central incisors and canine teeth were prepared by RaCe rotary system and randomly divided into 4 groups (n=10). Groups A1 and A2 were obturated by Epiphany/Resilon and AH26/Gutta-percha, respectively. The obturations were performed with a single cone technique after drying root canals. In B1 and B2 groups, the test groups, 0.02cc citrated human blood was injected into dried root canals and they were obturated in the same manner. Ten specimens were served as positive and negative controls (n=5).The apical leakage was measured by means of a computerized fluid filtration method after 1 day and 3 weeks. The data was analyzed by One-Sample Kolmogorov-Smirnov, Independent Sample t-test and univariate analysis. Statistical significances were preset at α=0.05. RESULTS: There was no significant difference in apical microleakage of the two sealers after 1 day and 3 weeks in dry and blood environment (P>0.05). Sealer and environment had no interaction (P>0.05). CONCLUSION: Blood contamination has no significant effect on the apical microleakage of Epiphny and AH26.

Histologic assessment of human pulp response to capping with mineral trioxide aggregate and a novel endodontic cement.

INTRODUCTION: This study was conducted to compare human pulp response to mineral trioxide aggregate (MTA) and a novel endodontic cement (NEC) when used as pulp capping materials after a time period of 2 and 8 weeks. METHODS: Thirty-two premolar teeth that were scheduled for extraction for orthodontic reasons were exposed and capped with either MTA or NEC. Half of the specimens underwent extraction and histologic analysis after 2 weeks, and the remaining half were assessed after 8 weeks. Each slide was graded histologically according to the morphology of the dentinal bridge, thickness of the dentinal bridge, presence of odontoblast cells, and inflammation of the pulp. RESULTS: Both MTA and NEC showed significantly better pulp response after 8 weeks compared with 2 weeks, with a thicker and more tubular pattern of the dentinal bridge, less pulp inflammation, and a palisade pattern of odontoblast cells. Although MTA and NEC groups had no significant difference in each measure in both time intervals, NEC induced a thicker dentinal bridge with less pulp inflammation at both 2 weeks and 8 weeks, compared with MTA. CONCLUSIONS: MTA and NEC showed similar biocompatibility and favorable response in pulp capping treatment and inducing the formation of the dentinal bridge.