The Effect of Adding Various Antibiotics on the Push-out Bond Strength of a Resin-based Sealer: An In Vitro Study.

AIM: This study aimed to compare the bond strength of AH Plus sealer to root canal dentin when used with or without various antibiotics including amoxicillin, clindamycin, and triple antibiotic mixture (TAM). MATERIALS AND METHODS: A total of 80 single-rooted extracted human teeth were instrumented and obturated with gutta-percha and four different sealer-antibiotic combinations (n = 20). Group I: AH Plus without any antibiotics, Group II: AH Plus with amoxicillin, Group III: AH Plus with clindamycin, and Group IV: AH Plus with TAM. After seven days, the roots were sectioned perpendicular to their long axis and 1 mm thick slices were obtained from the midroots. The specimens were subjected to a push-out bond strength test and failure modes were also evaluated. Data was analyzed using Kruskal-Wallis and Dunn's post hoc tests. RESULTS: Group IV had significantly higher bond strength compared to other groups (p ≤ 0.05). No significant differences were found between other groups. While the sealer-antibiotic groups predominantly showed cohesive failure modes, the control group displayed both cohesive and mixed failure modes. CONCLUSION: Within the limitations of this study, the addition of TAM increased the push-out bond strength of AH Plus. CLINICAL SIGNIFICANCE: Amoxicillin, clindamycin, or TAM can be added to AH Plus for increased antibacterial efficacy without concern about their effects on the bond strength of the sealer. How to cite this article: Adl A, Shojaei NS, Ranjbar N. The Effect of Adding Various Antibiotics on the Push-out Bond Strength of a Resin-based Sealer: An In Vitro Study. J Contemp Dent Pract 2024;25(3):231-235.

The efficacy of EndoActivator, passive ultrasonic irrigation, and Ultra X in removing calcium hydroxide from root canals: an in-vitro study.

BACKGROUND: This study aimed to compare the efficacy of EndoActivator, passive ultrasonic irrigation, and Ultra X in removing calcium hydroxide from the artificial grooves in root canal walls. METHODS: The root canals of 50 extracted human maxillary incisors were instrumented by using the ProTaper rotary system up to #F4 (size 40/0.06 ProTaper) and the teeth were split longitudinally. Lateral grooves were created in the apical and coronal parts of one half and the middle part of the other half. Calcium hydroxide paste was applied to the grooves and the root halves were reassembled. After seven days, the calcium hydroxide was removed from the canal by using one of the EndoActivator, passive ultrasonic irrigation, and Ultra X devices; one group went without irrigation (control group). The CH remnants in the grooves were scored at 20× magnification. The data were analyzed by using the Kruskal-Wallis, Dunn's post hoc, and Friedman tests. P < 0.05 was considered to be statistically significant. RESULTS: No statistically significant difference existed among the experimental groups at the coronal and middle grooves (P > 0.05). However, Ultra X was significantly more effective than passive ultrasonic irrigation at the apical grooves (P = 0.023). CONCLUSION: Within the limitations of this study, Ultra X can be reported to remove the calcium hydroxide from the apical third more efficiently than passive ultrasonic irrigation.

Effect of triple antibiotic paste on the bond strength of epoxy and methacrylate resin-based sealers to root canal dentin.

Purpose: This study aimed to evaluate the effect of triple antibiotic paste (TAP) as an endodontic intracanal medicament on the bond strength of epoxy and methacrylate resin-based sealers to root canal dentin. Materials and Methods: In this in vitro study, 80 single-rooted human mandibular premolars were prepared using ProTaper rotary system. The specimens were randomly divided into a control group (without intracanal dressing) and an experimental group receiving TAP (n = 40). The intracanal dressing was removed after 3 weeks. Then, samples of each group were randomly divided into four subgroups (n = 10) and obturated with gutta-percha and different resin-based sealers. G1: AH Plus, G2: Syntex, G3: EndoREZ, and G4: MetaSEAL. After 1 week, 16 slices of 1 ± 0.1 mm thickness were obtained from the midroots of teeth in each subgroup, and a push-out test was used to measure the bond strength. Slices were examined using a stereomicroscope at 30 × to determine the mode of failure. The data were analyzed using two-way analysis of variance, one-way analysis of variance, and Tukey post hoc tests (α = 0.05). Results: Compared to control group, TAP significantly increased the bond strength of MetaSEAL and EndoREZ (P < 0.05). In the control group, epoxy resin-based sealers showed higher bond strength compared to methacrylate ones (P = 0.00). In TAP group, Syntex and EndoREZ showed significantly the greatest and the lowest bond strengths, respectively, (P < 0.05). The analysis of failure modes revealed a predominance of mixed failures in all groups except for Syntex group in which most failures were cohesive. Conclusions: TAP significantly increased the bond strength of methacrylate resin-based sealers.

Disinfection of dentinal tubules with diclofenac sodium and N-Acetylcysteine compared with calcium hydroxide as intracanal medicaments against Enterococcus faecalis.

The purpose of this study was to evaluate the disinfection of dentinal tubules with diclofenac sodium (DS), N-acetylcysteine (NAC) and calcium hydroxide (CH). Contaminated dentinal blocks were divided into two control and seven experimental groups (n = 15): CH, DS, NAC, CH + 5% DS, 50% CH + 50% DS, CH + 5% NAC and 50% CH + 50% NAC. After seven days, dentine debris was obtained from two depths of 100 and 200 µm. The bacterial load was assessed by counting the number of colony-forming units (CFUs). Pure DS exhibited maximum antibacterial activity at both depths. At 200 µm, it showed statistically significant differences with all the other groups (P < 0.05). Mixing CH with either 5% or 50% of DS and NAC did not increase the antibacterial efficacy (P > 0.05). Pure DS was most effective in disinfecting dentinal tubules, and mixing CH with DS or NAC is not recommended.

Influence of calcium hydroxide residues after using different irrigants on the accuracy of two electronic apex locators: An in vitro study.

BACKGROUND: The purpose of this study was to evaluate the effect of calcium hydroxide (Ca[OH] 2) residues on the accuracy of two electronic apex locators (EALs) (Root ZX and Raypex 6) in the presence of different irrigants. MATERIALS AND METHODS: In this an in vitro study Eighty single-rooted human mandibular premolars were selected. The crowns of the teeth were removed to standardize the working lengths (WLs). Actual WLs (AWLs) were recorded, and the root canals were shaped using protaper rotary instruments up to size F3. Then, the root canals were dried and filled with injectable Ca (OH) 2 paste and the access cavities were temporarily sealed. Teeth were put into four alginate boxes, including two experimental groups (n = 30) and two control groups (n = 10). The pools of alginate were wrapped in wet gazes and stored at 37°C and 100% humidity for 7 days. Then, the root canals were exposed and Ca (OH) 2 paste was removed by normal saline or 5.25% sodium hypochlorite irrigation followed by 17% ethylenediaminetetraacetic acid (EDTA), and the electronic WL (EWL) was measured by Root ZX and Raypex 6. Differences of EWL from AWL were calculated. Furthermore, the percentage of acceptable measurements (tolerance limit of ± 0.5 and ± 1 mm) was calculated for each apex locator. One-way ANOVA test with post hoc paired t-test and Chi-square test was used to analyze the data (P < 0.05). RESULTS: The results showed that there was no significant difference between the accuracy of two EALs and irrigants (P > 0.05). CONCLUSION: The present study revealed that no statistically significant differences were observed between the two apex locators after Ca(OH)2 paste removal with different irrigants.

Evaluation of the Dislodgement Resistance of a New Pozzolan-Based Cement (EndoSeal MTA) Compared to ProRoot MTA and Biodentine in the Presence and Absence of Blood.

INTRODUCTION: This in vitro study investigated the dislodgement resistance of EndoSeal MTA, a new pozzolan-containing calcium silicate-based material, in comparison with ProRoot MTA and Biodentine in the presence and absence of contamination with blood. METHODS: Standard furcal perforations were created in 180 human mandibular first molars. The teeth were randomly allocated to 12 groups of 15 each. ProRoot MTA, Biodentine, and EndoSeal MTA were used to repair the perforations. In half of the samples, the walls of the perforated areas were contaminated with blood, whereas saline was injected into the other half. A push-out test was performed using a universal testing machine after 24 hours or 7 days. To evaluate failure patterns, the samples were split into half and were examined under a stereomicroscope at a 20x magnification. Data were analyzed using three-way analysis of variance, Tukey test, and Student's t-test. RESULTS: At both time intervals and in the presence and absence of contamination with blood, ProRoot MTA and Biodentine had significantly higher retention values than EndoSeal MTA (p < 0.001). Contamination with blood had no effect on EndoSeal MTA; however, it negatively affected the dislodgement resistance of Biodentine at 24 hours and ProRoot MTA at both time intervals (p < 0.05). Time significantly affected only the bond strength of the uncontaminated groups (p > 0.001). The most common type of failure was mixed for ProRoot MTA and Biodentine, whereas it was cohesive for EndoSeal MTA. CONCLUSIONS: ProRoot MTA and Biodentine showed higher values of bond strength than EndoSeal MTA and may thus be better options for the repair of root perforations.

Assessment of tooth discoloration induced by biodentine and white mineral trioxide aggregate in the presence of blood.

INTRODUCTION: In clinical dental application, using silicate-based cements is extremely popular. These materials come into direct contact with blood during or after placement and may cause tooth discoloration. OBJECTIVES: The purpose of this study was to compare the coronal tooth discoloration induced by white mineral trioxide aggregate (MTA) and biodentine in the presence of blood. MATERIALS AND METHODS: Seventy specimens were chemomechanically prepared and divided into four experimental and two control groups. In the experimental groups, the pulp chambers were filled with white MTA angelus or biodentine. Blood or saline saturated cotton pellets were placed within the canals. Saline or blood alone was used in the control groups. Color was assessed with a spectrophotometer at baseline, 1 week, and 1 and 3 months, and color change values were calculated. Tukey's honestly significant difference and Sidak tests were used for statistical analysis. RESULTS: The color change was significantly less with biodentine/saline than MTA/saline and MTA/blood (P < 0.05). Regardless of the material type and blood presence, discoloration increased after 3 months (P < 0.05). CONCLUSION: Discoloration induced by biodentine/saline may not be clinically noticeable and it was less than MTA-containing groups. Irrespective of blood presence or absence, MTA caused perceptible color change.

Effect of Different Water-to-powder Ratios on the Solubility and Microhardness of Calcium-Enriched Mixture Cement.

Introduction: The aim of this study was to evaluate the effect of different water-to-powder (WP) proportions on the microhardness and water solubility of calcium-enriched mixture (CEM) cement. Methods and Materials: One gram of CEM cement powder was mixed with 0.33 mL, 0.4 mL or 0.5 mL CEM liquid. For water solubility, a total of 60 specimens were prepared (n=20 per each ratio) in the disk-shaped stainless-steel molds with a height of 1.5±0.1 mm and internal diameter of 10.0±0.1 mm. The specimens of each WP ratio were randomly divided into two subgroups: half (n=10) were immersed for one day and the other half (n=10), were kept for 21 days in distilled water. The solubility was calculated as a percentage of the weight loss. To measure microhardness, a total of 30 samples were prepared (10 per each ratio, n=10). The mixtures were transferred to metallic cylindrical molds with internal dimensions of 6±0.1 mm height and 4±0.1 mm diameters. After 4 days the specimens were subjected to Vicker's test. The data were analyzed using two-way ANOVA and post-hoc Tukey's tests at a significance level of 0.05. Results: The 0.33 WP ratio showed significantly greater microhardness value (25.98±2.77) compared to 0.4 and 0.5 proportions (P=0.004 and P<0.001 respectively). Significant differences were observed between water solubility values of different WP ratios at both time intervals (P<0.001). At both time intervals, 0.33 and 0.5 WP ratios exhibited the lowest and highest solubility, respectively. Conclusion: According to the results of this in vitro study, higher WP ratios result in lower microhardness and higher water solubility of the CEM cement. Therefore, the 0.33 WP ratio would be the ideal proportion.

Effect of a New Imidazolium-based Silver Nanoparticle Irrigant on the Bond Strength of Epoxy Resin Sealer to Root Canal Dentine.

Introduction: The aim of this study was to evaluate the effect of a new imidazolium-based silver nanoparticle (ImSNP) root canal irrigant on the bond strength of AH-Plus sealer to root canal dentine. Methods and Materials: Forty single-rooted extracted human teeth were used in this study. The crowns were resected and according to the irrigation solutions used during root canal preparation, the roots were divided into 5 groups (n=8): Group 1: normal saline (control group), Group 2: 2.5% Sodium Hypochlorite (NaOCl), Group 3: 2.5% NaOCl+17% ethylene diamin tetracetic acid (EDTA), Group 4: silver nanoparticles (AgNPs), Group 5: AgNPs +17% EDTA. After root canal instrumentation, the canals were filled with AH-Plus. Then, after 7 days, 2 or 3 dentine disks were obtained from the mid-root of each sample. Bond strength was measured by the push-out test. Additionally, failure patterns were classified as adhesive, cohesive and mixed. Data were statistically analyzed by one-way ANOVA and Tamhane post hoc tests. The level of significance was set at 0.05. Results: There was no statistically significant differences between groups (P>0.05). Groups 4 (AgNPs), 3 (2.5% NaOCl+17% EDTA) and 2 (2.5% NaOCl) showed statistically higher bond strength compared to group 1 (control group) (P<0.05). Also, Group 4 showed a significant difference with group 5 (AgNPs+17% EDTA) (P=0.017). The failure patterns were mainly cohesive. Conclusion: This in vitro study showed that, when used without EDTA, AgNPs improved the bond strength of AH-Plus to radicular dentine.

Effect of Propylene Glycol on the Bond Strength of Two Endodontic Cements.

Introduction: This study evaluated the effect of propylene glycol (PG) on the push-out bond strength of calcium-enriched mixture (CEM) cement compared to mineral trioxide aggregate (MTA). Methods and Materials: The lumens of two hundred 2±0.2 mm-thick root sections from human extracted teeth were prepared to achieve a diameter of 1.3 mm. The samples were then allocated into eight groups of 25 on the basis of the materials used (MTA or CEM cement) and different proportions of PG (0%, 20%, 505, and 100%). In each group, 0.4 mL of the liquid was mixed with 1 g MTA or CEM cement. After incubation, the push-out strength of the samples was measured using a universal testing machine. Data were analyzed using the two-way ANOVA followed by one-way ANOVA and student's t-test. Results: The MTA group showed significantly higher bond strength in comparison with CEM group (P≤0.001). Also 100% and 20% PG increased the bond strength of MTA (P≤0.001). For CEM cement, 100% and 50% PG decreased the bond strength (P≤0.001). Conclusion: This in vitro study demonstrated that while PG increased the push-out bond strength of MTA, it is not recommended for mixing with CEM cement.

Effect of Different Water-to-Powder Ratios on the Compressive Strength of Calcium-enriched Mixture Cement.

INTRODUCTION: Calcium-enriched Mixture (CEM) cement is an endodontic reparative material available in the form of powder and liquid. The purpose of this in vitro study was to determine the effect of different water-to-powder (WP) proportions on the compressive strength (CS) of the cement. METHOD MATERIALS AND: One gram of CEM cement powder was mixed with either 0.33 g, 0.4 g or 0.5 g CEM liquid. The mixture was transferred to metallic cylindrical molds (n=10) with internal dimensions of 6±0.1 mm height and 4 ±0.1 mm diameter. After 4 days, the specimens were subjected to compressive strength tests using a universal testing machine. The data were analyzed by One-way ANOVA and Tukey's tests at a significance level of 0.05. RESULTS: Statically significant difference was found among experimental groups (P<0.05). The 0.33 WP ratio showed significantly greater CS value compared to 0.4 and 0.5 proportions (P=0.012 and P=0.000, respectively). The CS of 0.4 WP ratio was also significantly higher than that of 0.5 WP ratio (P=0.014). CONCLUSION: According to the results, higher WP ratios results in lower CS of the cement.

Physical and Chemical Properties of CEM Cement Mixed with Propylene Glycol.

INTRODUCTION: the aim of the present study was to evaluate the influence of propylene glycol (PG) on the flowability, microhardness, pH and calcium ion release of calcium-enriched mixture (CEM). METHODS AND MATERIALS: CEM cement was mixed with different proportions of PG, as follows: group 1,100% CEM liquid (CL); group 2, 100% PG; group 3, 50% PG and group 4, 20% PG. For assessment of flowability, methodology of ADA Specification No. 57 was applied. For measuring microhardness, 80 cylindrical molds (6×4 mm) were filled with CEM cement and divided into 2 subgroups (4, 21 days) and tested using Vickers Test. Data were analyzed using the one-way ANOVA test and Tukey's post hoc and student's t test. In order to check pH and calcium release, the mixed cements were placed in cylindrical molds (5×2 mm). After 3, 24, 72 and 168 h, pH determined by a pH meter and the calcium release was measured by an atomic absorption spectrophotometer. Data were analyzed using the repeated measure ANOVA, one way ANOVA test and Tuckey's post hoc test. RESULTS: The present study showed that the presence of PG did not affect the flowability. With the elapse of time, microhardness was significantly increased in all groups except CL group. Regardless of time, samples with 50% PG showed the lowest pH value which was significantly different from other groups (P<0.05) and samples with 100% and 20% PG showed significantly higher calcium ion release compared to other group. CONCLUSION: addition of PG did not have any positive or negative effect on the flowability and pH of CEM cement but increased its microhardness in long term. Calcium ion release also increased in the concentration of 20% and 100%.

Compressive Strength of Mineral Trioxide Aggregate and Calcium-enriched Mixture Cement Mixed with Propylene Glycol.

INTRODUCTION: The aim of the present study was to evaluate and compare the compressive strength (CS) of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement when mixed with propylene glycol (PG). METHODS AND MATERIALS: Twenty four custom-made split molds with 5 holes in each were prepared. Molds were allocated into eight groups (n=15 holes) as follows: Groups 1,5: CEM and MTA mixed with PG (100%), Groups 2,6: CEM and MTA mixed with PG (20% )+CEM or MTA liquid (80%) respectively, Groups 3,7: CEM and MTA mixed with PG (50% )+CEM or MTA liquid (50% ) respectively, Groups 4,8: CEM and MTA mixed with CEM or MTA liquid respectively as control groups. All specimens were kept in 37°C in an incubator and the compressive strength was evaluated after 7 days. Data were analyzed using the Kruskal Wallis and Dunne tests. The level of significance was set at 0.05. RESULTS: In all concentration of PG, MTA samples showed better results than CEM cement. In CEM samples, adding 20% PG could significantly increase the compressive strength in comparison with control group and 100% PG (P=0.047 and P=0.011, respectively). In MTA samples, adding 100% and 50% PG significantly increased the compressive strength of the cement in comparison with control group (P=0.037 and, P=0.005, respectively). CONCLUSION: Considering the limitations of the present study, appropriate concentration of PG could improve the CS of MTA and CEM cement.

Effect of Propylene Glycol on the Sealing Ability of Mineral Trioxide Aggregate and Calcium-Enriched Mixture Cement Apical Barriers.

INTRODUCTION: Propylene glycol (PG) improves the handling, physical, and chemical properties of mineral trioxide aggregate (MTA). This study aimed to evaluate the effect of PG on the sealing ability of MTA and calcium-enriched mixture (CEM) apical barriers. METHODS AND MATERIALS: A total of 70 extracted human maxillary single-rooted teeth were prepared using ProTaper rotary system. The apical 3 mm of the root tips were resected and the root canals were enlarged with Peeso reamers up to #4, to create open apex teeth. The teeth were then randomly divided into four experimental (n=15) and two control (n=5) groups. Group1: MTA+ MTA liquid, group2; MTA+MTA liquid (80%) + PG (20%), group3; CEM+CEM liquid, group4; CEM+ liquid (80%) + PG (20%). Cements were mixed with their respective mixing agents and a 4-mm thick apical plug was fabricated. The microleakage was measured on day 1, 3, 7 and 21 using a fluid filtration technique. The repeated measures ANOVA and Sidak test were used to analyze the data. RESULTS: All experimental groups demonstrated various amounts of microleakage. No significant difference was found between MTA and CEM cement (P=0.193), regardless of time and liquid components. There was no significant difference was observed between liquids (P=0.312) in all time intervals. The rate of microleakage decreased over time and a significant differences was observed between all intervals (P<0.05), except 3-7 and 7-21 (P=0.190) days. CONCLUSION: PG demonstrated neither a positive nor a negative effect on the sealing ability of Angelus MTA and CEM cement.

Success Rate and Time for Bypassing the Fractured Segments of Four NiTi Rotary Instruments.

INTRODUCTION: The aim of this in vitro study was to compare the success rate and time required for bypassing the fractured segments of four different nickel-titanium (NiTi) rotary systems. METHODS AND MATERIALS: This study was conducted on the mesiobuccal canals of 60 mandibular molars with fully-formed apices. Fifteen Flex Master, K3, RaCe and Hero Shaper instruments with 0.04 taper and tip size of #30 and 25 mm in length, were obtained. These instruments were notched at a point 3 mm from the tip of the instrument and were driven into the canals using a handpiece until the instruments fractured and became lodged therein. In the next step, an endodontist tried to bypass the fractured segment using K-files. The number of bypassed samples and the time required for bypassing of each sample were recorded. The Chi-square test was used to compare the bypassing rate among the experimental groups. One-way analysis of variance followed by Tukey's post hoc test was conducted to compare the time taken for bypassing of the fractured fragments. RESULTS: One instrument in Flex Master group and two broken segments in each of the K3 and Hero groups were not bypassed. All of the samples in RaCe group were bypassed. No significant difference was found among four tested groups regarding rate of bypassing (P=0.738). The time taken to bypass fragments in the Hero group was significantly more than in those of K3 (P=0.047) and RaCe (P=0.024). CONCLUSION: Under the limitations of this study, design features of rotary files can influence the time needed to bypass separated fragments.

Diagnosis and Treatment of a Type III Dens Invagination Using Cone-Beam Computed Tomography.

A 20-year-old man presented with the history of pain and swelling in the anterior maxillary segment. The periapical radiography was indicative of a dental anomaly in right maxillary lateral incisor. Due to the insufficient information from conventional radiography, cone-beam computed tomography (CBCT) was ordered. CBCT showed apical root resorption, large apical lucency and two separate canals with distinct apical foramen (Oehlers type III dens invagination). The CBCT image was used as a guide for dentine removal with an ultrasonic tip. Conventional root canal therapy was done using lateral compaction technique. One-and two-year follow-up radiographies revealed periapical repair and absence of symptoms.

In Vitro Evaluation of Different Solvents for Retrieval of Mineral Trioxide Aggregate and Calcium-Enriched Mixture.

INTRODUCTION: The purpose of this study was to evaluate the effect of different solvents; carbonic acid (H2CO3), hydrochloric acid (HCl), chlorhexidine (CHX) and sodium hypochlorite (NaOCl) on the surface hardness of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement. METHODS AND MATERIALS: Plexiglass molds were prepared and filled with Angelus MTA or CEM cement and then exposed to 2% carbonic acid, 37% hydrochloric acid, 2% chlorhexidine, 5.25% sodium hypochlorite and normal saline at intervals of 1 and 21 days, respectively (n=4). Surface microhardness of all specimens was analyzed by a universal testing machine and an electron microscope for some selected samples. Data were analyzed using the three-way ANOVA. Subgroup analysis was performed by Student's t-test, One-way ANOVA and Tukey's tests. The level of significance was set at 0.05. RESULTS: On the first day, all solvents and on 21(st) day HCl, and H2CO3 were more effective in reducing the microhardness of MTA compared to CEM cement (P<0.05). CONCLUSION: The two experimental cements were differently affected by the solvents at specific time intervals. The solvents were more effective on MTA.

The Effect of Various Mixing Techniques on the Push-Out Bond Strength of Calcium Enriched Mixture.

STATEMENT OF THE PROBLEM: Correct proportioning and mixing are essential to ensure cements attain their optimum physical properties. PURPOSE: The aim of this experimental study was to evaluate the influence of various mixing techniques including manual, mechanical mixing, and ultrasonic vibration on push-out bond strength of calcium enriched mixture (CEM). MATERIALS AND METHOD: Ninety 2-mm-thick dentin disks were prepared from single-rooted human teeth and filled with CEM mixed with manual, trituration, or ultrasonic methods. Push-out bond strength values of the specimens were measured by a universal testing machine after 3 and 21 days. The samples were then examined under a stereomicroscope at 40× magnification to determine the nature of bond failure. Data were analyzed by Kruskal-Wallis and Mann-Whitney test. (p< 0.05). RESULTS: The highest (7.59 MPa) and lowest (4.01 MPa) bond strength values were recorded in conventional method (after 21 days) and trituration method (after 3 days), respectively. There was no statistically significant difference between the three techniques in 3 and 21 days. CONCLUSION: According to the results, various mixing techniques had no effect on the push-out bond strength of CEM cement.

In vitro comparison of antimicrobial effect of sodium hypochlorite solution and Zataria multiflora essential oil as irrigants in root canals contaminated with Candida albicans.

INTRODUCTION: This study compared the antifungal effect of Zataria multiflora essential oil (EO) with that of sodium hypochlorite (NaOCl) as an irrigant for root canals infected with Candida albicans. MATERIALS AND METHODS: Sixty mandibular premolars were infected with C. albicans suspension. After 72 h of incubation, the samples were divided into four groups. Teeth in Group 1 were irrigated with minimum fungicidal concentration (MFC) of Z. multiflora EO, in Group 2 with twice the MFC of Z. multiflora, in Group 3 with MFC of NaOCl, and in Group 4 with distilled water (DW). Pre- and post-operative samples were cultured, and fungal colony count of each specimen was obtained. Data were analyzed using Kruskal-Wallis and Mann-Whitney tests (P < 0.05). RESULTS: NaOCl at MFC and Z. multiflora EO at twice the MFC showed the highest antifungal efficacy, with no significant difference (P > 0.05). However, antifungal efficacies of these irrigants were significantly different from those of Z. multiflora EO at MFC and DW (P < 0.05). CONCLUSION: Our results showed that Z. multiflora EO at twice the MFC had the same antifungal efficacy as NaOCl at MFC.

Root canal treatment of a hypertaurodont mandibular second molar: a case report.

Taurodontism is a morphologic feature of generally multi-rooted teeth with large pulp chambers and shortened roots. A case of endodontic treatment in a 24-year-old male with the chief complaint of swelling and pain in the right mandibular region is described. Periapical lesion was present in the radiographic examination of hypertaurodont second mandibular molar.Four root canals were detected with an endodontic microscope. The canals were prepared and obturated with lateral condensation technique in the second appointment. The patient was asymptomatic in the 18-month follow-up.