Comparative Outcomes of Pulpotomy in Mature Molars with Irreversible Pulpitis: A Non-Randomized Trial Evaluating Calcified and Non-Calcified Pulp Chambers

Introduction

This non-randomized clinical trial investigated the outcomes of full pulpotomy in adult molars with irreversible pulpitis, comparing those with calcified and non-calcified pulp chambers over 6 and 12 months.

Materials and Methods

A total of 101 adult permanent molars with irreversible pulpitis, in individuals over 12 years old, were categorized based on pulp chamber calcification observed in radiographic images by two endodontists. Subsequently, full pulpotomy procedures were performed, achieving hemostasis, and applying a 2 mm layer of calcium-enriched mixture (CEM) cement as a pulp covering agent. After 48 hours, the setting of the CEM cement was verified, followed by the application of a layer of resin-modified glass-ionomer. The tooth was then restored using amalgam. Clinical and radiographic evaluations were conducted at 6-month and 1-year follow-ups by blinded endodontists. Success rates were compared using Fisher's exact test and logistic regression tests with a significance level of 0.05.

Results

Among the 97 patients with 6-month and 1-year follow-ups, all achieved clinical success. Radiographic success rates were 99% at 6 months and 96.9% at 1 year, regardless of pulp calcification. In the 6-month follow-up, success rates were 98.07% for non-calcified pulp chambers and 100% for calcified pulp chambers. At the 1-year follow-up, success rates were 96.1% and 97.8%, respectively. Statistical analysis showed no significant difference in radiographic success rate between the two groups at both follow-ups (P>0.05).

Conclusions

Full pulpotomy using CEM cement is a successful treatment for adult permanent teeth with calcified and non-calcified pulp chambers presenting signs and symptoms of irreversible pulpitis up to a 1-year follow-up. This study provides compelling evidence that vital pulp therapy can be effectively employed in the pulpotomy of calcified teeth, at least in the short term.

Microhardness of Calcium-enriched Mixture Cement and Covering Glass Ionomers after Different Time Periods of Application

Introduction

Various studies have recommended using calcium-enriched mixture (CEM) cement in different endodontic treatments, including vital pulp therapy. However, possible reciprocal effects of the covering glass ionomer cement (GIC) on their mechanical properties have not been yet investigated in detail. The current research aimed to experimentally evaluate the surface microhardness of CEM cement and the covering GICs after different application/testing times.

Materials and Methods

Using stainless steel moulds (8×4×4 mm), CEM cement samples were prepared (n=120) and randomly divided into 12 experimental groups (n=10). CEM cement with thickness of 4 mm was inserted into the moulds, and the remaining spaces were filled with self-cured or light-cured resin-modified GICs at three-time intervals; immediate, in 15 min and after 24 h. Then, the samples were incubated for one and seven days. Using a Vickers microhardness tester, the microhardness of CEM and GICs was measured. The data were analyzed using two-way ANOVA and Tukey's test, and the significance level was set at 5% (P<0.05).

Results

The reciprocal effects of the type/time of application of GICs on the surface microhardness of CEM cement or GICs were statistically significant (P<0.001). The surface microhardness of CEM cement and both covering GICs significantly increased over time and in seven-day samples was significantly higher than in one-day samples (P<0.05).

Conclusions

Low surface microhardness of CEM/GICs in short-term (24 h) seems transient; and appears to be compensated over a longer period (i.e. 7-day). Therefore, using GICs adjacent to CEM cement in single-visit restorative treatments may be advocated.

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 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.

Partial Necrosis Consequence of the Infection Spreading from an Adjacent Apical Periodontitis: A Case Report

As the dental pulp could not be directly inspected before endodontic treatment, indirect evaluation of the pulp status via (para)/clinical tests should be performed which need careful inspection. This report presents a root-treated right maxillary first molar with recurrent abscess formation and a radiolucent periradicular lesion surrounding the distobuccal root of the right maxillary second molar. The patient underwent surgical retreatment, employing CEM root-end filling, which resulted in no relief from sign/symptoms. In the cone-beam computed tomography (CBCT), the relationship of the lesion with the mesio-buccal root of the second maxillary molar was detected. Despite the latest tooth showed positive responses to pulp sensibility tests, endodontic therapy was planned for it. During treatment, it became clear that the mesiobuccal canal pulp was necrotic, although vital pulp tissues were present in two other root canals. Following treatment, full recovery from all discomforts was obtained and the lesion healed after 18 months. This case showed that a more complicated evaluation such as CBCT should be used for diagnosis of perpetuated lesions. Furthermore, it might be probable that root canals of vital teeth become necrotic due to involvement in the adjacent apical lesion, a phenomenon known as anachoresis.

Effect of the Bone Graft on the Surface Microhardness of Endodontic Biomaterials

Introduction

During periapical surgery, using of bone products in large endodontic lesions, is a treatment option that could affect the properties of the retro-filling endodontic material. The aim of present study was to evaluate the effect of Osteon II bone powder on the surface microhardness of calcium-enriched mixture (CEM) and mineral trioxide aggregate (MTA).

Methods and Materials

Each material was mixed and carried into 40 sterile custom-made plastic cylinders. Half of the samples in each group were exposed to Osteon II. All cylinders were submerged in simulated tissue fluid and incubated at 37^°C and 100% relative humidity for 7 days. Surface microhardness values of each study group was attained using Vickers microhardness test. The data were analyzed statistically using two-way ANOVA and independent t-test at a significance level of 0.05.

Results

The highest and lowest microhardness values were recorded in the MTA/without Osteon and MTA/with Osteon groups, respectively. Irrespective of the presence or absence of bone powder, the overall microhardness of CEM cement and MTA was not significantly different. In the MTA group, the presence of the powder resulted in a significant decrease (P<0.05) of the microhardness; however, its effect on CEM cement was not significant (P>0.05).

Conclusion

Under the limitations of the present in vitro study, the presence of Osteon bone powder had no negative effect on the microhardness of CEM cement, contrary to its effect on MTA.

Influence of Immediate Coronal Restoration on Microhardness of CEM Cement: An In Vitro Study

Introduction

Coronal restoration could affect the setting reaction of the underlying CEM cement. The aim of the present study was to evaluate the effect of immediate coronal restoration placement on the subsurface microhardness of CEM cement.

Methods and Materials

In 50 extracted human mandibular molars, access cavities were prepared and CEM cement was placed in the pulp chamber at a 3-mm thickness. Samples were divided into ten groups (n=5). CEM cement was placed and after 10 min, two groups were restored with Zonalin temporary restoration and eight groups were restored with glass ionomer cement (GIC), resin modified glass ionomer (RMGI), resin based composite and amalgam respectively. Vickers microhardness number (VHN) of CEM cement was measured in two time intervals (7- and 21-days). Data was analyzed with SPSS and two-way analysis of variance and Bonferroni tests. Level of significance was set at the 5%.

Results

The mean VHN of CEM cement showed statistically significant differences only between Zonalin and amalgam groups (P=0.021). There were also significant differences considering the effect of time (P=0.042) and material (P=0.046). Although the effect of time-material on the microhardness values showed no statistically significant differences (P=0.636).

Conclusion

Based on the results of the present study, immediate placement of final restorations affects the setting reaction in underlying CEM cement. Therefore, sufficient moist curing and hydration should be guaranteed before placement of the coronal restoration.

Double Antibiotic Paste for Management of External Inflammatory Root Resorption

External inflammatory root resorption (EIRR) is one of the common complications following dental trauma which when remained untreated, may lead to tooth loss. Successful treatment outcomes depend on elimination of bacteria from root canal system and apical sealing. This case presents the endodontic management of an EIRR that was nonresponsive to calcium hydroxide (CH) therapy. An 11-year-old boy was referred for management of a traumatized maxillary central incisor. Tooth #8 was symptom-free, nonresponsive to vitality pulp tests and had an immature root with sever EIRR. Using chemomechanical debridement and CH dressing, the treatment was initiated. The tooth was remained asymptomatic; however, after five weeks the size of periradicular lesion increased and intracanal exudate was present, signifying a resistant endodontic infection. In second appointment, double antibiotic paste (DAP; ciprofloxacin/metronidazole) was applied to the canal. Eight weeks later, the tooth continued to be asymptomatic and the size of the lesion decreased. Finally, the root canal was entirely obturated with calcium-enriched mixture (CEM). At 18-month follow-up, the tooth was asymptomatic/functional, EIRR did not further progress and tooth discoloration was not observed. Based on the results, DAP has the potential to be used to manage the CH-resistant endodontic infection. Furthermore, CEM root filling/sealing seems to be an applicable choice in EIRR management.

Histopathological Evaluation of Primary Teeth after Pulp Capping with Calcium-Enriched Mixture and Bioactive Glass

Introduction

Direct pulp capping (DPC) is a conservative vital pulp therapy, which has some limitations in primary dentition. The aim of this study was to evaluate pulpal response of primary teeth after DPC with two biocompatible materials naming calcium-enriched mixture (CEM) and bioactive glass (BAG).

Methods and Materials

This study was designed as a randomized clinical trial. After obtaining informed consent, 20 sound primary canines scheduled for orthodontic extraction, were selected. Following mechanical pulp exposure, the exposed site was capped with either CEM cement or BAG and then restored with amalgam. Teeth were extracted after two months and examined histopathologically. Parameters of hard tissue bridge (HTB) formation, its type and pulpal inflammation scores, were compared between the two groups. Data were analysed using the Fisher's exact test.

Results

All CEM specimens showed inflammation scores of 0 (less than 10%). In the BAG group, inflammation scores of 0, 1 and 2 were observed in 7, 2 and 1 specimens, respectively. Fisher's exact test showed no significant differences (P>0.05). All CEM specimens (100%) formed HTB, which was irregular in all cases. In 7 of 10 teeth in BAG, HTB formed and was irregular. Fisher's exact test revealed no significant differences between the two groups in this regard (P<0.001).

Conclusion

Both CEM and BAG are suitable DPC agents in terms of HTB formation and pulp inflammation scores.

Effects of Two Calcium Silicate Cements on Transforming Growth Factor-β1 Secretion from Human Dental Pulp Stem Cells

Introduction

The aims of this in vitro study were to evaluate the effects of two calcium silicate based cements, Calcum-enriched Mixture (CEM) and Biodentine on proliferation of human dental pulp stem cells (hDPSCs) and the effects of proposed cements on the secretion of Transforming Growth Factor β1 (TGF-β1).

Methods and materials

The cell cultures of human Dental Pulp Stem Cells (hDPSCs) at passage 3-5 were treated with various dilutions (1/1, 1/2, 1/4, 1/8, 1/16, and 1/32) of CEM and Biodentine extracts to assess the cell proliferation using 3-(4, 5-dimethylthiazol-2-Y1)-2, 5-diphenyltetrazolium brovide (MTT) assay after 48 and 72 h. The amount of TGF-β 1 secretion were estimated after 72 h using an enzyme-linked immunosorbent assay. Data were analyzed using the one-way analysis of variance (ANOVA) followed by the Dunnett's test at the level of significance set at 0.05.

Result

CEM showed the highest rates of cell proliferation compared to Biodentine after 72 h (P<0.05). A greater amount of TGF-β1 was secreted by hDPSCs treated with Biodentine compared to CEM (P<0.05). These differences were statistically significant (P<0.05).

Conclusion

In this in vitro study hDPSCs showed more proliferation capacity with CEM rather than Biodentine and TGF-β1 secretion rate in Biodentine was higher.

Failure of Cone-Beam Computed Tomography in Detection of Fiber Post Perforation

Detection of iatrogenic root perforation during post-space preparation especially in labiolingual plane can be challenging due to the two-dimensional nature of conventional radiography; this can be even more challenging if the cemented post is radiolucent. Cone-beam computed tomography (CBCT) scans were shown to be a valuable diagnostic aid in diagnosis of such cases. However, in this case, the application of CBCT did not help in diagnosis of a labial fiber post perforation in a maxillary central incisor which was finally detected through exploratory surgery.

Apical Microleakage in Root Canals Containing Broken Rotary Instruments

INTRODUCTION

Broken instruments in root canals complicate routine endodontic treatment. This study aimed to compare apical microleakage in root canals containing broken rotary instruments filled with mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement, laterally compacted gutta-percha and injected gutta-percha.

METHODS AND MATERIALS

In this in vitro, experimental study, 80 extracted human premolars were decoronated and then the roots were randomly divided into four groups (n=20). Root canals were instrumented with Mtwo rotary files. The files were scratched 3 mm from the tip by a high speed handpiece and they were intentionally broken in the apical third of the canals. The middle and coronal thirds of the canals were then filled with MTA, CEM cement, gutta-percha with lateral compaction technique and injected gutta-percha. Apical microleakage was measured using dye penetration method. Data were analyzed using ANOVA and Tukey's test.

RESULTS

Root canals filled with CEM cement showed the lowest and those filled with injected gutta-percha showed the highest microleakage according to dye penetration depth. No significant difference was noted between the microleakage of CEM cement and MTA or between lateral compaction of gutta-percha and injected gutta-percha (P>0.05). However, CEM cement and MTA groups had significantly lower microleakage than laterally compacted and injected gutta-percha groups (P<0.05).

CONCLUSION

Due to their superior sealing ability, MTA and CEM cement are suitable for filling of root canals containing a broken instrument compared to laterally compacted and injected gutta-percha.

Endodontic Surgery of a Symptomatic Overfilled MTA Apical Plug: A Histological and Clinical Case Report

This case report presents the successful surgical treatment of a symptomatic open apex upper central incisor with a failed overfilled mineral trioxide aggregate (MTA) apical plug. Unintentional overextension of the MTA had occurred two years before the initial visit. An apical lesion adjacent to the excess MTA was radiographically detectable. Endodontic surgery was performed using calcium-enriched mixture (CEM) cement as a root-end filling material. Curettage of the apical lesion showed a mass of unset MTA particles; histopathological examination revealed fragments of MTA and granulation tissues. Up to 18-month follow-up, the tooth was clinically asymptomatic and fully functional. Periapical radiograph and CBCT images showed a normal periodontal ligament around the root. In conclusion, favorable outcomes in this case study suggested that root-end filling with CEM cement might be an appropriate approach; in addition, however many factors probably related to the initial failure of the case, the extrusion of MTA into the periapical area should be avoided.

In Vitro Microleakage of Mineral Trioxide Aggregate, Calcium-Enriched Mixture Cement and Biodentine Intra-Orifice Barriers

Introduction:

This in vitro study compared the coronal microleakage of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement and Biodentine as intra-orifice barriers.

Methods and Materials:

The study was conducted on 76 extracted single-canal human teeth. Their root canals were prepared using ProTaper rotary files and filled with gutta percha and AH-26 sealer using lateral condensation technique. Coronal 3 mm of the gutta percha was removed from the root canals and replaced randomly with MTA, CEM cement or Biodentine in the three experimental groups (n=22). A positive and a negative control group were also included (n=5). The entire root surfaces of all teeth were covered with two layers of nail varnish in such a way that only the access openings were not coated. In the negative control group, the access opening was also coated with nail varnish. All teeth were immersed in India ink and after clearing, the samples were evaluated under a stereomicroscope under ×10 magnification to assess the degree of dye penetration. The data were analyzed using the Kruskal-Wallis test. The level of significance was set at 0.05.

Results:

The negative control group showed no leakage while the positive control group showed significantly higher microleakage than the test groups (P>0.05). CEM cement had the lowest (0.175±0.068 mm) and MTA showed the highest dye penetration (0.238±0.159 mm) among the experimental groups; although these differences were not statistically significant (P=0.313).

Conclusion:

CEM cement exhibited the least microleakage as an intra-orifice barrier in endodontically treated teeth.

Scanning Electron Microscopy and Energy-Dispersive X-Ray Microanalysis of Set CEM Cement after Application of Different Bleaching Agents

INTRODUCTION

The present study evaluated the element distribution in completely set calcium-enriched mixture (CEM) cement after application of 35% carbamide peroxide, 40% hydrogen peroxide and sodium perborate as commercial bleaching agents using an energy-dispersive x-ray microanalysis (EDX) system. The surface structure was also observed using the scanning electron microscope (SEM).

METHODS AND MATERIALS

Twenty completely set CEM cement samples, measuring 4×4 mm², were prepared in the present in vitro study and randomly divided into 4 groups based on the preparation technique as follows: the control group; 35% carbamide peroxide group in contact for 30-60 min for 4 times; 40% hydrogen peroxide group with contact time of 15-20 min for 3 times; and sodium perborate group, where the powder and liquid were mixed and placed on CEM cement surface 4 times. Data were analyzed at a significance level of 0.05 through the one Way ANOVA and Tukey's post hoc tests.

RESULTS

EDX showed similar element distribution of oxygen, sodium, calcium and carbon in CEM cement with the use of carbamide peroxide and hydroxide peroxide; however, the distribution of silicon was different (P<0.05). In addition, these bleaching agents resulted in significantly higher levels of oxygen and carbon (P<0.05) and a lower level of calcium (P<0.05) compared to the control group. SEM of the control group showed plate-like and globular structure. Sodium perborate was similar to control group due to its weak oxidizing properties. Globular structures and numerous woodpecker holes were observed on the even surface on the carbamide peroxide group.

CONCLUSION

The mean elemental distribution of completely set CEM cement was different when exposed to sodium perborate, carbamide peroxide and hydrogen peroxide.

Regenerative Endodontic Treatment versus Apical Plug in Immature Teeth: Three-Year Follow-Up

This report compares and evaluates the treatment outcomes of regenerative endodontic treatment and apical plug as two accepted treatment protocols in a pair of necrotic immature maxillary central incisors of a 12-year old female. The patient was referred complaining of a dull pain and swelling in her upper lip area. She had a history of trauma to the anterior maxilla two years earlier. Both teeth were clinically diagnosed with pulp necrosis and periapical radiographs revealed that separate periapical radiolucent lesions surrounded the immature apices of both teeth. The left and right incisors were treated with apical plug and regenerative endodontic treatment, respectively, using calcium-enriched mixture (CEM) cement. The patient was followed-up for three years. During this period, both teeth were clinically asymptomatic and showed complete radiographic healing of the periapical lesions. The right central incisor showed root development. No tooth discoloration was evident. Apexification by apical plug placement and pulp regeneration are both reliable treatments for immature non-vital teeth. In order to choose the right treatment the advantages of either technique should be weighed against its drawbacks. CEM cement can be successfully applied for both purposes. This biomaterial causes less discoloration of the tooth.

Vital Pulp Therapy of a Symptomatic Immature Permanent Molar with Long-Term Success

Vital pulp therapy (VPT) is the preferred conservative treatment for preservation of symptomatic pulps in immature permanent teeth. The present case report summarizes VPT of an immature permanent molar with irreversible pulpitis associated with apical periodontitis in a 9-year-old boy. Cervical pulpotomy was performed and radicular pulp stumps were covered with calcium-enriched mixture (CEM) cement; the tooth was then restored with stainless steel crown. After a 50-month follow-up period, the pulpotomized molar was clinically functional and asymptomatic. Moreover, radiographic evaluation revealed evidence of complete root development as well as normal periodontal ligament around the roots. The successful outcome achieved through VPT using CEM biomaterial in the reported case suggests that this method may produce favorable outcome for vital immature permanent teeth with irreversible pulpitis and periapical disease.

Conservative Management of Unset Mineral Trioxide Aggregate Root-End Filling: A Case Report

This case report presents conservative management of unset mineral trioxide aggregate (MTA) after being placed as a root-end filling material following periapical surgery. Periapical surgery was indicated for a maxillary lateral incisor of a 15-year-old male due to persistent exudate and a large periapical lesion. During surgery Angelus MTA was placed as root-end filling. The next session it was noticed that MTA had failed to completely set. In an orthograde approach, calcium-enriched mixture (CEM) cement was used to obturate the root canal space. The patient was followed up for 27 months and did not exhibit any clinical signs and symptoms. Radiographic images showed complete healing of the lesion.

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.

Comparison of Tooth Discoloration Induced by Calcium-Enriched Mixture and Mineral Trioxide Aggregate

Introduction:

The aim of this in vitro study was to evaluate the tooth discoloration induced by calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA).

Methods and Materials:

Forty five endodontically treated human maxillary central incisors were selected and divided into three groups (n=15) after removing the coronal 3 mm of the obturating materials. In the MTA group, white MTA plug was placed in pulp chamber and coronal zone of the root canal. In CEM cement group, CEM plug was placed in the tooth in the same manner. In both groups, a wet cotton pellet was placed in the access cavity and the teeth were temporarily sealed. After 24 h the teeth were restored with resin composite. In the negative control group the teeth were also restored with resin composite. The color change in the cervical third of teeth was measured with a colorimeter and was repeated 3 times for each specimen. The teeth were kept in artificial saliva for 6 months. After this period, the color change was measured again. Data were collected by Commission International de I'Eclairage's L*a*b color values, and corresponding ΔE values were calculated. The results were analyzed using the one-way ANOVA and post-hoc Tukey’s test with the significance level defined as 0.05.

Results:

There was no significant differences between CEM group and control group in mean discoloration. The mean tooth discoloration in MTA group was significantly greater than CEM and control groups (P<0.05).

Conclusion:

According to the result of the present study CEM cement did not induce tooth discoloration after six months. Therefore it can be used in vital pulp therapy of esthetically sensitive teeth.

Bacterial Leakage of Mineral Trioxide Aggregate, Calcium-Enriched Mixture and Biodentine as Furcation Perforation Repair Materials in Primary Molars

Introduction:

Adequate seal of iatrogenically perforated area within the root canal system can improve the long term treatment prognosis. This in vitro study evaluated the sealing ability of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement and Biodentine in repair of furcation perforation in primary molars.

Methods and Materials:

A total of 61 freshly extracted primary mandibular second molars were randomly divided into three groups (n=17) and 10 teeth were put in negative (without perforation, n=5) and positive (perforated without repair, n=5) control groups. Turbidity was used as the criteria of bacterial leakage, when detected in the model of dual-chamber leakage. Data were analyzed using the Chi-Square and Kaplan-Meier survival analysis in SPSS software. The level of significance was set at 0.05.

Results:

All positive samples showed turbidity, whereas none of the negative samples allowed bacterial leakage. There was no significant difference between the number of turbidity samples in repaired teeth with all test materials (P=0.13). No significant difference was also detected in the mean survival time (P>0.05).

Conclusion:

CEM cement and Biodentine showed promising results as perforation repair materials and can be recommended as suitable alternatives of MTA for repair of furcation perforation of primary molars.

Effect of Calcium Hydroxide on the Push-out Bond Strength of Endodontic Biomaterials in Simulated Furcation Perforations

Introduction:

The aim of this in vitro study was to evaluate the effect of calcium hydroxide (CH) on push-out bond strength of white mineral trioxide aggregate (WMTA) and calcium-enriched mixture (CEM) cement in simulated furcation perforations.

Methods and Materials:

Furcation perforations, measuring 1.3 mm in diameter and 2 mm in height, were created in 80 human mandibular first molars. The teeth were then divided into 4 groups (n=20). In groups 1 and 3 CH was placed in the perforation for one week, before placement of WMTA and CEM. In groups 2 and 4 perforations were repaired without placement of CH. In groups 1 and 2 the perforation sites were repaired with WMTA and CEM cement was used in groups 3 and 4. After 7 days, the push-out test was carried out using a universal testing machine. Data were analyzed with two-way ANOVA. The level of significance was set at 0.05.

Results:

The maximum and minimum bond strength values were recorded in the WMTA/CH (13.08±1.8 MPa) and CEM cement groups (8.03±0.98 MPa), respectively. There were significant differences in resistance to dislodgement between the WMTA/CH and other groups (P<0.05).

Conclusion:

Placement of CH before placement of WMTA in furcation perforation improves the push-out bond strength of this material.

Interdisciplinary Approach for Management of Iatrogenic Internal Root Resorption: A Case Report

For management of a symptomatic maxillary lateral incisor with dull pain on chewing, suppurative sinus tract, defective metal-ceramic crown and iatrogenic internal root resorption, an interdisciplinary approach was taken. Two-visit nonsurgical treatment with calcium-enriched mixture (CEM) cement, replacement of metal-ceramic crown with all-ceramic crown and corrective periodontal plastic surgery were included in the treatment plan. Six-month and one-year follow-ups revealed complete resolution of signs and symptoms and radiographic healing. This case report highlights the importance of adequate cooling during crown preparation to preserve the pulp vitality and prevent internal resorptive lesions and also the profound sealing ability and biocompatibility of CEM cement.

Cytotoxicity of Various Endodontic Materials on Stem Cells of Human Apical Papilla

INTRODUCTION

This in vitro study assessed and compared the cytotoxicity of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement, Biodentine (BD) and octacalcium phosphate (OCP) on stem cells of the human apical papilla (SCAP).

METHODS AND MATERIALS

SCAPs were isolated from two semi-impacted third molars. The cells were cultured in wells of an insert 24-well plate and were then incubated. The plates were then removed from the incubator and randomly divided into four experimental groups that were exposed to 1-mm discs of set MTA, CEM, BD or OCP, and one untreated control group. After 24, 48 and 168 h, the plates were removed from the incubator and 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) solution was added to each well. Data were analyzed at different time points using the repeated measures ANOVA followed by Bonferroni test and the level of significance was set at 0.05.

RESULTS

Cytotoxicity of the four materials was not significantly different from that of the control group at 24, 48 and 168 h (P>0.05). Two-by-two comparison revealed that cytotoxicity of MTA and CEM cement was significantly different from each other at 168 h (P<0.05) although the cytotoxicity of CEM was less than MTA. Cytotoxicity of OCP and MTA was also significantly different from each other at 48 h and OCP had more favorable biocompatibility than MTA (P<0.05).

CONCLUSION

CEM, OCP, BD and MTA showed acceptable biocompatibility when exposed to SCAP. Over time, CEM showed the least cytotoxicity among the materials under study.

Miniature Pulpotomy of Symptomatic Mature Permanent Teeth: A Report of Two Cases

Human dental pulp inflammation can progress to periapical lesion formation and conventional root canal treatment (RCT) has been the traditional method for disease management. This observational study presents two cases of vital pulp therapy in mature molars diagnosed with irreversible pulpitis and associated with apical periodontitis. In these two clinical cases, the involved teeth had deep carious lesions with a history of spontaneous/lingering pain and radiographic examinations revealed the presence of apical radiolucencies. A conservative miniature pulpotomy (MP) using calcium-enriched mixture (CEM) was performed and the teeth were permanently restored with amalgam. Clinical evaluations indicated resolution of pain 24 hours after treatment; the teeth showed normal vitality, remained asymptomatic and maintained normal function after recall examinations. Furthermore, the 18-month radiographic evaluation showed healing of the apical lesions. Vital pulp therapy using the MP technique with CEM appeared successful in avoiding RCT intervention. These two reports of case outcome suggest that simple MP using a CEM bioregenerative technique may provide a favorable outcome for permanent teeth diagnosed with irreversible pulpitis and associated with apical periodontitis.

In Vitro Spectrophotometry of Tooth Discoloration Induced by Tooth-Colored Mineral Trioxide Aggregate and Calcium-Enriched Mixture Cement

Introduction:

There are numerous factors that can lead to tooth discoloration after endodontic treatment, such as penetration of endodontic materials into the dentinal tubules during root canal treatment. The aim of this in vitro study was to compare discoloration induced by tooth colored mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement in extracted human teeth.

Methods and Materials:

Thirty two dentin-enamel cuboid blocks (7×7×2 mm) were prepared from extracted maxillary central incisors. Standardized cavities were prepared in the middle of each cube, leaving 1 mm of enamel and dentin on the labial surface. The specimens were randomly divided into two study groups (n=12) and two positive and negative control groups (n=4). In either study groups the cavities were filled with MTA or CEM cement. The positive and negative control groups were filled with blood or left empty, respectively. The cavities were sealed with composite resin and stored in normal saline. Color measurement was carried out by spectrophotometry at different time intervals including before (T₀), and 1 week (T₁), 1 month (T₂) and 6 months (T₃) after placement of materials. Repeated-measures ANOVA was used to compare the discoloration between the groups; the material type was considered as the inter-subject factor. The level of significance was set at 0.05.

Results:

No significant differences were detected between the groups in all time intervals (P>0.05).

Conclusion:

Tooth discoloration was similarly detectable with both of the two experimental materials.

Vital Pulp Therapy of a Mature Molar with Concurrent Hyperplastic Pulpitis, Internal Root Resorption and Periradicular Periodontitis: A Case Report

Vital pulp therapy (VPT) of permanent mature teeth is continuously ascertaining to be a more reliable endodontic treatment. The purpose of this case report was to describe successful VPT of a mature mandibular left first molar with concurrent hyperplastic pulpitis, internal root resorption and periradicular periodontitis in a 35-year-old male patient. After complete caries removal and access cavity preparation, the dental pulp was removed from the coronal third of the roots. To protect the remaining pulp, calcium-enriched mixture (CEM) cement was placed and adapted into the cavities; the tooth was then restored with amalgam. Six months after VPT, radiographic examination showed evidence of periradicular healing. Clinically, the tooth was functional without signs and symptoms of infection/inflammation. The successful outcome of this case suggests that diseased dental pulp (i.e. irreversible pulpitis) has the potential to heal after pulp protection with CEM biocement.

The Effect of Different Mixing Methods on Working Time, Setting Time, Dimensional Changes and Film Thickness of Mineral Trioxide Aggregate and Calcium-Enriched Mixture

INTRODUCTION

The aim of the present study was to evaluate the effect of different mixing techniques (conventional, amalgamator and ultrasonic mixing) on the physical properties the working time (WT), setting time (ST), dimensional changes (DC) and film thickness (FT)] of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA).

METHODS AND MATERIALS

The mentioned physical properties were determined using the ISO 6786:2001 specification. Six samples of each material were prepared for three mixing techniques (totally 36 samples). Data were analyzed using descriptive statistics, two-way ANOVA and Post Hoc Tukey's tests. The level of significance was defined at 0.05.

RESULTS

Irrespective of mixing technique, there was no significant difference between the WT and FT of the tested materials. Except for the DC of MTA and the FT of the all materials, other properties were significantly affected with mixing techniques (P<0.05). The ultrasonic technique decreased the ST of MTA and CEM cement and increased the WT of CEM cement (P<0.05).

CONCLUSION

The mixing technique of the materials had no significant effect on the dimensional changes of MTA and the film thickness of both materials.

Effects of Chlorhexidine and Sodium Hypochlorite on the Setting Time of Calcium-Enriched Mixture Cement

Introduction:

The aim of the present study was to evaluate whether adding 2% chlorhexidine (CHX) and 2.6% sodium hypochlorite (NaOCl) to calcium-enriched mixture (CEM) cement would affect its setting time (ST), or not.

Methods and Materials:

In this study, the setting time of CEM cement was evaluated in three groups (n=9) as follows: group 1; CEM cement, group 2; CEM cement+2% CHX and group 3; CEM cement+2.6% NaOCl. Then the mean values of ST were calculated and the Kolmogorov-Smirnov test was used to evaluate the normal distribution of data. The Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis. Statistical significance was set at 0.05.

Results:

The mean ST for groups 1, 2 and 3 were 105, 120 and 220 min, respectively. There was a significant increase in the duration of ST in group 3 (NaOCl) in comparison with the two other groups (P<0.05).

Conclusion:

NaOCl significantly increased the ST of CEM cement, whereas chlorhexidine did not alter the ST.

A Successful Endodontic Outcome with Non-Obturated Canals

This case report represents the outcome of endodontic treatment in an infected mandibular molar with periradicular periodontitis and inherent poor prognosis of root canal treatment due to severe root curvature. The tooth was successfully treated by leaving the mesial root non-obturated, the canal orifices were coronally sealed with calcium enriched mixture cement and a definitive coronal amalgam restoration, was placed at the subsequent visit.

A review on vital pulp therapy in primary teeth

Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed.

The effect of different mixing methods on the flow rate and compressive strength of mineral trioxide aggregate and calcium-enriched mixture

INTRODUCTION

Flow rate (FR) and compressive strength (CS) are important properties of endodontic biomaterials that may be affected by various mixing methods. The aim of this experimental study was to evaluate the effect of different mixing methods on these properties of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement.

MATERIALS AND METHODS

Hand, amalgamator and ultrasonic techniques were used to mix both biomaterials. Then 0.5 mL of each mixture was placed on a glass slab to measure FR. The second glass slab (100 g) was placed on the samples and 180 sec after the initiation of mixing a 100-g force was applied on it for 10 min. After 10 min, the load was removed, and the minimum and maximum diameters of the sample disks were measured. To measure the CS, 6 sample of each group were placed in steel molds and were then stored in distilled water for 21 h and 21 days. Afterwards, the CS test was performed. Data were analyzed with multi-variant ANOVA and post hoc Tukey tests. The level of significance was set at 0.05.

RESULTS

There were significant differences in FR of MTA and CEM cement with different mixing techniques (P<0.05). In the MTA group, none of the mixing techniques exhibited a significant effect on CS (P>0.05); however, in CEM group the CS at 21-h and 21-day intervals was higher with the hand technique (P<0.05).

CONCLUSION

Mixing methods affected the flowability of both biomaterials and compressive strength of CEM cement.

The effect of chlorhexidine on the push-out bond strength of calcium-enriched mixture cement

INTRODUCTION

The aim of this in vitro study was to evaluate the effect of 2% chlorhexidine (CHX) on the push-out bond strength (BS) of calcium-enriched mixture (CEM) cement.

METHODS AND MATERIALS

Root-dentin slices from 60 single-rooted human teeth with the lumen diameter of 1.3 mm were used. The samples were randomly divided into 4 groups (n=15), and their lumens were filled with CEM cement mixed with either its specific provided liquid (groups 1 and 3) or 2% CHX (groups 2 and 4). The specimens were incubated at 37(°)C for 3 days (groups 1 and 2) and 21 days (groups 3 and 4). The push-out BS were measured using a universal testing machine. The slices were examined under a light microscope at 40× magnification to determine the nature of bond failure. The data were analyzed using the two-way ANOVA. For subgroup analysis the student t-test was applied. The level of significance was set at 0.05.

RESULTS

After three days, there was no significant difference between groups 1 and 2 (P=0.892). In the 21-day specimens the BS in group 3 (CEM) was significantly greater than group 4 (CEM+CHX) (P=0.009). There was no significant difference in BS between 3 and 21-day samples in groups 2 and 4 (CEM+CHX) (P=0.44). However, the mean BS after 21 days was significantly greater compared to 3-day samples in groups 1 and 3 (P=0.015). The bond failure in all groups was predominantly of cohesive type.

CONCLUSION

Mixing of CEM with 2% CHX had an adverse effect the bond strength of this cement.

Effect of different mixing and placement methods on the compressive strength of calcium-enriched mixture

INTRODUCTION

The aim of this experimental laboratory study was to evaluate the effect of different mixing and placement techniques on compressive strength (CS) of calcium-enriched mixture (CEM) cement.

METHODS AND MATERIALS

CEM powder was mixed with its liquid either by hand mixing or amalgamator mixing. The mixture was loaded to cylindrical acrylic molds with 6.0±0.1 mm height and 4.0±1 mm diameter. Half of the specimens in each group were selected randomly and ultrasonic energy was applied to them for 30 sec. All samples were incubated for 7 days at 37(°)C. The CS test was performed by means of a universal testing machine. The data were analyzed by the two-way analysis of variance (ANOVA) and Tukey's post hoc tests. The level of significance was set at 0.05.

RESULTS

The maximum CS was seen in the amalgamator-mixed samples that did not receive ultrasonic agitation. The CS value of amalgamator-mixed samples was significantly higher than manually-mixed ones (P=0.003). Ultrasonic vibration did not change the CS of specimens.

CONCLUSION

According to the results, mixing with amalgamator increases the CS of CEM cement, while ultrasonic vibration had no positive effect.

The Effect of Different Mixing Methods on the pH and Solubility of Mineral Trioxide Aggregate and Calcium-Enriched Mixture

INTRODUCTION

The aim of this study was to evaluate the effect of different mixing techniques on the pH and solubility of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM).

METHODS AND MATERIALS

Five samples were prepared from each biomaterial with different mixing techniques including hand-, amalgamator- or ultrasonic-mixing and were then placed in pre-weighted plastic tubes to determine their pH values. Each tube was then incubated in 10 mL deionized distilled water for 1 h at 37(º)C. An electrode was placed in the fluid in each flask at 24(º)C and the pH was recorded. In the next stage, six samples from each mixing technique/material were separately placed in glass bottles containing 50 mL of distilled water at 37(º)C for 1 h and were let dry for 1 h at 37(º)C. The samples' weights were measured and recorded twice. The procedure was repeated at 1-, 7- and 21-day intervals. Data were analyzed with the repeated measures ANOVA (for solubility) and two-way ANOVA (for pH) and then the post-hoc Tukey's test was done.

RESULTS

The pH of the materials was not significantly affected by mixing methods. (P=0.8 for CEM and P=0.1 for MTA). The solubility of all test groups was within the acceptable range (=3%). However, the solubility of CEM at 1- and 21-day intervals was significantly different (P=0.03 for 1 day and P=0.001 for 21 days). Different mixing techniques had significant effects on the solubility of MTA at the three time points (P=0.004, 0.003 and 0.002 for 1-, 7- and 21-day intervals, respectively).

CONCLUSION

The pH of biomaterials was not influenced by the mixing technique and their solubility was within the acceptable range.

Surgical Treatment of an Immature Short-Rooted Traumatized Incisor with an Extensive Apical Lesion Using CEM Cement

Severe traumatic injuries to immature teeth often cause damage to periodontal ligament as well as dental pulp; pulp necrosis, root resorption and subsequent apical lesion are common consequences. This article reports the surgical management of an infected immature maxillary central incisor associated with a gigantic periradicular lesion and severe root resorption. The tooth had a history of trauma and the patient suffered from purulent sinus tract and tooth mobility. After unsuccessful multi-session disinfection with calcium hydroxide, root end surgery was planned. During flap surgery and lesion enucleation, the root end was cleaned and filled with calcium-enriched mixture (CEM) cement. After one year, the radiographic examination revealed that the lesion was almost completely replaced with newly formed bone. In addition, clinical examination showed favorable outcomes; the tooth was symptom-free and in function. Due to chemical, physical and biological properties of CEM cement, this biomaterial might be considered as the root-end filling material of choice.

Nano-hydroxyapatite and calcium-enriched mixture for pulp capping of sound primary teeth: a randomized clinical trial

INTRODUCTION

Nano-hydroxyapatite (NHA) has been used for regeneration of osseous defects. Calcium-enriched mixture (CEM) cement is also used for various dental treatments. This trial compared the efficacy of NHA and CEM cement for direct pulp capping (DPC) of sound primary teeth.

METHODS AND MATERIALS

In this randomized clinical trial with split-mouth design, after attaining informed consent, 20 sound primary canines scheduled for orthodontic extraction, were selected. After mechanical pulp exposure, the exposed site was capped with either NHA or CEM cement and then immediately restored with glass-ionomer and resin composite. The teeth were extracted after two months and examined histologically. Parameters of hard tissue bridge (HTB) formation, its type and quality as well as pulpal inflammation scores were compared between the two experimental groups. The data were analyzed using the Mann Whitney U and Fisher's exact test. The level of significance was set at 0.001.

RESULTS

All CEM specimens showed inflammation score of 0 (less than 10%). However, in NHA group, inflammation scores of 0 (less than 10%), 1 (10%-30%) and 2 (30%-50%) were observed in 2 (20%), 4 (40%) and 4 (40%) specimens, respectively (P<0.001). HTB was formed in all CEM specimens while it was developed in 2 specimens of NHA (20%; P<0.001). All CEM specimens showed normal pulp; only two cases in NHA group (20%) demonstrated uninflamed normal pulp.

CONCLUSION

CEM cement was superior to NHA as a DPC agent in terms of HTB formation and pulp inflammation scores. It is a suitable material for the DPC of primary teeth.

A review on vital pulp therapy in primary teeth

Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed.

Sealing ability of mineral trioxide aggregate and calcium-enriched mixture cement as apical barriers with different obturation techniques

INTRODUCTION

Endodontic treatment in pulpless immature teeth is challenging due to the lack of an apical stop. Insertion of an apical plug is an alternative to conventional long-term apexification with calcium hydroxide. The aim of this study was to compare the apical microleakage of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement as apical plugs with three different obturation techniques.

METHODS AND MATERIALS

This experimental study was conducted on 130 single rooted human teeth with one canal. Samples were randomly divided into 2 experimental groups (n=60) and two negative and positive control groups containing 5 samples each. After cleaning and shaping, an open apex configuration was prepared in all samples. MTA or CEM cement apical plugs with 5 mm thicknesses were placed. Then, each group was divided to 4 subgroups and the remaining space of root canals were filled with either lateral compaction or thermoplasticized injectable gutta-percha or was obturated by filling the entire canal with apical plug material. In one remaining subgroup the canal space was left unfilled. Microleakage was measured by the fluid filtration method and results were analyzed by means of the two-way ANOVA test.

RESULTS

There were no significant differences between microleakage of MTA and CEM cement apical plugs (P=0.92). The difference between three obturation methods was not significant, either (P=0.39).

CONCLUSION

MTA and CEM cement have similar sealing ability as apical plugs and no significant difference was found in microleakage of the three groups.

Management of Complicated Crown Fracture with Miniature Pulpotomy: A case report

Crown fractures account for the majority of dental traumas. If handled properly, prognosis of the pulp following a traumatic crown fracture can be favorable. The present case report focuses on the treatment of a traumatized mature permanent incisor with exposed pulp that was treated with the novel technique of miniature pulpotomy using calcium-enriched mixture (CEM) cement. One-year follow-up revealed that the tooth was responsive to vitality tests and radiographic assessment showed the presence of a thick dentinal bridge beneath the CEM layer.

Effect of smear layer on the push-out bond strength of two endodontic biomaterials to radicular dentin

INTRODUCTION

This in vitro study was designed to evaluate the effect of smear layer removal on push-out bond strength of white mineral trioxide aggregate (WMTA) and calcium-enriched mixture cement (CEM).

MATERIALS AND METHODS

Dentin discs with 3 mm thicknesses were divided into 4 groups (n=15): group 1: irrigation of the canal with normal saline and filling with WMTA; group 2: irrigation with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), and then filling with WMTA; group 3: same as group 1 but the lumens were filled with CEM; group 4: same as group 2 but the lumens filled with CEM. The samples were incubated at 37(°)C for 3 days after wrapping in gauze pieces moistened with distilled water. The push-out bond strengths were then measured by the universal testing machine and the failure modes were examined under a stereomicroscope at 40× magnification. Data were analyzed using two-way ANOVA and post-hoc Tukey's test for bond strength. Statistical significance was set at P<0.05.

RESULTS

The greatest and lowest mean standard deviation for push-out bond strength were observed for groups 4 (3.13±1.46 MPa) and group3 (1.44±0.96 MPa), respectively. The effect of smear layer removal on push-out bond strength of CEM was significant (P=0.01), however, it was not significant for WMTA (P=0.52). The failure mode for all the groups was of mixed type.

CONCLUSION

Under the limitations of this study, smear layer removal is recommended for CEM in order to gain higher push-out strength.

Effect of acidic environment on the push-out bond strength of calcium-enriched mixture cement

INTRODUCTION

This laboratory study was performed to evaluate the effect of different acidic pH values on the push-out bond strength of calcium-enriched mixture (CEM) cement.

METHODS AND MATERIALS

Forty-eight root dentin slices were obtained from freshly extracted single rooted human teeth and their lumen were instrumented to achieve a diameter of 1.3 mm. Then, CEM cement was mixed according to manufacturers' instruction and placed in the lumens with minimal pressure. The specimens were randomly divided into four groups (n=12) which were wrapped in pieces of gauze soaked in either synthetic tissue fluid (STF) (pH=7.4) or butyric acid which was buffered at pH values of 4.4, 5.4 and 6.4. They were then incubated for 4 days at 37°C. The push-out test was performed by means of the universal testing machine. Specimens were then examined under a digital light microscope at 20× magnification to determine the nature of the bond failure. The data were analyzed using the Kruskal-Wallis test followed by Dunn's test for pairwise comparisons.

RESULTS

The highest push-out bond strength (10.19±4.39) was seen in the pH level of 6.4, which was significantly different from the other groups (P<0.05). The values decreased to 2.42±2.25 MPa after exposure to pH value of 4.4.

CONCLUSION

Lower pH value of highly acidic environments (pH=4.4), adversely affects the force needed for displacement of CEM cement; while in higher pH values (pH=6.4) the bond-strength was not affected. CEM cement is recommended in clinical situations where exposure to acidic environment is unavoidable.

The Effect of Acidic pH on Microleakage of Mineral Trioxide Aggregate and Calcium-Enriched Mixture Apical Plugs

INTRODUCTION

The purpose of this laboratory study was to evaluate the effect of acidic pH on the sealing ability of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA) apical plugs.

METHODS AND MATERIALS

Seventy single-rooted human maxillary anterior teeth were recruited. The teeth were randomly divided into 4 experimental groups (n=15), and 1 negative and 1 positive control groups of 5. The root canals were cleaned and shaped and the terminal 3 mm of the roots were resected. Then MTA and CEM cement plugs were condensed in apical region with 3 mm thicknesses. The samples were exposed to pH values of 5.5 and 7.4. Leakage was evaluated by the fluid filtration technique at 1, 7, 14, 30 day intervals. Data were analyzed by the repeated measures MANOVA, one-way ANOVA and MANOVA/Bonferroni test.

RESULTS

Acidic pH significantly reduced the sealing ability of MTA after 1, 14 and 30 days (P<0.05). The rate of microleakage in CEM cement samples in acidic pH was significantly greater than that in neutral pH in day 30 (P<0.05). There was no significant difference between the sealing property of MTA and CEM cement at both pH levels (P>0.05).

CONCLUSION

It can be concluded that the CEM cement exhibited similar sealing ability as MTA at both pH levels. In addition, an acidic pH environment reduced the sealing ability of MTA and CEM cement after 30 days.

Cytotoxic effects of various mineral trioxide aggregate formulations, calcium-enriched mixture and a new cement on human pulp stem cells

INTRODUCTION

This in vitro study compared the cytotoxic effects of three commercially available MTA formulations naming ProRoot MTA (PMTA), Angelus MTA (AMTA), and Root MTA (RMTA), with calcium-enriched mixture (CEM) cement and a new nanohybrid MTA (NMTA) on human dental pulp stem cells (DPSC).

METHODS AND MATERIALS

Four disc-shaped specimens of each material were prepared. After completion of setting, 2 different (neat and 1/2) elutes of the test materials were made. Then in each cavity of a 96-well plate, 3000 cells were seeded and incubated in a humidified incubator with 5% CO2 and 95% air at 37(°)C for 24 h. After this period, the culture medium of each well was replaced with 200 μL of test material elutes. Plain culture medium was used as the negative control and distilled water as the positive control group. Cell viability was assessed using 2, 5-diphenyl-SH-tetrazelium bromide colorimetric assay, aka Mosmann's tetrazolium toxicity (MTT) assay, at three time intervals (24, 48, and 72 h after mixing). Data were analyzed using the ANOVA and Tukey's post hoc test (P=0.05).

RESULTS

After 24 h, the viability of cells in neat concentration had no significant differences (P>0.05) except for the NMTA. However, CEM and AMTA, at 1/2 concentration exerted significant proliferative effects on cells. At 48 and 72-h intervals, significant proliferation of DPSCs was seen in all samples, except for the NMTA which exerted toxic effects on cells.

CONCLUSION

All of the three commercial MTAs and CEM cement showed comparative biocompatibility. However, NMTA had cytotoxic effects on DPSCs at all the time intervals.

Outcomes of different vital pulp therapy techniques on symptomatic permanent teeth: a case series

In modern endodontics, vital pulp therapy (VPT) has been considered an ultra-conservative treatment modality. Based on the level of pulp preservation, VPT includes stepwise excavation, indirect pulp capping (IDPC), direct pulp capping (DPC), miniature pulpotomy (MP), partial/Cvek pulpotomy and coronal/complete pulpotomy (CP). The present article reviews the treatment outcomes of 94 permanent teeth with irreversible pulpitis treated with either IDPC (n=28), DPC (n=28), MP (n=29) or CP (n=9) using calcium-enriched mixture (CEM) cement. After a mean follow-up time of 12.3 months, 93 treated teeth were radiographic/clinically successful; only one radiographic failure was observed in the DPC group.

Periradicular surgery of human permanent teeth with calcium-enriched mixture cement

INTRODUCTION

Root-end preparation and restoration with an endodontic material are required when nonsurgical endodontic retreatment has failed or is impossible. The present clinical study reports the treatment outcomes of periradicular surgery using calcium-enriched mixture (CEM) cement.

MATERIALS AND METHODS

A prospective outcome study of periradicular surgery using CEM was conducted on 14 permanent teeth with persistent apical periodontitis. Using a standardized surgical protocol, 2-3 mm of the root apex was resected; approximately 3 mm deep root-end cavities were ultrasonically prepared and filled with CEM cement. All patients were available for recall.

RESULTS

Clinical and radiographic examination revealed complete healing of periradicular lesions, i.e. regeneration of periodontal ligament and lamina dura in 13 teeth (93% success) during a mean time of 18 months; moreover, the teeth were functional and asymptomatic.

CONCLUSION

Favorable treatment outcomes in this prospective clinical study suggested that CEM cement may be a suitable root-end filling biomaterial.

Short term effect of calcium hydroxide, mineral trioxide aggregate and calcium-enriched mixture cement on the strength of bovine root dentin

INTRODUCTION

Some studies in dental literature have proposed that short term and long term exposure of root dentin to calcium hydroxide predisposes it to fracture. Mineral trioxide aggregate (MTA) and a recently introduced endodontic material, calcium-enriched mixture (CEM) cement may be used instead of calcium hydroxide and might have an effect on the strength of root dentin. Therefore, the aim of this in vitro study was to compare the short-term effect of calcium hydroxide, MTA and CEM cement on the strength of bovine root dentin.

MATERIALS AND METHODS

In this experimental study, 15 freshly extracted intact bovine incisors were selected. A cylinder with uniform wall thickness (internal diameter of 2.5 and external diameter of 5.5) was prepared. The cylinders were cut longitudinally into 4 symmetrical pieces. The 60 prepared samples were divided into four groups (n =15). The samples were placed in 4 petri-dishes containing calcium hydroxide, MTA, CEM cement and normal saline as the control group. They were then subjected to flexural forces applied by Instron universal machine. Data was analyzed using ANOVA and Tukey test.

RESULTS

The mean flexural force in the calcium hydroxide, MTA and CEM cement groups was significantly lower than that in the control teeth (77.9 N, 90.66 N, 94.40 N, compared to 125.12 N respectively, P=0.001). There were no significant differences between calcium hydroxide, MTA and CEM cement group.

CONCLUSION

MTA and CEM cement decreased the flexural strength of bovine root dentin, like their counterpart calcium hydroxide. Further studies are required to determine the effect of these materials on human root dentin clinically.