Journal of Dental Medicine

Statement of Problem: The pulp may be exposed during remove of caries or by traumatic and iatrogenic injuries. The material used to DPC, must be biocompatible, scalable and prevent bacterial leakage.Furthermore, it is better to stimulate dentinogenesis. Calcium hydroxide is most usual material for DPC. But it cannot provide a suitablcbiologic seal. Mineral irioxide aggregate (MTA) is also a suitable material for DPC.
Purpose: The aim of this study was to compare the clinical success of DPC done with MTA or calcium hydroxide cement.

Materials and Methods: In this study eighteen posterior teeth without previous spontaneous pain that involved mechanicaly exposure was randomly selected and capped with MTA or calcium hydroxide. These teeth were evaluated by clinical vitality test and radiograph after 3 and 12 months, and patients were questioned about irritative or spontancus pain in this period. Statistical analysis was carried out by Usher exact
test (a-0.05).
Results: This study showed that in calcium hydroxid groud three had irreversible pulpitis and two teeth had symptom and signs of reversible pulpitis. While, In MTA group all cases were normaL and no clinical sign was evident.
Conclusion: MTA exhibited better results than calcium hydroxide cement for the capping of the pulp in human

Background and Aim: The goal of endodontics is to seal the root canal system from the orifice to apical constriction completely and tridimensionally.Hence perforations during root canal therapy, because of caries or resorptions must be sealed and obturated with ideal materials. The aim of this study was to histologically compare two kinds of mineral trioxide aggregate Root MTA and Pro Root MTA for furcal perforation repair in developed teeth in dog.

Materials and Methods: In this experimental study, thirty teeth consisting of second, third and fourth mandibular premolars of five German shepherd dogs were selected. Twenty-four teeth were randomly divided into four experimental groups (6 teeth each). One pair of Root MTA and Pro Root MTA groups studied in one month and the other in three months intervals. Positive and negative control groups was each contained three teeth. In positive control group, perforations were not treated and negative control group contained intact teeth. In experimental groups perforations repaired after one week exposure to oral cavity with Root MTA or Pro Root MTA. After time intervals animals were subjected to vital perfusion and 6 m histologic sections were prepared. Inflammation and hard tissue formation were ranked by Cox criteria. Data were analysed using Mann-Whitney and Chi-Square statistical tests with P<0.05 as the limit of significance.

Results: There was statistically significant lower inflammation and higher hard tissue formation in three months Root MTA and Pro Root MTA groups compared to one month interval (P<0.05). There was no statistically significant difference in inflammation and hard tissue formation between Root MTA and Pro Root MTA in each intervals (P>0.05).

Conclusion: Mineral Trioxide Aggregate is an adequate material for furcal perforation repair in dog’s teeth. Root MTA could be a good substitute for Pro Root MTA considering the lower cost and similar characteristics.

Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro Root MTA in in-vitro and in-vivo studies has been proven. On the other hand, based on some studies, Root MTA (Iranian Pro Root MTA) and Portland cement are similar to Pro Root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time) of four root- end filling materials.

Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro Root MTA, white Pro Root MTA, Root MTA (Iranian Pro Root MTA), Portland Cement (type I) and positive and negative control groups. Root canals were instrumented using the step- back technique. Root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556). Culture media were observed every 24h for colour change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance.

Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro Root MTA, White Pro Root MTA. Root MTA and Portland Cement (type I) had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time) of the four tested root- end filling materials (P=0.9958).

Conclusion: Based on the results of this study, there were no significant differences in leakage among the four tested groups at 60 days. The results suggest that Root MTA and Portland Cement can be used as less expensive root filling materials.

Background and Aim: Achieving appropriate seal in canal obturation is the main goal of endodontic therapy. However, in some cases, it can not be obtained by non-surgical procedures alone. Retrograde surgery is one of the most common procedures in endodontics. Apical seal improvement can be obtained by root end filling and decreasing the root end resection angle (bevel angle). The aim of this study was to investigate the role of bevel angle on apical microleakage following the use of amalgam and MTA as root end filling materials.

Materials and Methods: In this experimental study, 128 extracted human teeth were instrumented and obturated by lateral condensation technique. The teeth were divided into two groups and the apical root resection was performed by high speed fissure bur (one group perpendicular to the long axis of the teeth and the other 45 to the long axis. The 3 mm root end cavity was prepared by ultrasonic device. Each group was divided into two subgroups: One filled with amalgam and the other with MTA. Teeth were incubated for 72 h, covered by two layers of nail polish (except for apical 3mm) and submerged in methylene blue for 48 h. Teeth were washed under tap water and mesiodistally dissected by low speed disc. Dye penetration was evaluated by stereomicroscope. Data were analysed by two way ANOVA and Tukey tests with p<0.05 as the limit of significance.

Results: The results showed that retrofill material type had a significant effect on microleakage and MTA was superior to amalgam in this respect. Bevel angle failed to show any significant effect on apical microleakage.

Conclusion: Based on the results of this study, it seems that the use of MTA instead of amalgam in clinical practice can improve the success rate of endodontic surgery whereas the bevel angle can be determined based on the status of each individual case However, increasing the bevel angle seems to increase microleakage due to exposure of more dentinal tubules.

Background and Aim: Vital pulpotomy in primary teeth is performed to maintain the vitality of the pulp and tooth until normal exfoliation. Different materials such as zinc oxide- eugenol, calcium hydroxide and formocresol are used in this procedure. The aim of this study was to evaluate the application of formocresol (FC) and mineral trioxide aggregate (MTA) in pulpotomy of primary molars.

Materials and Methods: In this clinical trial, one hundred and twenty six children (aged 5 to 9 years old) with dental caries that were candidate for pulpotomy were selected and randomly divided into two groups. After removing the roof of the pulp chamber, coronal pulp was cut at the orifices and bleeding controlled. In control group, formocresol was applied for 5 minutes. In case group, MTA paste was used as pulpotomy agent. The crowns of both groups were restored with amalgam and the teeth were evaluated clinically and radiographically after 3 and 6 months follow up. Data were analyzed by Fisher test with p<0.05 as the limit of significance.

Results: No sign of clinical failure was observed after 3 and 6 months follow-up. Comparison between the two methods revealed no significant difference in radiographic findings of the teeth and surrounding tissues after 3 months follow-up. However, after 6 months follow-up, internal resorption was observed radiographically in four cases of formocresol group.

Conclusion: Based on the results of this study, pulpotomy with MTA showed more successful results than formocresol radiographically. MTA is recommended as a good substitute for formocresol in pulpotomy of primary molars.

Background and Aim: Furcal perforation has a great impact on prognosis of endodontic treatments, requiring immediate and proper intervention. Gray MTA is applied as material of choice in repairing perforations. The aim of this study was to evaluate the repair of mechanical furcal perforations, histologically using white MTA and Portland cement and compare them with gray MTA.

Materials and Methods: In this experimental study, second to fourth mandibular and maxillary premolar teeth of five dogs received endodontic treatment, then the furcation area of the teeth were perforated and repaired as follow: gray MTA in group1, white MTA in group 2, Portland cement in group 3 and cotton pellet in group 4 (control). Animals were controlled for 4 months and sacrificed using an over dosage of sodium thiopental intravenous injection and perfusion of 10% formaldehyde. Chi-square and Fisher exact tests were used to compare hard tissue formation between groups and between each two groups, respectively. Non-parametric Kruskall Wallis and Dunn procedure were also used to compare degree of inflammation among groups and between each two groups, respectively.

Results: Gray MTA had more favorable results (90.9% hard tissue formation and only 9.1% severe inflammation) but the difference between gray MTA, white MTA and Portland cement was not statistically significant.

Conclusion: The difference between gray MTA, white MTA and Portland cement groups was not statistically significant for degree of inflammation and hard tissue formation. In conclusion both white MTA and Portland cement can be used instead of gray MTA to repair perforations in accordance to esthetic considerations.

Background and Aim: Mineral Trioxide Aggregate (MTA) is a material used in many endodontic problems. Recently a number of studies, have reported that Portland Cement (PC) and MTA have similar physical, chemical and biologic properties. In addition, a material known as Root MTA which is produced in Iran has been claimed to have similar properties to Pro Root MTA. If these claims are true, possible use of PC and Root MTA in clinic instead of Pro Root MTA will be quite cost effective. The aim of this study was to investigate the toxicity of Pro Root MTA, Root MTA and Portland Cement on L929 mouse fibroblasts.

Materials and Methods: In this experimental study 0, 4, 24 hours and 7 days' extracts of materials were transferred to cell culture plates containing L929 fibroblasts. After 24 hours incubation, cells were stained by Neutral Red (NR), and optical density (OD) of each cell was read with ELISA reader. Data were analyzed using Tukey HSD and one way analysis of variance. P<0.05 was considered as the level of significance.

Results: In all surveyed groups and negative control group, at all time points separated cells from the base of the well were round. Refraction which is a characteristic of cellular death was not observed, whereas the separated cells from the base of well in positive control group showed refractional characteristic.

Conclusion: Based on the findings of this study Pro Root MTA, PC and Root MTA have the same biocompatibility. PC seems to have the potential to be used in the same clinical situation as MTA. However in order to replace MTA with these less expensive materials more in vitro and in vivo studies are suggested.

Background and Aim: Incomplete root development caused by trauma ,caries, or pulpal pathosis requires special attention and treatment . Although calcium hydroxide apexification has been used successfully for years but it requires patient cooperation and multiple appointments . Single visit apexification with MTA has been used in recent years. The purpose of this study was to compare bacterial microleakage of two types of MTA (Made in Iran and Brazil) applied as apical barrier in open apex teeth.

Materials and Methods: 48 single root teeth were used in this experimental in vitro study. Teeth apices were prepared as open apex teeth. For canal obturation the 4mm of root end was filled with 2 types of MTA (white Iranian MTA salami co. Iran and Angelus MTA Angelus Brazil) from coronal access. Teeth were mounted in self-cured acryl and put in BHI microbial culture. A suspension of Staphylococcus epidermidis was injected from coronal area into the root canals.The teeth were incubated and examined every 24 hours for microbial microleakage, indicated as turbidity in culture. Data were analyzed using Fisher exact test with p<0.05 as the level of significance.

Results: Microleakage appeared after 15 days in all Iranian and after 17 days in Angelus MTA samples.There was no significant difference between microleakage of two types of MTA (P = 0.48).

Conclusion: Based on the results of this study, there was no significant difference between microleakage of Iranian and Angelus MTA. If further studies confirm other physical, chemical, biological and sealing properties of Iranian MTA, it could be recommended for clinical application

Background and Aim: Osteoblasts and periodontal ligament cells play a major role in wound healing after root end resection. The interaction of osteoblasts with filling materials is critical in healing of surgical lesions. The aim of this study was to evaluate the morphology and adhesion of human osteoblasts (MG-63 cell line) in contact with IRM, gray MTA, white MTA and Portland cement (PC) as root end filling materials.

Materials and Methods: In this in vitro study, human osteoblasts of osteosarcoma were provided from the cell bank of Iran Pasteur Institute, and cultured in RPMI 1640 medium. Test materials were mixed according to the manufacturer's instructions and placed in contact with osteoblast cells. After the first, third and seventh days discs of materials with grown cells were fixed and examined by scanning electron microscopy.

Results: Results showed that after 7 days most of the osteoblasts were attached to the surface of both gray and white MTA and PC and appeared flat or round, however cells adjacent to IRM were round without any adhesion and spread.

Conclusion: Based on the results of this study, human osteoblasts have a favorable response to gray and white MTA and Portland cement compared to IRM.

Background and Aim: Several materials have been introduced for retrograde fillings, pulp capping and sealing root perforations, but their biological effect on vital tissues and cells is not clear. The purpose of this study was to evaluate the reaction of human periodontal ligament fibroblasts to four root canal filling materials: Pro Root MTA, Root MTA, Portland cement and amalgam.

Materials and Methods: In this experimental study, impacted or semi impacted third molar teeth were extracted in aseptic conditions and tissues around the roots were used to obtain fibroblast cell line. After proliferation, cells were cultured in chamber slides and extracts of materials were added to wells. Fibronectin, type I collagen and TGF-  expression were measured by immunocytochemistry method. Data were analyzed by SPSS 11.0 using one way ANOVA and Tukey test. P<0.05 was considered as the limit of significance.

Results: Collagen I expression was higher in Pro Root MTA group after 24 hours (p<0.05) and in Portland cement group and positive controls after 48  hours. Portland cement group showed the highest expression of collagen after 1 week. There was no significant difference in fibronectin expression after 24 hours. After 1 week the highest expression of fibronectin was seen in Portland cement, Root MTA and Pro Root MTA groups. TGF-  expression was higher in amalgam, Root MTA and Pro Root MTA specimens after 24 hours and was the highest in Pro Root MTA group after 48 hours.

Conclusion: Based on the results of this study, Portland cement and Root MTA are comparable with Pro Root MTA and better than amalgam regarding their effects on human periodontal ligament fibroblasts.

Background and Aim: Three Dimensional obturation of root canal is one of the main goals of root canal therapy to preserve health or reach the regeneration or healing of periapical tissues. Root end filling materials are used in numerous situations to reach the mentioned goals. One of the common root end- filling materials is mineral trioxide aggregate (MTA) which the foreign and Iranian ones are different in their prices. The aim of this study was to compare the rat connective tissue reaction to Iranian and foreign MTA.

Materials and Methods: This was an animal study in which 40 rats were divided into 5 groups of each 8. The polyethylene tubes filled with foreign (Pro Root MTA) and Iranian (Root MTA) white MTA and were implanted in subcutaneous connective tissue. Similarly, the empty tubes were inserted in subcutaneous connective tissue as control group. The samples were examined histologically after 7, 14, 30, 60 and 90 days and were scored as followings: 0, was characterized to samples without inflammatory cells without inflammatory reaction 1, for samples with less than 25 inflammatory cells mild inflammatory reaction. 2, for samples with 25 to 125 inflammatory cells moderate inflammatory reaction and 3, for ones with more than 125 inflammatory cells severe inflammatory reaction. The data were analyzed using Kruskal-Wallis test and p<0.05 was considered as the level of significance.

Results: In general, inflammatory reactions were reduced in all groups. Experimental groups had moderate to severe inflammation in the 7th day which had significant difference with the control group having mild to moderate inflammation (p=0.04). There was not any significant differences between experimental and control group in 14th, 30th, 60th and 90th days (p>0.05).

Conclusion: Based on the findings of this investigation, inflammatory subcutaneous connective tissue reaction to Iranian (Root MTA) and foreign (Pro Root MTA) MTA was the same.

Background and Aim: One of the unique properties of MTA is its setting ability in presence of moisture. The sealing ability of MTA used as a root-end filling was shown to be unaffected by the presence of blood, in vitro. It has been recommended that, because of MTA ability to set in the presence of blood, there is no need to dry the perforation site before MTA placement. On the other hand, based on an in vitro study, it is recommended that hemorrhage be controlled at the perforation site and blood be removed from the perforation walls before placement of tooth-colored MTA. Blood contamination may also affect the crystalline structure of MTA. The microhardness of a material is influenced substantially by some fundamental properties of the material such as crystal structure stability. Thus, it can be used as an indicator of the setting process. It can also indicate the effect of various setting conditions on the overall strength of a material. The aim of this study was to evaluate the effect of blood contamination on microhardness of white and gray MTA as an indicator of their setting process.

Materials and Methods: In groups 1 and 2 each material has been mixed with distilled water according to manufacturer^,s instruction (No contamination groups). In groups 3 and 4 samples were prepared like groups 1 and 2 but the surface of material placed in contact with blood (Surface blood contamination groups). Samples of groups 5 and 6 were mixed with blood instead of distilled water and also the surfaces of the materials were placed in contact with blood (Mixed with blood groups). All samples were stored in 37⁰C and 100% humidity for 96 hours. The microhardness of the samples was measured with Vickers test.

Results: White MTA samples which have not contaminated with blood had the highest microharness (59.9±11.4 N/mm²) while gray MTA mixed with blood had the lowest hardness (18.45±7.8 N/mm²). One-way ANOVA test showed that contamination with blood significantly reduces the microhardness of both white and gray MTA (p<0.001). The difference between white MTA and gray MTA was significant in groups of no contamination (p<0.001), surface blood contamination (p=0.043), and mixed with blood (p<0.001) according to T-Test analysis. In all of them white MTA had higher hardness than gray MTA.

Conclusion: According to results of our study we recommend that hemorrhage should be controlled and any blood contamination should be removed before placement of both white and gray MTA.

Endodontic treatment of immature permanent teeth accompanies with several issues. The primary goal when treating such teeth is to maintain pulp vitality so that root development can occur normally. Indications and requirements for vital pulp therapy include asymptomatic and reversible pulpitis. Also there are controversial opinions regarding the ultimate clinical treatment of the vital pulp therapy techniques. In this manuscript we report 3 cases of immature symptomatic permanent molars with irreversible pulpitis caused by caries exposure of the pulp that have been undergone vital pulp therapy successfully.

Background and Aim: Several agents were used for pulpotomy in primary molars. Formocresol is the most common drug in this procedure. In some studies it has been shown that, this material has potential some side effects, so it is essential to find other alternatives. The aim of this study was to evaluate clinical and radiographic success rates of mineral trioxide aggregate and formocresol.

Materials and Methods: In this randomized clinical trial study, 70 carious primary teeth of 4 to 7-year-old children were pulpotomized, and remaining pulp was dressed with Root MTA and formocresol. The clinical and radiographic follow up evaluations were performed at 6, 12 months by a blind dentist. The data were analyzed by Fisher's exact test.

Results: At the end of 1-year follow-up period, in formocresol group sinus tract and tenderness to percussion were seen in 2 teeth, internal resorption was seen in 1 tooth, and furcation radiolucency was seen in 2 teeth. Clinical and radiographic signs of failure were not seen in any case of (Iranian) Root MTA group.

Conclusion: Based on the results of this study, Iranian MTA can be used for pulpotomy in primary molars.

Background and Aims: Considering advantages and disadvantages of mineral trioxide aggregate (MTA), Calcium Enriched Mixture (CEM) cement has been developed recently. The purpose of this study was to compare the apical microleakage of the root-end cavities prepared by ultrasonic or Er,Cr:YSGG laser and filled with MTA or CEM cement.

Materials and Methods: Eighty single-rooted, extracted human teeth were instrumented and obturated. Root-end resection was made by removing 3 mm of the apex. The teeth were randomly divided into two experimental (n=30) and two positive and negative control (n=10) groups. After that, the retrograde cavities were prepared using ultrasonic or Er,Cr: YSGG Laser. According to the root-end filling materials (MTA or CEM cement), each group was then divided into two subgroups. Finally, specimens were cleared for assessing the amount of apical dye (Indian ink) penetration. The data were analyzed using Kruskall-Wallis and Dunn tests.

Results: Laser/CEM cement group showed significantly the lowest mean apical dye penetration. There were no statistically significant differences between Laser/MTA, ultrasonic/MTA and ultrasonic/CEM cement groups.

Conclusion: Based on the findings of this study, CEM cement demonstrated lower rate of apical leakage compared with MTA, when the root-end cavities prepared with Er,Cr:YSGG Laser. The sealing ability of MTA was not different following root-end preparation by ultrasonic or Er,Cr:YSGG Laser.

Background and Aims: It is important to use intracanal medicaments in teeth with necrotic pulp. Calcium hydroxide is the intracanal medicament of choice in such cases. Also, Mineral Trioxide Aggregate (MTA) is a suitable root canal filling material because of its favorable characteristics. MTA can be used in some cases where calcium hydroxide is used. The purpose of this study was to evaluate the Ca++ and OH ˉ diffusion through root dentin using calcium hydroxide paste and two different brands of MTA as root canal filling materials.
Materials and Methods: In this in vitro study, the root canals of 52 single-rooted teeth were instrumented and shaped. External defects were created on the middle one-third of the root surface. 17% EDTA and 5% NaOCl were used to remove the smear layer. All surfaces except the external defects were sealed and the teeth were placed in normal saline. Ten teeth were selected as the control group. Forty-two remaining teeth were divided into three groups of 14 teeth each (A,B, and C groups). ProRoot MTA was placed in group A. Angelus MTA was placed in group B and Calcium hydroxide paste was placed in group C. After sealing the coronal access, all specimens were placed in normal saline solution. Ca++ concentration and pH were determined after 24 hours, 48 hours and one week in all groups. The data were analyzed with Repeated Measure ANOVA and Pair T- tests.
Results: Ca++ release and pH in group C was significantly higher than those in groups A and B in all time periods (P<0.001). The difference between groups A and B was not significant (P>0.05).
Conclusion: The results of this study indicate that in necrotic cases with lesion which MTA is indicated (open apex and perforation), calcium hydroxide might be better used as an intracanal dressing before using MTA as a permanent filling material.