• The Journal of the Korean dental association
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• v.37 no.3 s.358
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• pp.205-205
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• 1999

• Restorative Dentistry and Endodontics
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• v.33 no.2
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• pp.107-114
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• 2008

This study was performed to assess the radiopacity of a variety of canal filling and retrograde root-end filling materials according to the specification concerning root canal obturation materials. Ten materials including Gutta-percha pellets, amalgam, Fuji II LC, $Dyract^{(R)}$ AP, Super $EBA^{(R)}$, $IRM^{(R)}$, AH $26^{(R)}$, $Sealapex^{TM}$, Tubli-$Seal^{TM}$, and dentin were evaluated in this study. In the first part, densitometric reading of an each step of aluminum step wedge on occlusal film were performed at 60 kVp (0.2, 0.3, 0.4 s), 70 kVp (0.2, 0.3, 0.33 s) to decide appropriate voltage and exposure time. In the second part, ten specimens which are 5 mm in diameter and 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mm in thickness, were fabricated from each material studied. The specimens were radiographed simultaneously with an aluminum step wedge under decided condition (60 kVp, 0.2 s). The mean radiographic density values of the materials were transformed into radiopacity expressed equivalent thickness of aluminum (mm Al). The following results were obtained. 1. Among the various conditions including 0.2 s, 0.3 s, 0.4 s at 60 kVp and 0.2 s, 0.3 s, 0.33 s at 70 kVp, the appropriate voltage and exposure time that meet the requirement of density from 0.5 to 2.0 was 0.2 s at 60 kVp. 2. All of the materials in this study had greater radiopacity than the minimun level recommended by ISO No. 4049 standards. 3. Most of the materials had greater radiopacity than 3 mm Al requirement of ANSI/ADA specification No. 57 (2000) and ISO No. 6876 (2001) standards except for Fuji II LC and Dyract. It suggests that all experimental canal filling and retrograde root-end filling materials have a sufficient radiopacity that meet the requirement concerning root canal obturation materials except for Fuji II LC and Dyract.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.222-228
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• 2010

The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 ($TGF{\beta}1$) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.17-32
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• 1995

The purpose of this study was to examine the response of periradicular tissues to amalgam, IRM, Ketac-silver and MTA(Mineral trioxide aggregate) used as a root end fillings. The lower third and fourth premolars of 5 mongrel dogs were used. Each root was resected, followed by root end fillings with experimental materials. The animals were sacrificed after 16 weeks and radiographic and histologic results were evaluated. The results were as follows : 1. Severe inflammation around apex and disruption of cortical were noted in relation to the amalgam. 2. With IRM, there was severe infiltration of inflammatory cells around filling material, but healing of cortical bone was noted. 3. With Ketac-silver, mild inflammation and thick band of fibrous connetive tissue around filling material were seen, with a cortical bone healing. 4. In case of MTA, complete regeneration of cortical bone was seen, and free MTA was surrounded with newly formed bone tissue.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.499-512
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• 1994

The purpose of this study was to evaluate the microleakage electrochemically using different retrograde filling materials, different root resection angle, and different cavity preparation instruments. 104 extracted single-rooted teeth were selected for this study. 100 teeth were used as experimental groups and four was used as controls. Anatomical crowns were resected, root canals were prepared, and the apical 2 mm of roots were removed. The experimental roots were randomly divided into five equal groups. Experimental groups : Group 1. no bevel, cavity preparation with ultrasonic instruments, amalgam filling Group 2. no bevel, cavity preparation with ultrasonic instruments, SuperEBA cement filling Group 3. no bevel, cavity preparation with ultrasonic instruments, desiccated ZOE filling Group 4. $45^{\circ}$ bevel, cavity preparation with ultrasonic instruments, amalgam filling Group 5. no bevel, cavity preparation with conventional bur, amalgam filling Microleakage was measured once a day for 30 days using electrochemical method and were analyzed statistically. The results were as follows : 1. The group with Super EBA cement filling showed the least marginal leakage from second to fourth day(p<0.05), there was no significant difference between the group with amalgam filling during eighth to eighteenth day(p>0.05), but after the nineteenth day here was a higher marginal leakage than the group with amalgam filling(p<0.05). 2. The group with desiccated ZOE filling demostrated that the highest marginal leakage, started on the eighth day(p<0.05). 3. The group using ultrasonic instrument showed lower marginal leakage than the group using bur until the nineteenth day(p<0.05), but there was no significant differnce with the group using bur after twentythird day(p>0.05). 4. The group without bevel showed lower marginal leakage than the group with bevel (p<0.05). 5. Whether bevel or nor had much more effect on marginal leakage than with cavity perparation instrument when the cavity was retrogrdefilled with amalgam(stepwise regression).