effect of one-step or two-step MTA plug and tooth apical width on coronal leakage in open apex teeth

Mineral trioxide aggregate [MTA] has been suggested as an effective material for apical barrier, forming an effective seal against bacterial leakage in teeth with open apices. MTA needs moisture for setting; which can come from the apical region or a moist cotton pellet. This study was intended to compare bacterial leakage in one- and two-step MTA apical barrier technique in open apices with different diameters. The root canals of 52 extracted human maxillary incisors were prepared and open apices in two different diameters of 1 and 1.4 mm were created. The samples put in experimental groups randomly. A 4-mm thickness of MTA was placed as apical barrier for both one- and two-step methods. In one-step groups [1.4 mm diameter; n=12 and 1 mm diameter; n=12], the samples were obturated immediately after placing MTA plug. For two-step groups [1.4 mm diameter; n=12 and 1 mm diameter; n=12], a moist cotton pellet was placed over the MTA plug for 3 days before root canal obturation. Four samples served as positive/negative control groups. After one week, microleakage was evaluated using bacterial penetration technique and results were statistically analyzed utilizing SPSS software and Chi-square test. In one-step technique 13 and in two-step technique 12 samples showed bacterial leakage. There was no statistically significant differences between two techniques [Chi square, P=1]. The difference between the results related to 1 and 1.4 mm apical foramens was also not significant [P=1]. Also 12 and 13 samples showed bacterial contamination in teeth with 1 mm and 1.4 mm apical foramens, respectively [P=1]. It seems that leakage of MTA apical plug using one- and two-step technique is comparable; however, in vivo investigations are highly recommended for more accurate results

effect of blood on apical microleakage of Epiphany and AH26: an in vitro study

Blood contamination of the canal during preparation can be a major problem in endodontics; this may result in apical microleakage. The aim of this in vitro study was to evaluate the effect of blood on apical microleakage of a resin-based root canal sealer [AH26] and a polymer-based root canal sealer [Epiphany].In this experimental study, 50 decoronated' central incisors and canine teeth were prepared by RaCe rotary system and randomly divided into 4 groups [n=10]. Groups A[1] and A[2] were obturated by Epiphany/Resilon and AH26/Gutta-percha, respectively. The obturations were performed with a single cone technique after drying root canals. In B[1] and B[2] groups, the test groups, 0.02cc citrated human blood was injected into dried root canals and they were obturated in the same manner. Ten specimens were served as positive and negative controls [n=5].The apical leakage was measured by means of a computerized fluid filtration method after 1 day and 3 weeks. The data was analyzed by One-Sample Kolmogorov-Smirnov, Independent Sample t-test and univariate analysis. Statistical significances were preset at a=0.05. There was no significant difference in apical microleakage of the two sealers after 1 day and 3 weeks in dry and blood environment [P>0.05]. Sealer and environment had no interaction [P>0.05]. Blood contamination has no significant effect on the apical microleakage of Epiphny and AH26

Efficacy of two rotary systems in removing gutta-percha and sealer from the root canal walls

The aim of this in vitro study was to compare the efficacy of two retreatment rotary systems in removal of gutta-percha [GP] and sealer from the root canal walls with and without use of solvent. Sixty single-canalled distal roots of mandibular molars were prepared and root filled with gutta-percha and AH26. Each canal was randomly allocated to receive one of the retreatment techniques, Mtwo R or ProTaper. The groups were further divided into two subgroups: with or without the use of solvent. The cleanliness of canal walls was determined by stereomicroscope and scanning electron microscopy. The results showed that Mtwo R without the use of solvent was more efficient in material removal compared to ProTaper D [P<0.05]. Most remnants were found in the apical third of the canals [P<0.05]. Mtwo R seems to be an efficient rotary system for endodontic retreatment of root canal with GP

[Comparison of MTA ,CEM and geristore on quantity of human gingival fibroblasts attachment]

Background and Aim: Quality and quantity of cells attachment to retrograde filling materials, determines its biocompatibility, the aim of this study was comparison of quantity of fibroblasts cell attachment to three retrogradefilling materials: Geriostore, MTA and CEM

Materials and Methods : In this invitro study, eight discs from each retrofilling materials were prepared and placed in fibroblasts culture, then specimens were fixed in Osmium and different concentration of alchohol , after three time periods of 24,48 hours and one week, fibroblast cells counting was done by scanning electron microscope [SEM] and data were analyzed by one way Anova and Tukey Tests

Results: The result showed that fibroblasts cell attachment to CEM were [1.4 +/- 0.24],[8.6 +/- 0.4],[8.2 +/- 0.2] to MTA were [0.4 +/- 0.24] ,[2.8 +/- 0.96],[6.8 +/- 0.37] and to Geriostore were [0.6 +/- 0.2],[0.4 +/- 0.2],[0.2 +/- 0.2] in 24 ,48 hours and one week respectively. There was significant differences between three materials in every periods of time. [p<0.05]

Conclusion: the most fibroblasts cell attachment related to CEM in 72 hours and the least one was Geriostore in one week period. Cell attachment increased with increasing the time in CEM and MTA but decreased in Geriostore

Endodontic treatment of a maxillary first premolar with type IV buccal root canal: a case report

The maxillary first premolar may present large number of anatomic variations. The clinician should be aware of the configuration of the pulp system. Maxillary first premolars usually have two canals. The incidence of three canals in these teeth is quite rare. This case report presents the diagnosis and clinical management of a maxillary first premolar with two distinct canals in the apical third of buccal root [type IV], drawing particular attention to tactile examination of all the canal walls

Comparison of canal preparation pattern of K3 and ProTaper rotary files in curved resin blocks

The purpose of this study was to evaluate and compare canal preparation pattern of K3 and ProTaper rotary files in curved resin blocks. Twenty-four resin blocks were used in this experimental study and randomly divided into two groups. Their initial images were scanned. After preparation, their images were scanned again in the same position. Pre and post preparation images were superimposed by Photoshop software and the removed resin was measured in 5 different points, and then analyzed statistically by ANOVA and t-tes. At O point [orifice], significantly [p

Delayed tooth replantation after traumatic avulsion: a case report

Avulsion is serious injury cause damage to dental and supportive tissues, ranges from 1-16% among dental injuries and itmostly occurs in maxillary incisors. This report presents a case of replantation of a traumatically avulsed central incisor. The left central incisor of an 8 yearold boy with open apex was avulsed and was left in unclean and dry conditions. Tooth was replaced after 270 min and splinted. After 24 hours, tooth was treated endodontically. The calcium hydroxide paste was applied as intracanal medicament. After one year the calcium hydroxide was not replaced and was maintained in the canal, permanently. The tooth followed for 5 years. During follow up, the tooth kept stable. However, the resulted dentoalveolar ankylosis prevented growth of the alveolar process. Spite of the fact that in children, replacement resorption leads to the loss of ankylosed teeth within 1-5 years; this tooth has remained in a stable, infra-position for 5 year and in functional position after coronal restoration. However, in such cases other treatments such as decoronation should be considered

Comparison of extracted teeth and simulated resin blocks on apical canal transportation

We aimed to compare apical canal transportation of extracted teeth and two types of simulated resin blocks. Mesiobuccal root of extracted maxillary molars, high hardness simulated resin blocks [Knoop hardness=40] and low hardness simulated resin blocks [Knoop hardness=22] were prepared with K-files using step-back technique [n=15 canals in each group]. Double exposure radiographic technique was used for extracted teeth. Simulated resin blocks were stabilized and scanned before and after preparation. Pre and post-preparation pictures were superimposed and apical transportation was measured. The data were analyzed statistically using ANOVA and Tukey HSD tests. There was no significant difference in apical canal transportation between extracted teeth and high hardness resin blocks [P>0.05]. Low hardness resin blocks showed more apical transportation than the other groups [P<0.05]. Under the conditions of this study, apical canal transportation for extracted teeth and high hardness simulated resin blocks were similar