ABSTRACT
Statement of Problem: Previous studies have shown discoloration of mineral trioxide aggregate [MTA] in contact with root canal irrigation solutions. However, there are limited data on colour stability of other calcium silicate-based materials [CSMs]
Objectives: This in vitro study aimed to evaluate the colour stability of three CSMs in contact with different irrigation solutions
Materials and Methods: Three CSMs including White MTA [wMTA] Angelus, calcium enriched mixture [CEM], and Biodentine were assessed in this study. Forty five samples of each material were mixed according to the manufactures' instructions and then placed in silicone tubes. After 24 hours, the materials were removed from the moulds and 9 samples of each material left dry or immersed in normal saline, 5% sodium hypochlorite [NaOCL], 2% chlorhexidinegluconate [CHX], or 17%EDTA for 24 hours. Colour changes were measured with a spectrophotometer. Data were evaluated with 2-way analysis of variance, one way analysis of variance and Tukey post hoc tests
Results: The highest discoloration of all materials was observed after contact with CHX. In the MTA Angelus and CEM cement groups, significant differences were observed between CHX and NaOCl and also between these two irrigants with the other three irrigants [p < 0.05]. In the Biodentine group, CHX created statistically significant discoloration compared to other irrigants [p < 0.05]. Only wMTA Angelus showed a significantly higher discoloration in contact with EDTA compared to normal saline and dry condition [p < 0.05]. wMTA Angelus showed a significantly higher colour change compared with CEM cement and Biodentine after contact with NaOCl, CHX, and EDTA [p < 0.05]
Conclusions: The contact of wMTA, CEM cement, and Biodentine with CHX should be avoided because this leads to severe discoloration. Contact with sodium hypochlorite also leads to discoloration of wMTA and CEM cements. Among of the three tested materials, wMTA showed the highest discoloration after contact with NaOCl, CHX, and EDTA
ABSTRACT
Statement of Problem: Adhesion to root canal dentin is one of the necessary characteristics of endodontic sealers. MTA Fillapex [Angelus, Londria, PR, Brazil] is one of the recently introduced MTA-based sealer. Only a limited number of studies have evaluated the bonding of this sealer to the dentin, with conflicting results
Objectives: The purpose of this study was to evaluate the bond strength of MTA Fillapex sealer] to root canal dentin compared to an epoxy resinbased sealer [AH26 sealer]
Materials and Methods: Twenty root blocks [6mm length] were acquired from the middle part of the extracted single-rooted central or lateral maxillary incisor roots and their lumens were enlarged to achieve a diameter of 1.3 mm. MTA Fillapex and AH26 were placed in the lumens of root blocks [n = 10]. The specimens were kept in an incubator for 7 days, the roots were sectioned perpendicular to their long axis to achieve slices with thickness of 1 mm and the push-out test was carried out by a universal testing machine
Results: The mean value of bond strength was 1.84 +/- 0.7 Mpa for AH26 and 0.19 +/- 0.1 Mpa for MTA Fillapex. The difference between the two groups was statistically significant [p < 0.001]
Conclusions: With in the limitation of this study, AH 26 showed significantly higher bond strength in comparison to MTA Fillapex
Subject(s)
Root Canal Filling Materials , Dental Bonding , Dentin , Dental Pulp Cavity , In Vitro Techniques , Drug Combinations , Oxides , Aluminum Compounds , Calcium Compounds , SilicatesABSTRACT
Calcium hydroxide which is commonly used as an intracanal medicament, changes the pH of dentin and periradicular tissues to an alkaline pH. In some clinical situations, endodontic reparative cements like calcium enriched mixture cement are used after calcium hydroxide therapy. However, the alkaline pH may affect the physical properties of this cement. This study was designed to evaluate the effect of alkaline pH on the push-out bond strength of calcium enriched mixture. 80 root slices were prepared from single-rooted human teeth and their lumens were instrumented to achieve a diameter of 1.3mm. Calcium enriched mixture [CEM] was mixed according to the manufacturer's instruction and introduced into the lumens of root slices. The specimens were then randomly divided into 4 groups [n = 20] and wrapped in pieces of gauze soaked in synthetic tissue fluid [STF] buffered in potassium hydroxide at pH values of 7.4, 8.4, 9.4, or 10.4. The samples were incubated for 4 days at 37 degree C. The push-out bond strengths were then measured using a universal testing machine. Failure modes were examined under a light microscope at ×20 magnification. The data were analyzed using one-way analysis of variance and Tukey's post hoc tests. The greatest [1.41 +/- 0.193 MPa] and lowest [0.8 +/- 0.06 MPa] mean push-out bond strengths were observed after exposure to pH values of 7.4 and 8.4, respectively. There were significant differences between the neutral group and the groups with pH of 8.4 [p = 0.008] and 10.4 [p = 0.022]. The bond failure was predominantly of cohesive type for all experimental groups. Under the condition of this study, alkaline pH adversely affected the Push-out bond strength of CEM cement
ABSTRACT
Statement of Problem: The pH of the human abscess has been measured as low as 5.0. This low pH could potentially inhibit setting reactions, affect adhesion, or increase the solubility of root end filling materials hence affect the compressive strength. Moreover, root end filling materials might expose or even mix with lidocaine HCL during periapical surgery
Objective: The aim of this in vitro study was to evaluate the effect of acidic pH and lidocaine on the compressive strength of calcium-enriched mixture [CEM]
Materials and Methods: CEM was mixed according to the manufacturer's instructions or with lidocaine [L], and condensed into 6 × 4 mm split moulds. The samples were exposed to phosphate buffered saline [PBS] at pH 5 or 7.4 for 7 or 28 days. Cylindrical blocks of CEM [total number = 120 and 15 for each group] were subjected to compressive strength test using a universal testing machine. Data were analysed using three-factor analysis of variance [ANOVA]
Results: Regardless of pH and time, significant differences were not found between lidocaine groups and the groups that were mixed according to the manufacturer's instruction [p = 0.083]. For both mixing agents, regardless of time, there were no significant differences between the two pH levels [p = 0.157]. Regardless of the material and pH, there was a significant increase in the compressive strength from days 7 to 28 [p < 0.001]
Conclusion: Mixtures with lidocaine and exposure to an acidic environment had no adverse effects on the compressive strength of CEM Cement
ABSTRACT
There is a great challenge in the treatment of deeply fractured and un-restorable teeth among dentists. Orthodontic force eruption is a method of treatment for these teeth to preserve natural root system and periodontal structures. This technical report is a new modification of this procedure presented in an 11- year old boy with deeply fractured left second mandibular incisor. The fractured teeth were treated with root canal therapy and a file #80 was modified to become a hook cemented into the fractured tooth Anterior teeth were splinted and used as anchorage to help the root extrusion. 1-year follow up of the tooth showed the convenience of the treatment. This simple and low-cost method can be an acceptable alternative to the current high cost techniques, achieving the same results
ABSTRACT
Statement of Problem: Studies reported that nearly 60% of endodontic failures have been attributed to inadequate obturation of the root canal system. Thus, complete obturation of the root canal system and proper apical seal are essential elements in the longterm success of root canal treatment
Purpose: This study aimed to compare the apical seal of lateral condensation technique in the room and in body- simulated temperature
Materials and Method: In this experimental study, 70 extracted, single- rooted, human premolar teeth were instrumented and divided up into four groups. All tooth's canals were obturated by lateral condensation technique except the teeth in the positive control group. Group 1 and 2, each with 30 teeth, were obturated in the room and intracanal temperature respectively. The other two groups were positive and negative control group each with 5 teeth. All groups except negative control were covered by two layers of nail polish. Then linear dye penetration was evaluated with a stereomicroscope. Data was analyzed with student-t test and also Kolmogorov- Smirnov Goodness- of- Fit test to make sure of data
Results: Results showed that dye penetration in group one [obturation in room temperature] was 0.6mm more than group 2 [obturation in simulated-body temperature] although this was not statistically significant [p> 0.05]
Conclusion: Under the condition of this invitro study, apical sealing ability was better in the body-simulated temperature than the room temperature, although it was not statistically significant