Evaluation of the seal of various amalgam products used as root-end fillings

Apical Microleakage of four Materials after Root End Resection (In Vitro Study)

Hermetic sealing of the apical area after root end resection is essential to the success of endodontic surgery. To compare microleakage after root end resection of the two bioceramic sealers without retrograde filling - Total Fill BC Sealer and MTA Fillapex, and two materials for retrograde filling-MTA and Biodentine, using the method of penetration of dye - 2% methylene blue. Forty eight extracted single-rooted human teeth were used in this study. The resection was made at 3 mm from the root tip at an angle of 90 degree to the long axis of the tooth. The teeth were divided into 4 groups: 1st group (n = 9) - root canal obturation with Total Fill BC Sealer without retrograde filling; 2nd group (n = 8) - root canal obturation with MTA Fillapex without retrograde filling. 3rd group (n = 10) - retrograde ultrasonic cavity preparation and filling with MTA. 4th group (n = 8) - retrograde ultrasonic cavity preparation and filling with Biodentine. The outer surface of the root was covered with two layers of varnish, with the exception of the apical 3 mm and then immersed in 2% methylene blue for 72 h. The degree of penetration of the dye is measured in millimeters. The data was entered and processed with the statistical package IBM SPSS Statistics 22.0. We reject the null hypothesis when p < 0.05. With significantly higher value is the arithmetic mean of the group with the root canal obturation with Total Fill BC Sealer without retrograde filling - 2,01 mm; versus a retrograde filling with MTA - 0,68 mm and Biodentin - 0,51 mm; and no statistically significant difference with the group root canal obturation with MTA Fillapex - 1,76 mm. In the four material microleakage dye was observed, but to varying degrees.

The effect of post space preparation in teeth obturated with Mineral Trioxide Aggregate evaluated using a fluid filtration system

The aim of this study was to evaluate the seal of a 4-mm Mineral Trioxide Aggregate (MTA) filling after post space preparation. Forty single-rooted premolar teeth without curved root anatomy and fractures were selected. The root length was standardized to 12 mm by removing excess from the apical end. The roots were instrumented to a 50 K-file by the step-back technique. The roots were randomly divided into groups A and B, of fifteen each. In group A, the canals were obturated with 7 mm of white MTA. After 24 h, 3 mm of MTA was removed to simulate post space preparation using a long shank diamond round bur. In group B, the canals were filled with 4 mm of white MTA. All samples were attached to a fluid filtration device. Measurements (µl min⁻¹ cm H₂O⁻¹) were taken every 2 min, for 10 min and data were analyzed by an independent t-test (P > 0.05). Fluid transport averaged in groups A and B at 9.2 × 10⁻⁴, and 11.8 × 10⁻⁴ µl min⁻¹ cm H₂O⁻¹, respectively. Independent t-test showed no significant difference between the groups (P < 0.05). Removing set MTA using a round bur for post space preparation does not affect its sealing ability, when 4 mm of MTA remains.

Effect of root resection on the apical sealing ability of mineral trioxide aggregate

OBJECTIVE

The purpose of this in vitro study was to determine the minimum depth of mineral trioxide aggregate (MTA; ProRoot; DENTSPLY/Tulsa Dental, Tulsa, Okla) required to maintain an apical seal following root resection. Study design. In 10 instrumented teeth, MTA was used to obturate the apical 6 mm of the root canal and was allowed to set for 48 hours. Leakage was determined by means of a fluid filtration method at a pressure of 20 cm H(2)O. Leakage was measured before root resection, and after 3, 4, 5, and 6 mm apical resections. Data were analyzed by means of a Kruskal-Wallis one-way analysis of variance with P <.05.

RESULTS

Fluid leakage was shown to increase after each resection, but did not reach statistical significance (P <.05) until 4 mm of the apex had been removed.

CONCLUSION

The results indicate that root resection did not significantly affect the sealing ability of MTA when at least 3 mm of the MTA remained. Although there was a statistically significant difference in leakage following the 4 mm resection, it is unknown what the biological difference would be between the 3 mm and 4 mm resections.

A new single-step technique for apical retrofilling that significantly reduces microleakage

One of the properties of an ideal retrofilling material is little or no microleakage. A new dentin bonding agent based on polyacrylic acid (PAA) is ideally suited to the moist apical environment because of its hydrophilic nature. PAA as a dentin bonding agent for apical retrofillings was tested in an in vivo leakage study using single canal roots of extracted human teeth. Bonding was attained by pretreatment of the dentin in apical retrofilling preparations with a solution of PAA, followed by placement of a nonaqueous restorative material. Using PAA as dentin bonding agent reduced apical leakage at statistically significant levels with Super EBA as a restorative material. In vivo testing is required to validate these findings.

Review of dental materials citations: Part B, July to December 1995

OBJECTIVE

A lag of many months occurs between journal issue publication and updates to electronic databases. The objective of this literature analysis was to identify and categorize all of the dental materials citations in biomedical journals that were published from July 1995 through December 1995.

METHODS

Seventeen primary and 51 secondary journals were searched using their tables of contents to detect and record dental materials publications from July to December of 1995. Those journals that were typically rich in dental materials articles were classified as primary ones. Citations were categorized into 17 topics and divided into subsections. The review excluded case reports, most literature related primarily to dental implants, and most articles on biomedical materials used outside of the field of general dentistry.

RESULTS

The greatest number of citations was related to topics of dentin bonding and resin-based restorative filling materials (composites and glass ionomers). There was no major change in the number of dental materials publications per year reported from 1993 (n = 786) to 1995 (n = 751).

SIGNIFICANCE

This citation list provides a comprehensive resource for use by academicians and researchers to bridge the gap between initial publication and access to electronic searching methods for major databases.