Sealing ability and adaptation of root-end filling materials in cavities prepared with different techniques

Utility of biphasic calcium phosphate cement as a seal for root-end filling

The recently developed biphasic calcium phosphate cement (BCPC) consists of α-tricalcium phosphate-tetracalcium phosphate as the solid phase and calcium phosphate solution as the liquid phase. BCPC powder is composed of a single solid solution with a monomodal size distribution. Here, we used a bacterial leakage model to examine the utility of BCPC as a seal for root-end filling. We prepared large (median particle size=9.96 µm; BCPC-L) and small (median particle size=4.84 µm; BCPC-S) BCPC powders. In total, 45 single-rooted teeth were instrumented, resected at the root-end, and retrofilled with experimental materials. Mineral trioxide aggregate (MTA) was used as the control. After visual confirmation of BCPC powder size and retrofilling quality by microscopy, bacterial leakage tests were conducted using Enterococcus faecalis. The bacterial leakage tests did not reveal any significant differences between BCPC-S and MTA. Our findings suggest that BCPC-S is useful for root-end filling.

Sealing Ability of Bioactive Root-End Filling Materials in Retro Cavities Prepared with Er,Cr:YSGG Laser and Ultrasonic Techniques

The aim of this in vitro study was to compare the apical sealing ability of total fill bioceramic root repair material (BC-RRM) and mineral trioxide aggregate (MTA), regarding the retrograde preparation technique used: ultrasonic or erbium, chromium: yttrium, scandium, gallium, or garnet (Er,Cr:YSGG) laser. The study sample consisted of 48 human single-rooted teeth. After root-end resection, the samples were divided into two groups, according to the retrograde preparation technique used: Group 1: ultrasonic; Group 2: Er,Cr:YSGG laser. In each group, half of the retrograde cavities were filled with BC-RRM, and the other half were filled with MTA. The specimens were mounted in tubes and sterilized in plasma. The root canals were inoculated with Enterococcus faecalis, and the tubes were filled with fetal bovine serum, leaving the apical part of the root in the serum. After 30 days, the canals were sampled and cultured, and the colony forming units (CFUs) were counted with the additional polymerase chain reaction (PCR analysis). There was no significant difference between ultrasonic groups and the Er,Cr:YSGG-MTA group, regarding the number of CFUs (p > 0.05). The Er,Cr:YSGG-BC-RRM group showed the highest number of remaining viable bacteria (p < 0.001). Both filling materials filled in ultrasonic preparations presented similar sealing abilities. The BC-RRM showed more leakage when used in retro cavities prepared with the Er,Cr:YSGG laser.

How do imaging protocols affect the assessment of root-end fillings?

Objectives

This study investigated the impact of micro-computed tomography (micro-CT)-based voxel size on the analysis of material/dentin interface voids and thickness of different endodontic cements.

Materials and Methods

Following root-end resection and apical preparation, maxillary premolars were filled with mineral trioxide aggregate (MTA), Biodentine, and intermediate restorative material (IRM) (n = 24). The samples were scanned using micro-CT (SkyScan 1272; Bruker) and the cement/dentin interface and thickness of materials were evaluated at voxel sizes of 5, 10, and 20 µm. Analysis of variance and the Tukey test were conducted, and the degree of agreement between different voxel sizes was evaluated using the Bland and Altman method (p < 0.05).

Results

All materials showed an increase in thickness from 5 to 10 and 20 µm (p < 0.05). When evaluating the interface voids, materials were similar at 5 µm (p > 0.05), while at 10 and 20 µm Biodentine showed the lowest percentage of voids (p < 0.05). A decrease in the interface voids was observed for MTA and IRM at 20 µm, while Biodentine showed differences among all voxel sizes (p < 0.05). The Bland-Altman plots for comparisons among voxel sizes showed the largest deviations when comparing images between 5 and 20 µm.

Conclusions

Voxel size had an impact on the micro-CT evaluation of thickness and interface voids of endodontic materials. All cements exhibited an increase in thickness and a decrease in the void percentage as the voxel size increased, especially when evaluating images at 20 µm.

Push-out bond strength and marginal adaptation of apical plugs with bioactive endodontic cements in simulated immature teeth

Objectives

This study evaluates the bond strength and marginal adaptation of mineral trioxide aggregate (MTA) Repair HP and Biodentine used as apical plugs; MTA was used as reference material for comparison.

Materials and Methods

A total of 30 single-rooted teeth with standardized, artificially created open apices were randomly divided into 3 groups (n = 10 per group), according to the material used to form 6-mm-thick apical plugs: group 1 (MTA Repair HP); group 2 (Biodentine); and group 3 (white MTA). Subsequently, the specimens were transversely sectioned to obtain 2 (cervical and apical) 2.5-mm-thick slices per root. Epoxy resin replicas were observed under a scanning electron microscope to measure the gap size at the material/dentin interface (the largest and smaller gaps were recorded for each replica). The bond strength of the investigated materials to dentin was determined using the push-out test. The variable bond strengths and gap sizes were evaluated independently at the apical and cervical root dentin slices. Data were analyzed using descriptive and analytic statistics.

Results

The comparison between the groups regarding the variables' bond strengths and gap sizes showed no statistical difference (p > 0.05) except for a single difference in the smallest gap at the cervical root dentin slice, which was higher in group 3 than in group 1 (p < 0.05).

Conclusions

The bond strength and marginal adaptation to root canal walls of MTA HP and Biodentine cement were comparable to white MTA.

Sealing ability of three different materials to repair furcation perforations using computerized fluid filtration method

Background. The present study aimed to evaluate the sealing ability of three different calcium silicate-based materials in furcation perforations.

Methods. Seventy-six human mandibular molar teeth were selected. Perforations were created in the center of the pulp chamber floor. The experimental teeth were randomly divided into three groups (n=22). Perforations were repaired with MTA Angelus, Endocem MTA, or EndoSequence BioCeramic Root Repair Material Fast Set Putty (BC-RRM Putty). Microleakage of the different repair materials to be tested was measured by computerized fluid filtration method at 24- and 72-hour intervals.

Results. For each time interval, no statistically significant difference was observed between the groups. For Endocem MTA and BC-RRM Putty groups, the difference between the leakage values measured at both periods was not statistically significant (P > 0.05). However, there was a significant difference for the MTA Angelus group (P < 0.05).

Conclusion. All the calcium silicate-based materials used in the present study showed similar performance in repairing furcation perforations at 24- and 72-hour intervals.

Scanning electron microscopy analysis of marginal adaptation of mineral trioxide aggregate, tricalcium silicate cement, and dental amalgam as a root end filling materials

The aim of this research was to examine marginal adaptation of three root end filling materials mineral trioxide aggregate (MTA), Biodentine and amalgam. Ninety single-rooted extracted human teeth of the maxillary intercanine sector were used in the study. After the endodontic treatment and retrograde preparation, teeth were divided into three groups, depending on the root-end filling material. Teeth were cut in longitudinal manner. Measurements of the total width of the marginal gap in micrometers were performed using scanning electron microscopy. The results showed that MTA and Biodentine have better marginal adaptation compared to amalgam expressed through the mean value of the measured edge crack, however without significant difference (p > .05). Mean value of the measured edge crack in Group 1 (MTA) was 8.17 μm, in Group 2 (Biodentine) 8.53 μm, and in Group 3 (amalgam) 9.13 μm. All tested materials show a satisfactory degree of marginal adaptation, but MTA and Biodentine proved to be superior to amalgam.

Do the intracanal medicaments affect the marginal adaptation of calcium silicate-based materials to dentin?

Background/purpose

In order to prevent reinfection of the pulp canal space and dressing for regenerative purpose, the coronal seal should have a perfect marginal adaptation. Mineral trioxide aggregate (MTA) and Biodentine are among the most popular sealing materials. These are commonly used in combination with antibiotic medicaments, to ensure disinfection. Aim of the present study was to evaluate the effect of 3 different medicaments on the marginal adaptation of MTA and Biodentine to the dentin.

Materials and methods

Teeth were divided into 4 groups (n = 20) that were treated with the following medicaments; triple antibiotic paste (TAP), double antibiotic paste (DAP), a calcium hydroxide (CH) and a control group. The specimens were then assigned into two subgroups (n = 10), which received a coronal barrier of MTA or Biodentine. The specimens were scanned using an ex vivo micro-CT scanner. The data were statistically analysed using one-way ANOVA and the unpaired Student's t-test (P < 0.05).

Results

Percentage volume of external voids in the MTA group was as follows: DAP > TAP > Control > CH. In the Biodentine group, the percentage of voids was determined in the following order: TAP ≥ DAP > CH > Control. Significantly lower percentage of voids was observed in the CH-medicated specimens in the MTA group when compared to all test groups (P = 0.04).

Conclusion

The application of CH as an intracanal medicament reduced the void occurrence between the ProRoot MTA and root dentin. However, TAP and or DAP decreased the marginal adaptation in both ProRoot MTA and Biodentine.

Adaptation of mineral trioxide aggregate to dentine walls compared with other root-end filling materials: A systematic review

This systematic review analysed the literature comparing marginal adaptation of mineral trioxide aggregate (MTA) with other filling materials in root-end cavities. The PubMed, Ovid, Web of Science, SCOPUS, and Cochrane library databases were searched using appropriate keywords related to root-end filling materials and adaptation. Of 38 articles assessed, 20 met the inclusion criteria. No in vivo study was identified. In 10 studies, MTA gave the best marginal adaptation results, but no significant differences were found between MTA and any of the tested filling materials in seven studies. There was great variability in the study designs including analysed surface, unit of gap measurement and magnification amount during analysis. On the basis of available evidence, MTA presented good marginal adaptation to dentine walls. This review identified the need for the development of standardised methods to evaluate the adaptation property of root-end filling materials in ex vivo studies as well as in clinical studies evaluating outcome.

X-ray diffraction analysis of MTA mixed and placed with various techniques

OBJECTIVES

The aim of this study was to evaluate the effect of various mixing techniques as well as the effect of ultrasonic placement on hydration of mineral trioxide aggregate (MTA) using X-ray diffraction (XRD) analysis.

MATERIALS AND METHODS

One gram of ProRoot MTA and MTA Angelus powder was mixed with a 0.34-g of distilled water. Specimens were mixed either by mechanical mixing of capsules for 30 s at 4500 rpm or by manual mixing followed by application of a compaction pressure of 3.22 MPa for 1 min. The mixtures were transferred into the XRD sample holder with minimum pressure. Indirect ultrasonic activation was applied to half of the specimens. All specimens were incubated at 37 °C and 100% humidity for 4 days. Samples were analyzed by XRD. Phase identification was accomplished by use of search-match software utilizing International Centre for Diffraction Data (ICDD).

RESULTS

All specimens comprised tricalcium silicate, calcium carbonate, and bismuth oxide. A calcium hydroxide phase was formed in all ProRoot specimens whereas among MTA Angelus groups, it was found only in the sample mixed mechanically and placed by ultrasonication.

CONCLUSIONS

Mechanical mixing followed by ultrasonication did not confer a significant disadvantage in terms of hydration characteristics of MTA.

CLINICAL RELEVANCE

Clinicians vary in the way they mix and place MTA. These variations might affect their physical characteristics and clinical performance. For ProRoot MTA, the mixing and placement methods did not affect its rheological properties, whereas for MTA Angelus, mechanical mixing combined with ultrasonic placement enhanced the calcium hydroxide phase formation.