MTA apexification combined with conventional root canal retreatment

A Silk Fibroin Based Hydration Accelerator for Root Canal Filling Materials

Mineral trioxide aggregate (MTA) is widely used in various dental endodontic applications such as root-end filling, furcal perforation repair, and vital pulp therapy. In spite of many attempts to improve handling properties and reduce the discoloration of MTA, the ideal root canal filling material has yet to be fully developed. The objective of this study was to investigate the setting time, mechanical properties, and biocompatibility of MTA set by a silk fibroin solution. A 5 wt% silk fibroin (SF) solution (a novel hydration accelerant) was used to set SavDen® MTA and ProRoot® white MTA (WMTA). Changes in setting time, diametral tensile strength (DTS), material crystallization, in vitro cell viability, and cell morphology were assessed by Vicat needle measurement, a universal testing machine, scanning electron microscopy (SEM), and WST-1 assay, respectively. The initial setting time of ProRoot® MTA and SavDen® MTA experienced a drastic decrease of 83.9% and 42.1% when deionized water was replaced by 5 wt% SF solution as the liquid phase. The DTS of SavDen® MTA showed a significant increase after set by the SF solution in 24 h. A human osteoblast-like cell (MG-63)-based WST-1 assay revealed that both ProRoot® MTA and SavDen® MTA hydrated using SF solution did not significantly differ (p > 0.05) in cell viability. MG-63 cells with pseudopodia attachments and nuclear protrusions represent a healthier and more adherent status on the surface of MTA when set with SF solution. The results suggest that the 5 wt% SF solution may be used as an alternative hydration accelerant for MTA in endodontic applications.

Behavior of mineral trioxide aggregate apical plugs and root fillings under cyclic loading

AIM

The aim of the present study was to develop a methodology for constant monitoring of the resistance to fluid flow during functional loading and to then compare the efficacy of 4-mm mineral trioxide aggregate (MTA) apical plugs and full-length MTA root fillings.

METHODS

The root canals of 24 single-rooted teeth were instrumented and assigned into two groups: group 1 (filled with a 4-mm MTA apical plug and gutta percha) and group 2 (filled with MTA to cementoenamel junction level). All teeth were subjected to stepwise cyclic loading with a constant simulated interstitial pressure of 25 cm H₂ O applied apically. A Flodec machine (De Marco Engineering, Geneva, Switzerland) constantly monitored the rate and direction of fluid flow. Student's t-test, Kruskal-Wallis test, Fisher's exact test, and Newcombe-Wilson test were used for statistical analysis, with P < 0.05.

RESULTS

Crown fractures occurred in 21 teeth with no change in the rate of fluid flow. Three teeth (filled with full-length MTA) showed sudden change in the rate of fluid flow through the root canal after cyclic loading.

CONCLUSIONS

The methodology reliably monitored fluid flow during cyclic loading. There was no difference between a 4-mm MTA apical plug and full-length MTA root filling after cyclic loading using a dynamic fluid-flow monitoring technique.

Bioactive materials in endodontics

Endodontic treatment in dentistry is a delicate procedure and many treatment attempts fail. Despite constant development of new root canal filling techniques, the clinician is confronted with both a complex root canal system and the use of filling materials that are harmful for periapical tissues. This paper evaluates reported studies on biomaterials used in endodontics, including calcium hydroxide, mineral trioxide aggregate, calcium phosphate ceramics and calcium phosphate cements. Special emphasis is made on promising new biomaterials, such as injectable bone substitute and injectable calcium phosphate cements. These materials, which combine biocompatibility, bioactivity and rheological properties, could be good alternatives in endodontics as root canal fillers. They could also be used as drug-delivery vehicles (e.g., for antibiotics and growth factors) or as scaffolds in pulp tissue engineering.

Endodontic Treatment of a Non-Vital Permanent Tooth with an Open Root Apex Using Mineral Trioxide Aggregate

A 2-year-old domestic feline patient was presented for evaluation of a complicated crown fracture of the right maxillary canine tooth. Clinical and radiographic examination revealed a non-vital immature permanent canine tooth with an open apex. This case report describes a two-visit technique using mineral trioxide aggregate in an apical barrier method for the treatment of a non-vital immature permanent canine tooth in a cat.

The use of white Portland cement as an apical plug in a tooth with a necrotic pulp and wide-open apex: a case report

AIM

To present a case in which substantial periapical healing occurred with the use of white Portland cement (WPC) to create an apical plug in the root of an immature tooth.

SUMMARY

Radiographic examination indicated an immature tooth (35) with a wide-open apex and a periapical radiolucency. The canal was mechanically cleaned using intracanal instruments and 5% NaOCl irrigation. Small pieces of resorbable collagen sponge were packed beyond the root apex with the aim of creating a periapical barrier for the compaction of filling material. WPC powder was then mixed with sterile water and delivered to the apical portion of the canal (approximately 3 mm). The patient was asked to return 1 week later for the continuation of treatment but he did return as planned. Seven months after the intervention the patient returned and another radiograph was exposed to reveal complete radiographic healing of the periapical region. The remainder of the canal was filled with thermoplastic gutta-percha. Clinical follow-up 1 year later revealed adequate clinical function, absence of clinical symptoms and no signs of periapical rarefaction.

KEY LEARNING POINT

The positive clinical resolution of this case is encouraging for the use of WPC as an apical plug in immature teeth with necrotic pulps and wide-open apices.

The use of mineral trioxide aggregate in one-visit apexification treatment: a prospective study

AIM

To assess the outcome of apexification using mineral trioxide aggregate (MTA).

METHODOLOGY

Fifty-seven teeth with open apices on 50 patients referred for root canal treatment received an apexification procedure in one appointment with MTA by the same operator. Patients were recalled at 6 months, 12 months and every year thereafter. Blind to the treatment record, two examiners assessed the pre-treatment, post-treatment and control radiographs of the study patients in a dark room using a magnifier. Each apex visible on the radiographs was scored with the periapical index (PAI), and the size of the apical lesion was measured. The presence of an apical bridge was also noted. Kappa-Cohen test was used for examiners calibration. The paired t-test was used for statistical analysis of apical healing.

RESULTS

Forty-three cases were included with at least 12 months follow-up. When considering the PAI score and the decrease in size of the apical lesion, healing occurred in 81% of cases.

CONCLUSION

Apexification in one step using an apical plug of MTA can be considered a predictable treatment, and may be an alternative to the use of calcium hydroxide.

Anatomical redesign for the treatment of dens invaginatus type III with open apexes

BACKGROUND

Dens invaginatus is a rare dental anomaly that may give rise to many complex anatomical forms. The complexity of the internal anatomy may create challenges for the complete removal of the diseased pulpal tissue and the subsequent sealing of the canal system.

CASE DESCRIPTION

The authors discuss the modification of the internal anatomy under the operating microscope, allowing the clinician better access to treat predictably the canal system with conventional or alternative techniques.

CONCLUSION AND CLINICAL IMPLICATIONS

Considering the anatomical variations and the challenges that a dens invaginatus may present, a practitioner may consider a modification of the internal anatomy of the canal system to gain better access for proper instrumentation, disinfection and sealing of the root canal system using conventional or contemporary techniques.

Weakened anterior roots--intraradicular rehabilitation

This paper highlights the fact that many anterior teeth requiring restoration are severely weakened having wide, flared canal spaces, and thin dentinal walls that are prone to fracture. Traditionally these teeth have been restored using metal posts and are often unsuccessful because of lack of retention or root fracture. This paper describes how mineral trioxide aggregate (MTA) can be used to form an immediate apical seal rather than waiting months for apexification. Weakened roots can be reinforced using dentine bonding agents and composite resin and if insufficient coronal tooth structure is present a quartz-fibre post can be placed to retain a composite core.

MTA solubility: a long term study

The purposes of this long-term study was to assess the amount of soluble material released by Mineral Trioxide Aggregate to a water medium, to determine if the solubility differences between specimens of various water/powder ratio, as demonstrated in a previous study, would be maintained over time, and to measure the pH of the water that was in contact with the specimens. Specimens were processed at 0.28 and 0.33 water/powder ratios, and immersed in water according to the ISO 6876 standard. The specimens were periodically removed to assess salt content release and reimmersed in fresh water. Assay testing was periodically performed over a 78-day period. Results were expressed as Daily Solubility (solubility rate), and Cumulative Solubility. The mathematical projection from Cumulative Solubility to infinite time showed that MTA could solubilize 22.06% at 0.28 water/powder ratio, and 31.095% at 0.33 water/powder ratio of the specimens' mass in regards to their initial dry weight. MTA did maintain a high pH for an extended period of time under these study conditions.