Tissue reaction to implanted root-end filling materials in the tibia and mandible of guinea pigs

Comparative Effectiveness of Regenerative Endodontic Treatment Versus Apexification for Necrotic Immature Permanent Teeth With or Without Apical Periodontitis: An Umbrella Review

BACKGROUND/AIM

The evidence related to the superiority of the recommended treatment protocols for necrotic immature permanent teeth is unclear. We aimed to compare the clinical, radiographic, and overall success rates of apexification and regenerative endodontic treatment (RET), assess the methodological quality, and assess the strength of evidence for outcomes.

METHODS

A search was performed in PubMed, Scopus, LILACS, EMBASE, Web of Science, and the Cochrane Library. The titles, abstracts and full texts of systematic reviews (SRs) comparing RET and apexification were screened. The quality and strength of evidence were analyzed via AMSTAR-2, ROBIS, and modified Kohler's criteria.

RESULTS

Twelve SRs were included, with nine having meta-analytic outcomes. The quality of only one study was high, and the risk of bias was low in two studies. Comparable success and survival rates for RET and apexification, with no superiority of any treatment, were reported. RET was superior in stimulating root thickness and lengthening. Weak evidence was noted for a higher clinical and radiographic success rate of the apical plug technique and for root lengthening and an increase in root thickness in RET.

CONCLUSION

RET and apexification exhibited comparable success rates of > 85% across all domains. Most comparisons did not reveal significant differences in clinical, radiographic, or overall success. However, the quality of evidence was weak (class IV) for both outcomes, and the majority of systematic reviews exhibited low or critically low quality and high risk of bias.

Periapically Extruded Calcium Silicate Cements in Retreated Teeth: A Case Report and Literature Review

Calcium silicate-based materials, known for their bioactive properties, are increasingly being used in endodontic therapy. Accidental extrusion of these materials into the periapical tissue is a relatively common phenomenon that can impede periapical healing. The aim of this article is to present three endodontically retreated case reports with moderate to extensive periapical lesions and to review the literature on this topic. The comprehensive search and analysis of the relevant literature included a review of 51 articles, of which nine case reports/series from 2010 to 2023 were considered. Based on the summarized data, over 80% of the retreated cases showed complete healing of the periapical lesions, while the success rate in initially treated teeth was over 90%. Healing of periapical lesions is the most common therapeutic outcome, even in cases where extrusion occurs. Despite this conclusion, extrusion of materials into periapical tissues should be avoided. Further case reports on the extrusion of calcium silicate-based materials other than MTA are recommended. When evaluating the success rate of periapical healing in such cases, it is recommended to extend the follow-up periods to several years.

A Comparison of the Apical Sealing Efficacy Between Guttaflow Bioseal and Mineral Trioxide Aggregate as Root-End Filling Materials: An In Vitro Study

Aim The objective of this study is to evaluate the efficacy of Guttaflow Bioseal (Coltene/Whaledent, Altstätten, Switzerland) in achieving an apical seal when utilized as a retrograde filling material in comparison to mineral trioxide aggregate (MTA). Methods Twenty single-rooted single-canaled human teeth were randomly allocated into two equal groups according to the used retrograde filling materials: Guttaflow Bioseal in group I and MTA in group II. The crowns were sectioned, and the root canals were prepared with rotary files and obturated (single cone technique with a resin-based sealer). Following a 24-hour setting period, apex cutting and ultrasonic retrograde preparation were conducted. Following cavity preparation, the materials were applied into the retrograde cavity (Guttaflow Bioseal in group I and MTA in group II). Both groups were incubated at 37°C with 100% humidity for an additional 24 hours. Subsequently, the teeth were coated with two layers of varnish, leaving the apex exposed by 1 mm. The specimens were then desiccated and immersed in 2% methylene blue dye for 36 hours. Afterwards, the teeth were thoroughly rinsed, dried, and sectioned longitudinally. Dye leakage was examined under optical magnification, and the results were statistically analyzed utilizing the Mann-Whitney U test. Results The comparative evaluation revealed no statistically significant difference in microleakage between the two study groups (p-value > 0.05). The apical seal achieved with Guttaflow Bioseal was comparable to that achieved using MTA. Conclusions Guttaflow Bioseal demonstrated comparable low microleakage rates and an effective apical sealing capacity similar to that of MTA. Consequently, both materials are deemed suitable for use in retrograde filling applications. Guttaflow Bioseal is a viable option for use as a root-end filling material.

An Evaluation of the Cytocompatibility of Endodontic Bioceramics in Human Periodontal-Ligament-Derived Cells

The present study evaluated the cytocompatibility of three endodontic bioceramics in human periodontal-ligament-derived cells (hPDLCs): MTA Repair HP (HP), MTA Flow White (F), and Nishika Canal Sealer BG multi (BG). In addition, we also evaluated the effect of the powder-liquid (paste) ratio of F and BG on cytocompatibility. Discs of endodontic bioceramics (diameter = 8 mm, thickness = 1 mm) were prepared with HP, F, and BG. hPDLCs obtained from extracted teeth and cultured for three to five passages were used in the experiment. The prepared discs were placed at the bottom of a 48-well plate, seeded with hPDLCs at 100,000 cells/well, cultured for 7 or 28 days, and subjected to a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay. hPDLCs cultured without any discs were used as a negative control (NC) group. Discs made of F or BG mixed in three different consistencies were also used in this experiment. The absorbance values at days 7 and 28 were high in the order of HP > NC > BG > F. Furthermore, F or BG with higher consistency showed higher absorbance values. MTA Repair HP had the highest cytocompatibility among the three materials. Furthermore, it also showed that higher consistency improved cytocompatibility.

Management of Ellis Class-IV Fractured Tooth With an Open Apex: A Case Report

Dental professionals face difficulty in managing "immature non-vital teeth with an open apex." It is considered to be challenging because, in this situation, root canal filling material should be confined within the boundaries of the root canal without extruding peri-apically. Apexification tries to create a hard tissue barrier that will cause the open apex to close, allowing root filling to be compacted. The current case report describes the application of mineral trioxide aggregate (MTA) to create an apical plug in an open apex, as MTA is considered a versatile material for apexification, which was followed by the reinforcing of the weekend root using glass fiber post and core build-up to manage the Ellis class IV fracture.

A Comparative Study of Biocompatibility in Rat Connective Tissue of a New Mineral Trioxide Compound (Theracal) versus MTA and a Bioactive G3 Glass

The aim of this paper was to assess the differences in tissue response to implantation during 15, 30 and 45 days in the subcutaneous connective tissue of Wistar rats from three biomaterials: Angelus MTA^®, Theracal LC^®, and Angelus MTA^® to which 25% bioglass G3 was added. Twenty-four Wistar rats were used, the materials were inserted into the rat’s dorsal area in silicone tubes 5 mm long by 1.5 mm diameter. Histological reaction was assessed at 15, 30, and 45 days after implantation. They were then stained with hematoxylin eosin and evaluated by two observers. Data were analyzed using Fisher’s exact test and Mann–Whitney’s U test was used to determine the association between variables. Angelus MTA induced the formation of dystrophic calcifications twice as much as Theracal LC (p < 0.05). The addition of G3 did not affect the greater or lesser occurrence of calcifications (p > 0.05). Theracal LC and MTA plus G3 caused an inflammatory reaction, which was chronic at 15 days and decreased in intensity, almost disappearing after 45 days. Theracal LC, as well as Angelus MTA plus G3, were well tolerated when implanted in the subcutaneous connective tissue of rat. Histologically, no inconvenience was found for the use by direct contact of Theracal LC, and the mixture of MTA with 25% bioactive glass G3, in the tissue of Wistar rats.

Successful Use of MTA Fillapex as a Sealant for Feline Root Canal Therapy of 50 Canines in 37 Cats

Intentional or unintentional pulp exposure of cat canines can lead to periapical disease, osteomyelitis, and oral pain. Root canal therapy (RCT) allows the retention of cat canines with pulp exposure by removing the infected pulp and replacing it with an inert material. This study used MTA Fillapex™ as a root canal sealant with gutta percha single cone obturation in 37 cats (50 canine teeth). Roots were classified as "successful," "no evidence of failure (NEF)," or "failed" at 6-month radiographic reviews. Therapy was considered "successful" if a preoperative periapical lucency had healed or not formed after treatment and any preoperative external inflammatory root resorption (EIRR) had stabilized without progression. Therapy was categorized as "NEF" if a periapical lucency had remained the same or decreased in size but not completely resolved and any preoperative EIRR had stabilized without progression. "Failed" if a periapical lucency had occurred or increased in size posttreatment or if EIRR had developed or progressed posttreatment. Thirty-two canine teeth (64%) were classified as "successful," 14 canine teeth (28%) were classified as "NEF," and 4 canine teeth (8%) were classified as "failed". The study concluded that RCT using MTA Fillapex as a root canal sealant is a suitable endodontic treatment for fractured cat canines, especially those that are periodontally or endodontically challenged.

Bioactive tri/dicalcium silicate cements for treatment of pulpal and periapical tissues

Over 2500 articles and 200 reviews have been published on the bioactive tri/dicalcium silicate dental materials. The indications have expanded since their introduction in the 1990s from endodontic restorative and pulpal treatments to endodontic sealing and obturation. Bioactive ceramics, based on tri/dicalcium silicate cements, are now an indispensable part of the contemporary dental armamentarium for specialists including endodontists, pediatric dentists, oral surgeons andfor general dentists. This review emphasizes research on how these materials have conformed to international standards for dental materials ranging from biocompatibility (ISO 7405) to conformance as root canal sealers (ISO 6876). Potential future developments of alternative hydraulic materials were included. This review provides accurate materials science information on these important materials. STATEMENT OF SIGNIFICANCE: The broadening indications and the proliferation of tri/dicalcium silicate-based products make this relatively new dental material important for all dentists and biomaterials scientists. Presenting the variations in compositions, properties, indications and clinical performance enable clinicians to choose the material most suitable for their cases. Researchers may expand their bioactive investigations to further validate and improve materials and outcomes.

A Short Time Period in the Treatment of an Open Apice Intruded Tooth: An 8-year Follow-up

AIM

Among traumatic dental injuries, intrusive dislocation is considered to be one of the most serious injuries. Despite the high success rate in complacent patients, the traditional technique of calcium hydroxide inoculation has drawbacks. The good antimicrobial and sealing properties combined with excellent biocompatibility and high success rates of the mineral trioxide aggregate (MTA) encourage its use.

BACKGROUND

The objective of this study was to report a successful case of intrusive dislocation in a short time with a follow-up of eight years.

CASE DESCRIPTION

A patient, seven years of age, presented intrusive dental dislocation, confirmed by radiographic examination, which revealed besides axial displacement of the central incisor towards the bone, incomplete root development. The passive repositioning was chosen as the treatment modality. After cleansing of the root canal, therapy with hydroxide paste was performed for 30 days, and then the apex was closed using an artificial barrier made with apical MTA buffer to facilitate root canal obturation.

CONCLUSION

Clinical and radiographic signs at 6 months and 8 years of preservation evidence the success of the therapy.

CLINICAL RELEVANCE

Teeth with incomplete root formation when traumatized may have their development process interrupted; consequently their root canals remained ample with thin and fragile walls and the open apex which represents a great challenge to the accomplishment of endodontic therapy. The process of apexification with MTA as in this case is an alternative to traditional therapy based on calcium hydroxide, conferring a faster treatment and a decrease in the odds of fracture of the tooth since from the confection of the apical barrier there is a possibility of being the same restored at an early stage.

HOW TO CITE THIS ARTICLE

de Sá MAB, Nunes E, et al. A Short Time Period in the Treatment of an Open Apice Intruded Tooth: An 8-year Follow-up. Int J Clin Pediatr Dent 2019;12(2):160-163.

Biocompatibility Investigation of New Endodontic Materials Based on Nanosynthesized Calcium Silicates Combined with Different Radiopacifiers

INTRODUCTION

The aim of this article was to analyze biocompatibility and bioactivity of new endodontic materials on the basis of nanosynthesized calcium silicates (ALBO-MPCA₁ and ALBO-MPCA₂) combined with different radiopacifiers in comparison with MTA⁺.

METHODS

Morphology of the samples was studied by scanning electron microscopy, and the pH and ion release analysis were also assessed. Biocompatibility of materials' eluates (24-hour, 7-day, and 21-day) was conducted by using MTT test. Twelve New Zealand white rabbits were used for intraosseous implantation. Four calvarial defects per animal were created and filled with freshly prepared investigated materials.

RESULTS

Samples mostly consisted of agglomerates built up from nanoparticles, preferably spherical and rod-like. There was no significant difference among pH values of materials' eluates after 24 hours (P > .05). The amount of calcium and aluminum ion release decreased, whereas the amount of magnesium and bismuth (ALBO-MPCA₁, MTA⁺) and barium (ALBO-MPCA₂) increased during 21-day period. The metabolic activity of cells increased after the extraction time, except in case of undiluted elutes of ALBO-MPCA₂ and ALBO-MPCA₁ (21-day). Histologic analysis of the samples revealed newly formed bone tissue with moderate inflammation for all investigated materials, which subsided during 90-day period to mild. Both MTA⁺ and ALBO-MPCA₁ were in direct contact with the newly formed bone tissue. After 90 days, statistically significant difference in hard tissue formation was observed in comparison of MTA⁺ and ALBO-MPCA₁ with control group (P < .05).

CONCLUSIONS

Experimental materials ALBO-MPCA₁ and ALBO-MPCA₂ possess both biocompatibility and bioactivity. Because ALBO-MPCA₁ provokes favorable biological response, it is especially good candidate for further clinical investigations.

Mineral Trioxide Aggregate-A Review of Properties and Testing Methodologies

Mineral trioxide aggregate (MTA) restoratives and MTA sealers are commonly used in endodontics. Commonly referenced standards for testing of MTA are ISO 6876, 9917-1 and 10993. A PubMed search was performed relating to the relevant tests within each ISO and "mineral trioxide aggregate". MTA restoratives are typically tested with a mixture of tests from multiple standards. As the setting of MTA is dependent upon hydration, the results of various MTA restoratives and sealers are dependent upon the curing methodology. This includes physical properties after mixing, physical properties after setting and biocompatibility. The tests of flow, film thickness, working time and setting time can be superseded by rheology as it details how MTA hydrates. Physical property tests should replicate physiological conditions, i.e. 37 °C and submerged in physiological solution. Biocompatibility tests should involve immediate placement of samples immediately after mixing rather than being cured prior to placement as this does not replicate clinical usage. Biocompatibility tests should seek to replicate physiological conditions with MTA tested immediately after mixing.

Effect of Biomineralization Ability on Push-out Strength of Proroot Mineral Trioxide Aggregate, Mineral Trioxide Aggregate Branco, and Calcium Phosphate Cement on Dentin: An In vitro Evaluation

CONTEXT

Biomineralization is a process which leads to the formation of an interfacial layer with tag-like structures at the cement-dentin interface. It is due to interaction of mineral trioxide aggregate (MTA) and Portland cement with dentin in phosphate-buffered solution (PBS). This study is aimed to evaluate the effect of influence of biomineralization process on push-out bond strength of ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK, USA), MTA Branco (Angelus Soluc¸o˜es Odontolo´gicas, Londrina, PR, Brazil) and calcium phosphate cement (BioGraft CPC).

AIM

The aim of this study was to evaluate the effect of biomineralization process on the push-out strength of ProRoot MTA, MTA Branco, and CPC after mixing with 0.2% chlorhexidine gluconate solution (0.2% CHX) and 2% lidocaine solution (2% LA) on the bond strength of MTA-dentin.

MATERIALS AND METHODS

Dentin discs with uniform cavities were restored with ProRoot MTA, MTA Branco, and calcium phosphate cement after mixing with 0.2% CHX solution and 2% lidocaine solution. The samples were uniformly distributed into two groups. Experimental group being immersed in PBS solution and control group being immersed in saline for 2 months. Instron testing machine (Model 4444; Instron Corp., Canton, MA, USA) was used to determine the bond strength.

STATISTICAL ANALYSIS USED

A two-way analysis of variance and post hoc analysis by Bonferroni test.

RESULTS

All samples immersed in experimental group displayed a significantly greater resistance to displacement than that observed for the samples in control group (P < 0.05). MTAs displayed a significantly greater resistance to displacement than calcium phosphate cements.

CONCLUSION

The main conclusion of this study was that the push-out bond strength of the cements, mainly the MTA groups, was positively influenced by the biomineralization process.

Endodontic Surgery of a Symptomatic Overfilled MTA Apical Plug: A Histological and Clinical Case Report

This case report presents the successful surgical treatment of a symptomatic open apex upper central incisor with a failed overfilled mineral trioxide aggregate (MTA) apical plug. Unintentional overextension of the MTA had occurred two years before the initial visit. An apical lesion adjacent to the excess MTA was radiographically detectable. Endodontic surgery was performed using calcium-enriched mixture (CEM) cement as a root-end filling material. Curettage of the apical lesion showed a mass of unset MTA particles; histopathological examination revealed fragments of MTA and granulation tissues. Up to 18-month follow-up, the tooth was clinically asymptomatic and fully functional. Periapical radiograph and CBCT images showed a normal periodontal ligament around the root. In conclusion, favorable outcomes in this case study suggested that root-end filling with CEM cement might be an appropriate approach; in addition, however many factors probably related to the initial failure of the case, the extrusion of MTA into the periapical area should be avoided.

Hard tissue reaction to mineral trioxide aggregate and experimental root-end filling material in guinea pig mandibles

Background/purpose

Root-end filling materials are used to fill and seal the root apex during periradicular surgery. Mineral trioxide aggregate (MTA) is a widely-used material because of its particular characteristics. Cold ceramic (CC) is an experimental material that has been recently introduced. The purpose of this study was to compare bone tissue response to CC and MTA in an animal model.

Materials and methods

Forty-five male guinea pigs (weighing 750–850 g) were anesthetized with 10 mg/kg ketamine HCL and 12 mg/kg xylazine. A triangular incision of around 15 mm was prepared in the posterior site along the symphysis in both right and left sides of the mandible. A 3 mm × 3 mm diameter cylindrical hole was prepared in each side using a trephine. Two Teflon cylindrical tube applicators were filled with white MTA and CC and inserted into the defects separately. Histopathological evaluation of the specimens was completed after 2 weeks and 12 weeks. The extent of inflammation was recorded and analyzed using the Mann–Whitney U test and SPSS software version 12 at a significance level of 0.05.

Results

MTA and CC produced moderate and mild hard tissue responses respectively after 2 weeks and 12 weeks. No significant differences were found in the distribution of the responses between the two groups at either time point.

Conclusion

Both CC and MTA demonstrated biocompatibility with minor adverse impact on hard tissue and healing recovery after 12 weeks.

A comparative evaluation of endodontic treatments for immature necrotic permanent teeth based on clinical and radiographic outcomes: a systematic review and meta-analysis

BACKGROUND

Dental trauma and deep caries are frequent findings in children and adolescents that may lead to pulp necrosis in young permanent teeth. As a consequence, the root stops its development, and managing these immature teeth becomes challenging due to the presence of open apexes and fragile dentinal walls.

AIM

We aimed to carry out a systematic review including a meta-analysis to compare the endodontic treatments available in the management of immature necrotic permanent teeth and determine which one provides the best clinical and radiographic outcomes.

DESIGN

The literature was screened via PubMed/MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials databases until August 2015 to select randomized clinical trials that compared at least two different treatments regarding immature necrotic permanent teeth comprising clinical and radiographic success as outcome. Two reviewers independently performed the screening and evaluation of the articles. A total of 648 studies were retrieved from the databases, in which only 14 were selected to full-text analysis by the appliance of inclusion criteria. After the exclusion criteria, the remaining seven studies had their data extracted and assessed for bias risk. Pooled-effect estimates were obtained comparing clinical and radiographic success rates among MTA Versus other treatments.

RESULTS

Evaluation of clinical (Z = 2.32, P = 0.02, OR = 5.37, 95% CI: 1.29-22.23, I = 0%) and radiographic (Z = 2.45, P = 0.01, OR = 4.31, 95% CI: 1.34-13.82, I = 0%) outcomes favored the MTA (control group) when compared to other endodontic treatments (P < 0.05). No evidence of heterogeneity was detected among the studies (I < 50%), whereas a moderate risk of bias was identified in five of them.

CONCLUSIONS

Although almost all of the identified studies presented moderate risk of bias, MTA apexification seems to produce overall better clinical and radiographic success rates among the endodontic treatment available in immature necrotic permanent teeth.

Root-end Filling Materials Alter Fibroblast Differentiation

Root-end filling materials are commonly used following endodontic surgical procedures; however, their effect on adjacent soft tissues is poorly understood. We predict that, due to the differences in their chemical composition, these materials will have profoundly different effects on the survival and differentiation of fibroblasts. Many of the root-end filling materials examined were initially cytotoxic to both PDL and gingival fibroblasts in co-culture experiments; however, this was reduced after the materials were washed in either mineral trioxide aggregate (MTA) or hybrid ionomere composite resin (HICR) for 2 wks. Additionally, PDL fibroblasts displayed enhanced proliferation on MTA and survival on amalgam when compared with gingival fibroblasts. MTA preferentially induced alkaline phosphatase expression and activity in both PDL and gingival fibroblasts. In contrast, HICR inhibited alkaline phosphatase expression and activity. In addition, MTA and HICR repressed pleiotrophin in PDL fibroblasts, while HICR repressed periostin in both fibroblasts. Thus, root-end filling materials differentially affect periodontal fibroblast differentiation. Abbreviations: mineral trioxide aggregate (MTA), zinc-oxide eugenol cement (ZOEC), hybrid ionomer composite resin (HICR), reverse-transcriptase polymerase chain-reaction (RT-PCR).

Effect of the plant-based hemostatic agent Ankaferd Blood Stopper® on the biocompatibility of mineral trioxide aggregate

Background

Due to the detrimental effect of blood contamination on the physico-chemical properties of mineral trioxide aggregate (MTA), obtaining an effective hemostasis in the surgical crypt during apical surgery is of paramount importance. The purpose of this in vivo study was to analyze the effect of Ankaferd Blood Stopper® (ABS) contamination on the biocompatibility of MTA.

Methods

Forty of 56 Wistar–Albino rats were divided randomly and equally into two groups (MTA and MTA-ABS) according to whether or not a hemostatic agent was used. The remaining 16 rats were designated as the control group. Rats in the experimental groups received freshly mixed MTA-Angelus in polyethylene tubes, which were inserted into monocortical bore holes created in their tibias. In the MTA-ABS group only, 0.5 mL of ABS solution was administered topically on the defect sites followed by implantation of MTA tubes. Inflammation, foreign-body reaction (FBR), necrosis, fibrosis, and new bone formation (NBF) were studied 7, 30, 60, and 90 days after implantation.

Results

On day7, statistically significant differences were found in tissue reactions with regard to NBF and necrosis (p = 0.044 and p = 0.024, respectively), the latter being observed in 40 % of the samples only in the MTA-ABS group. Slight inflammation in all groups was confined to day-7 only. Mild necrosis was present in the MTA-ABS group only on day-7. Severity of the foreign body reaction and fibrosis was limited. New bone formation increased gradually over time in all groups, reaching a maximum on day-90.

Conclusions

MTA and ABS-contaminated MTA are equally biocompatible. ABS does not impair the properties of MTA.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-016-0302-0) contains supplementary material, which is available to authorized users.

Physical properties and biocompatibility of an injectable calcium-silicate-based root canal sealer: in vitro and in vivo study

Background

The aim of this study was to investigate the physical properties and biological effects of an experimentally developed injectable premixed calcium-silicate root canal sealer (Endoseal) in comparison with mineral trioxide aggregate (MTA) and a resin-based sealer (AHplus).

Methods

The pH, solubility, dimensional change, flow, and radiopacity of the materials were evaluated. Biocompatibility was evaluated on the basis of cell morphology and a viability test using MC3T3-E1 cells. For evaluate inflammatory reaction, the tested sealers were implanted into dorsal subcutaneous connective tissue of Sprague Dawley rats. After 7 days, the implants with the surrounding tissue were retrieved, and histological evaluation was performed.

Results

Endoseal showed high alkalinity similar to that of MTA. The solubility of the tested materials was similar. The dimensional change and flow of Endoseal was significantly higher than that of other materials (P < 0.05). The radiopacity of Endoseal was lower than that of AHplus (P < 0.05). The biocompatibility was similar to those of MTA. Inflammatory reaction of Endoseal was similar with that of MTA, but lower than that of AHplus (P < 0.05).

Conclusions

The present study indicates that Endoseal has favorable physical properties and biocompatibility. Therefore, we suggest that Endoseal has the potential to be used as a predictable root canal sealer.

Assessment of the cytotoxicity of a mineral trioxide aggregate-based sealer with respect to macrophage activity

AIM

To assess the influence of co-culture with mineral trioxide aggregate (MTA) and MTA Fillapex (FLPX) on the viability, adherence, and phagocytosis activity of peritoneal macrophages from two mouse strains.

METHODOLOGY

Cellular viability, adherence, and phagocytosis of Saccharomyces boulardii were assayed in the presence of capillaries containing MTA and MTA Fillapex. The data were analyzed using parametric (Student's t) and non-parametric (Mann-Whitney) tests.

RESULTS

FLPX was severely cytotoxic and decreased cell viability, adherence, and phagocytic activity of both macrophage subtypes. Cells that were treated with MTA Fillapex remained viable (>80%) for only 4 h after stimulation. Macrophages from C57BL/6 mice presented higher adherence and higher phagocytic activity compared with macrophages from BALB/c mice.

CONCLUSION

Comparison of MTA and FLPX effects upon macrophages indicates that FLPX may impair macrophage activity and viability, while MTA seems to increase phagocytic activity.

Aloe vera as vehicle to mineral trioxide aggregate: study in bone repair

AIM: Mineral trioxide aggregate (MTA) was associated to Aloe vera to verify the coadjutant action of that medicinal plant in the bone neoformation process in tibia of rats.MATERIAL AND METHOD: 36 male rats (Rattus norvegicus) were used, divided into two groups of 18 rats each. Two circumferential bone defects with approximately 5 mm in diameter were made on the right tibia of each animal: the upper defect was filled with blood coagulates in both groups to serve as experimental control and the lower defect was filled with MTA and Aloe vera in experimental (group E1) and MTA and distilled water in experimental (group E2). Seven, 15 and 30 days after surgery, six animals from each group were euthanized and the right tibia of each animal was removed for histological analysis.RESULT: Histologically, experimental group E1 presented better results for the two variables, inflammation [at seven days (p=0.045)] and bone formation [at seven days (p=0.018) and 30 days (p=0.034)], compared to the E2 group.CONCLUSION: The association of MTA and Aloe vera showed potential to reduce the effects of the inflammatory cascade and promote bone neoformation making it to a promising proposal for future use in endodontic therapy.

Rat subcutaneous tissue response to calcium silicate containing different arsenic concentrations

Objective

To evaluate the response of rat subcutaneous tissue in implanted polyethylene tubes that were filled with GMTA Angelus and Portland cements containing different arsenic concentrations.

Material and Methods

Atomic absorption spectrophotometry was utilized to obtain the values of the arsenic concentration in the materials. Thirty-six rats were divided into 3 groups of 12 animals for each experimental period. Each animal received two implants of polyethylene tubes filled with different test cements and the lateral of the tubes was used as a control group. After 15, 30 and 60 days of implantation, the animals were killed and the specimens were prepared for descriptive and morphometric analysis considering: inflammatory cells, collagen fibers, fibroblasts, blood vessels and other components. The results were analyzed utilizing the Kuskal-Wallis test and the Dunn´s Multiple test for comparison (p<0.05).

Results

The materials showed, according to atomic absorption spectrophotometry, the following doses of arsenic: GMTA Angelus: 5.01 mg/kg, WPC Irajazinho: 0.69 mg/kg, GPC Minetti: 18.46 mg/kg and GPC Votoran: 10.76 mg/kg. In a 60-day periods, all specimens displayed a neoformation of connective tissue with a structure of fibrocellular aspect (capsule). Control groups and MTA Angelus produced the lower amount of inflammatory reaction and GPC Minetti, the highest reaction.

Conclusions

There was no direct relationship between the concentration of arsenic present in the composition of the materials and the intensity of the inflammatory reactions. Higher values, as 18.46 mg/kg of arsenic in the cement, produce characteristics of severe inflammation reaction at the 60-day period. The best results were found in MTA angelus.

A review of the bioactivity of hydraulic calcium silicate cements

OBJECTIVES

In tissue regeneration research, the term "bioactivity" was initially used to describe the resistance to removal of a biomaterial from host tissues after intraosseous implantation. Hydraulic calcium silicate cements (HCSCs) are putatively accepted as bioactive materials, as exemplified by the increasing number of publications reporting that these cements produce an apatite-rich surface layer after they contact simulated body fluids.

METHODS

In this review, the same definitions employed for establishing in vitro and in vivo bioactivity in glass-ceramics, and the proposed mechanisms involved in these phenomena are used as blueprints for investigating whether HCSCs are bioactive.

RESULTS

The literature abounds with evidence that HCSCs exhibit in vitro bioactivity; however, there is a general lack of stringent methodologies for characterizing the calcium phosphate phases precipitated on HCSCs. Although in vivo bioactivity has been demonstrated for some HCSCs, a fibrous connective tissue layer is frequently identified along the bone-cement interface that is reminiscent of the responses observed in bioinert materials, without accompanying clarifications to account for such observations.

CONCLUSIONS

As bone-bonding is not predictably achieved, there is insufficient scientific evidence to substantiate that HCSCs are indeed bioactive. Objective appraisal criteria should be developed for more accurately defining the bioactivity profiles of HCSCs designed for clinical use.

Effect of endodontic cement on bone mineral density using serial dual-energy x-ray absorptiometry

INTRODUCTION

Materials with new compositions were tested in order to develop dental materials with better properties. Calcium silicate-based cements, including white mineral trioxide aggregate (WMTA), may improve osteopromotion because of their composition. Nano-modified cements may help researchers produce ideal root-end filling materials. Serial dual-energy x-ray absorptiometry measurement was used to evaluate the effects of particle size and the addition of tricalcium aluminate (C3A) to a type of mineral trioxide aggregate-based cement on bone mineral density and the surrounding tissues in the mandible of rabbits.

METHODS

Forty mature male rabbits (N = 40) were anesthetized, and a bone defect measuring 7 × 1 × 1 mm was created on the semimandible. The rabbits were divided into 2 groups, which were subdivided into 5 subgroups with 4 animals each based on the defect filled by the following: Nano-WMTA (patent application #13/211.880), WMTA (as standard), WMTA without C3A, Nano-WMTA + 2% Nano-C3A (Fujindonjnan Industrial Co, Ltd, Fujindonjnan Xiamen, China), and a control group. Twenty and forty days postoperatively, the animals were sacrificed, and the semimandibles were removed for DXA measurement.

RESULTS

The Kruskal-Wallis test followed by the Mann-Whitney U test showed significant differences between the groups at a significance level of P < .05. P values calculated by the Kruskal-Wallis test were .002 for bone mineral density at both intervals and P20 day = .004 and P40 day = .005 for bone mineral content.

CONCLUSIONS

This study showed that bone regeneration was enhanced by reducing the particle size (nano-modified) and C3A mixture. This may relate to the existence of an external supply of minerals and a larger surface area of nano-modified material, which may lead to faster release rate of Ca(2+), inducing bone formation. Adding Nano-C3A to Nano-WMTA may improve bone regeneration properties.

Biocompatibility and setting time of CPM-MTA and white Portland cement clinker with or without calcium sulfate

Objective:

To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM.

Material and Methods:

Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level.

Results:

Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s).

Conclusions:

All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinker.

Long-term observation of the mineral trioxide aggregate extrusion into the periapical lesion: a case series

One-step apexification using mineral trioxide aggregate (MTA) has been reported as an alternative treatment modality with more benefits than the use of long-term calcium hydroxide for teeth with open apex. However, orthograde placement of MTA is a challenging procedure in terms of length control. This case series describes the sequence of events following apical extrusion of MTA into the periapical area during a one-step apexification procedure for maxillary central incisor with an infected immature apex. Detailed long-term observation revealed complete resolution of the periapical radiolucent lesion around the extruded MTA. These cases revealed that direct contact with MTA had no negative effects on healing of the periapical tissues. However, intentional MTA overfilling into the periapical lesion is not to be recommended.

Processing and in vivo evaluation of multiphasic calcium phosphate cements with dual tricalcium phosphate phases

Calcium phosphate cements (CPCs) use the simultaneous presence of several calcium phosphates phases. This is done to generate specific bulk and in vivo properties. This work has processed and evaluated novel multiphasic CPCs containing dual tricalcium phosphate (TCPs) phases. Dual TCPs containing α- and β-TCP phases were obtained by thermal treatment. Standard CPC (S-CPC) was composed of α-TCP, anhydrous dicalcium phosphate and precipitated hydroxyapatite, while modified CPC (DT-CPC) included both α- and β-TCP. Physicochemical characterization of these CPCs was based on scanning electron microscopy, X-ray diffraction, specific surface area (SSA) and particle size (PS) analysis and mechanical properties. This characterization allowed the selection of one DT-CPC for setting time, cohesion and biological assessment compared with S-CPC. Biological assessment was carried out using a tibial intramedullary cavity model and subcutaneous pouches in guinea pigs. Differences in the surface morphology and crystalline phases of the treated TCPs were detected, although PS analysis of the milled CPC powders produced similar results. SSA analysis was significantly higher for DT-CPC with α-TCP treated at 1100°C for 5h. Poorer mechanical properties were found for DT-CPC with α-TCP treated at 1000°C. Setting time and cohesion, as well as the in vivo performance, were similar in the selected DT-CPC and the S-CPC. Both CPCs created the desired host reactions in vivo.

Management of Root Perforations Using MTA with or without Er:YAG Laser Irradiation: An In Vitro Study

The aim of this in vitro study is to compare the microleakage of a root perforation sealed with MTA (mineral trioxide aggregate) (group M) to that sealed with MTA following Er:YAG laser irradiation (group ML). Forty-two recently extracted human monoroot teeth were used. Two cavities were prepared on each root surface. Randomly, on each root, the exposed dentine of one cavity was irradiated prior to MTA filling using an Er:YAG laser with the following settings: 200 mJ/pulses under an air water spray, 10 Hz, pulse duration of 50 μsec, and 0.7 mm beam diameter. All cavities were then sealed with MTA. submitted to thermocycling and immersed in 2% methylene blue dye solution for 12 h. The penetration of methylene blue in the microleakage of cavity was observed and recorded. The mean value dye penetration in cavities sealed with MTA following Er:YAG laser irradiation (23.91 ± 14.63%) was lower than that of unlased cavities sealed only with MTA (25.17 ± 17.53%). No significant difference was noted. The use of an Er:YAG laser beam for dentinal conditioning prior to MTA filling of perforated roots did not decrease significantly the microleakage of MTA sealing when compared to the conventional use of MTA filling.

Physicochemical properties and in vitro biocompatibility of a hydraulic calcium silicate/tricalcium aluminate cement for endodontic use

This study sought to prepare a calcium silicate cement (CSC) with varying additions of tricalcium aluminate (Ca(3)Al(2)O(6), C(3)A), and to find an optimal amount of C(3)A by evaluating the effect of C(3)A on the physicochemical and in vitro biological properties of the CS/C(3)A cement. The results indicated that the addition of C(3)A into CSC reduced the setting time and improved the compressive strength especially at the early stage of setting. However, the 15% C(3)A was too much for the CS/C(3)A system and did harm to its strength development. Furthermore, the CS/C(3)A cement was bioactive and biocompatible in vitro, and had a stimulatory effect on the cell growth, when the content of C(3)A was 5 or 10%. When compared with the commercially available Dycal(®), the CS/C(3)A cement was notably more compatible with the human dental pulp cells. Therefore, the CS/C(3)A cement with 5-10% C(3)A produced the best compromise between setting and in vitro biological properties, and may be a promising candidate for endodontic use.

The effect of various concentrations of iodine potassium iodide on the antimicrobial properties of mineral trioxide aggregate--a pilot study

BACKGROUND

Mineral trioxide aggregate (MTA) is a multi-purpose dental material with various uses in dentistry. Iodine potassium iodide (IKI) is the most commonly used iodine compound in endodontics. We aimed to assess the antimicrobial activity of tooth-colored ProRoot MTA combined with IKI.

MATERIALS AND METHODS

The antimicrobial activity of IKI was assessed at three concentrations (1%, 2%, and 4%) as the mixing agents combined with MTA against Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. For each microorganism, three plates were inoculated with 100 μl of a microbial suspension (McFarland 0.5). Four wells were prepared in each plate. MTA (70 mg) was mixed with any of the three concentrations of IKI (25 μl) or sterile distilled water (25 μl) and placed in each well. The plates were incubated for 24 h at 37°C. Zones of inhibition (ZOI) were measured in millimeters by a blinded observer. Data were analyzed using analysis of variance and the Dunnett t-test.

RESULTS

All MTA mixtures with water or IKI solutions showed inhibitory zones. The mean ZOI of each MTA/IKI mixture was not significantly different from MTA/water mixture (P > 0.05). MTA/1% IKI had smaller ZOI than MTA/water against E. coli, E. faecalis, and C. albicans. MTA/2% IKI showed larger ZOI only against P. aeruginosa. MTA/4% IKI showed larger ZOI against P. aeruginosa and E. coli (P < 0.05).

CONCLUSIONS

Substitution of IKI solutions (1%, 2%, and 4%) for water did not significantly increase the antimicrobial activity of MTA.

Use of cone beam computed tomography in the diagnosis, planning and follow up of a type III dens invaginatus case

AIM

To present the case of a maxillary left lateral incisor with Oehlers' type III dens invaginatus in which cone beam computed tomography (CBCT) was used as an adjunctive resource in the diagnosis as well as in the planning and 2-year follow-up of the nonsurgical/surgical treatment.

SUMMARY

The tooth had two root canals: a primary (main) canal with vital pulp that appeared to be closed apically and an invaginated canal that was necrotic, wide-open at the portal of exit and associated with a large chronic periapical lesion extending to the apex of the maxillary left central incisor. Radiographic tracking of a sinus tract in the labial gingiva of the affected tooth with a gutta-percha point revealed its origin to be the invagination. The CBCT scans revealed that the periapical radiolucency was significantly larger than seen radiographically as well as an increased thickness of the buccal cortical plate. Conventional root canal treatment of the primary canal was undertaken. As nonsurgical access to the invaginated canal was not possible, endodontic surgery was performed for curettage of the lesion, root-end cavity preparation using ultrasonic tips and root canal filling with white mineral trioxide aggregate (MTA). CBCT scanning after 17 months and clinical and radiographic follow-up after 24 months revealed complete periapical repair and absence of symptoms.

KEY LEARNING POINTS

The combination of nonsurgical and surgical treatments produced periapical repair in a tooth with type III dens invaginatus with two root canals. CBCT may aid the diagnosis as well as the management plan and follow-up of teeth with this developmental anomaly.

Single Step Endodontic Management of Immature Apices using MTA

AIM

To examine the clinical and radiographic appearance of teeth with immature apices that were treated by single step procedure using mineral trioxide aggregate (MTA).

SUMMARY

Creation of a physiological hard tissue barrier with calcium hydroxide in a nonvital tooth although quite predictable has certain limitations, such as the very long duration of the treatment spread over multiple visits and increased risk of root fracture. Plugging the root canal end with MTA has been advocated as an alternative treatment modality for open apices. The technique has been proven to be successful in many recently reported cases. The cases reported here present the successful treatment of two traumatized maxillary central incisors with open apices and periapical lesions using MTA. In this case report, MTA has been used to create a hard tissue barrier after disinfection of the root canal.

Mineral trioxyde aggregate versus calcium hydroxide in apexification of non vital immature teeth: study protocol for a randomized controlled trial

Background

Pulp necrosis is one of the main complications of dental trauma. When it happens on an immature tooth, pulp necrosis implies a lack of root maturation and apical closure. A therapy called apexification is required to induce the formation of a calcified apical barrier allowing a permanent and hermetic root filling. The aim of this prospective randomized clinical trial is to compare Mineral Trioxide Aggregate(MTA)with Calcium Hydroxide(CH)as materials used to induce root-end closure in necrotic permanent immature incisors.

Methods/Design

This study, promoted by AP-HP, was approved by the ethics committee(CPP Paris Ile de France IV). 34 children aged from 6 to 18 years and presenting a non-vital permanent incisor are selected. Prior to treatment, an appropriate written consent has to be obtained from both parents and from children. Patients are then randomly assigned to either the MTA(experimental)or CH(control)groups. Recalls are performed after 3, 6 and 12 months to determine the presence or absence of a calcified apical barrier through the use of clinical and radiographic exams. Additional criteria such as clinical symptoms, apical radiolucencies, periapical index(PAI)are also noted.

Trial registration

ClinicalTrials.gov no. NCT00472173 (First inclusion: May 10, 2007; Last inclusion: April 23, 2009; study completed: April 15, 2010)

Mineral trioxide aggregate inhibits osteoclastic bone resorption

Mineral trioxide aggregate (MTA), a commonly used endodontic repair material, is useful for both basic and clinical research, and the effect of MTA on osteoblast differentiation has been well-defined. However, the effects of MTA on osteoclastic bone resorption are not fully understood. Hence, the aim of this study is to examine the effect of MTA solution in the regulation of osteoclast bone-resorbing activity using osteoclasts formed in co-cultures of primary osteoblasts and bone marrow cells. MTA solution dose-dependently reduced the total area of pits formed by osteoclasts. The reduction of resorption induced by 20% MTA treatment was due to inhibition of osteoclastic bone-resorbing activity and had no effect on osteoclast number. A 20% MTA solution disrupted actin ring formation, a marker of osteoclastic bone resorption, by reducing phosphorylation and kinase activity of c-Src, and mRNA expressions of cathepsin K and mmp-9. A high concentration of MTA solution (50%) induced apoptosis of osteoclasts by increasing the expression of Bim, a member of the BH3-only (Bcl-2 homology) family of pro-apoptotic proteins. Taken together, our results suggest that MTA is a useful retrofilling material for several clinical situations because it both stimulates osteoblast differentiation and inhibits bone resorption.

Setting properties and biocompatibility of dicalcium silicate with varying additions of tricalcium aluminate

This study sought to prepare biphasic mixtures by adding tricalcium aluminate (Ca3Al2O6) into dicalcium silicate (Ca2SiO4) and to evaluate the effect of Ca3Al2O6 on setting properties and biocompatibility of the Ca2SiO4/Ca3Al2O6 mixtures as compared to pure Ca2SiO4. The results indicated that the addition of Ca3Al2O6 into Ca2SiO4 reduced the setting time and improved the compressive strength. Furthermore, Ca2SiO4/Ca3Al2O6 mixtures were bioactive and biocompatible, and had a stimulatory effect on the L929 cell growth when the content of Ca3Al2O6 was below 10%. Therefore, the mixtures with 10% Ca3Al2O6 produced the best compromise between setting and in vitro biological properties.

Effect of tricalcium aluminate on the properties of tricalcium silicate-tricalcium aluminate mixtures: setting time, mechanical strength and biocompatibility

AIM

To prepare biphasic mixtures by adding Ca(3) Al(2) O(6) into Ca(3) SiO(5) and to evaluate the effect of Ca(3) Al(2) O(6) on physical and ex vivo biological properties of the Ca(3) SiO(5) /Ca(3) Al(2) O(6) mixtures derived from mineral trioxide aggregate (MTA).

METHODOLOGY

Combinations of Ca(3) SiO(5) and Ca(3) Al(2) O(6) (0, 5%, 10% and 15%) powders were mixed with deionized water. After hydration, setting time, compressive strength, ex vivo bioactivity and biocompatibility of each mixture were investigated and compared to pure Ca(3) SiO(5) .

RESULTS

With the addition of Ca(3) Al(2) O(6) from 0% to 15%, the initial setting time and final setting time of the Ca(3) SiO(5) /Ca(3) Al(2) O(6) mixtures decreased from 110 to 43min and from 220 to 97min, respectively (P≤0.05). However, the compressive strength increased from 6.75 to 16.20MPa after one day (P≤0.05) and from 17.73 to 29.13 Mpa after 28 days. Furthermore, the mixtures with 10% Ca(3) Al(2) O(6) or less had similar bioactivity and biocompatibility when compared to the pure Ca(3) SiO(5).

CONCLUSIONS

The addition of Ca(3) Al(2) O(6) into Ca(3) SiO(5) accelerated the hydration process, reduced the setting time and improved the compressive strength. Furthermore, these mixtures were bioactive and biocompatible and had a stimulatory effect on the L929 cell growth when the content of Ca(3) Al(2) O(6) was below 10%. Therefore, the mixtures with 10% Ca(3) Al(2) O(6) produced the best compromise between hydration and ex vivo biological properties.

Periapical bone regeneration after endodontic microsurgery with three different root-end filling materials: amalgam, SuperEBA, and mineral trioxide aggregate

INTRODUCTION

The purpose of this study was to determine the bone regeneration potential to different root-end filling materials by evaluating the distance between the materials and newly regenerated bone after root-end surgery.

MATERIAL AND METHODS

Periapical lesions were induced in premolars and molars of five female beagle dogs. The teeth were treated endodontically after the development of the lesions. After 1 week, the teeth underwent root-end surgery using modern microsurgical techniques. Three different root-end filing materials were used: amalgam (Tytin; Kerr Mfg Co, Romulus, MI), SuperEBA (Bosworth, Skokie, IL), and mineral trioxide aggregates (MTA; Dentsply, York, PA). After 4 months, the dogs were sacrificed, and the jaws were prepared for histological sectioning. The distances from the root-end filling materials to the regenerated bone were determined by the evaluation of microradiographic images of the sections with imaging software (Sigma Scan/Image; Jandel Scientific Software, San Rafael, CA). The results were statistically analyzed with analysis of variance using Sigma Stat software (Jandel Scientific Software, San Rafael, CA).

RESULTS

The mean distances from the newly regenerated bone were 0.397 +/- 0.278 mm in the MTA group, 0.756 +/- 0.581 mm in the SuperEBA group, and 1.290 +/- 0.386 mm in the amalgam group. There was a statistically significant difference between the amalgam and MTA groups (p < 0.05). No significant differences existed for amalgam versus SuperEBA and SuperEBA versus MTA.

CONCLUSION

MTA showed the most favorable periapical tissue response. The distance from MTA to the regenerated bone was similar to the normal average periodontal ligament thickness in dogs.