Histological responses of the periodontium to MTA: a systematic review

An Evaluation of the Fracture Resistance of Teeth with Simulated External Cervical Resorption Cavities Categorized Using Three-Dimensional Classification

(1) Background: External cervical resorption causes dental hard tissue destruction that may reduce the fracture resistance of affected teeth. By using a compressive strength test, this study aimed to evaluate the fracture resistance of teeth with simulated external cervical resorption cavities that have different three-dimensional classifications. (2) Methods: In total, 170 teeth with simulated external cervical resorptions were divided into 16 experimental groups (n = 10) and 1 control group (n = 10) based on the three-dimensional classification: 1Ap, 1Bp, 1Cp, 1Dp, 2Ap, 2Bp, 2Cp, 2Dp, 3Ap, 3Bp, 3Cp, 3Dp, 4Ap, 4Bp, 4Cp, 4Dp and a control group. Defects were restored with mineral trioxide aggregate. The fracture resistances of the samples were statistically analyzed using two-way repeated ANOVA and the Bonferroni correction for multiple comparisons at a significance level of p < 0.05. (3) Results: The lowest resistance to fracture was observed in samples with vertical height level "4" and circumferential spread of "D" (p < 0.001). In the groups with circumferential spreads "B", "C" and "D", there were significant differences between the samples with vertical height levels "1", "2", "3" and "4" regarding fracture resistance (p < 0.001). (4) Conclusions: The circumferential spread and vertical height of the external cervical resorption influenced the fracture resistance of the affected teeth.

The Washout Resistance of Bioactive Root-End Filling Materials

Fast-setting bioactive cements were developed for the convenience of retrograde fillings during endodontic microsurgery. This in vitro study aimed to investigate the effect of irrigation on the washout of relatively fast-setting materials (Biodentine, EndoCem Zr, and MTA HP) in comparison with MTA Angelus White and IRM in an apicectomy model. Washout resistance was assessed using artificial root ends. A total of 150 samples (30 for each material) were tested. All samples were photographed using a microscope, and half of them were also scanned. The samples were irrigated and immersed in saline for 15 min. Then the models were evaluated. Rinsing and immersing the samples immediately after root-end filling and after 3 min did not disintegrate the fillings made of all tested materials except Biodentine. Root-end fillings made of Biodentine suffered significant damage both when rinsing was performed immediately and 3 min after the filling. Quantitative assessment of washed material resulted in a slight loss of IRM, EndoCem MTA Zr, and MTA HP. MTA Angelus White showed a slightly greater washout. Rinsing and immersion of Biodentine restorations resulted in their significant destruction. Under the conditions of the current study, the evaluated materials, excluding Biodentine, showed good or relatively good washout resistance.

Successful Orthograde Treatment of Teeth with External Inflammatory Root Resorption and Perforation Using a Tricalcium Silicate-Based Material

One possible consequence of dentoalveolar trauma is the development of external inflammatory root resorption (EIRR), which represents an anatomic and microbiologic challenge for clinicians. This case report describes different strategies implemented for successful endodontic management of teeth with multiple EIRR lesions, highlighting the orthograde root canal filling using a tricalcium silicate-based material (Biodentine, Septodont, Saint-Maur-des-Fossés, France). A 17-year-old female patient presented with severe pain in the anterior maxillary teeth and a history of trauma. Two- and three-dimensional radiographic exams confirmed EIRR in three teeth, with a total of 11 EIRR lesions, three exhibiting communication with the root canal. Therefore, chemo-mechanical preparation complemented by ultrasonic activation of irrigants and some changes of intra-canal dressing with calcium hydroxide were performed to reduce the microbiologic load of the affected teeth as much as possible. Then, the canals were entirely filled with Biodentine to interrupt the root resorption process and strengthen the remaining root structure. A 60-month follow-up showed the disappearance of bone rarefactions and the complete repair of the 11 EIRR lesions. The favorable long-term response indicates the feasibility of using tricalcium silicate-based putty as part of orthograde endodontic treatment of teeth with EIRR and root perforations.

Management of Isolated Labial Mucosal Fenestration by Endodontic Microsurgery Along With Platelet-Rich Fibrin and Connective Tissue Graft: A Report of Four Cases

INTRODUCTION

The purpose of this case report is to present endodontic and periodontal management of mucosal fenestrations with exposed root apices. The treatment protocol in present cases includes a combination of regenerative therapy using platelet-rich fibrin (PRF) with connective tissue graft (CTG) and endodontic microsurgery. Pre-existing condition of these teeth exhibits apical lesion with prominent root position and complete buccal bone dehiscence/fenestration presents a true challenge to successful outcome.

CASE PRESENTATION

Four patients having concomitant mucosal fenestrations with an apical lesion and complete denudation/fenestration of buccal plate were treated with root canal treatment and then by endodontic microsurgery. After the root-end resection and retrograde filling, PRF was placed in the bone defect maintaining intimate contact with the bone surface. CTG was harvested from the palate, placed over the PRF, and beneath the flap corresponding to the mucosal fenestration defect, and sutured with the flap to ensure a secured position. The flap was then repositioned and sutured. All patients showed complete coverage of the mucosal fenestration with no post-operative complications and were followed upto 2-5 years.

CONCLUSION

Peri-radicular endodontic microsurgery and CTG along with PRF may be used as a predictable treatment option to manage the mucosal fenestrations in such challenging cases. This article is protected by copyright. All rights reserved.

Update on Endodontic, Restorative, and Prosthodontic Therapy

Endodontic therapy is intended to preserve the function of mature teeth with irreversible pulpitis or pulp necrosis or to maintain the vitality of endodontically compromised immature teeth. Standard root canal therapy and vital pulp therapy are 2 mainstays of endodontic treatment. Recent knowledge has improved the outcomes of endodontic treatment with newer materials, such as mineral trioxide aggregate. Composite or prosthodontic crown restoration is also a critical key to success.

Does MTA provide a more favourable histological response than other materials in the repair of furcal perforations? A systematic review

BACKGROUND

There is no consensus on which furcal perforation repair material induces a more favourable histological response. This systematic review of laboratory studies provides an overview of the studies comparing repair materials in animal models.

OBJECTIVES

To evaluate whether mineral trioxide aggregate (MTA) yields a more favourable histological response than other materials when used to repair furcal perforations in animal experimental models.

METHODS

This review followed the PRISMA checklist. The studies included various materials used to repair furcal perforations and compared the histological responses with MTA. An electronic search was conducted in EMBASE, PubMed, Scopus and Web of Science up to 2 September 2020, with no language or publication date restrictions. Studies whose full text was unavailable were excluded. The ARRIVE and SYRCLE tools were used to assess the methodological quality and risk of bias (RoB) of the studies.

RESULTS

The studies included in the qualitative synthesis were conducted in rat (n = 3) and dog (n = 17) models. They were classified as having a low quality, high methodological heterogeneity and high RoB. MTA and Biodentine, the materials most often compared, reduced the inflammatory reaction to mild over time. In addition, a mineralized tissue was formed in all studies. The response yielded by MTA was better than or equivalent to that of the other tested materials.

DISCUSSION

This review confirmed that MTA is the reference standard material for furcal perforation repair. However, research using animal models has inherent limitations, and the substantial methodological heterogeneity across the studies included should be considered. Therefore, the knowledge generated by this systematic review should be translated into clinical practice cautiously.

CONCLUSIONS

Features described in the report and quality assessment guidelines, such as PRIASE, ARRIVE and SYRCLE, should guide researchers. Despite the high RoB and the low methodological quality of the studies included, findings indicated that MTA yields a more favourable histological response than other materials in the repair of furcal perforations.

REGISTRATION

PROSPERO (CRD42020181297).

Performance of the dentogingival junction with mta and biodentine on the treatment of invasive cervical resorptions. A literature review and case report

Invasive cervical resorption (ICR) is an uncommon phenomenon (0.1%), however, it represents a challenge to the structural and functional integrity of the dentogingival junction, as well as a risk for the survival of the affected tooth. They are characterized by their location and invasive character, being able to appear in any tooth of the permanent dentition. It shows up after the damage to the cervical insertion apparatus, leaving the pulp without participation in the origin of the lesion. They may appear just below the junctional epithelium or at a more apical level. The MTA® (Dentsply, Tulsa dental, Tulsa OK) and the Biodentine® (Septodent, Saint Maur of Fossés, France) are two biomaterials that have demonstrated the ability to promote the neoformation of cement so they are considered an alternative in the treatment of the ICR. This article presents an ICR clinical cases treated with these biomaterials, in which favorable post-operative healing is observed.

Key words:MTA, Biodentine, biomaterials, root resorption, invasive cervical resorption.

A review on nanotoxicity and nanogenotoxicity of different shapes of nanomaterials

Nanomaterials (NMs) generally display fascinating physical and chemical properties that are not always present in bulk materials; therefore, any modification to their size, shape, or coating tends to cause significant changes in their chemical/physical and biological characteristics. The dramatic increase in efforts to use NMs renders the risk assessment of their toxicity highly crucial due to the possible health perils of this relatively uncharted territory. The different sizes and shapes of the nanoparticles are known to have an impact on organisms and an important place in clinical applications. The shape of nanoparticles, namely, whether they are rods, wires, or spheres, is a particularly critical parameter to affect cell uptake and site-specific drug delivery, representing a significant factor in determining the potency and magnitude of the effect. This review, therefore, intends to offer a picture of research into the toxicity of different shapes (nanorods, nanowires, and nanospheres) of NMs to in vitro and in vivo models, presenting an in-depth analysis of health risks associated with exposure to such nanostructures and benefits achieved by using certain model organisms in genotoxicity testing. Nanotoxicity experiments use various models and tests, such as cell cultures, cores, shells, and coating materials. This review article also attempts to raise awareness about practical applications of NMs in different shapes in biology, to evaluate their potential genotoxicity, and to suggest approaches to explain underlying mechanisms of their toxicity and genotoxicity depending on nanoparticle shape.

Bone morphogenetic proteins in biomineralization of two endodontic restorative cements

To assess the effect of biodentine (BD) and MTA-angelus (MTA) on biocompatibility, BMP2, BMP4, and osteocalcin (OC) expression. Subcutaneously implanted tubes of four groups (MTA, BD, Control, and Sham) were kept over 15, 30, and 60 days; histological analyses were performed using H&E and Von Kossa; ELISA quantified IL-1β and IL-8 expression; and qRT-PCR verified gene expression of BMPs and OC. Sham showed slight changes in profile/intensity of inflammatory infiltrate in all periods. Control had an inflammatory score significantly higher than Sham at 15 days (p < .05). BD revealed a similar inflammatory response to Sham, without significant changes over periods. MTA group exhibited an increase in chronic inflammatory profile at 30 days, with significant reduction at 60 days, when compared to Sham (p < .05). At 30/60 days, experimental groups presented birefringent areas. At 30/60 days, BD and MTA significantly increase IL-1β compared to Control, whereas an increase in IL-8 was observed only in BD. At 30/60 days, BD produces an expression of BMP2 whereas MTA influenced BMP4 and OC. Materials tested are biocompatible and they have osteoinductive activity; the materials influenced the expression of the tested mediators differently, suggesting different affinities with the substrate and the dental substrates.

Retro MTA and tricalcium phosphate/retro MTA for guided tissue regeneration of periodontal dehiscence defects in a dog model: a pilot study

Objectives

Retro MTA is a fast setting Calcium silicate cement used in endodontic regeneration procedures in recent years. Beta-tricalcium phosphate (β-TCP) is another common biomaterial used for bone augmentation procedures. The present pilot study was undertaken to evaluate and compare the efficacy of Retro MTA and a mixture of Retro MTA / β-TCP for periodontal tissue regeneration.

Materials and methods

In 4 beagle dogs, periodontal dehiscence type defects were created. In each side, one dehiscence defect was left empty as a control site and three treatment modalities were randomly applied for the others: Retro MTA covered with a collagen membrane, Retro MTA + β-TCP covered with a membrane and covering the defect with a membrane without any bone augmentation. After 8 weeks Animals were sacrificed and Histomorphometric and histologic analysis were conducted.

Results

Histologic analysis showed more cementum formation for both Retro MTA+ β-TCP (3.74 ± 0.34 mm) and Retro MTA group (3.24 ± 0.56 mm) compared to control group 1 (1. 15 ± 0.45 mm) and control group 2 (0.78 ± 0.65 mm). Formation of newly formed bone and cementum in the experimental groups were significantly higher as compared to the control groups (P < 0.0001).

Conclusions

Retro MTA or Retro MTA+ β-TCP covered with a collagen membrane resulted in regeneration of periodontal tissues. However, Retro MTA+ β-TCP showed tendency towards better results than the use of Retro MTA alone.

Response of periodontium to mineral trioxide aggregate and Biodentine: a pilot histological study on humans

BACKGROUND

The aim of this study was to investigate for the first time the histological response of human periodontium to mineral trioxide aggregate (MTA) and Biodentine.

METHODS

Six patients scheduled for implant full-arch rehabilitation were randomly assigned to one of the two test groups: MTA or Biodentine treatment. For each patient, two teeth scheduled for strategic extraction were randomly assigned either to the test or to the control treatment. A lateral perforation was drilled on the root and either repaired with MTA/Biodentine or filled with gutta-percha(control). Three months later, the teeth were extracted along with the coronal third of the alveolar bone and a portion of gingival tissue, while performing implant placement, and processed for histological analysis.

RESULTS

Biodentine resulted in less extrusion into the periodontal environment. All the materials showed good biocompatibility. A new mineralized cementum-like tissue incorporating periodontal fibres was visible in all cases treated with MTA. A small amount of new mineralized tissue was found in two Biodentine cases but not in control cases. Biodentine resulted in less damage to the periodontal ligament.

CONCLUSIONS

Bioactivity and biocompatibility of MTA were confirmed in human models. Biodentine proved to be biocompatible, but it seems not to induce cementum regeneration.

Cementum regeneration using stem cells in the dog model: A systematic review

OBJECTIVE

Restoring lost tissues of the periodontium, such as cementum, is essential in reducing the risk of tooth loss due to periodontitis and/or severe root resorption. Stem cell therapy is a regenerative strategy in cementum regeneration. This systematic review aimed to analyze the effect of various stem cells and their transplantation method on cementum regeneration in the dog model.

METHODS

Electronic databases were searched, in addition to performing hand searches and a gray literature search. Titles and abstracts were searched according to the inclusion criteria and full texts were selected to be included in this systematic review. Data was extracted from each article and risk of bias was assessed for individual studies.

RESULTS

Most studies reported that the treatment using a variety of stem cells resulted in significantly greater cementum regeneration.

CONCLUSIONS

Because of variations in additional factors included in each study and varied risk of bias among those studies, the effect of each type of stem cell on cementum regeneration in dogs is difficult to clarify. Additional information needs to be obtained from each study in order to further analyze the individual effect of stem cells on cementum regeneration in dogs.

Evaluation of the bioactivity of fluoride-enriched mineral trioxide aggregate on osteoblasts

AIM

To investigate whether a combination of mineral trioxide aggregate (MTA) and fluoride compounds affects bone cells.

METHODOLOGY

Mineral trioxide aggregate (MTA) discs (ProRoot^® , Dentsply Sirona, Ballaigues, Switzerland) with and without the addition of 0.1%, 0.25% and 0.5% sodium fluoride were characterized for their surface roughness by laser scanning microscopy and for the adhesion of human alveolar osteoblasts by scanning electron microscopy. Using eluates from fluoride-enriched MTA discs, the cell proliferation was measured by monitoring the DNA incorporation of 5-bromo-2'-deoxyuridine. Further, gene expression was evaluated by qPCR arrays, extracellular matrix mineralization was quantified by absorption measurement of Alizarin red stains, and effects were calculated with repeated measures analysis and post hoc P-value adjustment.

RESULTS

Irrespective of fluoride addition, cell adhesion was similar on MTA discs, of which the surface roughness was comparable. Control osteoblasts had a curvilinear proliferation pattern peaking at d5, which was levelled out by incubation with MTA. The addition of fluoride partly restored the MTA-related reduction in the cellular proliferation rate in a dose-dependent manner. At the mRNA level, both fluoride and MTA modulated a number of genes involved in osteogenesis, bone mineral metabolism and extracellular matrix formation. Although MTA significantly impaired extracellular matrix mineralization, the addition of fluoride supported the formation of mineralized nodules in a dose-dependent manner.

CONCLUSION

The addition of fluoride modulated the biocompatibility of MTA in terms of supporting bone cell proliferation and hard tissue formation. Hence, fluoride enrichment is a trend-setting advancement for MTA-based endodontic therapies.

Reformulated mineral trioxide aggregate components and the assessments for use as future dental regenerative cements

Mineral trioxide aggregate, which comprises three major inorganic components, namely, tricalcium silicate (C3S), dicalcium silicate (C2S), and tricalcium aluminate (C3A), is promising regenerative cement for dentistry. While mineral trioxide aggregate has been successfully applied in retrograde filling, the exact role of each component in the mineral trioxide aggregate system is largely unexplored. In this study, we individually synthesized the three components, namely, C3S, C2A, and C3A, and then mixed them to achieve various compositions (a total of 14 compositions including those similar to mineral trioxide aggregate). All powders were fabricated to obtain high purity. The setting reaction of all cement compositions was within 40 min, which is shorter than for commercial mineral trioxide aggregate (~150 min). Over time, the pH of the composed cements initially showed an abrupt increase and then plateaued (pH 10-12), which is a typical behavior of mineral trioxide aggregate. The compression and tensile strength of the composed cements increased (2-4 times the initial values) with time for up to 21 days in an aqueous medium, the degree to which largely depended on the composition. The cell viability test with rat mesenchymal stem cells revealed no toxicity for any composition except C3A, which contained aluminum. To confirm the in vivo biological response, cement was retro-filled into an extracted rat tooth and the complex was re-implanted. Four weeks post-operation, histological assessments revealed that C3A caused significant tissue toxicity, while good tissue compatibility was observed with the other compositions. Taken together, these results reveal that of the three major constituents of mineral trioxide aggregate, C3A generated significant toxicity in vitro and in vivo, although it accelerated setting time. This study highlights the need for careful consideration with regard to the composition of mineral trioxide aggregate, and if possible (when other properties are satisfactory), the C3A component should be avoided, which can be achieved by the mixture of individual components.

Effect of root canal sealers on human periodontal ligament fibroblast viability: ex vivo study

The aim of the study was to compare ex vivo the toxic effects of six root canal sealers immediately after mixing or setting on human periodontal ligament fibroblasts (HPdLF). Freshly mixed (I group) or set (allowed to dry for 24 h) (II group) specimens of AH Plus Jet (AH), Apexit Plus (AP), MTA Fillapex (FL), GuttaFlow (GF), MetaSEAL Soft (META), and Tubli-Seal (TS) were prepared. HPdLF were exposed for 24 h to the specimens. 3-(4,5-dimethylthiazolo-2-yl)-2,5-diphenyltetrazolium bromide assay was used to examine the effect of the root canal sealers on mitochondrial metabolic activity. Fluorescein isothiocyanate (FITC)-annexin V (AnV) and propidium iodide staining followed by flow cytometry was used to identify the effects of the materials on cell apoptosis/necrosis. Statistical analyses were performed by one-way ANOVA followed by post hoc tests, and significance was determined at P < 0.05. Most materials from the two groups reduced the viability of the cultured cells compared with the control group (P < 0.05). Statistical analysis showed significant differences in HPdLF viability between the individual materials in each group (P < 0.001). AH and AP induced a significant increase in the percentage of apoptotic cells, while TS, FL, and META elevated the proportion of necrotic cells compared with other materials and the controls (p < 0.05). The cytotoxic effects of the tested root canal sealers (both fresh and set) on HPdLF varied. Both forms of sealers were able to cause toxic effects by inducing apoptosis and necrosis in HPdLF. The cytotoxicity of FL, META, TS was mainly associated with necrosis, while AH and AP with apoptosis.

Radiopacity of Mineral Trioxide Aggregate with and without Inclusion of Silver Nanoparticles

AIM

The aim of this study was to investigate the inclusion of silver nanoparticles (Ag NPs) in the mineral trioxide aggregate (MTA) composition to know which changes will result in the radiopacity of the material.

MATERIALS AND METHODS

The experiment was performed according to the American National Standard Institute/American Dental Association specification no. 57/2000 and ISO 6876/2001. Five plates with five holes measuring 1 mm in depth and 5 mm in internal diameter were filled according to the different experimental groups as follows: white mineral trioxide aggregate (WMTA) + NP50 - W MTA with liquid Ag NP 50 ppm, WMTA + NP30 - W MTA with liquid Ag NP 30 ppm, WMTA + NP22 - W MTA with liquid Ag NP 22 ppm, WMTA + NPP - white MTA with liquid Ag NP and powder 1%, WMTA (control). After filling the plates, they were kept in an incubator at 37°C in relative humidity for setting. Each sample was positioned along an aluminum step-wedge placed above the Opteo digital sensor system. The image was divided into four quadrants, and three readings were made for each quadrant to render the average of each quadrant. The resulting data were submitted to Kruskal-Wallis and Dunn's tests.

RESULTS

The results showed statistically significant differences between WMTA + NP30, WMTA + NP22, and WMTA + NPP interactions compared with WMTA (control) (p < 0.05). The radiopacity was in descending order: WMTA + NPP, WMTA + NP22, WMTA + NP30, MTA + NP50, and WMTA.

CONCLUSION

Silver NPs changed the radiopacity of WMTA, being more evident in WMTA + NP powder at 1% weight.

CLINICAL SIGNIFICANCE

The low radiopacity of MTA makes it difficult for any radiographic observation. The Ag NPs appear as an alternative, being an excellent radiopacifier as they have excellent antimicrobial property and relatively low toxicity.

Portland cement induces human periodontal ligament cells to differentiate by upregulating miR-146a

BACKGROUND/PURPOSE

Bioaggregates such as Portland cement (PC) can be an economical alternative for mineral trioxide aggregate (MTA) with additional benefit of less discoloration. MTA has been known to induce differentiations of several dental cells. MicroRNAs are important regulators of biological processes, including differentiation, physiologic homeostasis, and disease progression. This study is to explore how PC enhances the differentiation of periodontal ligament (PDL) cells in microRNAs level.

METHODS

PDL cells were cultured in a regular PC- or MTA-conditioned medium or an osteoinduction medium (OIM). Alizarin red staining was used to evaluate the extent of mineralization. Transfection of microRNA mimics induced exogenous miR-31 and miR-146a expression. The expression of microRNAs and differentiation markers was assayed using reverse-transcriptase polymerase chain reaction.

RESULTS

PC enhanced the mineralization of PDL cells in a dose-dependent manner in the OIM. Exogenous miR-31 and miR-146a expression upregulated alkaline phosphatase (ALP), bone morphogenic protein (BMP), and dentin matrix protein 1 (DMP1) expression. However, miR-31 and miR-146a modulates cementum protein 1 (CEMP1) expression in different ways. PC also enhanced ALP and BMP but attenuated CEMP1 in the OIM. Although the OIM or PC treatment upregulated miR-21, miR-29b, and miR-146a, only miR-146a was able to be induced by PC in combination with OIM.

CONCLUSION

This study demonstrated that PC enhances the differentiation of PDL cells, especially osteogenic through miR-146a upregulation. In order to control the ankylosis after regenerative endodontics with the usage of bioaggregates, further investigations to explore these differentiation mechanisms in the miRNA level may be needed.

In vitro evaluation of different dental materials used for the treatment of extensive cervical root defects using human periodontal cells

INTRODUCTION

Repair materials for extensive cervical root defects may come in direct contact with periodontal tissues. This in vitro study compared the effects of four calcium silicate cements (CSC), one resin-modified glass ionomer cement, and one glass carbomer cement on primary human gingival fibroblasts (HGF), alveolar osteoblasts (HAO), and a human osteoblast cell line (hFOB 1.19).

METHODS

HGF, HAO, and hFOB were seeded on discoid test specimens. Relative numbers of viable cells were quantitatively assessed after 1 and 24 h for cytotoxicity/adhesion assays and after 4, 24, 48, and 72 h for proliferation assays. Data were statistically analyzed using non-parametric tests (α = 0.05).

RESULTS

Relative to the control (100 %), CSC allowed for mean numbers of 71-81 % viable HGF and 80-82 % viable HAO. Then, 64 % of HGF and 56 % of HAO were assessed on GC Fuji II LC. Mean numbers of viable cells were 59-64 % HGF and 67-68 % HAO for GCP Glass Fill specimens. Cells exposed to CSC over 24 h remained viable and even increased in number. Both cell types adhered almost equally well to CSC and GC Fuji II LC. GCP Glass Fill continued to decrease cell viability and adhesion. CSC-based materials and GC Fuji II LC allowed for HGF and hFOB proliferation; however, none of the tested materials specifically stimulated cell proliferation.

CONCLUSIONS

CSC characterized by low cytotoxicity. GC Fuji II LC shows moderate cytotoxic effects. ProRoot MTA, Harvard MTA, Biodentine, EndoSequence putty, and GC Fuji II LC allow HGF and HAO to adhere and HGF and hFOB to proliferate. GCP Glass Fill decreases cell viability, adhesion, and proliferation.

CLINICAL RELEVANCE

CSC remain the paramount biologic choice for the repair of extensive cervical root defects. GC Fuji II LC might be considered in addition to CSC when the defect comprises supracrestal areas and the restoration requires superior aesthetic and mechanical characteristics.

Dental pulp stem cells. Biology and use for periodontal tissue engineering

Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors.

Papillary reconstruction and guided tissue regeneration for combined periodontal-endodontic lesions caused by palatogingival groove and additional root: a case report

We described a combined periodontal–endodontic lesion, which was caused by a palatogingival groove and an additional root. An interdisciplinary approach involving endodontic therapy, mineral trioxide aggregate (MTA) filling, root resection, guided tissue regeneration, and papillary reconstruction was used for the case. The tooth presents morphologically and functionally normal except tooth discoloration caused by MTA.

Osteogenic differentiation of dental pulp stem cells under the influence of three different materials

Background

Regeneration of periodontal tissues is a major goal of periodontal therapy. Dental pulp stem cells (DPSCs) show mesenchymal cell properties with the potential for dental tissue engineering. Enamel matrix derivative (EMD) and platelet-derived growth factor (PDGF) are examples of materials that act as signaling molecules to enhance periodontal regeneration. Mineral trioxide aggregate (MTA) has been proven to be biocompatible and appears to have some osteoconductive properties. The objective of this study was to evaluate the effects of EMD, MTA, and PDGF on DPSC osteogenic differentiation.

Methods

Human DPSCs were cultured in medium containing EMD, MTA, or PDGF. Control groups were also established. Evaluation of the achieved osteogenesis was carried out by computer analysis of alkaline phosphatase (ALP)-stained chambers, and spectrophotometric analysis of alizarin red S-stained mineralized nodules.

Results

EMD significantly increased the amounts of ALP expression and mineralization compared with all other groups (P < 0.05). Meanwhile, MTA gave variable results with slight increases in certain differentiation parameters, and PDGF showed no significant increase in the achieved differentiation.

Conclusions

EMD showed a very strong osteogenic ability compared with PDGF and MTA, and the present results provide support for its use in periodontal regeneration.

Can MTA be: Miracle trioxide aggregate?

Mineral trioxide aggregate (MTA) has been used for more than 10 years in the dental community and has often been thought of as a material of choice for the endodontist. The dental pulp is closely related to periodontal tissues through apical foramina, accessory canals, and dentinal tubules. Due to this interrelationship, pulpal diseases may influence periodontal health and periodontal infections may affect pulpal integrity. It is estimated that pulpal and periodontal problems are responsible for more than 50% of tooth mortality. Thus, these associations recommend an interdisciplinary approach. MTA appears to exhibit significant results even in periodontal procedures as it is the first restorative material that consistently allows for over-growth of cementum and may facilitate periodontal tissue regeneration. Thus, in the present review, an attempt is made to discuss the clinical applications of MTA as an interdisciplinary approach.

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.

Antibacterial Activity of a Chitosan-PVA-Ag+-Tobermorite Composite for Periodontal Repair

A polymer-mineral composite was prepared by solvent casting a mixture of chitosan, poly(vinyl alcohol), and Ag+-exchanged tobermorite in dilute acetic acid and characterised by scanning electron microscopy and Fourier transform infrared spectroscopy. The in vitro bioactivity of the CPTAg membrane was confirmed by the formation of hydroxyapatite on its surface in simulated body fluid. The alkaline dissolution products of the tobermorite lattice buffered the acidic breakdown products of the chitosan polymer and the presence of silver ions resulted in marked antimicrobial action against S. aureus, P. aeruginosa, and E. coli. The in vitro cytocompatibility of the CPTAg membrane was confirmed using MG63 osteosarcoma cells. The findings of this preliminary study have indicated that chitosan-poly(vinyl alcohol)-Ag+-tobermorite composites may be suitable materials for guided tissue regeneration applications.