Evaluation of Two Different Types of Mineral Trioxide Aggregate Cements as Direct Pulp Capping Agents in Human Teeth

Traumatic human dental injuries involving the pulp might necessitate direct capping procedures. This clinical study aimed to analyse the histological outcomes using two different direct capping materials. Twenty patients with bilateral premolars, scheduled for orthodontic extraction, were selected. The teeth were treated either using ProRoot MTA or RetroMTA. All patients were recalled after 30 and 60 days for teeth extraction. The histopathologically stained specimens were blindly evaluated using hard tissue bridge formation, inflammatory reaction and pulpal findings criteria. Data were evaluated statistically. Results: After 60 days, only the parameter for hard tissue bridge formation showed significant difference in the ProRoot MTA group (p = 0.010), while both direct capping materials performed similarly regarding inflammatory pulp reaction and pulpal findings. Although, during the first 30 days, RetroMTA presented better results in terms of continuity, morphology, hard tissue bridge localisation, and extension/general state of the inflammatory reaction, the continuity was better at 60 days when ProRoot MTA was applied. Treatment with RetroMTA healed the pulpal tissue faster compared with ProRoot MTA but it seemed to be rather a reparative process.

Expression of Fibronectin and Tenascin after Direct Capping of the Pulp with Mineral Trioxide Aggregate and Biodentine®

BACKGROUND: Caries is a destructive process leading to progressive demineralization of the inorganic part of the tooth, accompanied by enzyme disintegration of the organic component of the tooth tissue. Considering the fact that caries activity can be stopped if the demineralization process is stopped, it is clear that the objectives of caries treatment are focused toward elimination of etiological factors and stimulation of regeneration of the dental tissues. That is why in the last years treatment of the caries disease is targeted to remineralization of the initial carious lesions, as well as on the biological behavior of the pulp-dentine complex after application of certain medications. AIM: The aim of this study is to evaluate impact of the two materials for direct capping, mineral trioxide aggregate (MTA) and Biodentine®, on the expression of glycoproteins fibronectin (FN), and tenascin (TN), responsible for dentinogenesis. METHODS: In the tests were used materials MTA and Biodentine, as agents for direct capping of pulp exposure. From 60 extracted teeth included in this in vitro study, tissue cuts were made. Each of them was then analyzed on a light microscope to determine the amount of two extracellular matrix glycoproteins, FN-C, and TN-C. RESULTS: Our study show that there is an expressed immunoreactivity for FN and for TN in the fibronectin bridge under MTA and Biodentine® after 8, and even after 30 days of their application. CONCLUSION: Based on this study, we can conclude that both materials – MTA and Biodentine – may induce reparative dentinogenesis, in which FN and TN have certainly a major role in the formation of the fibronectin matrix.

Translation Approach for Dentine Regeneration Using GSK-3 Antagonists

The canonical Wnt/β-catenin signaling pathway is crucial for reparative dentinogenesis following tooth damage, and the modulation of this pathway affects the rate and extent of reparative dentine formation in damaged mice molars by triggering the natural process of dentinogenesis. Pharmacological stimulation of Wnt/β-catenin signaling activity by small-molecule GSK-3 inhibitor drugs following pulp exposure in mouse molars results in reparative dentinogenesis. The creation of similar but larger lesions in rat molars shows that the adenosine triphosphate (ATP)–competitive GSK-3 inhibitor, CHIR99021 (CHIR), and the ATP noncompetitive inhibitor, Tideglusib (TG), can equally enhance reparative dentine formation to fully repair an area of dentine damage up to 10 times larger, mimicking the size of small lesions in humans. To assess the chemical composition of this newly formed dentine and to compare its structure with surrounding native dentine and alveolar bone, Raman microspectroscopy analysis is used. We show that the newly formed dentine comprises equal carbonate to phosphate ratios and mineral to matrix ratios to that of native dentine, both being significantly different from bone. For an effective dentine repair, the activity of the drugs needs to be restricted to the region of damage. To investigate the range of drug-induced Wnt-activity within the dental pulp, RNA of short-term induced (24-h) molars is extracted from separated roots and crowns, and quantitative Axin2 expression is assayed. We show that the activation of Wnt/β-catenin signaling is highly restricted to pulp cells in the immediate location of the damage in the coronal pulp tissue with no drug action detected in the root pulp. These results provide further evidence that this simple method of enhancement of natural reparative dentinogenesis has the potential to be translated into a clinical direct capping approach.

Home management of crown fractures of two central incisors complicated by exposure of the pulp

Aim: As dental trauma is an unpredictable event, the patient is sometimes unable to receive dental care immediately in case of tooth fracture complicated by exposure to the pulp. It is conceivable that a long wait may favor bacterial contamination that can lead to necrosis of the pulp. The aim of this paper is to present a clinical case in which the pulp has been protected domiciliary to reduce post-traumatic hypersensitivity and the risk of pulpal necrosis. Materials and methods: In the presented clinical case, the nail polish was used as an emergency material for the direct capping of the pulp of two fractured incisors. In thisway itwas possible to protect the pulp and seal the dentinal tubules for 5 days, such it is the time between trauma and therapy. Results: application of the nail polish led to a reduction in hypersensitivity; at 2-year follow-up both teeth were still vital. Conclusions: Based on this experience, it is suggested the possibility to recommend the use of nail polish as a protective material for the pulp and for reducing symptoms in case of complicated and uncomplicated fractures, if the dentist is consulted by telephone and the patient is not in condition to reach it quickly.

Effect of 4-Allyl-1-hydroxy-2-methoxybenzene (Eugenol) on Inflammatory and Apoptosis Processes in Dental Pulp Fibroblasts

Eugenol (mixed with zinc oxide powder) is widely used as direct capping material during pulp therapy in primary teeth. The aim of the present study was to evaluate the effect of eugenol on diverse genes involved in inflammatory and cell apoptosis processes. The regulatory effect of eugenol on the expression of inflammation and apoptotic genes was evaluated in dental pulp fibroblasts from extracted third molars, cultured under concentration of eugenol of 13 μM. Eugenol allowed the expression of inflammatory and apoptotic genes when compared with positive and negative controls. Eugenol is a proinflammatory agent when it is in direct contact with healthy tissues and behaves as an anti-inflammatory agent in tissues undergoing inflammatory/apoptotic processes, as in cases of pulp inflammation in primary teeth. These findings are relevant for dentistry, when considering the application of safer pulp treatments to grossly carious children’s teeth.