Recent Trends in Tricalcium Silicates for Vital Pulp Therapy

Evaluation of the physical properties of bromelain-modified biodentine for direct pulp capping

BACKGROUND

This study aims to evaluate the compressive strength, solubility, radiopacity, and flow of Bromelain (BR)-modified Biodentine (BD) for direct pulp capping (DPC). This is suggested to determine the impact of BR on the physical properties of BD.

METHODS

Eighty samples were prepared according to the ISO and ADA specifications and evaluated for compressive strength, solubility, radiopacity, and flow. The compressive strength was evaluated at 24 h and 21 days via a universal testing machine. The solubility was determined by weight loss after 24-hours immersion in deionized water. Radiopacity was assessed via X-ray with aluminum step-wedges, and flow was measured by the diameter of the discs under a standard weight. Independent sample t-tests were used to statistically assess the data. A significance level of 5% was considered.

RESULTS

The compressive strength was 41.08 ± 1.84 MPa for BD and 40.92 ± 1.80 MPa for BR + BD after 24 h, and 88.93 ± 3.39 MPa for BD and 87.92 ± 3.76 MPa for BR + BD after 21 days, with no significant differences. Solubility was slightly greater in the BR + BD (2.75 ± 0.10%) compared to BD (2.62 ± 0.25%), but not significantly different. The radiopacity was similar between BD (2.82 ± 0.11 mm) and BR + BD (2.73 ± 0.10 mm). BR + BD resulted in significantly greater flow (9.99 ± 0.18 mm) than did BD (9.65 ± 0.27 mm) (p ≤ 0.05).

CONCLUSION

BR-modified BD maintains BD's physical properties, with improved flow, making it a promising DPC agent that warrants further study.

Novel self-setting cements based on tricalcium silicate/(β-tricalcium phosphate/monocalcium phosphate anhydrous)/hydroxypropyl methylcellulose: From hydration mechanism to biological evaluations

Despite the clinical success of tricalcium silicate (TCS)-based materials in endodontics, the inferior handling characteristic, poor anti-washout property and slow setting kinetics hindered their wider applications. To solve these problems, an injectable fast-setting TCS/β-tricalcium phosphate/monocalcium phosphate anhydrous (β-TCP/MCPA) cement was developed for the first time by incorporation of hydroxypropyl methylcellulose (HPMC) and β-TCP/MCPA. The physical-chemical characterization (setting time, anti-washout property, injectability, compressive strength, apatite mineralization and sealing property) of TCS/(β-TCP/MCPA) were conducted. Its hydration mechanism was also investigated. Furthermore, the cytocompatibility and osteogenic/odontogenic differentiation of stem cells isolated from human exfoliated deciduous teeth (SHED) treated with TCS/β-TCP/MCPA were studied. The results showed that HPMC could provide TCS with good anti-washout ability and injectability but slow hydration process. However, β-TCP/MCPA effectively enhanced anti-washout characteristics and reduced setting time due to faster hydration kinetics. TCS/(β-TCP/MCPA) obtained around 90 % of injection rate and high compressive strength whereas excessive additions of β-TCP/MCPA compromised its injectability and compressive strength. TCS/(β-TCP/MCPA) can induce apatite deposition and form a tight marginal sealing at the dentin-cement interface. Additionally, TCS/(β-TCP/MCPA) showed good biocompatibility and promoted osteo/odontogenic differentiation of SHED. In general, our results indicated that TCS/(β-TCP/MCPA) may be particularly promising as an injectable bioactive cements for endodontic treatment.

Biodentine™ as a temporary filling in deep carious lesions in permanent teeth: a prospective observational 33-month follow-up study

PURPOSE

The study aimed to evaluate temporary fillings using Biodentine™ in asymptomatic deep carious lesions after 12, 24, and 36 months in school children from the remote village of Kerung, Nepal.

METHODS

From November 2018 to November 2019, 91 temporary fillings were placed using Biodentine™ (a hydraulic calcium silicate cement) in permanent molars with deep carious lesions of schoolchildren in the remote district of Kerung, Nepal. These restorations were performed after selective caries removal in a non-dental setting with hand instruments and cotton roll isolation, as electric motors and saliva ejection systems were unavailable. In total, 78 single-surface and 13 multi-surface fillings were placed. Clinical and radiographic follow-up periods encompassed 12, 21, and 33 months, respectively.

RESULTS

After 12 months, all single-surface fillings (100%) survived, whilst all multi-surface fillings were partially or entirely lost. The survival rate of single-surface restorations after 21 and 33 months was 67.6% and 50%, respectively. Radiographically, no pathology was observed.

CONCLUSION

This study showed that Biodentine could be used in deep carious lesions as a temporary filling in single-surface lesions for at least up to 1 year and in a substantial number of cases for up to 21 and 33 months.

Direct pulp capping procedures - Evidence and practice

The aim of direct pulp capping (DPC) is to promote pulp healing and mineralized tissue barrier formation by placing a dental biomaterial directly over the exposed pulp. Successful application of this approach avoids the need for further and more extensive treatment. In order to ensure a complete pulp healing with the placement of restorative materials, a mineralized tissue barrier must form to protect the pulp from microbial invasion. The formation of mineralized tissue barrier can only be induced when there is a significant reduction in pulp inflammation and infection. Consequently, promoting the healing of pulp inflammation may provide a favorable therapeutic opportunity to maintain the sustainability of DPC treatment. Mineralized tissue formation was observed as the favorable reaction of exposed pulp tissue against a variety of dental biomaterials utilized for DPC. This observation reveals an intrinsic capacity of pulp tissue for healing. Therefore, this review focuses on the DPC and its healing procedure as well as the materials used for DPC treatment and their mechanisms of action to promote pulpal healing. In addition, the factors that can affect the healing process of DPC, clinical considerations and future perspective has been described.

Radio Frequency IDentification for Meat Supply-Chain Digitalisation

Digitalised supply-chain traceability systems can offer wide prospects both for improving safety as well as enhancing perceived quality. However, the coupling between physical goods and information is often difficult for agri-food items. A solution could be the use of RFID (Radio Frequency IDentification) systems. Due to its wide reading range, Ultra-High Frequency (UHF) technology is already widely used in logistics and warehousing, mostly for the identification of batches of items. A growing interest is also emerging in Near Field Communication (NFC), as several smartphones embed an integrated NFC antenna. This paper deals with the automatic identification of meat products at item level, proposing and evaluating the adoption of different RFID technologies. Different UHF and NFC solutions are proposed, which benchmark tag performances in different configurations, including four meat types (fatty beef, lean beef, chicken and pork), by using a specifically designed test bench. As avoiding the application of two different tags could be advantageous, dual frequency devices (UHF and NFC) are also considered. Significant differences in tag performances, which also depend on meat type and packaging, are highlighted. The paper highlights that tag positioning should consider the geometry of the packaging and the relative positioning of tag, meat and reader antenna.

Pulp capping materials modulate the balance between inflammation and regeneration

The interrelations between inflammation and regeneration are of particular significance within the dental pulp tissue inextensible environment. Recent data have demonstrated the pulp capacity to respond to insults by initiating an inflammatory reaction and dentin pulp regeneration. Different study models have been developed in vitro and in vivo to investigate the initial steps of pulp inflammation and regeneration. These include endothelial cell interaction with inflammatory cells, stem cell interaction with pulp fibroblasts, migration chambers to study cell recruitment and entire human tooth culture model. Using these models, the pulp has been shown to possess an inherent anti-inflammatory potential and a high regeneration capacity in all teeth and at all ages. The same models were used to investigate the effects of tricalcium silicate-based pulp capping materials, which were found to modulate the pulp anti-inflammatory potential and regeneration capacity. Among these, resin-containing materials such as TheraCal^® shift the pulp response towards the inflammatory reaction while altering the regeneration process. On the opposite, resin-free materials such as Biodentine™ have an anti-inflammatory potential and induce the pulp regeneration capacity. This knowledge contradicts the new tendency of developing resin-based calcium silicate hybrid materials for direct pulp capping. Additionally, it would allow investigating the modulatory effects of newly released pulp capping materials on the balance between tissue inflammation and regeneration. It would also set the basis for developing future capping materials targeting these processes.