A novel bio-active adhesive monomer induces odontoblast differentiation: a comparative study

Novel Universal Bond Containing Bioactive Monomer Promotes Odontoblast Differentiation In Vitro

The development of multifunctional materials has been expected in dentistry. This study investigated the effects of a novel universal bond containing a bioactive monomer, calcium 4-methacryloxyethyl trimellitic acid (CMET), on odontoblast differentiation in vitro. Eluates from bioactive universal bond with CMET (BA (+), BA bond), bioactive universal bond without CMET (BA (-)), and Scotchbond Universal Plus adhesive (SC, 3M ESPE, USA) were added to the culture medium of the rat odontoblast-like cell line MDPC-23. Then, cell proliferation, differentiation, and mineralization were examined. Statistical analyses were performed using a one-way ANOVA and Tukey's HSDtest. The cell counting kit-8 assay and alkaline phosphatase (ALP) assay showed that cell proliferation and ALP were significantly higher in the 0.5% BA (+) group than in the other groups. In a real-time reverse-transcription polymerase chain reaction, mRNA expression of the odontogenic markers, dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1), was significantly higher in the 0.5% BA (+) group than in the BA (-) and SC groups. Calcific nodule formation in MDPC-23 cells was accelerated in the BA (+) group in a dose-dependent manner (p < 0.01); however, no such effect was observed in the BA (-) and SC groups. Thus, the BA bond shows excellent potential for dentin regeneration.

The Retention Effect of Resin-Based Desensitizing Agents on Hypersensitivity-A Randomized Controlled Trial

Recently, the development of dental materials has increased the availability of various hyperesthesia desensitizers. However, there are no studies on the duration of retreatment in terms of adherence rates. Thus, the adhesion rates of resin-based desensitizers were investigated. We used a conventional desensitizer and a recently developed desensitizer containing calcium salt of 4-methacryloxyethyl trimellitic acid (C-MET) and 10-methacryloyloxydecyl dihydrogen calcium phosphate (MDCP). These colored agents were applied to the surfaces of premolars and molars, and the area was measured from weekly oral photographs. Areas were statistically analyzed and mean values were calculated using 95% confidence intervals. A p-value of <0.05 was considered statistically significant. These rates were significantly higher on the buccal side of the maxilla and lower on the lingual side of the maxilla. In addition, the desensitizer containing C-MET and MDCP displayed significantly higher adhesion rates. It is suggested that this will require monthly follow-ups and reevaluation because both agents cause less than 10% adherence and there is almost no sealing effect after 4 weeks. In addition, the significantly higher adhesion rate of the desensitizer containing C-MET and MDCP indicated that the novel monomer contributed to the improvement in the adhesion ability.

Evaluation of a Hypersensitivity Inhibitor Containing a Novel Monomer That Induces Remineralization-A Case Series in Pediatric Patients

BACKGROUND

Recently, tooth deformities have been frequently encountered by pediatric dentists. Severe enamel hypomineralization sometimes induces pain such as hyperesthesia, but composite resin restoration is difficult because it often detaches without any cavity preparation. Resin-based hypersensitivity inhibitors for tooth physically seal the dentinal tubules. It was reported that hypersensitivity inhibitor containing novel adhesive monomers forms apatite and induces remineralization in vitro. Therefore, these case series assessed the clinical effects of remineralization and the suppression of hypersensitivity by Bio Coat Ca (Sun Medical, Shiga, Japan).

METHODS

After mechanical tooth cleaning was performed, the hypersensitivity inhibitors were applied and cured by light exposure. Changes in hypersensitivity were determined by visual analog scale (VAS). The improvement of hypomineralization was evaluated by the change in color tone based on the digital images of intraoral photographs.

RESULTS

After repeated monthly treatments, these cases showed decreased hypersensitivity after the fourth application, while the opaque white and brownish color improved on the seventh application.

CONCLUSION

This novel hypersensitivity inhibitor with calcium salt of 4-methacryloxyethyl trimellitic acid (C-MET) and 10-methacryloyloxydecyl dihydrogen calcium phosphate (MDCP) not only suppressed hypersensitivity but also improved cloudiness and brown spots in recently erupted permanent teeth in presented cases.

Novel Bioactive Adhesive Monomer CMET Promotes Odontogenic Differentiation and Dentin Regeneration

This study aimed to evaluate the in vitro effect of the novel bioactive adhesive monomer CMET, a calcium salt of 4-methacryloxyethyl trimellitate acid (4-MET), on human dental pulp stem cells (hDPSCs) and its capacity to induce tertiary dentin formation in a rat pulp injury model. Aqueous solutions of four tested materials [4-MET, CMET, Ca(OH)₂, and mineral trioxide aggregate (MTA)] were added to the culture medium upon confluence, and solvent (dH₂O) was used as a control. Cell proliferation was assessed using the Cell Counting Kit-8 assay, and cell differentiation was evaluated by real-time quantitative reverse transcription-polymerase chain reaction. The mineralization-inducing capacity was evaluated using alizarin red S staining and an alkaline phosphatase activity assay. For an in vivo experiment, a mechanical pulp exposure model was prepared on Wistar rats; damaged pulp was capped with Ca(OH)₂ or CMET. Cavities were sealed with composite resin, and specimens were assessed after 14 and 28 days. The in vitro results showed that CMET exhibited the lowest cytotoxicity and highest odontogenic differentiation capacity among all tested materials. The favorable outcome on cell mineralization after treatment with CMET involved p38 and c-Jun N-terminal kinases signaling. The nuclear factor kappa B pathway was involved in the CMET-induced mRNA expression of odontogenic markers. Similar to Ca(OH)₂, CMET produced a continuous hard tissue bridge at the pulp exposure site, but treatment with only CMET produced a regular dentinal tubule pattern. The findings suggest that (1) the evaluated novel bioactive adhesive monomer provides favorable biocompatibility and odontogenic induction capacity and that (2) CMET might be a very promising adjunctive for pulp-capping materials.