Insights into chitosan hydrogels on dentine bond strength and cytotoxicity

Abstract

<p style="text-align:justify;"> <span style="font-size:10.0pt;"><span style="font-size:12px;">Contemporary dental adhesives show favorable immediate results in terms of bonding effectiveness. However, the durability of resin-dentin bonds is their major problem. Materials and Methods: Preparation of 3 chitosan-antioxidant hydrogels was achieved using modified hydrogel preparation method. Their effect on the bond strength to dentine both short term (after 24 hours) and long term (after 6 months) were evaluated using shear bond strength measurements using Instron Universal Testing Mascine). The SEM was used to study the surface of the hydrogels. The cell survival rate (cytotoxicity) of the antioxidants resveratrol, </span><i><span style="font-size:12px;">β</span></i><span style="font-size:12px;">-carotene and propolis towards Balb/c 3T3 mouse fibroblast cells was also assessed using the standard MTT assay. Results: It was found that chitosan-H treated dentine gives significantly (p < 0.05; Non-parametric ANOVA test) higher shear bond values than dentine treated or not treated with phosphoric acid. The anti-oxidants chitosan hydrogels improved the shear bond strength. Overall, there was a relapse in the shear bond strength after 6 months. The SEM study showed that the hydrogel formulations have a uniform distribution of drug content, homogenous texture and yellow color. The pH of the growth medium adjusted to relevant values had a highly significant influence (Tukey-Kramer Multiple-Comparison Test; p < 0.01) on the cell survival rate of Balb/c mouse 3T3 fibroblast cells and therefore most probably also to tooth pulp fibroblast cells. The lower the pH value the higher the negative influence. Furthermore, the sequence of survival rate was found to be: </span><i><span style="font-size:12px;">β</span></i><span style="font-size:12px;">-carotene (92%) > propolis (68%) > resveratrol (33%). Conclusion: the antioxidant-chitosan hydrogels significantly improved bonding to dentine with or without phosphoric acid treatment. The pH of the growth medium had a high influence on the cell sur</span></span>vival rate of Balb/c mouse 3T3 fibroblast cells. The release of the antioxidant <i style="font-size:10pt;line-height:1.5;"><span style="font-size:12px;">β</span></i>-carotene would not have an influence on the pulp cells. These materials might address the current perspectives for improving bond durability. </p

Bioactive-Functionalized Interpenetrating Network Hydrogel (BIOF-IPN): A Novel Biomaterial Transforming the Mechanism of Bio-Repair, Bio-Adhesion and Therapeutic Capability – An In Vitro Study

“…Higher adhesiveness of the gels is desired to maintain an intimate contact with skin or tooth structure and results are summarized in Table 3. BIOF-INPs showed the highest adhesive force, and this result can be expected because of the well-known intrinsic bio-adhesive properties of chitosan [12]. The adequate water absorption capacity together with the cationic nature, which promotes binding to the negative surface of skin or dentin structure, could also explain these results.…”

Towards Bioactive Dental Restorative Materials with Chitosan and Nanodiamonds: Evaluation and Application

“…Shear bond strength tests for dentin bonding [11,12] Extracted non-carious, intact, human molars stored in water containing a few crystals of thymolat 4°C, were used within two months. Samples were checked before use for any damage caused by their removal.…”

“…Chitosan is hypoallergenic and has natural antibacterial properties, which further support its use in the army as field bandages [10]. Furthermore, very important findings were that antioxidantchitosan hydrogels (that of resveratrol, propolis and β-carotene) were found to significantly improve the bond strength to dentine with or without phosphoric acid pre-treatment [11] as many other hydrogels do [12].…”

Temporomandibular Disorders and BIO-IPNs: in vitro approach to find molecular solution to biological problem

“…The system optimizes the use of the host : guest science playing an important role as a "build-in" free radical defense mechanism, and acting as a "proof of concept" for the functional multi-dimensional restorative repair materials. This chapter reports the preliminary investigations of the BIOF-IPN utilizing a combination of materials such as CTS in the restorative and regenerative dental field specifically aimed at TMJ in vitro evaluations [84][85][86][87][88][89][90][91][92][93].…”

“…Our approach to the complexity of the developing suitable model for the in vitro TMJ prototype model to investigate excessive free radical generation and harnessing of the imbalance comes from a different angle: developing functional CTS based hydrogel system [84][85][86][87][88][89][90][91][92][93][94]. CTS is a natural cationic polysaccharide derived from chitin, with the structural composition being heavily influenced by the pH factors.…”