Chitosan-based materials for dental implantology: A comprehensive review

Chitosan, a versatile biopolymer, has gained recognition in the discipline of dental implantology due to possessing salient properties. This comprehensive review explores the potential of chitosan in dental implants, focusing on its biocompatibility, bioactivity, and the various chitosan-based materials that have been utilized for dental implant therapy. The review also highlights the importance of surface treatment in dental implants to enhance osseointegration and inhibit bacterial biofilm formation. Additionally, the chemical structure, properties, and sources of chitosan are described, along with its different structural forms. The characteristics of chitosan particularly color, molecular weight, viscosity, and degree of deacetylation are discussed about their influence on its applications. This review provides valuable insights into the promising utilization of polymeric chitosan in enhancing the success and functionality of dental implants. This study highlights the potential applications of chitosan in oral implantology. Chitosan possesses various advantageous properties, including muco-adhesiveness, hemostatic action, biocompatibility, biodegradability, bioactivity, and antibacterial and antifungal activities, which enhance its uses in dental implantology. However, it has limited aqueous solubility at the physiological pH, which sometimes restricts its biological application, but this problem can be overcome by using modified chitosan or chitosan derivatives, which have also shown encouraging results. Recent research suggests that chitosan may act as a promising material for coating titanium-based implants, improving osteointegration together with antibacterial properties.

Applications of Chitosan Nanoparticles in Dentistry: A Review

Recently, nanotechnology has garnered significant interest across various fields due to its emerging and diverse applications. Numerous investigators have proposed that chitosan nanoparticles (CSNPs) stand out as some of the most promising nanomaterials for facilitating various activities. Chitosan, a natural biopolymer established through the deacetylation of chitin, has been extensively studied using interdisciplinary approaches for a wide range of applications. Chitosan biomaterials exhibit distinctive attributes, including biodegradability, muco-adhesion, and biocompatibility, as well as a broad spectrum of antibacterial and antifungal properties. Furthermore, chitosan stands as the sole naturally occurring cationic polysaccharide, and it can be chemically tailored into various derivatives, depending on the intended role and utilization. The potential applications of chitosan are vast and intriguing, with many yet to be fully explored and understood. The unique characteristics of chitosan have sparked growing attentiveness in pharmaceutical industries and biomedical areas around the globe. The characteristics of chitosan like its biocompatibility, and anti-inflammatory effects hold the potential to yield promising outcomes in wound healing and periodontal care following tooth extractions. The objective of this study is to provide an overview of potential applications of chitosan in the field of dentistry.

Radiographic evaluation of alveolar ridge preservation using a chitosan/polyvinyl alcohol nanofibrous matrix: A randomized clinical study

The objective of this randomized clinical trial (RCT) was to assess the effectiveness of electrospun chitosan/polyvinyl alcohol (CS/PVA) nanofibrous scaffolds in preserving the alveolar ridge and enhancing bone remodeling following tooth extraction when compared to a control group. In this split RCT, 24 human alveolar sockets were randomly assigned to two groups, with 12 sockets receiving CS/PVA nanofibrous scaffold grafts (test group) and 12 left to heal by secondary intention as the control group. Cone-beam computed tomography (CBCT) was performed at two different time points: immediately after extraction (T0) and 4 months post-extraction (T4). After 4 months, linear vertical and horizontal radiographic changes and bone density of extraction sockets were assessed in both the test and control groups. The RCT included 12 patients (4 male and 8 female) with a mean age of 24 ± 3.37 years. The test group had a significantly lower mean vertical resorption vs the control group, with a mean difference of 1.1 mm (P < 0.05). Similarly, the control group's mean horizontal bone resorption was -2.01 ± 1.04 mm, while the test group had a significantly lower mean of -0.69 ± 0.41 mm, resulting in a mean difference of 1.35 mm (P < 0.05). Furthermore, the study group exhibited a significant increase in bone density (722.03 ± 131.17 HU) after 4 months compared to the control group (448.73 ± 93.23 HU). In conclusion, we demonstrated within the limitations of this study that CS/PVA nanofibrous scaffold significantly limited alveolar bone resorption horizontally and vertically and enhanced bone density in alveolar sockets after 4 months when compared to results in the control group (TCTR20230526005).

South Sulawesi Milkfish (Chanos Chanos) Scale Waste as a New Anti-inflammatory Material in Socket Preservation

BACKGROUND: One of South Sulawesi’s huge brackish water fishery product is milkfish (Chanos chanos). Scales are wasted in milkfish processing. However, they are a good source of chitosan, which has been found to promote anti-inflammation, wound healing, and bone regeneration. AIM: This study aims to determine the effect of milkfish scales waste on the inflammatory response of wound healing after tooth extraction by tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 analysis. METHODS: This is a post-test-only control group design study. Thirty-two Cavia cobaya were divided into four groups: (1) Socket preservation using milkfish scales chitosan, (2) milkfish scales chitosan + bovine xenograft, (3) bovine xenograft as a positive control, and (4) placebo as a negative control, then were sacrificed on 3rd, 7th, 14th, and 28th days. The mandible jaw specimen was taken for immunohistochemical analysis to determine the levels of TNF-α and IL-6. The data were analyzed using the Kolmogorov–Smirnov test, Levene’s test, and one-way analysis of variance. RESULTS: On days 3, 7, 14, and 28, groups with chitosan added showed lower levels of TNF-α and a faster decrease in IL-6 expressions compared to those without chitosan. CONCLUSION: Milkfish scale chitosan suppresses TNF-α and IL-6 production, thus reducing inflammation in socket preservation.

Preparation and application of chitosan biomaterials in dentistry

Chitosan is a biodegradable and biocompatible natural polysaccharide that has a wide range of applications in the field of dentistry due to its functional versatility and ease of access. Recent studies find that chitosan and its derivatives can be embedded in materials for dental adhesives, barrier membranes, bone replacement, tissue regeneration, and antimicrobial agent to better manage oral diseases. In this paper, we provide a comprehensive overview on the preparation, applications, and major breakthroughs of chitosan biomaterials. Furthermore, incorporation of chitosan additives for the modification and improvement of dental materials has been discussed in depth to promote more advanced chitosan-related research in the future.

The Effect of Combination Spirulina-chitosan on Angiogenesis, Osteoclast, and Osteoblast Cells in Socket Models of Hyperglycemic Rattus norvegicus

Background

Prolongation of the inflammatory process in hyperglycemic interferes with bone formation, inhibits the healing process, and triggers bone resorption. A combination of spirulina and chitosan in the tooth socket of Rattus norvegicus is expected to promote the bone remodeling process. This study aimed to evaluate the effect of spirulina and chitosan on angiogenesis, osteoclast, and osteoblast cell in tooth socket models of type 1 diabetes.

Materials and Methods

A laboratory-based experiment involving 36 R. norvegicus, divided into three groups (nondiabetes mellitus (DM), uncontrolled DM, and controlled DM) and further divided into six subgroups. The controlled groups (K1, K2, and K3) were induced with 3% carboxymethyl cellulose Na, while the treated groups were induced with 12% spirulina and 20% chitosan. On the 14^th day, the mandibles of the rats were removed. The capillary lumen, osteoblasts, and osteoclast cells were counted by hypothalamic-pituitary-adrenal examination and the results analyzed by means of Shapiro-Wilk, Levene's, one-way ANOVA, and post hoc Tukey's honestly significant difference test.

Results

There was a significant increment in the number of capillary lumen, osteoblast cells, and a decrease in osteoclasts in all three treated groups (P1, P2, and P3).

Conclusions

A combination of spirulina and chitosan can effectively promote the healing process in postextraction sockets of type 1 DM R. norvegicus.

Efficacy of Platelet Rich Fibrin versus chitosan as a hemostatic agent following dental extraction in patients on antiplatelet therapy

Objectives

The aim of this study is to compare the effectiveness of Platelet Rich Fibrin gel and Chitosan gel dressing in providing hemostasis in patients receiving Oral Antiplatelet Therapy and also to evaluate their surgical healing outcome following dental extractions.

Methodology

A total of 60 patients under Oral Antiplatelet Therapy indicated for tooth extraction were included for treatment in the study without altering the oral antiplatelet regimens. Patients were allocated equally in two groups; Group A: where PRF gel was packed into the extraction socket, while Group B: Chitosan hydrogel was packed. Timing of hemostasis was noted for each patient of both the groups. Patients were examined for any pain/secondary bleeding/healing/soft tissue dehiscence/alveolar osteitis in the extraction site on first, third and seventh post-operative days.

Results

All extraction sockets with Platelet-rich fibrin achieved hemostasis in 2.64 min and sockets with Chitosan hydrogel achieved hemostasis in 1.182 min (p < 0.001). Post-operative pain in Group A sites (3.2, 1.4, 0.37 on 1st, 3rd & 7th day respectively) was significantly lower than the control sites (3.4, 1.67, 0.53 on 1st, 3rd & 7th day respectively) p-value 0.001, 0.001 respectively.

Conclusion

In this study, Chitosan hydrogel dressing thus proved to be a superior hemostatic agent compared to PRF gel, that significantly shortens the clotting time following dental extraction in patients under antiplatelet therapy. But, PRF gel has superior wound healing properties than Chitosan with less postoperative pain following minor oral surgical procedures under local anesthesia.

Local application of osteoprotegerin-chitosan gel in critical-sized defects in a rabbit model

BACKGROUND

Osteoprotegerin (OPG) is used for the systemic treatment of bone diseases, although it has many side effects. The aim of this study was to investigate a newly formulated OPG-chitosan gel for local application to repair bone defects. Recent studies have reported that immunodetection of osteopontin (OPN) and osteocalcin (OC) can be used to characterise osteogenesis and new bone formation.

METHODS

The osteogenic potential of the OPG-chitosan gel was evaluated in rabbits. Critical-sized defects were created in the calvarial bone, which were either left unfilled (control; group I), or filled with chitosan gel (group II) or OPG-chitosan gel (group III), with rabbits sacrificed at 6 and 12 weeks. Bone samples from the surgical area were decalcified and treated with routine histological and immunohistochemical protocols using OC, OPN, and cathepsin K (osteoclast marker) antibodies. The toxicity of the OPG-chitosan gel was evaluated by biochemical assays (liver and kidney function tests).

RESULTS

The mean bone growth in defects filled with the OPG-chitosan gel was significantly higher than those filled with the chitosan gel or the unfilled group (p < 0.05). At 6 and 12 weeks, the highest levels of OC and OPN markers were found in the OPG-chitosan gel group, followed by the chitosan gel group. The number of osteoclasts in the OPG-chitosan gel group was lower than the other groups. The results of the liver and kidney functional tests indicated no signs of harmful systemic effects of treatment. In conclusion, the OPG-chitosan gel has many characteristics that make it suitable for bone repair and regeneration, highlighting its potential benefits for tissue engineering applications.

Formulation and in vitro and in vivo evaluation of a new osteoprotegerin-chitosan gel for bone tissue regeneration

The osteoprotegerin (OPG) system plays a critical role in bone remodelling by regulating osteoclast formation and activity. The study aimed to determine the physicochemical properties and biocompatibility of a newly formulated OPG-chitosan gel. The OPG-chitosan gel was formulated using human OPG protein and water-soluble chitosan. The physicochemical properties were determined using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Gel morphology was determined using scanning electron microscopy (SEM) and then it was subjected to a protein release assay and biodegradability test. An in vitro cytotoxicity test on normal human periodontal ligament (NHPL) fibroblasts and normal human (NH) osteoblasts was carried out using the AlamarBlue assay. In vivo evaluation in a rabbit model involved creating critical-sized defects in calvarial bone, filling with the OPG-chitosan gel and sacrificing at 12 weeks. In vitro results demonstrated that the 25 kDa OPG-chitosan gel had the highest rate of protein release and achieved 90% degradation in 28 days. At 12 weeks, the defects filled with 25 kDa OPG-chitosan gel showed significant (p < 0.05) new bone formation and the highest expression of osteocalcin and osteopontin compared to controls. Thus, the 25 kDa OPG-chitosan gel could be a promising new biomaterial for tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 398-407, 2017.

In vitro evaluation of osteoprotegerin in chitosan for potential bone defect applications

Background

The receptor activator of nuclear factor kappa-B (RANK)/RANK ligand/osteoprotegerin (OPG) system plays a critical role in bone remodelling by regulating osteoclast formation and activity. OPG has been used systemically in the treatment of bone diseases. In searching for more effective and safer treatment for bone diseases, we investigated newly formulated OPG-chitosan complexes, which is prepared as a local application for its osteogenic potential to remediate bone defects.

Methods

We examined high, medium and low molecular weights of chitosan combined with OPG. The cytotoxicity of OPG in chitosan and its proliferation in vitro was evaluated using normal, human periodontal ligament (NHPL) fibroblasts in 2D and 3D cell culture. The cytotoxicity of these combinations was compared by measuring cell survival with a tetrazolium salt reduction (MTT) assay and AlamarBlue assay. The cellular morphological changes were observed under an inverted microscope. A propidium iodide and acridine orange double-staining assay was used to evaluate the morphology and quantify the viable and nonviable cells. The expression level of osteopontin and osteocalcin protein in treated normal human osteoblast cells was evaluated by using Western blot.

Results

The results demonstrated that OPG in combination with chitosan was non-toxic, and OPG combined with low molecular weight chitosan has the most significant effect on NHPL fibroblasts and stimulates proliferation of cells over the period of treatment.