The replacement of traditional metals and alloy materials used in dentistry with biological materials continues to be of interest to researchers worldwide. Researchers have found that polymeric materials have excellent mechanical and biological properties that are ideal for dental applications.
A review of dental biomaterials
Traditionally, the materials used for these dental treatments consist of metals and alloys such as titanium, stainless steel, or gold-based alloys. Unfortunately, excessive exposure to these types of substances can be harmful and lead to a wide range of health effects, including local irritation, nausea, vomiting, and diarrhea.
To overcome these limitations, several advances in biomaterials science that have emerged in the past few years have revolutionized the way materials are used for preventive, restorative treatments in dentistry. In addition to eliminating potential toxicity for the patient, dental biomaterials have several advantages, some of which include reduced cost, increased availability, valuable mechanical properties, and improved corrosion behavior.
Polymer materials in dentistry
Polymeric materials (PMs) have been increasingly incorporated into biomedical applications due to their wide application and various beneficial properties. In dentistry, some of the most commonly used PMs are polyethylene, polymethyl methacrylate, polycarbonate, polyethylene glycol, polyurethane, and hexamethyldisilazane. Significant advances in the fields of engineering and nanotechnology have made these PMs designed for specific dental needs.
?How are polymer films used in dentistry
Polymeric films (PMFs) are a class of PMs that have become an area of interest for many researchers working on ways to improve the quality of materials used in dentistry. The development of these films has led to significant improvements in the antimicrobial properties of dental materials while also increasing the integrity of dental prostheses and implants. Further research on PMFs in dentistry has uncovered ways in which these remarkable materials can be used as drug delivery systems.
Antimicrobial PMFs
Dental biofilms can form as a result of microbial organisms adhering to teeth or implanted restorative materials. Once microbial adhesion is initiated, bacterial growth and colonization follow until a compact biofilm matrix is formed. Unfortunately, the presence of this protective biofilm matrix ensures bacterial overgrowth, simultaneously preventing the persistence of antibiotics as well as the host’s defense mechanisms from successfully fighting infections.
To prevent these infections as well as the inevitable failure of the dental implant resulting from the formation of this biofilm, several antibacterial polymer coatings have been investigated. For example, copolymers of acrylic acid, alkyl methacrylate and/or polydimethylsiloxane, as well as liposomes coated with pectin and carbopol have been used as coatings on traditional dental varnishes to provide better antibacterial protection of implanted dental materials.
PMFs as drug delivery systems
PMs and similar nanoparticle (NP) formulations have been investigated as potential drug delivery systems for oral drugs. Some of the key advantages associated with these types of adhesive formulations are due to their ability to protect encapsulated drugs that would otherwise be lost by the oral mucosa. In addition, these polymer formulations can improve the shelf life of loaded drugs and thus increase their efficacy in the treatment of a wide range of diseases.
Several biodegradable polymers have shown their potential as drug delivery systems, some of which include chitosan, alginate, gelatin, and methacrylic acid. In the dental field, various pectin-coated liposomes have been shown to retain their presence on enamel surfaces, thereby adding a protective layer to the enamel. In comparison, it has been shown that a mixture of polymeric micelles and antifungal agents such as amphotericin reduces the systemic toxicity of these agents and increases their bioavailability. While these results have been promising, it should be noted that there are certain limitations in the stability of these formulations and these studies remain in the early stages of development.
PMF for dental prostheses
Despite the widespread use of polymethyl methacrylate (PMMA) for medical and dental prostheses, this material is associated with certain disadvantages, including a greater likelihood of experiencing swelling and dissolution when exposed to organic solvents and chemicals. In addition, PMMA is not equipped with significant antibacterial or antifungal properties, which has prompted many researchers to investigate how some additives may improve this property of PMMA prostheses.
In addition to the wide variety of NPs added to PMMA prostheses, some of which include Ag silver NPs, platinum (Pt) NPs, and zirconium oxide (ZrO2) NPs, several PMFs have also been investigated. To this end, a 2016 study showed that the addition of a phospholipid polymer consisting of poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) to PMMA successfully prevented biofilm formation. This antibacterial activity was achieved by inhibiting the sucrose-dependent streptococci mutans (S. mutans), which normally develops on the denture base of PMMA materials.
Another study showed that incorporation of Ag-NPs into polymerized PMMA was able to kill Gram-positive and Gram-negative bacterial strains. Therefore, showing the promise of this type of technology combination has a promising future in dentistry.
