Polymeric Scaffolds for Dental, Oral, and Craniofacial Regenerative Medicine

Abstract

Dental, oral, and craniofacial (DOC) regenerative medicine aims to repair or regenerate DOC tissues including teeth, dental pulp, periodontal tissues, salivary gland, temporomandibular joint (TMJ), hard (bone, cartilage), and soft (muscle, nerve, skin) tissues of the craniofacial complex. Polymeric materials have a broad range of applications in biomedical engineering and regenerative medicine functioning as tissue engineering scaffolds, carriers for cell-based therapies, and biomedical devices for delivery of drugs and biologics. The focus of this review is to discuss the properties and clinical indications of polymeric scaffold materials and extracellular matrix technologies for DOC regenerative medicine. More specifically, this review outlines the key properties, advantages and drawbacks of natural polymers including alginate, cellulose, chitosan, silk, collagen, gelatin, fibrin, laminin, decellularized extracellular matrix, and hyaluronic acid, as well as synthetic polymers including polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), poly (ethylene glycol) (PEG), and Zwitterionic polymers. This review highlights key clinical applications of polymeric scaffolding materials to repair and/or regenerate various DOC tissues. Particularly, polymeric materials used in clinical procedures are discussed including alveolar ridge preservation, vertical and horizontal ridge augmentation, maxillary sinus augmentation, TMJ reconstruction, periodontal regeneration, periodontal/peri-implant plastic surgery, regenerative endodontics. In addition, polymeric scaffolds application in whole tooth and salivary gland regeneration are discussed.

Keywords: bone regeneration; periodontal regeneration; polymeric scaffolds; polymers; pulp regeneration; regenerative medicine; salivary gland regeneration; sinus augmentation; tissue engineering; whole tooth regeneration.

Figure 6

Photopolymerizable Cell-Laden Gelatin Methacryloyl Hydrogels for Regenerative Endodontics. Example of application of GelMA hydrogel in regenerative dentistry. (A) Synthesis of GelMA macromer (B) Cell encapsulation (C) Example intracanal hydrogel loading and photopolymerization (D) The resulting cell-laden hydrogel material. Note that although the schematic depicts an example for regenerative endodontics, the material can be used for any application of intra-oral regeneration, such guided periodontal regeneration, alveolar bone growth and others. Reprinted from [145] with permission from Elsevier.

Figure 1

Polymeric Scaffolds for Dental, Oral and Craniofacial Regeneration. (A) Polymeric scaffolds can be classified according to their appearance, charge, structure, composition, crosslinking and origin. (B) Polymeric scaffolds have a wide range of mechanical properties that can be tuned to affect cellular behavior. (C) Polymeric scaffolds have various applications in tissue engineering in the context of dental, oral, and craniofacial regeneration.

Figure 2

Lateral Window Approach for Maxillary Sinus Augmentation. (A) After the full thickness mucoperiosteal flap is raised, the outline of the lateral window is marked with a round bur or piezoelectric surgical tip. (B) Before elevating the sinus membrane, the buccal bone is either removed or pushed inward to gain access to the Schneiderian membrane. The membrane is carefully elevated using blunt instruments. (C) The sinus compartment is filled with grafting material and covered with resorbable barrier membrane, which can consist of polymeric scaffolds. Reprinted from [99] with permission from Elsevier.

Figure 3

Transalveolar Approach for Maxillary Sinus Augmentation. (A) A full thickness mucoperiosteal flap is raised on the edentulous ridge. (B) After marking the location of the future implant, the site is prepared with implant drills to approximately 1.0–1.5 mm below the sinus floor. Osteotomes are used to fracture the sinus floor and elevate the membrane. (C) The sinus compartment is gradually filled with grafting material until the appropriate depth for implant placement is achieved. Reprinted from [99] with permission from Elsevier.

Figure 4

Biomaterials for Periodontal Regeneration. Reprinted from [74] with permission from MDPI.

Figure 5

Volume-Stable Collagen Matrix for Periodontal Plastic Surgery. (A) Gingival recession defect on a maxillary canine (B) A split-full-split flap limited to the canine was performed (C) After the de-epithelialization of the anatomical papillae, a volume-stable collagen matrix was applied on the root surface and sutured to the de-epithelialized papillae (D) The flap was coronally advanced and sutured (E) One-year outcomes. Reprinted from [125] with permission from Wiley.

Figure 7

Egg White Alginate (EWA) hydrogel preparation for salivary gland spheroid-like structure formation. EWA is a novel hydrogel which combines the advantages of both egg white and alginate. The egg white material provides extracellular matrix (ECM)-like proteins that can mimic the ECM microenvironment, while alginate can be tuned mechanically through its ionic crosslinking property to modify the scaffold’s porosity, strength, and stiffness. Reprinted from [163] with permission from MDPI.