biomimetic dental materials endodontics.pptx

dental materials

1. INSIGHTS OF BIOMIMETIC MATERIALS

2. INTRODUCTION

3. Bios = life, Mimetic = to mimic Term coined by Otto Schmitt in the 1950’s Biomimetic dentistry is conservative, Less dentistry is best dentistry

4. In every field of dentistry and medicine, bioactive materials have been widely used. These materials are used for regeneration, repair, and reconstruction in the field of conservative dentistry and endodontics. Used in different forms and composition which act directly on vital tissue, helping in its healing and repair by inducting various growth factors and different cells.

5. Such materials can form a surface layer of an apatite-like substance in the presence of an inorganic phosphate solution. Their applications in dentistry include remineralization of dentin, maintenance of long-term bonded restorations, and repair of intrabony defects.

6. DEFINITION

7. Biomimetics , Biomimetic is defined as the study of the structure, and function of biological systems as models, for the design and engineering of materials and machines. Karma M, et al. Biomimetics in dentistry. Indian J Dent Edu 2010;3:107-113 A bioactive material is one that elicits a specific biological response, at the interface of the material which results in the formation of a bond between the tissues and the material Hench LL, Splinter RJ, Allen WC, Greenlee TK Jr.; Bonding mechanisms at the interface of ceramic prosthetic materials. J Biomed Mater Res., 1972; 2:117-141

8. WHY IS IT NECESSARY?

9. Biomimetics starts with the understanding of hard tissue arrangement and related stresses distribution. Hardness of enamel  protects soft underlying dentin. Crack-arresting effect of dentin & thick collagen fibers at the enamel-dentin junction  compensate for the inherently brittle nature of enamel.

10. Risk of Biomechanical mismatch : Restoration shouldn’t require to be strongest materials but rather, a restoration should be compatible with mechanical and biological properties of underlying dental tissues . When tooth is restored biomimetically , it flexes in a similar manner as natural dentin.

11. Hard crowns and traditional fillings do not offer this flexibility. This leads to breaks and cracks in natural teeth beneath the crown or filling and translates in to further damage.

12. DRAWBACKS OF CONVENTIONAL RESTORATIVE MATERIALS

13. Porcelain bonded to metal and other substances like amalgam which do not follow biomimetic principles and do not attempt to restore the tooth’s natural properties . Gold is excessively stiff, thereby also not following biomimetic principles .

14. GIs are excellent materials in particular restorative situations and clinical indications, but their ability to prevent recurrent caries may be somewhat variable . Likewise, the potential benefits of the use of adhesive monomers and self-adhesive cement formulations are still somewhat areas of debate.

15. GOAL OF BIOMIMETICS

16. The goal of biomimetics in restorative dentistry is to return all of the prepared dental tissues to full function by the creation of a hard tissue bond that allows functional stresses to pass through the tooth, drawing the entire crown into the final functional biologic and esthetic result.

17. USES OF BIOACTIVE MATERIALS

18. Can be used as pulp capping materials Used for permanent restorations. Can be used for occlusion of dentinal tubules. Used as scaffold Helps in regeneration of bone tissue. Promotes tooth remineralization

19. CLASSIFICATION

20. Singer, L., Fouda , A. & Bourauel , C. Biomimetic approaches and materials in restorative and regenerative dentistry: review article.  BMC Oral Health   23 , 105 (2023).

21. Synthetic Biomaterial Classification

22. Glass Ionomer Cement (GIC) Resin Based Composite Smart Dentin Replacement (SDR) Ceramic Castor Oil Bean Cement Calcium Hydroxide Calcium Sulfate Calcium Phosphate Calcium Enriched Mixture (CEM) Biomimetic materials used in dentistry

23. Mineral Trioxide Aggregate (MTA) Calcium Aluminate Cement Doxadent Ceramir Biodentine ™ Theracal Bioaggregate (BA) Endosequence Root Repair Material (ERRM) putty, ERRM paste RRM putty fast set (FS) and iroot FS

24. Bioceramic Sealers Bioceramic Gutta-Percha Bioactive Glass (BAG) Remineralizing Agents Casein phosphopeptide amorphous calcium phosphate (CPP-ACP) Enamel matrix derivative (EMD) Growth Factors Bone Morphgenic Proteins (BMP)

25. Platelet Concentrates Implant Biomaterials/Biomimetic Coatings on Implants Polymers Regenerative endodontics and tissue engineering Root Canal Revascularization Bio engineered tooth

26. SMART MATERIALS

27. Materials used in dentistry can be classified based on their interactions with the environment- - bioinert (passive)- conventional - bioactive- remineralising materials - bioresponsive - smart materials The term ‘smart materials’ refers to a class of materials that are highly responsive and have the inherent capability to sense and react according to changes in the environment.

28. SMART MATERIALS Smart Composites Self healing composite Smart Ceramics Smart sutures Smart antimicrobial peptide Smart pressure bandages Smart fibers for laser dentistry

29. Restorative materials Types Passive materials Glass ionomer cements Resin-modified glass ionomer Compomer Dental composites Active materials Dental materials Smart composites Smart ceramics Prosthodontics Smart impression material Orthodontics Shape memory alloys Pediatric and Fluoride releasing pit and fissure sealants preventive dentistry ACP releasing pit and fissure sealants Conservative dentistry Ni- Ti rotary instruments and endodontics Smart prep burs Oral surgery Smart suture Periodontics Smart antimicrobial peptide

30. Glass Ionomer Cement (GIC) Glass ionomer cement (GIC) which was invented in 1969 is composed of fluoroaluminosilicate glass powder and watersoluble polymer (acids). When powder and liquid is blended, it undergoes hardening reaction that involves neutralization of the acidic group together with significant release of fluorides.

31. Bioactive formulation (such as 45S5, S53P4) has bioactive glass and hydroxyapatite. The mechanical properties of GIC have been improved with incorporation of metals such as stainless steel and bio inert ceramics like zirconia. KT-308 a GIC sealer, provides more resistance to coronal ingress of bacteria into the root canal system better zinc oxide-eugenol-based sealer .

32. Active Gutta-Percha (GP) has GI impregnated Gutta-Percha (GP) cones that are bondable to GIC based sealer and claims to offer adhesive bonding of the active GP to intraradicular dentine ZUT a combination of GIC and an antimicrobial silver-containing zeolite is effective against E.faecalis and hence can be more effective in treating teeth of persistent apical periodontitis .

33. Resin Based Composite Introduced by Bowen in 1962, offers wear resistance, color stability, improved physical properties and radiopacity .

34. Smart Dentin Replacement (SDR) Smart Dentine Replacement is a first flowable composite material, characterized by low polymerization stress, low polymerization shrinkage, high depth of cure and bulk-fill material in increments of up to 4 mm in class i and ii cavities.

35. Ceramic Ceramics are being examined for bone tissue engineering and also have dental applications. Hydroxyapatite (HA), a major inorganic component of bone is a calcium phosphate based ceramic. In Novel ceramic bone replacement material Ceraball , new bone formation first takes place on the scaffold surface and act as a carrier for pluripotent mesenchymal stem cells, stromal cells and bone marrow

36. Castor Oil Bean Cement It consists of 81 to 96% triglyceride of ricinoleic acid and is considered a natural polyol containing three hydroxyl radicals and can be used as a pulp-capping material.

37. Calcium Hydroxide In 1928, Calcium Hydroxide was introduced by Hermann in dentistry. Calcium hydroxide has been widely used as a mineralizing agent and antimicrobial agent.

38. Calcium hydroxide causes release of extracellular matrix molecules (like dentine phosphoproteins, dentine sialoproteins), raises expression of biomolecules (like BMP, FGP etc .). To improve its biological performance, Controlled-release Calcium hydroxide loaded microcapsules based on polylactic acid (PLA) and ethyl cellulose (EC) have been developed. These formulations prolonge the ion release.

39. Calcium Sulfate Calcium sulfate (CS) has been shown to be completely bio absorbable, osteoconductive , allow fibroblast migration, do not cause an inflammatory response, it also do not elevate serum calcium levels. Recently, it has been shown that CS can be manufactured into a granular composite of CS and poly-l-lactic acid to decrease the degradation rate.

40. Calcium Phosphate Calcium phosphates plays important role in biological and pathological mineralization. Most commonly used in the form of paste, cement, ceramics and scaffold. It helps in induction of bridge formation with no superficial tissue necrosis and significant absence of pulpal inflammation.

41. Calcium Enriched Mixture (CEM) It was introduced by Asgary . It contains calcium oxide, sulfur trioxide, phosphorous pentoxide, and silicon dioxide. It might promote differentiation of stem cells and cementogenesis . It is also known as NEC (new endodontic cement)

42. Bio ceramic based material/ tricalcium silicate (calcium silicate based materials) MTA which was developed by Mahmood Torabinejad at Loma Linda University, consists of 50-75 % (wt.) calcium oxide and 15-25 % silicon dioxide. It has high pH (12.5), causes regeneration of the periodontal ligament (PDL), dentinal bridge formation, biomineralisation , stimulation of cell differentiation and has antimicrobial activity. However, difficulty in manipulation and longer setting time are its limitations

43. i ). MTA angelus is composed of 80% Portland cement and 20% bismuth oxide and has setting time of 14 minutes. ii) MTA fillapex is a calcium silicate-based bio ceramic sealer, created with an attempt to incorporate physical and chemical properties of a resin-based root canal sealer and the biological properties of MTA . iii). MTA plus is a fine powder root canal sealer with composition similar to ProRoot MTA . iv). Pozzolan cement is a fast setting MTA derived material which does not contain any chemical accelerator .

44. Calcium Aluminate Cement It was developed by the Federal University of São Carlos. It is composed of oxides of aluminium (Al2O3), calcium, ( CaO ), silicon (SiO2), magnesium( MgO ) and iron (Fe2O3) [27,28]. It also allows the control of impurities such as Fe2O3 (which promotes tooth darkening) and is free of MgO and CaO which restricts the undesirable expansion of the material upon moisture contact

45. Doxadent The calcium and aluminum present in this cement, which was first developed in 2000, react with water that contains salts of lithium to produce gibbsite and katoite . It is inorganic and non-metallic in nature. It is a tough substance with little wear resistance. It is equally potent as glass ionomer cement. It is employed as a long-lasting reparative material

46. Ceramir Ceramir is used for long-term cementation and contains calcium aluminate. The calcium released reacts with alkaline pH to rebuild dentin and enamel of all zirconia, inlay, gold, and fixed partial dentures . It reacts favorably with the inorganic phosphate in saliva to form hydroxyapatite and exhibits good gingival reaction when used as a luting agent

47. Biodentine It was introduced in 2011. It is a bioactive dentin replacement material having similar properties of dentin and has a positive effect on vital pulp cells stimulating tertiary dentin formation.

48. When biodentine comes in contact with dentine it results into formation odontoblast-like cell differentiation and mineralization next to an interfacial layer and is called ‘‘Mineral Infiltration Zone,’’ Mineralization occurs in the form of osteodentine by expressing markers of odontoblasts & increases TGF-Beta1 secretion from pulpal cells enabling early mineralization.

49. Theracal It is a light-cured, resin-modified calcium silicate–filled liner insulating and protecting the dentin–pulp complex. It can be used in direct and indirect pulp capping, as a protective base/liner under composites, amalgams, cements, and other base materials. Compared to Dycal and MTA, TheraCal has low calcium solubility and high calcium release

50. Bioaggregate (BA) It was introduced in 2006, is delivered as powder form of nanoparticles containing tricalcium silicate, dicalcium silicate, calcium phosphate, monobasic amorphous silicon dioxide, tantalum pentoxide (radio opacifier ) while it’s liquid form contains deionized water. It is aluminum free formulation, thus it stimulates proliferation of human PDL fibroblasts and aids in periodontal regeneration.

51. Endosequence Root Repair Material (ERRM) putty, ERRM paste RRM putty fast set (FS)& iroot FS Endosequence root repair material (ERRM) delivered as a premixed mouldable putty or as a preloaded paste in a syringe with delivery tips for intracanal placement. It contains calcium phosphate monobasic, calcium silicates, zirconium oxide and tantalum oxide.

52. These are premixed, single component materials which is ready to use from the syringe or a tiny screw-cap box and does not requires mixing, thus differentiating it from MTA, bioaggregate and biodentine . RRM putty fast set (FS) has the initial setting time of 20 min with improved handling properties and shorter setting time

53. Bioceramic Sealers Endosequence BC sealer or iRoot SP root canal sealer It is premixed bioceramic endodontic sealer containing tricalcium silicate, zirconium oxide, dicalcium silicate,calcium phosphate monobasic, colloidal silica, calcium silicates and calcium hydroxide The iRoot SP possesses high pH, hydrophilicity, and active calcium hydroxide release

54. Bioceramic Gutta-Percha These are Gutta-Percha cones impregnated and coated with bioceramic nanoparticles and are verified with laser, for tip and taper accuracy. Such cones with BC sealers allows “three-dimensional” bonded obturation .

55. Bioactive Glass (BAG) In 1969, Hench developed the first bioactive glass (BAG ). BAG has showed a remarkable regenerative capacity for repairing hard tissues due to the ability to release ions for apatite crystals formation that mimics the natural apatite found in bone and dental hard tissues. In dentistry, BAG is used in tissue engineering and for coating titanium and ceramic implants to promote bone regeneration.

56. When BAG contacts water or saliva, it releases calcium, sodium, and phosphorous ions, which promotes remineralisation at surfaces of dental tissues. BAG can also be used in pulp capping procedures since they are non-cytotoxic and were reported to promote the formation of reparative dentin

57. Bioengineered tooth Research on whole tooth regeneration is also advancing using a strategy of transplanting artificial tooth germ and allowing it to develop in the adult oral environment. Ikeda et al reported a fully functioning tooth replacement achieved by transplantation of a bioengineered tooth germ into the alveolar bone of a lost tooth region in an adult mouse. Biomimetics in dentistry – a review, Indian Journal of Research in Pharmacy and Biotechnology 2014;1384- 88

58. Remineralizing Agents Casein phosphopeptide amorphous calcium phosphate (CPP-ACP): Subsurface carious lesion can be remineralised through diffusion of calcium and phosphate ions into tooth structure. Casein is the predominant phosphoprotein in bovine milk and has organoleptic properties.

59. CPP stabilizes calcium and phosphate in solution state and thus acts as calcium and phosphate reservoir. The incorporation of the CPP-ACP nanoparticles into the cross-linked matrix of the GIC aids to increase compressive strength, microtensile bond strength and enhances release of calcium, phosphate and fluoride ions.

60. Demineralized dentin The dentin matrix which are used for implant biomaterial has osteogenic and chemotactic potential. Demineralized bone matrix when comes in contact with mesenchymal cells induces chondrogenesis and osteogenesis.

61. Enamel matrix derivative (EMD) Emdogain is made from enamel matrix protein from the tooth germ of swine and propylene glycol alginate as a matrix. Hertwig epithelial root sheath secretes an enamel matrix-derived protein that induces the formation of periodontal tissue. Emdogain imitates these tooth-developmental mechanisms.

62. Ameloblastin , enamelin , growth factor, tuftelin , and bone morphogenic protein are examples of non-collagen proteins that are also present in Emdogain . It has been used in the treatment of vital pulp therapy and pulpotomy because it causes reparative dentin formation. It is used to reduce external root resorption in replantation situations

63. Growth factors Growth factors are considered as engines that drive wound healing. Platelet derived growth factor (PDGF) plays key role in chemotaxis of neutrophils that acts with other growth factors to produce collagen. Keratinocyte growth factor (KGF) through keratinocyte differentiation, plays vital role in wound re-epithelialization. Transforming growth factor (TGF) induces extracellular matrix deposition and collagen formation.

64. Fibroblast growth factor (FGF) plays role in fibroblast proliferation, angiogenesis, and matrix deposition. Vascular endothelial growth factor (VEGF) increases vascular permeability at the capillary level. Epidermal growth factors (EGF) acts in an autocrine fashion. Kepivance (KGF-2) is used in preventing oral mucositis. Juvista , a recombinant TGF-b3 may be used as a growth factor enhancer for all surgically created wounds

65. Bone Morphgenic Proteins (BMP) BMP plays a key role in dental bone grafting and implant placement, fracture healing and spinal fusion. Increases alkaline phosphatase activity Stimulates proteoglycan synthesis in chondroblasts Collagen synthesis in osteoblasts Differentiation of neural cells Chemo taxis of monocytes.

66. Platelet Concentrates It was first described by Whitman et all. Platelet rich plasma (PRP) is generated by differential centrifugation and serves as reservoir of critical growth factors which regulates wound-healing such as Platelet-derived growth factor (PDGF), Transforming growth factor-b (TGF-B) Insulin-like growth factor-1 (IGF-1)

67. PRP requires biochemical blood handling with addition of anticoagulants while platelet rich fibrin (PRF) does not . A second generation platelet concentrate , Leucocyte and platelet rich fibrin (L-PRF) was developed by Choukroun et al in france does not contain any anticoagulant or gelifying agents

68. Implant Biomaterials/Biomimetic Coatings on Implants It includes metals and metallic alloys, ceramics, natural materials and synthetic polymers. Metals and metallic alloys include titanium, tantalum and alloy of Ti -Al- Va , Co-Cr-Mb, Fe-Cr-Ni. Devices made from zirconium, hafnium and tungsten have been evaluated recently. Hydroxyapatite-coated metal’s coating is done using robotic techniques for osteoconductivity .

69. Ceramics Ceramics are nonorganic, nonmetallic, non-polymeric materials manufactured by compacting and sintering at elevated temperatures. On the basis of tissue’s response it can be classified as bioactive ( bioglass /glass ceramic), bioresorbable (calcium phosphate) and bio inert (alumina, zirconia and carbon). The implant coating is intended for improving implant surface biocompatibility and longevity

70. Regenerative endodontics and tissue engineering Dental regeneration is a process in humans by which specialized dental tissues are replaced by the recruitment, proliferation, migration, and differentiation of dental stem cells. Stem cells, scaffolds, and growth factors are 3 key elements for tissue regeneration.

71. Root Canal Revascularization In the Root canal revascularization, the bioceramic material is placed as mid-root/coronal plug, thereby providing permanent and superior quality seal and causes odontoblastic differentiation and mineralization. Postnatal stem cell therapy, pulp implantation, scaffold implantation, injectable scaffold delivery, 3-D cell printing, bio engineered tooth and gene therapy are some regenerative approaches.

72. Smart pressure bandages - Upon exposure to blood, these bandages contracts thereby putting pressure on a wound. Smart suture - It ties itself into the Perfect knot and possesses shape memory. Smart composites containing amorphous calcium phosphate ( ACP)- Inclusion of ACP into composite resin results into release of calcium and phosphorous for an extended period and are thus helpful in caries prevention

73. . E) Smart ceramics( Cercon ) – It is a metal-free biocompatible life like restoration that has strength to resist crack formation. f) Smart antimicrobial peptide- A pheromone-guided “smart” antimicrobial peptide is targeted against killing of Streptococcus mutans which is the principal microorganism responsible for the cause of dental caries.

74. G) Smart fibers for laser dentistry - Hollow-core photonic-crystal fibers (PCFS) are used for the delivery of high-fluency of laser radiation and are capable of ablating tooth enamel. The PCF is used to transmit emission from plasmas on to the tooth surface for detection and optical diagnostics.

75. Conclusion Contemporary biomaterials have shown ability to overcome the limitations of traditional materials. However, there exists limitations when considering criteria for categorizing them as ideal materials. Several invitro and invivo studies have demonstrated good results, however randomized and double blind studies of sufficient duration have been needed to confirm long term success.

76. THANK YOU Its more than just mimicking the nature..