Bioactive and Biomimetic Materials in Dentistry PDF

Bioactive and Biomimetic Material Contents Introduction Definition Applications Various Biomimetic And Bioactive Materials Conclusion Refrences INTRODUCTION In every field of dentistry and medicine, bioactive materials have been widely used. These materials are used for regeneration, repair, and rec...

Bioactive and Biomimetic Material Contents Introduction Definition Applications Various Biomimetic And Bioactive Materials Conclusion Refrences INTRODUCTION 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 and act directly on vital tissue, helping in its healing and repair. Directly function because of induction of various growth factors and different cells. 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. Definition Biomimetics, term was coined by Otto Schmitt in the 1950s. 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. 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. Karma M, et al. Biomimetics in dentistry. Indian J Dent Edu 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 Applications of Bioactive Materials and Molecules in Dentistry ØRoot Canal Therapy Portland cement or MTA is a bioactive material used for maintaining pulp and periodontal tissue vitality as part of pulp-capping and perforation repair procedures. Mineral trioxide aggregate is also used as an obturating material after root canal therapy. It helps in apexification. Tooth Repair and Regeneration Dentin extracellular matrix proteins (ECMPs) contain growth factors that can promote tooth healing and pulp regeneration. Dentonin (peptide) can stimulate reparative mineralization of the coronal pulp and occlusion of the lumen of the root canal. A novel biomaterial (tissue regenerative gel), can promote the regeneration of tooth tissue. In Dental Surgery and Craniomaxillofacial Reconstruction Biomaterials, such as Emdogain containing Porcine proteins play an important role in periodontal regeneration after injury. Synthetic bone materials are used for maxillofacial and craniofacial reconstruction. The ideal biomaterial for dental reconstruction should be biocompatible and also able to maintain volume and can be easily shaped. n-Butyl-2-cyanoacrylate is widely used as a tissue adhesive. It is also used for filling and repairing bone defects. Coating of Implants Dental implants are made from titanium alloys and have a coating of hydroxyapatite to promote osteogenesis and bone healing. Hypersensitivity A novel bioactive glass-ceramic (biosilicate) is applied in hypersensitivity cases. It is capable of inducing HCA (hydroxyl carbonate apatite) deposition in open dentinal tubules, and thus occluding the dentinal tubules. Hence, biosilicate may be a new way for treating dentin hypersensitivity. Biomedical Stem Cell Therapy New methods of stem cells with bioactive materials renovate the function of injured tissue by replacing dead or damaged cells with new and healthy cells. Dental Tissue Regeneration A combination of nanostructure materials, such as biomimetic matrices and scaffold and stem cells, will certainly increase the regenerative impact of dental pathological tissues Bone Graft Bioactive materials, such as osteoconductive matrix, which act as scaffold to new bone growth, and osteoinductive proteins, which support mitogenesis of undifferentiated cells combined with osteogenic cells (mesenchymal stem cells), are capable of forming bones. Drug Delivery Mesoporous, which are silica based, are widely used in drug delivery and bone tissue engineering. The adequate combination of the synthesis techniques, additives, and template systems leads to the improvement of materials that combine the bioactive behavior with the drug carrier ability. Cosmetic Surgery Collagen is used in soft tissue repair for augmentation in cosmetic surgery. Tissue Engineering Gelatin is used as a natural polymer, which is derivative of collagen. Biomolecules released from gelatin are capable of maintaining their biological activity and help them in tissue engineering The ideal properties of bioactive material Bactericidal And Bacteriostatic Sterile Stimulate Reparative Dentine Formation Sterile And Maintain Pulp Vitality. Various biomimetic and bioactive materials are: Glass Ionomer Cement (GIC) Resin Based Composite Smart Dentin Replacement (SDR) Ceramic Castor Oil Bean Cement Calcium Hydroxide MTYA1-Ca filler Calcium Sulfate Calcium Phosphate Calcium Enriched Mixture (CEM) 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 Bioceramic Sealers Bioceramic Gutta-Percha Bioactive Glass (BAG) Remineralizing Agents Casein phosphopeptide amorphous calcium phosphate (CPP-ACP) Demineralized dentin (dDM) Enamel matrix derivative (EMD) Growth Factors Bone Morphgenic Proteins (BMP) Platelet Concentrates Polyhedral Oligomeric Silsesquioxanes (POSS) Metallic Biomaterials Implant Biomaterials/Biomimetic Coatings on Implants Polymers Root Canal Revascularization via Blood Clot ØSmart Materials A) Smart pressure bandages B) Smart suture C) Hydrogel D) Smart composites containing amorphous calcium phosphate (ACP) E) Cercon Glass Ionomer Cement (GIC) Glass ionomer cement (GIC) which was invented in 1969 is composed of fluoroaluminosilicate glass powder and water soluble 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. 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 (GC Corporation Company, Tokyo, Japan) a GIC sealers, provides more resistance to coronal ingress of bacteria into the root canal system. Active Gutta-Percha (GP) (Brasseler USA, Savannah, GA, USA) 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 (University of Toronto, Ontario, Canada) a combination of GIC and an antimicrobial silvercontaining zeolite is effective against E.faecalis and hence can be more effective in treating teeth of persistent apical periodontitis. Resin Based Composite Introduced by Bowen in 1962, offers wear resistance, color stability, improved physical properties and radiopacity Smart Dentin Replacement (SDR) Smart Dentine Replacement is a first flowable composite material. Its 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. 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. Calcium Hydroxide In 1928, Calcium Hydroxide was introduced by Hermann in dentistry. It has been widely used as a mineralizing agent and antimicrobial agent. Calcium hydroxide causes release of extracellular matrix molecules (like dentine phosphoproteins, dentine sialoproteins), raises expression of biomolecules, like BMP, and has antimicrobial and anti-inflammatory action Formation of tunnel defects and decrease in dentine strength following its long term use as intracanal medicament are its limitations. 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 prolonged ion release. MTYA1-Ca filler ØIt is a resin-based direct pulp-capping agent. ØComposition: § Powder :89.0% microfiller, 10.0% calcium hydroxide, and 1.0% benzoyl peroxide § Liquid : 67.5% triethyleneglycol dimethacrylate, 30.0% glyceryl methacrylate, 1.0% O-methacryloyl tyrosine amide, 1.0% dimethylaminoethylmethacrylate, and 0.5% camphorquinone ØMTYA1-Ca developed dentine bridge formation without formation of a necrotic layer, revealed to have good physical properties, and was not inferior to Dycal histopathologically. Niinuma A. Int Endod J. 1999 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. 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. The following are calcium phosphate materials Calcium Enriched Mixture (CEM) 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) and was introduced by Asgary. Bio ceramic based material/tricalcium silicate (calcium silicate based materials) MTA which was developed by Mahmoud Torabinejad at Loma Linda University, consists of 50-75 % (wt.) calcium oxide and 15-25 % silicon dioxide. Ø It has high pH (12.5), causes regeneration of the periodontal ligament (PDL) dentinal bridge formation biomineralisation and stimulation of cell differentiation has antimicrobial activity. Ø However, difficulty in manipulation and longer setting time are its limitations i). MTA angelus (Aangelus, Londrina, PR, Brazil) is composed of 80% Portland cement and 20% bismuth oxide and has setting time of 14 minutes. ii) MTA fillapex (angelus solutions odonatological, Londrina, PR, Brazil) 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 (Avalon biomed Inc., Bradenton, FL, USA) is a fine powder root canal sealer with composition similar to ProRoot MTA. iv). Pozzolan cement (Endocem) (Maruchi, Wonju, Korea) is a fast setting MTA derived material which does not contain any chemical accelerator. Calcium Aluminate Cement (Binderware, São Carlos, SP, Brazil), 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). It 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. Doxadent It is a calcium aluminate product available in powder liquid form. It can be used as a permanent restorative material. It consists of alumina, calcium oxide, water, zirconium dioxide and other alkali oxides. When powder and liquid are mixed water dissolves the calcium aluminate powder leading to the formation of calcium, aluminum and hydroxyl ions leading to the formation of katoite and gibbsite. Ceramir It is calcium aluminate cement used as a luting agent. It works on the principle of two cements they are calcium aluminate and glass ionomer cement. This cement helps in luting of permanent crowns and fixed partial dentures, gold inlays and onlays, prefabricated metal and cast dowel and cores, and highstrength all-zirconia or all-alumina crowns Biodentine™ (Septodont, Saint-Maur-des-Fossés, France), 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 Powder Tri-calcium silicate Di-calcium silicate Calcium carbonate & oxide Iron oxide Zirconium oxide Liquid Calcium chloride Hydrosoluble polymer When biodentine comes in contact with dentine it results into formation of the tag-like structures and is called ‘‘Mineral Infiltration Zone,’’ which may contribute to adhesive properties. It has improved- physical properties, -reduced setting time (12 min) -induces odontoblast-like cell differentiation -mineralization Mineralization occurs in the form of osteodentine by expressing markers of odontoblasts & increases TGF-Beta1 secretion from pulpal cells enabling early mineralization. During the setting of the cement Calcium hydroxide is formed. Due to its high pH, Calcium hydroxide causes irritation at the area of exposure. 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. When this material was compared with ProRoot MTA and Dycal, it was found that calcium release was higher and solubility was low. Bioaggregate (BA) Innovative Bioceramix Inc., Vancouver, BC, Canada) introduced in 2006 It is delivered as powder form of nanoparticles containing tricalcium silicate dicalcium silicate calcium phosphate monobasic amorphous silicon dioxide tantalum pentoxide (radio pacifier) 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. Used for pulp capping, apexification, root resorption, root perforation and root end filling material. Endosequence Root Repair Material (ERRM) putty, ERRM paste RRM putty fast set (FS) and iroot FS ØEndosequence root repair material (ERRM) (Brasseler USA, Savannah, GA) Ø delivered as § premixed mouldable putty (iRoot BP Plus) or § as a preloaded paste in a syringe with delivery tips for intracanal placement. ØIt contains calcium phosphate monobasic, calcium silicates, zirconium oxide and tantalum oxide. Inside dentinal tubules, ERRM forms tag-like structures. They 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. iRoot FS (Brasseler USA, Savannah, GA) is iRoot series material with improved handling properties and shorter setting time Ceramics ØCeramics are nonorganic, nonmetallic, non-polymeric materials manufactured by compacting and sintering at elevated temperatures. ØThey are being examined for bone tissue engineering and also have dental applications. Ø Hydroxyapatite (HA), a major inorganic component of bone is a calcium phosphate based ceramic. ØIn Novel ceramic bone replacement material Ceraball, new bone formation first takes place on the scaffold surface. Ceraballs may act as a carrier for pluripotent mesenchymal stem cells, stromal cells and bone marrow 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 profiles and longevity Bioceramic Sealers Endosequence BC sealer (Brasseler USA, Savannah, GA) or iRoot SP root canal sealer (Innovative Bioceramix Inc., Vancouver, BC, Canada) 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 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. Bioactive Glass (BAG) Calcium sodium phosphosilicate is used in cariology, restorative dentistry and periodontology, air polishing procedures, desensitizing toothpastes, and as a bonding and bone regeneration material Mohn et al mixed BAG particles with 50% bismuth oxide and used it as root canal filling material. BAG has directly and indirectly pH related antibacterial effect. BAG can be the material of choice for pulp capping & periapical bone healing because it is biocompatible & has antibacterial property. Schepers et al, 1991 BAG produce Less inflammation, dentin bridge formation & no internal resorption, necrosis or abscess compared to Ca(OH)2 Journal of Dentistry, Tehran University of Medical Sciences, Tehran, Iran(2007) Bioactive glass treatment leads to enhanced apatite formation in dentin. Size of the bioactive glass powder particles influences the rate of apatite formation with nano bioactive glass powders having faster apatite forming kinetics D. Fernando, et al, (2017) Remineralizing Agents ØCasein phosphopeptide amorphous calcium phosphate (CPP-ACP): Subsurface carious lesion can remineralize through diffusion of calcium and phosphate ions into tooth structure. 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. Tooth Mousse™ (Europe and Australasia) or MI Paste™ (USA and Japan) contains 10% w/w CPP-ACP nanocomplexes. Demineralized dentin (dDM) The dentin matrix which are used for implant biomaterial has osteogenic and chemotactic potential. Demineralized bone matrix when comes in contact with mesenchymal cells it induces chondrogenesis and osteogenesis. Incorporation of Galla chinensis extract into dentin matrix may improve biochemical and biomechanical properties. Enamel matrix derivative (EMD) Enamel matrix derivative is derived from pig enamel matrix (Emdogain; Straumann AG, Basel, Switzerland) It has been employed in patients with severe attachment loss through recruitment of cementoblasts on to the root-surface to restore functional periodontal ligament, cementum and alveolar bone. 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. 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 Bone Morphgenic Proteins (BMP) BMP plays a key role in dental bone grafting and implant placement, fracture healing and spinal fusion. It increases alkaline phosphatase activity, stimulates proteoglycan synthesis in chondroblasts, collagen synthesis in osteoblasts, differentiation of neural cells and chemo taxis of monocytes. 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 such as plateletderived growth factor (PDGF), transforming growth factor-b (TGF-B) and insulin-like growth factor-1 (IGF-1) , thus regulates wound-healing. 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 gellifying agents. Polyhedral Oligomeric Silsesquioxanes (POSS) Biomaterials such as polyhedral oligomeric silsesquioxanes (POSS) and polyhedral oligomeric silicates (POS) may be fabricated by the incorporation of POSS molecules to provide a nanoscopic topology which favors cellular modulation, bioavailability and differentiation. Advent of POSS has led to formulation of dental adhesives and composites with improved mechanical and physical properties. Metallic Biomaterials Metallic biomaterials are mainly used for fabrication of medical devices for hard tissue replacement such as artificial hip joints, bone plates and dental implants. Stainless steel, cobalt alloys, pure Ti and Ti-6al-4v are mainly used for biomedical applications. 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, FeCr-Ni. Devices made from zirconium, hafnium and tungsten have been evaluated recently. Hydroxyapatite-coated metal’s coating is done using robotic techniques for osteoconductivity. Polymers Polymers like polymethylmethacrylate (PMMA), polyethylene (PE), polyurethanes are used in dental surgery since decades. Polyglycolic acid (PGA), polylactide (PLA), polydioxanone (PDS) are mainly used as resorbable bone fixation devices or as suture materials. For surgical wound repair fibrin glue is used as tissue adhesive. Alginate can be used as growth factor delivery system. 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. Root Canal Revascularization via Blood Clot In the Root canal revascularization via blood clot in apical region, the bioceramic material is placed as mid-root/coronal plug, thereby providing permanent and superior quality seal. Jung et al. reported that by activation of MAPK pathway biodentine, bioaggregate and MTA causes odontoblastic differentiation and mineralization. Postnatal stem cell therapy, pulp implantation, scaffold implantation, injectable scaffold delivery, 3-D cell printing and gene therapy are some regenerative approaches. Smart Materials It is defined as the class of materials that are highly responsive and have the inherent capability to sense and react according to changes in the environment. They can be classified as active and passive smart materials. Passive smart materials responds to external change without any external control. While active smart materials utilizes a feedback loop to enable them to function like a cognitive response through an actuator circuit. A) Smart pressure bandages - Upon exposure to blood, these bandages contracts thereby putting pressure on a wound. B) Smart suture - It ties itself into the Perfect knot and possesses shape memory. C) Hydrogel - It exhibit plastic contraction upon changes in temperature, pH, magnetic or electrical field. D) 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. E) Cercon - smart ceramics - It is a metal-free biocompatible life like restoration that has strength to resist crack formation. The drawbacks of porcelain fused to metal like unsightly dark margins and artificial grey shadows from the underlying metal are no longer a problem with Cercon. Conclusion Biomimietic materials functions as root canal sealer, filling materials, cements and root and crown repair material and possesses features as like strengthening the root following obturation, good sealing ability, enhanced biocompatibility and antibacterial properties. 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 in vitro and in vivo studies have demonstrated good results, however randomized and double blind studies of sufficient duration with biomimetic materials have been needed to confirm long term success. REFRENCES Cohen's Pathways of the Pulp, 11th Edition Sonarkar S, Purba R. Bioactive materials in conservative dentistry. Int J Contemp Dent Med Rev. 2015;2015:4. Madfa AA, Al-Sanabani FA, Al-Kudami NH. Endodontic Repair Filling Materials: A Review Article. Bhushan M, Tyagi S, Nigam M, Choudhary A, Khurana N, Dwivedi V. Bioactive materials: A short review. J. Orofac. Res. 2015 Oct;5:138-41. Jefferies S. Bioactive and biomimetic restorative materials: a comprehensive review. Part II. Journal of Esthetic and Restorative Dentistry. 2014 Jan 1;26(1):27-39. Thank you