Lecture 5 Dental material used in pediatric restorative treatment-pdf.pdf

Course 5: Dental Materials used in Restorative Treatment in Pediatric Patient Dental materials 30.10.2023 There are a variety of restorative materials available today Many appropriate materials can be used to restore carious lesions in the primary dentition and permanent dentition. Please be aw...

Course 5: Dental Materials used in Restorative Treatment in Pediatric Patient Dental materials 30.10.2023 There are a variety of restorative materials available today Many appropriate materials can be used to restore carious lesions in the primary dentition and permanent dentition. Please be aware that all systems are operator and technique sensitive. Dental materials 30.10.2023 1- Dental amalgam. 2- Composite 3- Glass ionomer cements 4- Bioactive materials 5- Smart materials Dental materials 30.10.2023 Dental amalgam Dental amalgam contains a mixture of metals such as silver, copper, and tin, in addition to approximately 50 percent mercury. Dental materials 30.10.2023 Dental amalgam It has been used for restoring teeth for over 150 years and, despite the fact that it is not tooth coloured and there have been repeated concerns about its safety (largely unfounded), it is still widely used. Dental materials 30.10.2023 Dental amalgam A randomized trial (New England Children’s Amalgam Trial (NECAT)) could find no difference in neuropsychological or renal complications between the use of amalgam and compomer/composite when restoring posterior primary or permanent molars. Dental materials 30.10.2023 Dental amalgam Class I amalgam restorations in primary teeth have shown to have a success rate of 85 to 96 percent for up to seven years, with an average annual failure rate of 3.2 percent. Dental materials 30.10.2023 Dental amalgam 32 year old amalgam Letter Published: 24 July 2020 Restorative dentistry Thirty-year-old amalgams L. K. Bandlish British Dental Journal 229, 73 (2020)Cite this article 1115 Accesses Metrics Dental materials 30.10.2023 Composites Resin-based composite restorations were introduced in dentistry about a half century ago as an esthetic restorative material. They are classified according to their filler size, because filler size affects physical properties, polishability/esthetics, polymerization depth, and polymerization shrinkage. The smaller filler particle size allows greater polishability and esthetics, while larger size provides strength. Dental materials 30.10.2023 Dental materials 30.10.2023 Composites Composites may not be the ideal restorative material for primary teeth because: Technique is sensitive and requires longer placement time than amalgams. Isolation or patient cooperation may be a problem, Large multi-surface restorations High-risk patients with poor oral hygiene, numerous carious teeth and demineralization. Dental materials 30.10.2023 Composites Deterioration of the hybrid layer is considered as the primary reason for compromising the resin-dentin bond durability. Apart from the extrinsic factors, such as water or oral fluid sorption and polymer swelling, some intrinsic host-derived enzymes like matrix metalloproteinases (MMPs) are also responsible for disintegration of the hybrid layer. Dental materials 30.10.2023 Composites MMPs are a group of zinc and calcium-dependent enzymes, which are trapped within the mineralized dentin matrix during the tooth development process. Simplified etch and rinse adhesives and less destructive versions of self-etch adhesives used during dental procedures, and the caries process itself can contribute to the release and activation of these endogenous MMPs and lead to dentin-adhesive bond failure. Dental materials 30.10.2023 Despite the development of simplified adhesive systems in recent years, etch-and-rinse adhesives are still considered as the gold standard in terms of durability and bond strength. The acidic monomers in etch-and-rinse adhesives expose the collagen fibrils of the organic matrix during bonding procedures. Hybrid layer formation requires the infiltration of adhesive resin monomers to the exposed collagen network. Dental materials 30.10.2023 Composites Dentin MMPs can degrade these unprotected collagen fibrils. CHX chelates and sequestrates cations such as calcium and zinc which are required for the activation of the MMPs, thus inhibiting collagenase and gelatinase activity in dentin matrices. The application of CHX has a broad-spectrum MMP-inhibitory effect and considerably preserves the unity of the hybrid layer formed by etch-and-rinse adhesives. Dental materials 30.10.2023 Bulk Fill Composites Bulk fill composites are a type of new generation nanohybrid composite resin. They generally contain ytterbium trifluoride, barium glass, mixed oxide, proacrylate, zirconium / silica particles. These particles increase radiopacity and enable for the impact of light device to reach to deeper regions of material. It has been reported that polymerization takes place slowly due to modified methacrylate resins that are in the structure of bulk fill composites. Dental materials 30.10.2023 Conventional Glass Ionomer Cements In 1972 Wilson and Kent introduced Aluminumum Silicate Polyacrylic Acid It is a hybrid of silicate cement and polycarboxylate cement. Dental materials 30.10.2023 First developed glass ionomer cements Conventional  powder : alkaline alumino-fluoro silicate  liquid : glass block disintegration  It consists of poly into powder (sintering) Baig and Fleming 2015 .J Dent (acrylic, maleic, itaconic) acid, distilled water. Application areas of conventional glass ionomer cements  1) Sealing occlusal pits and fissures  2) Restoration in primary teeth  3) In all types of cavities, as a pulp capping and base material when biological covering and caries prevention effect is required  4) Cementation  5) Root caps for teeth under overdenture Characteristic Properties      They make chemical connection (chelation) with dental tissue. There is no need for bonding agent. They release fluoride ion to dental tissue and oral environment. This function can be considered valuable in preventing secondary caries by using ion exchange. They can be recharged with fluoride. They have acceptable translucency They show thermal compatibility with dental tissues, Modern Classification  Type 1 Luting  Type 2 Restorative material Conventional type Reinforced with metal (Cermet) High viscosity (condensable) glass ionomer cement  Type 3 Quick setting liner/base and fissure sealant cements Type 1: luting cements Type 2 Restorative cements Type 3 base/liner and fissure sealant Vitremer™ Core Buildup/Restorative Setting mechanism  Acid-base reaction Acid (liquid) and base (glass = powder) take the final physical form by reacting two different components by neutralizing the structure.  Result: The hydrogel salt occurs playing the role of the binding matrix. Setting mechanism  Ionized groups compete for surface areas and accessible cations.  Calcium ions bind to ionized carboxyl groups of acids by chelation reaction. The hydrolytic stability of the ionically crosslinked matrix occurs after setting.  Within 24-72 hours, calcium ions are replaced with aluminum ions, strong cross-links and glass ionomer cement becomes more resistant. The advantages of restorative glass ionomer cements Easy placement – no acid and base phase  Direct adhesion to teeth and metals (chemical bonding)  Quick setting time ( 3min 30 sec after mixing)  Anticariogenic properties due to fluoride release Thermal compatibility of tooth enamel and dentin due to tooth-like thermal expansion coefficient  Minimized micro-leakage due to low shrinkage on tooth-enamel surface  low cytotoxicity due to lack or low content of monomers The disadvantages of restorative glass ionomer cements  Low wear resistance  Short working time  Long setting time  Structure prone to breakage and moisture contamination during setting.  They can show microleakage even if they are minimalized. The disadvantages of conventional glass ionomer cements       Very low bond strength to dental tissues Very low resistance to chewing pressures Very low abrasion resistance Poor color stability They need an additional appointment for polishing Application techniques bring many problems (errors in powder-liquid ratio, moisture sensitivity, isolation, etc.).  Technical Accuracy  Chemical chelation will not occur when CIS contact dry or wet enamel / dentin surface  No metallic salt bridges can occur if GIS contact with saliva at the time of setting. ISOLATION is important.  If we study with any hand tools or rotary burs before setting time, the resulting stress effect sensitive chemical adhesion.  The acid-base reactions of the glass ionomer cements are completed within 24 hours. For this reason, it is recommended to perform POLISHING operation after 24 hours with the help of discs. Glass ionomer cements conventional Reinforced with metal Resin modified (Hybrid) Glass Ionomer Cements Hybrid Material Concept Composite resin Glass ionomer At the end of the 1980s, glass ionomer cements were added with resin. So resin modified CISs were developed. Restorative treatment in pediatric patient 10.10.2022 Glass ionomer cements Resin modified (hybrid) Conventional Reinforced with metal AIM: Making a «glass ionomer cement » more «composite» (80% GIC, 20% Composite) RESULT: Resin modified cement Restorative treatment in pediatric patient 10.10.2022 Resin modified glass ionomer cements Since the setting time can be controlled, the working time is no longer a problem. Since setting forms a moisture-resistant resin matrix layer on the surface, isolation is less important. There is no need to wait 24 hours for polishing. Wear and fracture resistance increased with resin additions. Bond strenght was increased with special primers applied before application. Restorative treatment in pediatric patient 10.10.2022 Resin modified glass ionomer cements Since the smear layer on the dentine is removed with the primer prior to application, it is directly bonded with dentine. The anti-caries effect of a material capable of releasing fluoride depends on the amount of fluoride release and the duration of release. They release the fluoride ion as long and as effectively as conventional CIS. They can be recharged with topical fluorine gels Restorative treatment in pediatric patient 10.10.2022 Resin modified glass ionomer cements Adhesion Reaction Chemical and micromechanic Setting reaction Acid/base and photopolymerisation Restorative treatment in pediatric patient 10.10.2022 Resin modified glass ionomer cements Since RMGIC sets hardness in light but 80% of the material is GIC, so the basic setting reaction is still due to acid-base reaction. This reaction continues for several days due to water absorption. Conventional GIC is very sensitive to moisture and has low resistance in the early stage following acid-base reaction In addition to the acid-base reaction, the light-polymerized RMGIC polymerizes with light, ie the curing reaction is dual (two direction). Restorative treatment in pediatric patient 10.10.2022 Glass ionomer cements Polyacid modified (compomers) Resin modified (hybrid) Conventional Reinforced with metal Compomers Polyacid-modified resin-based composites, or compomers, were introduced into dentistry in the mid-1990s. Moisture is attracted to both acid functional monomer and basic ionomer-type in the material. This moisture can trigger a reaction that releases fluoride and buffers acidic environments. Considering its ability to release fluoride, esthetic value, and simple handling properties, of compomer, it can be useful in pediatric dentistry. Restorative treatment in pediatric patient 10.10.2022 Compomers AIM: From a composite to a more «glass ionomer» 70% Composite, 30% GIC RESULT: “Polyacid modified glass ionomer cement Compomer Restorative treatment in pediatric patient 10.10.2022 COMPOsite +GlassionoMER All curing reactions are carried out by light polymerization. The adhesion can only be by micromechanical ways. Fluor ion release levels are not as successful as conventional and RM GIC’s. Cannot be recharged with topical fluoride ions Restorative treatment in pediatric patient 10.10.2022 Compomers Restorative treatment in pediatric patient 10.10.2022 Compomers (Dyract AP, Dentsply) is recommended by the manufacturer for the restoration of all types of cavities in children and adults, including stress-bearing occlusal surfaces, where the cavity is less than two-thirds the intercuspal distance. The presentation of a compomer material is shown. The clinical placement of a compomer material in a cervical cavity in an upper left central incisor tooth is illustrated Dental materials 30.10.2023 Compomers Restorative treatment in pediatric patient 10.10.2022 Compomers Restorative treatment in pediatric patient 10.10.2022 Compomers Restorative treatment in pediatric patient 10.10.2022 Compomers Restorative treatment in pediatric patient 10.10.2022 Glass ionomer cements Polyacid modified (compomers) Resin modified (hybrid) High viscosity (condensable) Conventional Reinforced with metal High viscosity (condensable) GIC Hybrid materials based on GIC technology have been modified with glass particles of different sizes. This feature significantly affects physical and mechanical properties of the material By applying a Nano-protective coating (micro-laminated technique), the properties of the material improve. Dental materials 30.10.2023 Bioactive materials A recently recognized category of materials is termed bioactive. Bioactive restorative materials release ions, typically calcium, fluoride, or phosphate , yet at times antibacterial monomers, silver particles, or strontium particles. These materials are broadly used in the field of conservative dentistry for regeneration, repair and reconstruction. Dental materials 30.10.2023 Bioactive materials A recently recognized category of materials is termed bioactive. Bioactive restorative materials release ions, typically calcium, fluoride, or phosphate , yet at times antibacterial monomers, silver particles, or strontium particles. These materials are broadly used in the field of conservative dentistry for regeneration, repair and reconstruction. Dental materials 30.10.2023 Smart materials Smart materials are materials whose properties may be changed in a controlled way by updates, for example, stress, temperature,moisture, pH and electric or engaging fields. A key fragment of able direct breakers a capacity to return to the main state after the overhaul has been cleared. These materials react to ordinary changes or outside effects, and are in any case called responsive materials. Dental materials 30.10.2023 Smart materials in pediatric dentistry 1- Glass ionomer cements 2- Calcium phosphate 3- Smart composite 4- Shape memory 5- Smart ceramics 6- Burs Dental materials 30.10.2023 Thank you