Dental Materials for Temporary Dressings, Cements, and Lining - Temporary dressings: - Zinc oxide eugenol is a common temporary dressing material that is bactericidal and easy to remove. - Eugenol, derived from oil of cloves, has an obtundant effect on the tooth and decreases toothache. - It is contraindicated if the final restorative material is composite. - Kalzinol and Sedanol are examples of brands of zinc oxide eugenol. - Temporary dressings are used to protect the pulp canal system during root canal therapy. - Cements: - Dental cements are used to bond indirect restorations like crowns to the natural tooth surface. - Examples of dental cements include zinc oxide cement, zinc phosphate cement, and glass ionomer cement. - Zinc oxide cement is self-setting and hardens when in contact with saliva. - Zinc polycarboxylate cement adheres to enamel and dentin. - Resin-based cement and copper-based cement are also used in dental restorations. - Impression materials: - Dental impressions are negative imprints of teeth and oral soft tissues used in various dental procedures. - Impression materials vary in rigidity to obtain accurate impressions. - Sodium alginate, polyether, and silicones are common dental impression materials. - Plaster of Paris, zinc oxide eugenol, and agar were historically used as impression materials. - Dental impressions are used in prosthodontics, orthodontics, restorative dentistry, dental implantology, and oral and maxillofacial surgery. - Lining materials: - Dental lining materials are placed between the remaining tooth structure and the restoration material. - They protect the dentinal tubules and sensitive pulp, reducing post-operative hypersensitivity. - Lining materials also act as an insulating layer, protecting the pulp from temperature changes. - They prevent corrosion by galvanic cell when dissimilar metals are placed next to each other. - Some examples of lining materials include calcium hydroxide, calcium silicate-based liners, and polycarboxylate cement. - Types of lining materials: - Calcium hydroxide is a lining material that stimulates the formation of secondary dentine. - It has a low compressive strength and is often used in combination with other materials. - Calcium silicate-based liners are preferred for their bioactive and sealing properties. - Polycarboxylate cement forms a strong bond with dentin and enamel, releasing fluoride. - Glass ionomer has the strongest compressive and tensile strength among lining materials.

Types of Dental Restorative Materials - Amalgam: metallic filling material composed of a mixture of mercury and a powdered alloy - Composite resin: mixture of nanoparticles or powdered glass and plastic resin - Glass ionomer cement: restorative material with fluoride release and acid-base content - Zinc oxide eugenol: lining material with low compressive and tensile strength - Radiopaque materials: added to dental materials for visibility and detection

Physical Properties of Dental Restorative Materials - Low thermal conductivity and expansion - Resistance to forces and wear such as attrition and abrasion - Resistance to chemical erosion - Good bonding strength to the tooth - Withstand everyday masticatory forces and conditions without fatigue

Biocompatibility and Aesthetics of Dental Restorative Materials - Biocompatibility: coexistence with biological equilibrium of the tooth and body systems - Common problems include chemical leakage, pulpal irritation, and allergic reactions - Aesthetics: matching surrounding tooth structure in shade, translucency, and texture - Tooth-colored fillings for cosmetic purposes - Consideration of aesthetics in material selection

Application, Failure, and Evaluation of Dental Restorative Materials - Application: direct restorations placed directly into a cavity on a tooth - Factors affecting the longevity of fillings - Failure of dental restorations: composites showing a higher failure rate than amalgam over five to seven years - Evaluation and regulation of dental materials: conducted by organizations like the Nordic Institute of Dental Materials (NIOM) and regulatory bodies like the FDA - Ongoing research and advancements in dental materials contribute to the improvement of dental treatments.