Operative Dentistry - Adhesive Dentistry III

Operative Dentistry - Adhesive Dentistry III

• This lecture covers operative dentistry and adhesive dentistry, specifically focusing on the third module of adhesive dentistry.
• The lecturer, Kostis Giannakopoulos, DDS, PhD, is an assistant professor in the Department of Dentistry at European University Cyprus.
• The date of the lecture is November 14, 2023.

Enamel Adhesion

• SEM images were displayed showcasing the structure of enamel adhesion to dental composites.
• A specific magnification of 2µm was noted.

Hybrid Layer

• SEM images also displayed the hybrid layer between composite and dentin.
• Key components labeled were composite, hybrid layer ("A", "B", and "D"), and dentin.

Solvents

• Solvents are the carriers for bonding agents to dentin.
• Examples of solvents include acetone, ethanol, and water.
• These solvents are often highly hydrophilic.

Three-Step Etch-and-Rinse

• A three-step etch-and-rinse technique is described.
• The first step involves phosphoric acid (approximately 35%) for etching, followed by rinsing.
• The second step uses a primer containing reactive hydrophilic monomers dissolved in ethanol, acetone, or water.
• The third step involves a non-solvated, unfilled, or filled resin bonding agent with hydrophobic monomers such as Bis-GMA, frequently combined with hydrophilic molecules like HEMA.

Two-Step Etch-and-Rinse Adhesive Systems (5th Generation)

• Advantages of this system include good immediate bonding, ease of use, and low cost.
• Disadvantages include acidic and hydrophilic nature, lack of collagen protection, faster degradation, and incompatibility with certain cure resins. The system usually uses light cure only.

Self-Etch Approach

• This method involves no etching and rinsing.
• The smear layer is retained.
• Interactions with dentin are more superficial, depending on the adhesive's pH, while maintaining HAp preservation.
• Enamel etching may not be adequate depending on the adhesive's pH.

Two-Step Self-Etch Adhesive Systems

• Advantages include modified smear layer, reduced post-operative sensitivity, ionic interactions with HAp, self-assembled nano-layering, and final hydrophobic layer; this system utilizes 10-MDP and protects collagen.
• Disadvantages include inadequate enamel etch.

One-Step Self-Etch Adhesive Systems

• Advantages of this system include ease of use.
• Disadvantages include inadequate enamel etching, too acidic and hydrophilic nature after curing, water tree formation, quick bond degradation, incompatibility with self-cure resins, and hydrolysis found inside the bottle.

Water Trees

• Microscopic images illustrate the formation of "water trees" which are associated with water permeability and degradation.

Nanoleakage

• SEM images showcase nanoleakage, a potential issue in adhesive systems.

Bonding Agent Acidity (pH)

• A table is presented categorizing different self-etch and etch-and-rinse systems based on their pH values.
  • Specific products are listed indicating the pH value for each.

Acidity of Self-etch Systems

• pH values below 2 result in demineralization of hydroxyapatite, exposure of collagen fibers, and the incorporation of unstable CaPO4 that cannot be rinsed away.
• pH values equal to or greater than 2 provide protection of collagen due to maintenance of HAp; with ionic interactions with HAp and a chemical bond similar to glass ionomer cements
• Selective etch pH is greater than or equal to 2.

Universal Adhesive Systems (2012 - All Bond Universal)

• This system can be used with or without etching.
• Used for direct and indirect restorations.
• Utilizes self-cure or light cure methods.
• Compatible with various materials and substrates.
• Contains silane and 10-MDP.

Functional Monomer: 10-MDP

• This monomer interacts with HAp to create strong, stable calcium salts through self-assembled nano-layering.
• The monomer provides a strong hydrophobic nature, protecting the bond against degradation.
• It enhances the resistance of residual HAp to acidic dissolution.
• It forms a protective hybrid layer with HAp, shielding collagen.

Universal DBA (pH)

• Various universal DBA products are listed and accompanied by their respective pH values.
• Components and ingredients of different products are detailed.

Universal One-Step Self-Etch Adhesive Systems

• Advantages include an improved version of self-etch systems, better bonding, inclusion of 10-MDP, and reduced sensitivity.
• Disadvantage include inadequate enamel etch, high acidity, rapid bond degradation or quick water permeability, sensitivity to self-cure, and hydrolysis inside the bottle.

Self-Etch Systems: Not All Are the Same

• Different self-etch systems may vary significantly.

Universal Adhesive Systems

• Laboratory and clinical evidence may not support the claim that universal adhesives can be used with any adhesive strategy.
• The stability of universal adhesive bonds may be material dependent.
• Long-term data regarding the clinical performance of universal adhesives is lacking.

Universal Adhesive Systems (Continued)

• Always employ a SEE (self-etching and priming) strategy.
• Additional hydrophobic layers are often incorporated.
• Active application techniques, such as scrubbing, are employed.
• Employing MMP inhibitors (for example, BAC or chlorhexidine).
• Implementing separate silane applications is recommended for silica-based ceramics.

What Bonding System?

• A table comparing different bonding systems (3-Step ER, 2-Step ER, 2-Step SE with SEE, 1-Step SE with SEE) highlighting their characteristics including technique sensitivity, etching methods, and final layer properties.

Universal Adhesives and Silane

• Silane does not function effectively when combined with resin monomers.
• It is deactivated in low pH environments.

Indirect Restorations - Adhesive Luting

• Images showcase examples of indirect restorations and adhesive luting procedures.

Tribochemical Silica Coating

• This technique involves a 3 step process.
• The process for this technique was illustrated with diagrams.

Bonding Agents

• Various bonding agents (e.g., Monobond Plus, ZirClean, etc.) are mentioned.

Bonding Agent Classifications

• Tables classify bonding agents based on their steps (3-steps, 2-step, self-etch) and the components involved
• Includes details about etch-and-rinse, and self-etch systems.

Bonding Steps Classification

• Tables organize the various steps needed for bonding methods

Classification Depending on Bonding Strategy

• Tables organize bonding strategies (etch and rinse, self-etch, self-etch with selective enamel etch) and the corresponding steps in each.

Incompatibility of Simplified Adhesives with Dual-Cure Resins

• Studies illustrate that incompatibility exists between simplified adhesives and dual cure resins.
• Advantages of the simplified technique include quick application, reduced sensitivity and good bonding.

Effective on all surfaces

• Characteristics of universal adhesives are detailed: high bonding strength to various materials, and high aesthetic value.
• The use and benefits of one- and two-step applications as well as the need for refrigeration are mentioned.

SC: BPO (Benzoyle Peroxide) + A Catalyst (base mix)

• Information relating to chemical reaction and incompatibility.

Bonding Agent Acidity

• Table compares different bonding agents in terms of pH levels and compatibility.
• This table specifically addresses the differences between self-etch, etch and rinse, and dual cure systems.

Dual Cure Compatible vs. Dual Cure

• Diagrams compare self-cure and dual-cure-compatible bonding agents.

Indirect Restorations - Adhesive Luting

• Visual examples illustrate the use of adhesive luting for indirect restorations.

This quiz focuses on the third module of adhesive dentistry within operative dentistry, highlighting key concepts such as enamel adhesion, hybrid layers, and solvents. The lecture, presented by Dr. Kostis Giannakopoulos, provides insights into the structures and techniques essential for effective dental bonding. Test your knowledge on these critical aspects discussed in the lecture.