White Paper: Primer for Dental Relining Agents

Primer For Dental Relining Agents
Table Of Contents
  1. Executive Summary
  2. Introduction
  3. Objective
  4. Market Products Analysis
  5. Basic Chemistry
  6. Patent and Non-Patent Literature Analysis
  7. Insights from Literature
  8. Product Development Challenges
  9. Partner with us for technical solutions
  10. References
  11. Get in Touch to get the complete white paper
  12. Get in Touch

Executive Summary

This white paper presents research on the “Primer for Dental Relining Agents”. The objective is to make an effective primer that enhances the adhesion between dental prosthetics made of polymethyl methacrylate (PMMA) and silicone-based relining materials. The paper delves into market analysis, basic chemistry, patent reviews, product development challenges, and references with hyperlinks for further reading.

Introduction

Soft denture liners are essential in removable prosthetic dentistry. They have been used for over a century to provide temporary relief to sore tissues, help condition the oral environment, provide retention, and distribute occlusal loads evenly over denture-bearing areas. For patients with thin atrophied ridges, bony undercuts, and non-resilient mucosa, soft tissue liners may be the only solution for comfortable denture wear.

Silicone rubber lining materials, however, poorly adhere to methacrylic resin-based dentures. Adhesion failure between resilient liners and denture bases is common, attributed to:

  • Non-use of primers
  • Mechanical property differences between acrylic resins and relining materials
  • Aging of relining materials due to saliva, water, and temperature changes

Primers have been developed to prevent these failures by interacting with the surfaces of acrylic resins and resilient liners. This paper explores the development of an effective primer that enhances adhesion between PMMA denture bases and silicone-based relining materials.

Objective

The objective is to make an effective primer that enhances the adhesion between dental prosthetics made of polymethyl methacrylate (PMMA) and silicone-based relining materials.

Market Products Analysis

1. MucoSoft™ Adhesive Agent

  • Description: A clear, easy-to-apply, chair-side, self-curing silicone for long-term soft lining.
  • Features:
    • Taste-free, odorless, translucent pink shade.
    • Used as an adhesive primer to bond relining material to the denture substrate.
  • Application:
    • Apply a thin layer to the prepared denture surface.
    • Air dry for about 2 minutes.
    • Spread the relining material onto the dried denture substrate.
  • Composition:
    • Methylene Chloride (CAS No: 75-09-2)

2. Acrylic Primer / Jet Seal

  • Description: A clear liquid with an acrid odor.
  • Features:
    • Applied over original acrylic surfaces for new acrylic additions.
    • Dilutable with Jet™ Adjusters Thinner.
  • Composition:
    • Methyl Methacrylate (CAS No: 80-62-6) < 80%
    • Acetone (CAS No: 67-64-1) > 10%

3. GC RELINE II Primer for Resin

  • Description: A clear liquid with a fruity odor.
  • Composition:
    • Methyl Acetate (CAS No: 79-20-9) 50-70%
    • Ethyl Acetate (CAS No: 141-78-6) 25-50%

Basic Chemistry

The primer consists of the following key components:

1. Organic Solvent

  • Purpose: Swells the resin surface to facilitate better adhesion.
  • Desirable Properties:
    • High volatility for easy drying.
    • High permeability to resin for increased adhesive strength.
  • Common Solvents:
    • Alcohols: Methanol, Ethanol, Isopropyl Alcohol.
    • Ketones: Acetone, Methyl Ethyl Ketone.
    • Esters: Ethyl Acetate, Butyl Acetate.
    • Chlorinated Solvents: Methylene Chloride, Chloroform.

2. Inorganic Powder

  • Purpose: Provides an anchor-like mechanical interlocking with the resin surface.
  • Characteristics:
    • Fixed on the resin surface to create roughness.
    • Enhances physical engagement with silicone rubber.
    • Hydrophobized (e.g., silanized) to improve dispersibility in organic solvents.
  • Common Inorganic Powders:
    • Silica (Silicon Dioxide)
    • Alumina
    • Titania

3. Siloxane-Modified (Meth)acrylic Polymer

  • Purpose: Improves initial adhesion by forming linkages between acrylic resin and silicone relining material.
  • Characteristics:
    • Contains Si-H groups reactive in hydrosilylation reactions.
    • Molecular weight between 200 to 10,000 for optimal performance.

4. (Meth)Acrylic Acid Lower Alkyl Ester Polymer

  • Purpose: Enhances durability of adhesion by molecularly entangling with the acrylic resin.
  • Examples:
    • Polymethyl Methacrylate (PMMA)
    • Polyethyl Methacrylate (PEMA)

Patent and Non-Patent Literature Analysis

primer for Dental Relining

1. Adhesive for Silicone Rubber (JP2001329229A)

  • Summary: Describes an adhesive comprising an organic solvent, inorganic powder, and optionally a polysiloxane with Si-H groups.
  • Findings:
    • Organic solvents like ethyl acetate (low toxicity) are preferred.
    • Inorganic powders like hydrophobic silica improve adhesion.
    • Si-H containing polysiloxanes enhance initial adhesion.
  • Mechanism:
    • Organic solvent swells resin surface.
    • Inorganic powder anchors onto the resin.
    • Physical interlocking and interactions with silicone rubber occur.

2. Adhesive for Silicone Rubber Lining Materials (US 6,866,742 B2)

  • Summary: Focuses on an adhesive using halogen-free organic solvents to enhance durability.
  • Components:
    • Organic solvent (e.g., ethyl acetate).
    • Reactive siloxane-modified (meth)acrylic polymer.
    • (Meth)Acrylic acid lower alkyl ester polymer.
  • Mechanism:
    • Molecular entanglement between adhesive layer and denture base.
    • Chemical bonding through hydrosilylation reactions with silicone rubber.

3. Tensile Bond Strength Study

  • Reference: Goiato & dos Santos, DOI:10.1590/1516-1439.024415
  • Findings:
    • Primer application increases tensile bond strength.
    • Cohesive failures were predominant after primer application, indicating strong adhesion.
    • Solvents in primers enhance surface wettability and cleaning.

Insights from Literature

  • Adhesive Composition:
    • Organic Solvent: 85-95% (e.g., Methylene Chloride, Ethyl Acetate).
    • Inorganic Powder: 1-5% (e.g., Hydrophobic Silicon Dioxide).
    • Siloxane-Modified Polymer: 1-5%.
    • (Meth)Acrylic Acid Lower Alkyl Ester Polymer: 1-5%.
  • Key Observations:
    • Organic solvents are critical for resin swelling.
    • Inorganic powders improve mechanical interlocking.
    • Siloxane-modified polymers enhance initial adhesion.
    • The addition of (meth)acrylic polymers increases durability.
  • Formulation Considerations:
    • Optimal ratios are essential to prevent adhesion inhibition.
    • Halogen-free solvents like ethyl acetate are preferred for low toxicity.
    • Particle size of inorganic powder should be ≤0.5 μm for stability.

Product Development Challenges

Primer for Dental Relining
  • Adhesion Testing: Evaluating the adhesive and cohesive forces between the acrylic plate and silicone paste requires precise testing methods.
  • Durability Assessment: Simulating long-term usage through thermocycling tests to assess the primer’s performance over time.
  • Surface Evaluation: Analyzing the treated surfaces before and after primer application can be subjective and may require advanced imaging techniques.

Partner with us for technical solutions

We are a technical consulting solutions and custom product development consultancy. Get in touch with us to get a free introductory session with us for project scoping.

References

  1. US Patent 6,866,742 B2: Adhesive For Silicone Rubber Lining Materials
  2. MucoSoft™ Adhesive Agent – Parkell
  3. Tensile Bond Strength of a Soft Liner to an Acrylic Resin after Primer Application and Thermocycling
  4. JP2001329229A: Adhesive for Silicone Rubber
  5. Sofreliner Primer Composition at GC America
  6. Sekisui Kasei Co.: Polymethylmethacrylate (PMMA)
  7. Substitutes for Methylene Chloride as a Dental Softening Agent, Eur J Oral Sci 2000
  8. Meghmani Finechem: Methylene Chloride
  9. Jubilant Ingrevia: Ethyl Acetate Overview

Get in Touch to get the complete white paper

This white paper is based on our State of Art (SOA) Analysis of “Primer for Dental Relining Agents”.

Note: The SOA has been put through o1-preview LLM to draft the report in White Paper Format.

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