Minimal Intervention in Operative Dentistry

Conservative Approach and Caries Management in Operative Dentistry

• Course Learning Outcome #2: Upon successful completion, students will be able to discuss the principles of tooth structure conservation and minimal intervention.

Objectives

• Shift from Black's principles: Discuss the reasons for shifting from Black's principles of extension for prevention to minimal intervention.
• Explain Conservative Approach: Explain the principles of the conservative approach.
• Biological Model of Treatment: Introduce the biological model of treatment.
• Caries Management: Describe caries management by risk assessment. Select treatment according to carious lesion activity.
• Minimal Invasive Tools: Introduce minimal invasive cutting tools.
• Conservative Alternatives: Explain more conservative restoration alternatives for initial carious lesions.
• Minimal Intervention Cavity Prep: Describe the steps of cavity preparation from a minimal intervention perspective.

Historical Review of the Conservative Approach (1901)

• Immune Areas: The tooth has no immune areas.
• Restoring Sound Tooth Structure: Dentists weren't guaranteed decay wouldn't spread to restored areas. Replacing sound tooth with foreign material was deemed problematic.

Minimal Intervention

• Focus on Minimal Invasive Dentistry: The focus is on a minimal invasive dentistry/preservative dentistry approach, allowing control of defects without unnecessary cutting if possible.

Consequences of Unnecessary Cutting

• Weakening of Tooth Structure: Gross weakening of the remaining tooth structure.
• Restoration Failure: Structural and marginal failure of the restoration.
• Pulpal Irritation: Increased potential for pulpal irritation. (Overextensions can maximize chemical, electrical, thermal, bacterial, osmotic and evaporative stimuli.)
• Gingival/Periodontal Irritation: Increased gingival and periodontal irritation, plaque accumulation.
• Increased Restorative Effort: Increased restorative display.
• Increased Time and Effort: More time, money, and effort consumption for restoration.
• Difficult Maintenance: Difficult maintenance of the restorative system.

Technological Advances

• Magnifiers and Early Caries Detection: Use of magnifiers and early caries detecting devices.
• Minimal Invasive Cutting: Introduction of minimal invasive cutting tools.
• Bonded and Biomimetic Restorative Materials: Use of bonded and biomimetic restorative materials.

Seeing Conservatism from a Different Perspective

• Control Cariogenicity: Control causative factors or cariogenicity to eliminate further demineralization.
• Remineralization: Remineralization of early lesions.
• Minimal Surgical Intervention: Minimal surgical intervention for cavitated lesions.
• Repair vs Replacement: Repair rather than replacement for defective restorations.

Adoption of Medical Model (Benefit)

• Prevention of New Cavities: Prevent the development of defects or new cavities.
• Stopping Lesion Progression: Stopping the progress of existing lesions or decay spots.
• Stronger Tooth Structure: Stronger remaining unprepared tooth structure.
• Lower Pulp Damage Potential: Lower potential for damaging the pulp.
• Problem Prevention: Prevent periodontal problems.
• Maintaining Existing Restorations: Maintaining existing old restorations.
• Intra-arch Relationship Conservation: Restorations that have less effect on intra-arch and inter-arch relationships and esthetics.

Dental Caries Management (Biological or Medical Model)

• Therapeutic (Non-Surgical): Diet and habit modification, salivary flow control, mechanical preventive measures. Use of antimicrobials. Remineralization of initial lesions, fissure sealing, follow-up.
• Restorative (Minimal Invasive Surgical): Treatment of diseased tissue that can't be remineralized.

To Drill or Not to Drill? Or When to Prepare a Cavity?

• Lesion Extension: Assess the extent of the lesion.
• Clinical Examination: Conduct a clinical examination.
• Radiographic Examination: Conduct a radiographic examination.
• Lesion Activity: Assess the activity of the lesion.
• Caries Risk Evaluation: Evaluate the overall caries risk.

Caries Risk Assessment (CRA)

• Definition: Determining the probability of caries incidence in a given period, considering factors influencing change in existing lesions.
• Applications: Used to determine if a preventive program is needed and to select a suitable program.

CRA Procedures

• Risk Factor Identification: Identification of risk factors and development of diagnostic tools.
• Diagnostic Model Development: Development of a diagnostic model.
• Outcome Significance Evaluation: Evaluate the significance of outcomes.
• Treatment Protocol Based on Model: Treatment according to developed model.

Caries Risk Factors and Diagnostic Tools

• Destructive Factors: -Caries experience (dental history) -Low saliva flow/rate -High fermentable carbohydrate intake/frequency -Poor oral hygiene -Low Fluoride -High caries activity -Bacterial count -Tooth anatomy -Non-oral factors (Age, sex, medical conditions, social factors, genetics)

Development of a Model

• Caries Risk Assessment Forms
• Traffic Light System
• Cariogram

Treatment According to the Model (CAMBRA)

• Caries Management By Risk Assessment: Assessment of caries risk for treatment and restoration recommendation based on patient risk.

Minimal Surgical Intervention for Cavitated Lesions

• Non-Invasive Cutting Tools
• Conservative Cavity Designs
• Restorative Alternatives

Ideal Cutting Tools

• Comfort: Comfort.
• Ease of use: Ease of use.
• Discrimination: Discriminate to remove diseased tissue only.
• Painless: Painless.
• Silent Operation: Silent.
• Minimal Pressure: Required minimal pressure.
• No Heat/Vibration: No heat generation or vibration.
• Affordability: Affordable.
• Air Abrasion Technology: Minimal or non-invasive cutting tools such as Air abrasion technology.
• Micro-Burs and Polymeric Burs: Minimal or non-invasive cutting tools such as Micro-Burs and Polymeric Burs.
• Laser Cutting: Minimal or non-invasive cutting tools such as Laser cutting.
• Ultrasonic Cutting: Minimal or non-invasive cutting tools such as Ultrasonic cutting.
• Ozone Treatment: Minimal or non-invasive cutting tools such as Ozone treatment.

Additional Cutting Technologies

• Sonno Abrasion: High-frequency, sonic, air-scalers with modified abrasive tips.
• Lasers: Light amplification by stimulated emission of radiation. Applications for cavity diagnosis, prep, prevention, whitening, surface modifications and photo-polymerization. Benefits for minimal damage to surrounding tissues, reduced operating time, etc.
• Polymer Burs: hard enough to remove carious dentin but stop at healthy dentin.
• Ozone: a gas that's an excellent preventative measure—rapidly penetrates and kills bacteria.

Guided Laser Ablation

• Hard Tissue Laser (Er:YAG): Utilizes laser-induced fluorescence feedback system that helps in minimal intervention caries removal, continuously measuring bacterial metabolites in carious tissue.
• Advantages: Minimal damage to surrounding tissues, reduced operating time, fewer post-operative issues.

CHEMO-MECHANICAL CARIES REMOVAL (CARISOLV)

• Sodium Hypochlorite: Dissolves decay.
• Amino Acids: Acts as a buffer, preventing damage to healthy tissue.

PAPAIN GEL

• Antibacterial and Anti-inflammatory: Has antibacterial and anti-inflammatory properties.
• Tissue Removal Assistance: Dissolves collagen fibers thus assisting carious tissue removal.

Advantages of Chemico-mechanical Method

• Effectiveness: Effective.
• Safety: Safe method.
• Anesthesia Avoidance: Eliminating the need for local anesthesia.
• Anxiety Reduction: Reduce patient anxiety.
• Sound Tissue Conservation: Conserve sound tissue.
• Simplified Application: Gel consistency simplifies application, reducing spillage risk.

ENZYMES

• Dentin Dissolution: Disintegrates decayed dentin.
• Nitrogen Presence: Solubilizes over 90% of nitrogen in carious dentin.
• No Effect on Healthy Tissue: Has no effect on sound dentin or enamel.

References

• Sturdevants Art & Science of Operative Dentistry 7th Ed., Andre V. Ritter et al, 2017.
• Operative Dentistry, Hugh Devlin, 2006.
• A Practical Approach to Operative Dentistry, Gordon B. Gray et al, 2020.

This quiz explores the principles and practices of minimal intervention in operative dentistry. It covers key concepts, including the transition from traditional methods to more conservative approaches and the biological focus of treatment. Enhance your understanding of how minimal invasive techniques impact cavity preparation and carious lesion management.