Composite Materials in Dentistry

Composite Materials

• Minimal tooth structure loss, little to no discomfort, short operating time, and modest patient expense compared to indirect restorations.
• Best option for extensive defects and aesthetic concerns: Ceramic onlay or crown.
• Factors affecting composite restoration lifespan:
  • Initial caries lesion or defect nature and extent
  • Treatment procedure
  • Restorative material and techniques
  • Operator skill
  • Patient factors:
    • Oral hygiene and caries risk
    • Occlusion and adverse habits

Composite Restoration Success

• Strong bond is crucial for longevity.
• Isolation of the operating field is paramount.
• Failure can occur due to:
  • Trauma
  • Improper tooth preparation
  • Inferior materials
  • Poor material selection
  • Patient-related risk factors

Composite Restoration Indications

• Class I, II, III, IV, V, and VI restorations
• Foundations and core buildups
• Sealants and preventive resin restorations
• Esthetic enhancements:
  • Partial veneers (tooth contour modifications)
  • Full veneers (diastema closures)
• Temporary or provisional restorations
• Periodontal splinting
• Luting of indirect esthetic restorations

Composite Restoration Contraindications

• Inability to obtain isolation
• Occlusal considerations related to wear and fracture
• Placement on occlusion or heavy occlusion
• Strengthening weakened tooth without assurance of patient recall
• Extending restoration to root surface (inferior marginal integrity)
• Operator factors (committed to isolation procedures)

Composite Restoration Advantages

• Aesthetics
• Conservative tooth preparation (minimal extension)
• Low thermal conductivity
• Universal use
• Adhesion to tooth
• Repairability

Composite Restoration Disadvantages

• Poor marginal and internal cavity adaptation on root surfaces (polymerization shrinkage and improper insertion)
• Marginal deterioration over time (absence of enamel bonding)
• More difficult and time-consuming placement
• Bonding requires multiple steps
• Insertion difficulty
• Proximal contact, axial contour, and embrasure establishment
• Occlusal contact, finishing, and polishing difficulty
• Costlier than amalgam
• Technique sensitivity
• Proper isolation of operating site
• Incremental placement technique
• Adherence to proper adhesive technique
• Greater occlusal wear in areas of high stress or when all tooth contacts are on composite

Initial Clinical Procedures

• Obtain and finalize complete examination, patient record review, radiographs, caries risk assessment, diagnosis, treatment plan, and informed consent prior to scheduling (exceptions for emergencies).

Local Anesthesia

• Required for many operative procedures.
• Profound anesthesia provides comfort, uninterrupted procedure, and reduced salivation.

Operating Site Preparation

• Clean the operating site with pumice slurry to remove plaque and superficial stains.
• Calculus removal is essential.
• Do not use prophy pastes containing flavoring agents, glycerin, or fluorides before composite restoration.
  • Acts as contaminants
  • Compromises adhesion process

Shade Selection

• Essential for all direct composite restorations.
• Determine shade before prolonged drying.
  • Dehydrated teeth appear lighter due to decreased translucency.
• Reminders:
  • Teeth to be matched must be clean.
  • Remove bright colors from the field of view: makeup, tinted eyeglasses, bright gloves, neutral operating walls.
  • View the patient at eye level.
  • Evaluate shade under multiple light sources.
  • Make shade comparisons at the beginning of the appointment.
  • Make comparisons quickly to avoid eye fatigue.

Isolation of the Operating Site

• Critical and achieved with rubber dam, an isolation device (Isolite), or cotton rolls and cellulose wafers.
• Essential for successful adhesion.
• Contamination of etched enamel and dentin by saliva decreases bond strength.
• Contamination of composite material can negatively impact adhesion.