Parafunction

Parafunctions - effects

Parafunctional activities can apply high forces to both implant and prosthetic components. These forces can lead to fracture or loosening of screws and abutments, chipping of the veneering material or fracture of the prosthetic reconstruction. Parafunctional activity may contribute to crestal peri-implant bone loss and/or implant fracture.

Functional risk assessment

To assess the possibility of past or ongoing parafunctional activity, the following assessments should be considered:

• Observe clenching, jaw closing path, jaw muscle hypertrophy
• Examine occlusion, functional movements, lateral forces, enamel/dentin condition, signs of abrasion. However abrasion evidently reveals the past and not necessarily ongoing parafunctions
• Look for repeated chipping of existing ceramic restorations, parafunctional habits and bruxism
• Assess loss of posterior support, tooth position, supra-/infraocclusion, bone structure and condition

Treatment considerations

If parafunction is detected or has already caused considerable damage to the natural dentition, it is recommended to adapt and plan the implant-based reconstruction accordingly and/or consider non-implant based treatment alternatives, especially in cases with myogenic dysfunctions. Consider functional treatment of dysfunctions before planning implant-supported rehabilitation.

• Adaptation of the implant type & diameter
• Distribution and number of placed implants adapted to the patient’s biomechanical and clinical requirements
• Selection of a strong connection (internal/conical)
• Adaptation and reinforcement of prosthetic superstructure and design, for example splinting of implants through bars, removable-only restoration , adaptation of occlusal concept/flat occlusion, short or no extensions and caution with full-ceramic constructions.
• Night guard protection