Dental Implant Diagnosis and Evaluation

Diagnosis - Clinical Evaluation

• Residual edentulous space:
  • Minimum 2 mm interarch distance in anterior sites and 4 mm in posterior sites
  • Mesio-distal distance should be about 7 mm
  • Implant size and number should be carefully considered when there is over 10 mm of distance to avoid overloading
  • Buccal cantilevering of the restoration might cause overloading
• Crown/implant ratio should be kept to 1:1 for sound biomechanics

Diagnosis - Adjacent Teeth

• Prognosis of the adjacent teeth is important for avoiding potential implant failure
• Soft tissue contours and levels should be reviewed to identify any defects that might have a direct impact on the esthetic outcome
• Position of the adjacent teeth (rotated, tilted, out of curve, extruded, intruded) can cause functional and esthetic problems if not addressed properly
• Wear facets should be carefully analyzed to understand the occlusal pattern

Treatment Planning - Restorative Design

• Biomechanical considerations:
  • Mandibular first molar sites should be carefully studied due to the usually large mesio-distal distance
  • Placement of a wide body implant (5 mm diameter instead of 4 mm) along with narrowing the occlusal plane can compensate for overloading
• Occlusal guidelines:
  • Light centric contact should be established
  • Shim stock should only be grasped when the musculature is fully engaged
  • Eccentric contacts should be avoided
  • Over-engineering and night guards are suggested for bruxors
  • Mild cusp heights are preferable to avoid bending moments and load magnification
• Abutment selection guidelines:
  • Screw or cement retained implant restorations can be fabricated
  • Various reasons (retrievability, amount of space, esthetics, occlusion, ease of operation, etc.) can be considered in choosing one over the other option
  • Decision should be made prior to the placement of the implant

Diagnosis - Clinical Evaluation

• Opposing teeth:
  • Plane of occlusion and occlusion play an important role in the loads exerted on the implant restoration
  • Occlusal scheme should be carefully evaluated for planning the centric and laterotrusive contacts
  • Type of restoration (fixed or removable) affects the amount of forces transmitted
  • Prognosis of a compromised tooth might be negatively impacted by a rigid implant restoration

Study Casts

• Edentulous site and adjacent structures can be analyzed in detail on the casts
• Diagnostic prototype in the missing tooth site helps visualize the proposed restoration
• Location and alignment of the proposed implant can be studied through the diagnostic work-up

Surgical Template

• Used for imaging and surgical purposes
• Fabricating a good template enhances the diagnostic value of imaging and guides successful placement of the implant
• Template contains barium sulfate mixed with clear acrylic at the missing tooth site for radio opaque marking during tomographic imaging