Comparison of Short Implant Assisted Mandibular Overdenture Designs

Primary Outcomes (5)

• Implant stability

  Stability was assessed using resonance frequency analysis measured with the Osstell device instrument. The Osstell unit records a numeric value of 1-100 which is referred to as the implant stability quotient (ISQ). The measurements were performed and 3 mean of three readings were recorded in each evaluation period.

  up to 12 months

• Peri-implant probing depth

  Peri-implant probing depth refers to the distance between the gingival margin and the most apically probable portion in millimeters (mm). The peri-implant probing depth was measured using a graduated plastic periodontal probe. The probe was held parallel to the long axis of the implant and introduced to the peri-implant sulcus until slight resistance was felt. Measurements were made at four sites around each implant; buccal, lingual, mesial and distal. Probing depth of 1 mm or less was recorded as "1mm", and those exceeding 1 mm but less than 2 mm were recorded as "2mm" and so forth. The mean records for each implant were then calculated.

  up to 12 months

• Clinical attachment loss

  It is the distance from the junction implant/abutment to the most apically probable portion, in millimeters. Assessment of the clinical attachment level was performed simultaneously while measuring the peri-implant probing depth.

  up to 12 months

• Gingival inflammation (Modified gingival index)

  The peri-implant mucosal tissues around the implants were assessed using Apse's modification of Löe and Silness index. The criteria for assessment were: 0 =Normal mucosa, 1 =Mild inflammation, slight change in colour and texture, slight oedema and no bleeding on probing, 2 =Mild inflammation, redness, in all portions of gingival margin, 3 =Moderate inflammation, 4 =Severe inflammation. The gingival index was assessed at 4 sites around each implant (buccal, lingual, mesial and distal) the sum gingival index score was calculated from all these surfaces and then divided by 4 to obtain the gingival index for each implant. Indices of the three implants were added to each other, and then divided by 3 to get the mean gingival index for each case. A score from 0.1-1.0 reflects mild inflammation; 1.1-2.0 reflects moderate inflammation from, and 2.1-3.0 signifies severe inflammation.