A Non-interventional Study Documenting Use and Success of Tissue-level Implants

Objectives: The purpose of this study is to document the use the success and the survival rates of implants in daily dental practice over a period of 2 years.
Methods: This is a multicentric study in which 12 experienced dentist participated. Patients who needed at least a placement of one implant to replace a tooth in the mandible or maxilla were included. The implants employed were screw-shaped implants (Klockner Essential Cone).
As a non-interventionist study, each clinician decided which implant, surgical and prosthetic technique to use. At the surgery the implant position, type of implant, moment of placement, quantity and bone quality, primary stability, need for bone increase, type of healing (submerged or non-submerged) and protocol of load were registered.The crestal bone level changes were evaluated measuring the shoulder-crest distance (SCD) on the mesial and distal aspects of each implant in the periapical radiographs took on the day of surgery, 8 weeks and 6, 12 and 14 months after surgery.
Frequency and ratios for qualitative variables and average quantitative variables and standard deviations were determined.

Results: 92 patients (35 men, 57 women) participated in the study, in which 196 implants were placed. The location more frequent was the first lower molar. The 81% were inserted in completely healed bone crest and the 42,6% healed in a semi-submerged way. The initial ISQ (quotient of implant stability) was 66,61 ISQ; and the two-years ISQ was 74,39. The 57% of the implants were restored with screw retained prosthesis. The SCD was 1,25mm and 2,04mm in the mesial and distal aspects at the day of the surgery; and 1,68mm and 2,16mm respectively at 2 years. The survival rate was 98,5% and the success rate was 93,4%.

Conclusions: The use of implants under standard conditions seemed to have success rates similar to those placed in controlled studies.