Vergleich des Knochenabbaus an Zähnen und Implantaten bei Patienten mit behandelter generalisierter aggressiver und chronischer Parodontitis

Background: Despite good log-term results with dental implants, one may also record biological and technical complications. It can be shown that implants may experience a bone loss by the time of their loading. One of the risk factors leading to crestal bone loss around dental implants is the patient‘s periodontal disease, which also induces a bone loss around teeth. Many research studies commonly regard bone levels around implants without including the teeth to their studies and are limited in their analysis about the attachment loss to the clinical measurements with negligence of a radiological evaluation. Aim of the Study: The present retrospective 5 to 20-year study draws a comparison between the bone loss at implants and teeth of patients treated for periodontitis and suggests possible risk factors for periimplant bone loss. Methods: 16 patients with treated generalised aggressive periodontitis (GAP) (321 teeth) and 15 with treated generalised chronic periodontitis (GCP) (348 teeth) orally rehabilitated with 151 implants participated in the study. After insertion of the final abutments they were examined clinically and radiologically. Further clinical examinations were performed during a 3- to 6-month recall schedule over a 5- to 20-year period. Radiological examinations of implants and teeth have been conducted 1, 3, 5, 10, 15 and 20 years after insertion of the superstructure (Baseline). Results: The implant's survival rate after 20 years of observation period was 94,0%, the teeth's survival rate after 20 years added up to 97,3%. After 15 and after 20 years of observation period bone loss around teeth (p=0,008; p<0,001) and implants (p=0,048; p=0,022) was significantly greater within patients treated for GAP (37,01% ±15,67; 35,84% ±12,73) than within patients treated for GCP (30,03% ±12,45; 29,15% ±11,9). Within patients treated for GAP there was greater bone loss within female patients, at implants with smooth surfaces as well as among implants with fixed superstructures, but without significance. In both patient groups there was no significant difference between bone loss around implants and teeth at any time. After one year of observation period 20,7% of all implants had no bone loss, 56,9% showed bone loss of ≥1mm. The mean Pocket Probing Depth (PPD) around teeth and implants showed results of less than 4mm throughout the whole study period. After 20 years of observation period PPDs at implants (3,62mm ±0,9, p=0,164) and teeth (3,24mm ±1,13, p<0,001) of patients with GAP were greater than PPDs at implants and teeth of patients with GCP (2,68mm ±0,82; 3,19mm ±0,59). In both patient groups PPD was significantly greater around implants than around teeth after 5 (GCP: p=0,035, GAP: p<0,001) and after 20 years (GCP: p=0,006; GAP: p=0,015). PPDs around implants runned similar at mesial, distal, vestibular and oral surfaces, around teeth they were smaller at vestibular and oral surfaces. A correlation between radiologically determined bone loss and clinically measured PPD could not be found. Conclusion: In both patient groups a continously increasing bone loss around teeth and implants could be found, which was greater among patients treated for GAP. A correlation between radiologically determined bone loss and clinically measured PPD around implants could be found at no point in time.