Posterior alveolar ridge resorption in bar-retained mandibular overdentures: 10-year results of a prospective clinical trial.
OBJECTIVE
Data on posterior alveolar ridge resorption (PARR) in patients with two implant supported mandibular overdentures is very heterogeneous. The aim of this prospective study was to observe the PARR after ten years for a study population treated with a titanium bar retained overdenture on two IMZ-implants.


METHODS
The data pool consisted of digital and digitized conventional panoramic radiographs taken prior to implant placement and at follow up appointments. Digital measurements were carried out following an established procedure ("Tuebingen method" by Gomez-Roman). For each patient a linear regression was calculated resulting in a relative area related PARR-value per year. A simplified geometrical scenario was used for the estimation of absolute bone height losses.


RESULTS
Data of 23 patients was available. The mean observation period was 9.4 years (±2.4 years). An average area related PARR-rate of 1.02% per year was observed with high individual differences ranging from 0.15% and 2.63% per year. The estimated average ten year vertical bone loss in the chewing center was 1.5 mm.


CONCLUSIONS
Posterior bone resorption was found to be in the range previously reported for different implant restorations and therefore does not represent a particular problem of two implant bar retained overdentures. The results strengthen the two implant concept.
Medical Faculty Carl Gustav Carus, Department for Prosthetic Dentistry, Technische Universität Dresden, Dresden, Germany.
Michael
M
Raedel
Medical Faculty Carl Gustav Carus, Department for Prosthetic Dentistry, Technische Universität Dresden, Dresden, Germany.
Kristina
K
Lazarek-Scholz
Medical Faculty Carl Gustav Carus, Department for Prosthetic Dentistry, Technische Universität Dresden, Dresden, Germany.
Birgit
B
Marré
Medical Faculty Carl Gustav Carus, Department for Prosthetic Dentistry, Technische Universität Dresden, Dresden, Germany.
Klaus W
KW
Boening
Medical Faculty Carl Gustav Carus, Department for Prosthetic Dentistry, Technische Universität Dresden, Dresden, Germany.
Michael H
MH
Walter
D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000473:pathology*; D003781:Denture Retention; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D011862:Radiography, Panoramic; D014025:Titanium
D014025:Titanium
bone implant interactions; clinical research; clinical trials; prosthodontics