Histological and Clinical Survey of Polylactic-Polyglycolic Acid and Dextrane Copolymer in Maxillary Sinus Lift: A Pilotin VivoStudy

Abstract

Of various proposed alternatives to autogenous bone, a synthetic, degradable copolymer of PLA-GLA and dextrane seems to be a promising biomaterial for maxillary sinus lift. Consecutive partially edentulous patients showing severe monolateral posterior maxillary atrophy were treated via sinus lift using PLA-GLA-dextrane copolymer as the sole filler. Delayed implant positioning was performed and cores of regenerated tissues and native bone controls were retrieved and evaluated by light and electron microscopy, histomorphometry, microhardness and qualitative X-ray analysis. Seven sinuses in 7 patients were augmented with PLA-GLA-dextrane copolymer. Six to nine months after the copolymer 'graft', 17 bone cores were retrieved: all histological sections contained newly synthesized, mineralized material and new bone in various stages of development. Histomorphometry revealed average Trabecular Bone Volume (TBV) values ranging from 51% (6 months) to 77% (9 months). Backscattered scanning electron microscopy (BSE) in experimental and control samples confirmed histology findings. Microhardness values suggested newly formed bone at nine months was not as hard as native bone. Ca and P content was similar in 9-month regenerated and native bone. Seventeen implants were inserted in the second stage of surgery: resulting Implant Success (SR) and Cumulative Success (CSR) up to 3 years were 100% following Albrektsson's criteria. Sinus lift augmentation using PLA-GLA-dextrane copolymer as the sole filler resulted in uneventful surgeries. New bone formation was evident histologically and its maturation was still in progress after 9 months. Successful, staged implant positioning was achieved in regenerated tissue. Severe horizontal and vertical residual ridge resorption in the posterior maxilla, coupled with age-linked sinus pneumatization, often represents an anatomical limitation for implant-supported fixed prosthesis in this area (1). The basic surgical technique, designed to treat such atrophy and provide adequate bone volume for implant positioning, is the "sinus lift", initially described by Boyne and co

Increase of homogenous new bone formation using osteoinductive factor rhGDF‐5 during sinus floor augmentation in Goettingen Minipigs

“…The outcomes of the sinus floor grafting in terms of bone formation in the augmented volume are difficult to assess. In clinical studies, the evaluation has been performed on histological specimens obtained from trephine drills (Martuscelli et al 2008). These evaluations are focussed on an area immediately adjacent to dental implants but disre-gard the remaining volume of the augmentation and cannot display interface reactions between dental implants and the adjacent augmentation.…”

Histomorphometrische Evaluation der Knochenneubildung mit Hilfe eines osteoinduktiven Faktors bei der Sinusbodenaugmentation im Göttinger Minipig

“…Es ist problematisch, die Knochenneubildung innerhalb der Sinusbodenaugmentate klinisch zu evaluieren. Die meisten Tiermodelle begrenzten sich auf die histologische Untersuchung des direkten Knochen-Implantat-Kontaktes (BIC) und waren auf eine zweidimensionale Betrachtung begrenzt (Martuscelli et al 2008). Durch solche Studien wird jedoch nur ein kleiner Bereich untersucht, der keine Aussagen über die Knochenneubildung innerhalb des gesamten räumlich komplex aufgebauten Augmentats machen kann.…”