Reconstruction of the Stapes Superstructure with a Combined Glass-Ceramic (Bioverit^®) Implant in Guinea Pigs

Abstract

Background: Reconstruction of the stapes superstructure continues to be a problem for otologists. Optimal fixation of implants on the stapes footplate has not yet been achieved. Methods: We postulated that bony fixation, between implant and stapes, could be confined exclusively to the footplate region by modifying the bioactivity of the implant material. Therefore, after removal of the superstructure in guinea pigs a combined biovitro ceramic implant (Bioverit^® I and Bioverit^® II) was placed on the stapes footplate in 10 guinea pigs. As a control, we employed a group of 6 animels in which the stapes superstructure was removed without placing any implant. Results: After 25 weeks the implants were found to be dislocated laterally. We observed fixation with the wall of the middle ear. In the control group we also found new bone formation and even a bow shaped regeneration of the stapes superstructure. Conclusion: Combined Bioverit^® stapedial implants were found to routinely fix to the middle ear wall of the guinea pig. The guinea pigs’ enormous potential for bone regeneration in the middle ear ossicular chain make this species unsuitable for exploring hypotheses on human middle ear reconstruction.

Free Bioverit ® II Implants Coated with a Nanoporous Silica Layer in a Mouse Ear Model — A Histological Study

“…Guinea pigs did not show a foreign body reaction to Bioverit Õ I þ II implants in the middle ear [18].…”

“…However, only one research group has dealt with a middle ear model of mice for ossicular chain replacements so far [20][21][22]. Dost et al found new bone formation surrounding Bioverit Õ I þ II, hydroxyapatite and Ceravital Õ implants, and also in contact with the middle ear wall in guinea pigs [18,19,23]. Additionally, a significant amount of new bone around the ossicle was observed in a reconstruction with hydroxyapatite cement and dahllite cement [24].…”

“…Additionally, a significant amount of new bone around the ossicle was observed in a reconstruction with hydroxyapatite cement and dahllite cement [24]. This fact leads to the conclusion that the extensive ossification limits the use of guinea pigs for research about ossicular chain replacements [18].…”

Osseointegration of Titanium Prostheses on the Stapes Footplate

“…However, the Merino sheep is a mammal and widely used and established in experimental setups to investigate bone turnover in metabolic bone disease (Sigrist et al 2007) and located fracture healing or integration of prostheses in the skeleton other than the middle ear (Cancedda et al 2007). Adverse mechanisms like the potential of regeneration of ossicular remnants, as known in rodents (Dost et al 2002), were neither reported in literature nor seen in our study. Therefore, we assume our data to be comparable to adult human conditions in metabolic concerns.…”

Osseointegration of alumina with a bioactive coating under load-bearing and unloaded conditions

“…Carl et al [13] generated dense non-porous coatings out of Bioverit s I on zirconia. Bioverit s I is a glass ceramic with good bone-bonding ability and long-term stability that has been used for orthopaedic implants [14][15][16][17]. The coatings on zirconia were produced by a sintering process and revealed a good stability and adhesive strength [13].…”