The interface of permucosal dense apatite ceramic implants in humans

Abstract

Dense apatite ceramic implants inserted into fresh extraction sockets of teeth and submerged under full lower dentures may develop permucosal dehiscences because of vertical alveolar ridge resorption. In a 5-year clinical follow-up study, 16 out of 81 of such implants showed this dehiscence, offering the opportunity to study histologically the reaction of the mucosal tissue and the alveolar bone to dense apatite ceramic implants in humans. The histologic findings indicate that there is no bonding between mucosa and the permucosal part of the dense apatite ceramic implant under full lower dentures in humans. On the other hand, a very intimate bonding exists between alveolar bone and the dense apatite ceramic material.

Dense Hydroxyapatite Inserted Into Postextraction Sockets: A Histologic and Histomorphometric 20‐Year Case Report

“…In clinical and in vitro studies, 3–6 it was demonstrated that Ca‐P materials are tolerated well, do not possess local or systemic toxicity, do not yield inflammatory responses when implanted in animals or humans, do not cause alterations of normal bone mineralization processes, and are fabricated easily into any size or shape. Moreover, they are considered biocompatible and osteoconductive and used widely in ridge preservation/augmentation procedures 7–11 . HA is generally recognized as the natural mineral component of vertebrate hard tissues, making up 60% to 70% of bone and 98% of dental enamel 4…”

“…Moreover, they are considered biocompatible and osteoconductive and used widely in ridge preservation/augmentation procedures. [7][8][9][10][11] HA is generally recognized as the natural mineral component of vertebrate hard tissues, making up 60% to 70% of bone and 98% of dental enamel. 4 There is a lack of data about HA degradation in the literature, with few long-term studies, 11 and conflicting views on the rate of resorption of this material.…”

Degradable Bisphosphonate-Alkaline Phosphatase-Complexed Hydroxyapatite Implants In Vitro

“…HA implants show alveolar bone bonding osteogenesis which means that incipient bone formation starts at and proceeds away from the implant surface. (46) The described surface changes in the chemistry (formation of carbonate-apatite) and the topography (dis- solution of intergrain boundaries and grains) of the HA surface elicited by the pH of PCP enhance the bonding of the HA in vivo. (40,43) Therefore, it is tempting to suggest that PCP might condition the complexed implant surface in such a way that it also enhances both bonding and degradation of the implant in vivo.…”

Estudo de poli acidos laticos, et, complexados a hidroxiapatita ou matriz de proteina ossea"

“…Este osso consiste de formações lamelares e sistemas de canais de Havers, idênticos àqueles existentes abaixo da crista óssea. Na interface e na camada externa da hidroxiapatita voltada para os tecidos moles foram encontradas uma camada densa de tecido conjuntivo fibroso e uma quantidade mínima de células inflamatórias crônicas (DENISSEN et al, 1984;PAGE & LASKIN, 1987).…”

“…Encontra-se uma íntima relação entre as fibras colágenas da matriz óssea e os cristais de hidroxiapatita, com as fibras geralmente posicionadas paralelamente à superfície do implante, e também são encontrados cristais minerais do osso, adjacentes aos da hidroxiapatita (DENISSEN et al, 1984;TRACY & DOMERUS, 1984). O íntimo contato do material implantado ao osso faz com que sua separação se torne difícil, precisando de uma força em média de 30 N.cm -2 (DENISSEN et al, 1980).…”