Histologic study of hydroxylapatite as an implant material for mandibular augmentation

Chang, Che Shoa; Matukas, Victor J.; Lemons, Jack E.

doi:10.1016/0278-2391(83)90190-8

Cited by 74 publications

(18 citation statements)

References 8 publications

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“…Studies of porous HA implants on the alveolar ridges of dogs [7] and human maxillary alveolus [8] demonstrated bone ingrowth into the open pores on the surface of the implants. Similar studies in dogs [9,10] and biopsy specimens from humans [11,12] showed that dense HA implants became surrounded by mature fibrous tissue, with a variable amount of new bone formation. However, HA implants often developed cracks [6,10].…”

Section: Introductionmentioning

confidence: 52%

Sintering behaviour and mechanical properties of hydroxyapatite and dicalcium phosphate

Wang

Chaki

1993

J Mater Sci: Mater Med

236

134

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The sintering behaviour of powders of two calcium phosphates, namely hydroxyapatite (HA) and dicalcium phosphate (DCP), were studied at various temperatures and in various environments. The density, flexural strength and Knoop hardness of HA sintered in air for 4 h initially increased with the sintering temperature, reaching maxima at around 1150°C, and then decreased due to decomposition of HA into tri-(TCP) and tetracalcium phosphates. Sintering in vacuum caused decomposition of HA at lower temperatures, and consequently the mechanical properties were poorer than those of HA sintered in air. The densification and mechanical properties of DCP sintered in air and vacuum showed similar behaviour to those of HA. In air DCP underwent phase transformation from 7-to [3-and to 0~-phases. In vacuum DCP started to decompose into tricalcium phosphate at 1000°C. To reduce dehydroxylation, HA powder was sintered in moisture at various temperatures up to 1350°C and X-ray diffraction study did not indicate any decomposition at the highest sintering temperature. The density, flexural strength and hardness of HA sintered in moisture increased with the sintering temperature and eventually reached plateaux at about 1300°C, but below 1200°C they were lower than those of HA sintered in air at corresponding temperatures. Thus, it is seen that dehydroxylation did not hinder sintering of HA. On the other hand, decomposition obstructed sintering of both HA and DCP.

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Section: Introductionmentioning

confidence: 52%

Sintering behaviour and mechanical properties of hydroxyapatite and dicalcium phosphate

Wang

Chaki

1993

J Mater Sci: Mater Med

236

134

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“…Studies of porous HA implants on dogs' alveolar ridges [11] and human maxillary alveolus [12] demonstrated bone ingrowth into the open pores on the surface of the implants. On the other hand, studies in dogs [13,14] and biopsy specimens from humans [15,16] showed that dense HA implants became surrounded by mature fibrous tissue, with a variable amount of new bone formation. However, HA implants often developed cracks [10,14].…”

Section: Introductionmentioning

confidence: 99%

Densification and strengthening of silver-reinforced hydroxyapatite-matrix composite prepared by sintering

Chaki

Wang

1994

J Mater Sci: Mater Med

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Ductile-phase reinforcement of hydroxyapatite (HA) was achieved by addition of silver particulates (5-30 vol %) in HA powder and subsequent sintering of HA-Ag powder compacts. A composite made by sintering 10 vol% Ag and the balance HA at 1200°C for 1 h in air had flexural strength of 75 4-7 MPa, which was almost double that of pure HA sintered under an identical condition. The density of HA-10 vol% Ag composite was 90 -t-2% of the theoretical density (as calculated from the rule of mixture) and was lower than that (98.7 ___ 0.4%) of pure HA sintered at a similar condition. The X-ray diffraction pattern of the composite did not indicate any decomposition of HA or any reaction between HA and Ag. Ag in the composite melted during sintering, but, due to poor wetting, did not spread in between HA particles. The addition of Ag reduced densification and grain growth during sintering of HA-Ag composites. Indentation cracks in the composites went around Ag inclusions and often stopped at Ag inclusions. The increase in the flexural strength of the composites was thought to be due to crack-bridging and crack-arrest by silver particles.

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“…These findings were consistent with several reports by light-microscopic studies4,10) on the graft/bone or graft/soft tissue interface after implantation. However, as these phenomena subsided with time after implantation, as have already been shown in the long-term observations8, [13][14][15][16] procollagen molecules arrange themselves into the collagen fibril. Thus, further studies are necessary to determine with higher magnification procedures whether collagen-like fibrils are genuine collagens and Type I or Type collagens.…”

Section: Discussionmentioning

confidence: 84%

“…These findings were consistent with some reports8-10,15) on the interspace between soft tissues and the HAP. In contrast, a new bone formation was usually observed in the bone/graft interface after subperiosteal or intrabony implantation4, [14][15][16].…”

Section: Discussionmentioning

confidence: 99%

Initial calcification processes inside the pores of porous hydroxyapatite ceramics implanted in the submandibular glands of rats.

Morimitsu¹,

Inoue²,

Nakamura³

et al. 1993

Jpn J Oral Biol

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Abstract:The initial calcification processes inside the po res of porous hydroxyapatite ceramics implanted into the submandibular salivary glands of rats were observed by light -microscopy and by scanning and transmission electron-microscopy at varying int ervals for 10 weeks after implantation .The inorgani c elements inside the pores were examined by line -and surface-analysis with x -ray-d etection energy-dispersive analysis .The porous hydroxyapatite ceramics were encapsulated with a layer of fibrous tissue during the later stages, although during the earlier stages the surr ounding tissues showed inflammatory phenomena .Insid e the pores of the implants , two types of calcification processes were observed. The first type was devoid of cells or any collagen fibrils , whereas in the second type, fibroblast-like cells, whichi nvaded the pores of the implants , and collagen fibrils appeared to be associated with the initial calcification processes .

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Histologic study of hydroxylapatite as an implant material for mandibular augmentation

Cited by 74 publications

References 8 publications

Sintering behaviour and mechanical properties of hydroxyapatite and dicalcium phosphate

Sintering behaviour and mechanical properties of hydroxyapatite and dicalcium phosphate

Densification and strengthening of silver-reinforced hydroxyapatite-matrix composite prepared by sintering

Initial calcification processes inside the pores of porous hydroxyapatite ceramics implanted in the submandibular glands of rats.

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