J Korean Acad Prosthodont.  2009 Oct;47(4):435-444. 10.4047/jkap.2009.47.4.435.

The influence of magnet on tissue healing after immediate implantation in fresh extraction sites in dogs

• Yu SM
• Cho IH
• Shin SY

• KMID: 2195592
• DOI: http://doi.org/10.4047/jkap.2009.47.4.435

Abstract

STATEMENT OF PROBLEM: The clinical use of electric and electomagnetic fields for fracture healing applications began in the early 1970s. Since then, several technologies have been developed and shown to promote healing of fractures. Developments of these devices have been aided in recent years by basic research and several well controlled clinical trials not only in the medical field but in dentistry. PURPOSE: The purpose of this study was to compare alveolar bone reduction following immediate implantation using implants onto which magnets were attached in fresh extracted sockets. MATERIAL AND METHODS: Four mongrel dogs were involved. Full buccal and lingual mucoperiosteal flaps were elevated and third and fourth premolars of the mandible were removed. Implants with magnets and implants without magnets were installed in the fresh extracted sockets and after 3 months of healing the animals were sacrificed. The mandibles were dissected and each implant sites were sampled and processed for histological examination.
RESULTS
The marginal gaps that were present between the implant and walls of the sockets at the implantation stage disappeared in both groups as a result of bone fill and resorption of the bone crest. The buccal bone crests were located apical of its lingual counterparts. At the 12 week interval the mean of marginal bone resorption in the control group was significantly higher than that of the magnet group. The majority of specimens in magnet group presented early bone formation and less resorption of the buccal marginal bone compared to the control group.
CONCLUSION
Within the limitations of this study, it could be concluded that implants with magnets attached in the early stages of implantation may provide more favorable conditions for early bone formation and reduce resorption and remodeling of marginal bone.

Keyword

Immediate placement; Magnet; Bone remodeling

MeSH Terms

Animals
Bicuspid
Bone Remodeling
Bone Resorption
Dentistry
Dogs
Fracture Healing
Magnets
Mandible
Osteogenesis

Figure

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  Fig. 1. Photograph illustrating the position of the implants placed.

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  Fig. 2. Schematic drawing describing bone contact (A) and bone area (B). The percentage of direct bone contact and the amount of bone (bone area), inside the threads were calculated directly in the light microscope.

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  Fig. 3. Schematic drawing describing the different landmarks between histometric measurements which were performed on implantation (A) and after 12 weeks of healing (B). B/I, marginal level of bone- to-implant contact; M, marginal shoulder of implant.

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  Fig. 4. Micrographs showing longitudinal section of magnet group (A) and control group (B) after 12 weeks of healing. B, buccal wall; L, lingual wall; I, implant; M, magnet. (H-E staining; original magnification×10).

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  Fig. 5. Micrographs showing longitudinal buccal section of magnet group (A) and control group (B) after 12 weeks of healing in the cervical region of the implants. CT, connective tissue; E, epithelial tissue; I, implant. (H-E staining; original magnification×40).

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  Fig. 6. Micrographs showing longitudinal lingual section of magnet group (A) and control group (B) after 12 weeks of healing in the cervical region of the implants. B, bone; CT, connective tissue; E, epithelial tissue; I, implant. (H-E staining; original magnification×40).

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  Fig. 7. Fluorescent images showing longitudinal section of magnet group after 12 weeks of healing. Note that the bone crest is closer to the neck of the implant at the lingual than at the buccal aspect of the implant. B, buccal bone; L, lingual bone; I, implant. (original magnification×100).

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  Fig. 8. Fluorescent images showing longitudinal section of magnet group after 12 weeks of healing. Note that the bone crest is closer to the neck of the implant at the lingual than at the buccal aspect of the implant. B, buccal bone; L, lingual bone; I, implant. (original magnification×100).

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  Fig. 9. Fluorescent images showing longitudinal buccal (A) and lingual (B) section of magnet group after 12 weeks of healing. The solid and dotted arrows indicate the bone resorption after early bone formation at 1 and 6 weeks. B, buccal wall; L, lingual wall; I, implant. (original magnification ×100).

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  Fig. 10. Fluorescent images showing longitudinal buccal (A) and lingual (B) sections of control group after 12 weeks of healing. The solid arrows indicate the bone resorption after early bone formation at 1 and 6 weeks. B, buccal wall; L, lingual wall; I, implant. (original magnification×100).

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