Evaluations of epithelial sealing and peri-implant epithelial down-growth around "step-type" implants

• Published in: Clinical oral implants research Vol. 23; no. 4; pp. 459 - 466
• Main Authors: Atsuta, Ikiru, Ayukawa, Yasunori, Ogino, Yoichiro, Moriyama, Yasuko, Jinno, Yohei, Koyano, Kiyoshi
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2012
• Subjects: Animals; Connective tissues; Dental Abutments; dental implant; Dental Implantation, Endosseous - methods; Dental Implants; Dental Prosthesis Design; Dentistry; down-growth; Epithelial Attachment; Immunoenzyme Techniques; Implants, Experimental; Male; Maxilla; Molar; Osseointegration; Peri-Implantitis - prevention & control; Rats; Rats, Wistar; Surface Properties; Titanium; Wound Healing
• ISSN: 0905-7161; 1600-0501
• DOI: 10.1111/j.1600-0501.2011.02163.x

Objective: Implant designs that can stimulate and integrate with an epithelial wound‐healing process may significantly enhance the efficacy of dental implants. Here, we evaluated the potential of “step‐type” implant systems to improve the sealing between the peri‐implant epithelium (PIE) and the implant surface, and investigated the effect of implant structure on PIE down‐growth. Materials and methods: Right maxillary first molars were extirpated from rats and implanted with either a straight‐type or a step‐type implant varying in step height and/or width (Ns: 0.8 mm height, 0.1 mm width; Ws: 0.8 mm height, 0.2 mm width; Hs: 0.4 mm height, 0.1 mm width). Maxillae were harvested at various time points over 16 weeks to evaluate laminin‐5 distribution as an indicator of wound healing and PIE formation, horse‐radish peroxidase (HRP) penetration as a measurement of epithelial sealing, and PIE down‐growth formation. Results: In all implant models, the PIE formed from the oral sulcular epithelium and spread apically along the implant surface. In the Ws group, HRP penetration was detected only in the coronal region of the PIE at 4 weeks, whereas in the straight‐type, it was observed in the apical region and the connective tissue. At 16 weeks, the Ws implants exhibited markedly less PIE down‐growth than the Con, Ns or Hs implants, and were equivalent to that observed in natural teeth. Conclusion: The step‐type implant system may have the potential for improving epithelial sealing at the tissue–implant interface, as well as reducing apical PIE down‐growth, thus enhancing dental implant efficacy. To cite this article:
Atsuta I, Ayukawa Y, Ogino Y, Moriyama Y, Jinno Y, Koyano K. Evaluations of epithelial sealing and peri‐implant epithelial down‐growth around “step‐type” implants.
Clin. Oral Impl. Res. 23, 2012 459–466
doi: 10.1111/j.1600‐0501.2011.02163.x