Effect of microthread on the maintenance of marginal bone level: a 3-year prospective study.

OBJECTIVES The purpose of the present study was to evaluate the long-term effect of the microthread on the maintenance of marginal bone level. MATERIAL AND METHODS Seventeen patients were selected and two types of Astra Tech implants were installed, with the Microthread on the coronal portion of the fixture [Astra Tech Single Tooth Implant (ST)] or without the Microthread [Astra Tech TiOblast Implant (TB)]. ST and TB were installed adjacent to each other within the same partially edentulous sites and marginal bone loss was evaluated by radiographic image. The marginal bone-level alteration of the each fixture after prosthesis insertion was analyzed. RESULTS The marginal bone loss of ST and TB differed significantly during the observation period (P<0.01). Marginal bone levels of both ST and TB were stabilized after 1 year of lading. CONCLUSIONS The Microthread might have an effect in maintaining the marginal bone loss against loading.