Magnet-Retained Two-Mini-Implant Overdenture: Clinical and Mechanical Consideration.

Two-implant overdentures have become the accepted treatment for restoring mandibular edentulism. The dimensions of regular implants sometimes limit their use, such as in the case of narrow ridges. Mini-implants with reduced diameters (less than 3.

Bone changes around hydroxyapatite and titanium implants after abutment placement in rabbits-observations using histological and three-dimensional examinations.

We have previously developed a computer-aided system for examination of the three-dimensional bone structure around implants and observed the bone changes in the healing period after implant placement. This paper describes the bone changes around hydroxyapatite (HA) and titanium (Ti) implants after abutment placement using histological and three-dimensional examinations. Twenty-four HA and Ti implants were embedded in the tibias of adult male New Zealand white rabbits.

Three-dimensional bone structure around hydroxyapatite and titanium implants in rabbits.

Long-term support of dental implants requires adequate bone thickness in the area surrounding the implant. A three-dimensional examination, including calculations of percent bone-implant contact and percent bone volume, was conducted to clarify the bone structure around pure titanium (Ti) and dense hydroxyapatite (HA) implants. The implants were installed in the tibiae of rabbits, and the bone structure was examined after 2, 4, 6 and 8 weeks.

Influence of bone quality on the stress distribution. An in vitro experiment.

Adequate bone quality and stress distribution to the bone are of decisive importance for implant success. The purpose of this in vitro study was to investigate the influence of bone quality on the stress distribution using 2 implant-bone mimicking models, simulating compact and cancellous bone quality. The resin model was made of an acrylic resin only simulating compact bone quality.

Three-dimensional examination of bone structure around hydroxyapatite implants using digital image processing.

This study introduced a new method for three-dimensional (3D) examination of the bone structure around an implant and presented 3D bone-implant contact rates. A block of nondecalcified implant tissue was ground gradually at an interval of 80 micrograms for the collection of serial two-dimensional (2D) images. An image of the stained block surface was instantly recorded by a charge-couple device (CCD) camera and computer-aided system.

In vitro study of mandibular implant-retained overdentures: the influence of stud attachments on load transfer to the implant and soft tissue.

This study investigated the occlusal stress distribution to the implant and soft tissue for the implant-retained overdenture. The stress at the molar residual ridge and the strain around the implant were measured on an experimental resin cast using static and dynamic loading. The influence of connecting structures of stud attachments on stress distribution was discussed.

Rapid bone resorption adjacent to hydroxyapatite-coated implants.

This paper describes rapid bone resorption in the peri-implantitis of HA implants based on both our clinical observations of and histological research on extracted dense hydroxyapatite (HA) implants. The surfaces of extracted HA implants were rough, although they were smooth at fixture placement. Plaque formed on the necks of the implants, whereas little plaque was seen on the bottoms.