John A Hobkirk

Learn More
Relative movement and force transmission between osseointegrated (OI) implants in the premolar regions of the edentulous mandible have been measured using intraoral transducers linked to OI implants. These have shown deformations of up to 420 microns and force transmission of up to 16 N as a result of jaw movement from the rest position. Greater(More)
PURPOSE The purpose of this study was to measure medial convergence, dorsoventral shear, and corporal rotation in the human mandible. MATERIALS AND METHODS Measurements were made using custom-fabricated strain gauge displacement transducers in 6 edentulous subjects who had been treated with mandibular endosseous dental implants. These were mounted on the(More)
Masticatory forces associated with porcelain and acrylic resin occlusal surfaces on osseointegrated implant-supported prostheses opposing natural teeth were studied in five healthy subjects. A three-channel electronic force transducer carrying a fixed prosthesis with either acrylic resin or porcelain occlusal surfaces and balanced articulation was used to(More)
PURPOSE Mandibular deformation during function in patients with implant-supported prostheses is associated with increased strain at the bone-implant interface when dental implants are connected by a relatively rigid superstructure. Whilst there is a body of evidence concerning deformation as measured between the corpora, there are little data on its effects(More)
Forces exerted on the right and left lingual and buccal flanges of Kennedy Type I mandibular dentures were studied using an 8 channel recording technique, during resting, swallowing, talking, reading and simulated mastication. The effects of adaptation, head position and incremental thickening of the flanges were determined. Highest forces were recorded(More)
PURPOSE This study investigated the changes that might occur in passive tactile sensibility during a period of 3 months following Implant placement in a group of edentulous subjects treated with dental implants. The effect of changing the velocity of force application on passive tactile sensibility was also investigated. MATERIALS AND METHODS Five(More)
The forces distributed on six Nobelpharma implants were analyzed by strain gauges fixed to various implant combinations that were placed in a replica of a human edentulous mandible and connected to a cast gold alloy superstructure. The mandible was supported on its lower border and the superstructure loaded in different locations. Although force(More)
This in vivo study examined forces exerted during the recording of impressions of dentate maxillary arches. This study consisted of 10 subjects; four impression materials in metal stock trays and disposable plastic trays were used. The load rate and the maximum insertion and removal forces were measured with strain gauges mounted on the tray handles. The(More)
There is considerable debate as to the effects of using bridges which are supported simultaneously by teeth and implants, due to the marked differences in their displaceability. This in-vivo experiment was carried out on three subjects, and measured the vertical and horizontal movement of implants and teeth, linked with a fixed superstructure, when this was(More)
  • 1