Subjective and photometric determination of bleaching outcomes.

Objective: Subjective and objective measures were used to determine the relative efficacy of 10% and 35% carbamide peroxide gels in bleaching extracted human teeth.

Method And Materials: Fifty-five teeth (premolars and molars) were sectioned longitudinally, and one-half of each tooth was assigned to group A (10%) and the other half to group B (35%). Prebleaching shades were evaluated subjectively by 5 experienced observers using standard shade tabs.

Dentinal crack incidence following ultrasonic vibration to intra-radicular posts.

Objective: To determine the incidence of dentinal cracks on the root-face of extracted teeth containing intra-radicular posts subjected to prolonged ultrasonic vibration. Design & Setting This in-vitro experiment, conducted at the University of Manchester, UK, used post type and ultrasonic vibration as dependent variables.

Materials And Methods: Forty canine teeth were decoronated and root-filled with gutta-percha and sealer.

Effect of ultrasonic vibration on the retention of adhesively luted intra-radicular posts.

The aim of this study was to determine the effect of prolonged ultrasonic vibration on tensile force necessary to dislodge two different post types luted with an adhesive resin. Extracted human canine teeth were decoronated and root-filled. Either a ceramic or stainless steel intra-radicular post was luted into each root with resin-based cement.

Potential for temperature change during application of ultrasonic vibration to intra-radicular posts.

The aim of this study was to assess the potential for heat production when intra-radicular posts were subjected to ultrasonic vibration. Thirty zirconium ceramic posts and thirty stainless steel posts were luted into canine roots. Ultrasonic vibration was applied to the top of each post for thirty minutes and temperature change on the root surface was measured.