The fluoride (F) uptake by, and the appearance of polished human enamel which was exposed to topical F agents directly or via an artificial membrane was studied in vitro. The topical F agents used included Duraphat® varnish, Gelution® APF gel and an experimental alginate-based formula (EF), which were applied for 5 min. In addition, Duraphat was applied for 24 h and the uptake of F by sound enamel treated for 5 min with EF was tested. The uptake of F was assessed by three successive layers sampled from experimental and control enamel using the acid-etch technique. All topical F agents increased the F concentrations in almost all depths of the membrane-uncovered enamel and to a level significantly higher than in the control group. The F uptake by membrane-covered enamel was mostly confined to the first depth of 2.5 μm. Application of Duraphat for 24 h significantly increased the F concentration compared with 5 min of treatment (p < 0.01). Polished enamel acquired more F (40%) and dissolved in acid at a higher rate (45%) than sound enamel. There is no correlation between the F contents in the agents and enamel F uptake. After relating the data to the F contents in the applied agents, a strong correlation was found between F released by the dialysis system and F uptake by enamel. SEM examination revealed remnants of the applied agents on the enamel surface which were not removed by brief washing and the acid-etch procedures.

Mineral trioxide aggregate (MTA) has been found to be very biocompatible in a large number of studies. However, the handling properties can be challenging and research on modified materials to enhance placement are few. The purpose of this study is to compare a new faster setting, and more easily placed preparation with classic MTA in an animal model. Canine premolar teeth from two dogs were randomized and received quadrant surgery timed to allow 50 day and 98 day comparisons. Histologic and radiographic comparisons were made. Results were essentially equal in healing, even close to the materials.