The effect of a NaF solution and a fluoride varnish on the acid resistance of root dentin

Effect of 4% titanium tetrafluoride application on shear bond strength of composite resin: An in vitro study

AIMS

The objective of thisstudy is to evaluate and compare 4% titanium tetrafluoride with 2% Sodium fluoride, and the bond strength of composite resin with dentin and their effects on the smear layer.

MATERIALS AND METHODS

Fifty freshly extracted non-carious molar and premolar teeth were selected. The occlusal surfaces of the teeth were ground, to prepare flat dentin surfaces at a depth of 2 mm and were randomly grouped with 10 specimens in each. Group I (Etching + Adhesive + Composite resin) was taken as a control group. In Group II, 4% titanium tetrafluoride was applied before etching and in Group III, 4% titanium tetrafluoride was applied after etching. In Group IV, 2% Sodium fluoride was applied before etching and in Group V, 2% Sodium fluoride was applied after etching. Shear bond strength was tested using the Lloyds Universal testing machine and was recorded in MPa.

RESULTS

The results were statistically analyzed using the one-way Anova test. Group III showed the highest bond strength among the experimental groups, but less than the control group.

CONCLUSIONS

Under the conditions of this in vitro study, titanium tetrafluoride did not significantly affect the bond strength of the composite. Sodium fluoride was found to deleteriously affect the bond strength of the composite.

In vitro fluoride uptake by enamel and dentin. A comparative study of two varnishes

The uptake of fluoride in enamel and dentin after application of an experimental fluoride varnish has been studied and compared with the uptake from a commercially available varnish (Duraphat). Each varnish was applied to 10 extracted human cuspid teeth. Successive etchings with perchloric acid were carried out separately in enamel and root dentin to obtain samples at three different depths. The concentrations of fluoride and calcium in the samples were determined, and the fluoride uptake was calculated. The experimental varnish gave a significantly greater fluoride uptake at all three sample depths in both enamel and dentin.

Effects of TiF4 solutions on root surfaces in vitro after different application periods

Topical application of aqueous solutions of TiF4 to root surfaces has been shown to result in a rapid uptake of fluoride. The purpose of this study was to assess whether the application period and/or the ionic strength of the TiF4 solution can be reduced without a corresponding reduction in the fluoride uptake. Root halves from human teeth were exposed to (a) 1% TiF4 for 10 sec and 1, 2, and 4 min, and (b) 3.4% TiF4 for the same application periods. Root surface areas protected by nail polish served as controls. Transverse ground sections through the treated root surface areas were then prepared and analyzed for F by electron microprobe analysis. Most treated specimens showed F concentrations in the 0.60-1.94% range, whereas control surfaces contained less than 0.30%. Similar F concentrations were found in the surfaces treated with the two solutions. Reducing the application period resulted in a shallower penetration of F into the hard tissue but only a slight reduction of the F concentration in the surface layer. High concentrations of Ti were found on the surface of all treated specimens. This shows that both the application period and the ionic strength of TiF4 solutions can be considerably reduced and still enable a high uptake of fluoride. The results indicate that TiF4 may be an efficacious agent for F application to root surfaces under clinical conditions.