Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dentin Permeability”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1993

Obturation of dentinal tubules with tannin-fluoride preparation (HY agent) incorporated into glass ionomer cement.

The degree of obturation of dentinal tubules as well as the dentinal uptake of F, Zn and Sr was investigated after placement of glass ionomer cement (GIC) containing variable proportions of the tannin-fluoride preparation, HY agent, into freshly prepared cavities. It was found that when HY agent was incorporated into the cement powder, there was both increase in electrical resistance in the dentinal floor of the GIC-restored cavity in addition to inhibition of dye penetration. Further, these changes were directly proportional to the concentration of HY agent. Electron probe microanalysis of the principal constituents of HY agent (F, Zn and Sr) revealed that the penetration depth for F and Zn was also directly proportional to the relative amount of incorporated HY agent, whereas Sr could not be detected regardless of HY concentration. Results clearly demonstrated that the higher the concentration of HY agent incorporated into GIC, the greater the degree of dentinal tubular obturation.

Animals↗
PubMed1994

Intracoronal bleaching: concerns and considerations.

The history of intracoronal bleaching and the development of the walking bleach technique are reviewed. External cervical resorption associated with intracoronal bleaching is a serious sequela that has been reported in the literature. One explanation given for this phenomenon is that it results from an inflammatory process initiated by the presence of bleaching agents in the attachment apparatus. The basis for this conclusion is discussed. A review of published case reports on external cervical resorption associated with intracoronal bleaching revealed that: 100 per cent of the affected teeth had no intermediate dental base placed, 84 per cent were treated with a thermocatalytic technique, 80 per cent were bleached after the root canal sealer was fully set and 72 per cent had a history of trauma before bleaching. Based on these observations, it should be possible to safely bleach teeth intracoronally provided specific concerns and considerations are taken into account. These are: 1) the use of heat should be avoided; 2) an intermediate dental base should be placed with due respect to the attachment level; and 3) a base should be selected with due respect to its effectiveness in sealing tooth structure.

Borates↗
PubMed1995

Dentinal diffusion of hydroxyl ions of various calcium hydroxide pastes.

The aim of this study was to analyze in vitro the dentinal diffusion of hydroxyl ions of calcium hydroxide pastes, prepared with different acid-base vehicles, in an inert nitrogen atmosphere. Sixty maxillary incisors with mature apexes were selected and after access and root canal preparation each root was filled with calcium hydroxide pastes prepared with different vehicles: saline solution, anesthetic and polyethylene glycol 400. The roots were then sectioned 2 mm from the apical vertex and the teeth mounted in the center of a round platform, filled with saline solution up to 2 mm from the root tip. The platforms remained inert in an atmosphere of nitrogen, completely sealed, in the absence of light and with a constant temperature of 36.5 degrees C. Diffusion analysis of the hydroxyl ions was carried out by a colorimetric method on days 7, 15, 30, 45 and 60. Calcium hydroxide pastes prepared with saline solution and anesthetic showed a pH change of 5-7 to 7-8 after 30 days, remaining at this level at 60 days. In the polyethylene glycol 400 group, the same alteration occurred at 45 days, and continued at 60 days.

Calcium Hydroxide↗
PubMedDate not supplied

In vivo adhesive interface between resin and dentin.

V-shaped cervical cavities prepared in monkey teeth were restored with several dentin bonding systems, and the in vivo resin-dentin interfacial structures were observed under the scanning electron microscope using an argon-ion etching technique. The hybrid layer could be clearly observed; its depth was dependent on the conditioner/primer used and tended to be thinner at the deep part of the cavity. Resin tags were also clearly observed, and their structure at the inner part was noted to be rougher than that closer to the tubule orifices. When 37% phosphoric acid gel was used, the tags in the deeper parts of the cavity were much rougher. Hemispherical and spherical roughened structures were observed directly above the tubule orifices, which were thought to be a mixture of dentinal fluid and bonding resin that had flowed out from the tubules. The acidic primer containing maleic acid and HEMA could not remove the smear plugs, and undissolved smear particles were observed in the tubules.

Acid Etching, Dental↗
PubMed1996

Heat propagation in dentin during instrumentation with different sonic scaler tips.

It is important to know how much heat is generated when a root surface is debrided with sonic scalers and if that heat can be released satisfactorily into the environment. The temperature changes that occurred in dentinal specimens treated with two different sonic scaler tips, used with and without coolant, were studied. Temperature increases of up to 4 degrees C were observed for both tips when a coolant was used. Heat propagation during instrumentation was dependent to a considerable degree on the temperature of the coolant. Sonic scalers should not be used without coolant, because the dentinal temperature may increase up to 35 degrees C, depending on the force of application. A high positive linear correlation was found between increase in temperature and force of application.

Dental High-Speed Equipment↗
PubMed1994

In vitro action of various bleaching agents on the microhardness of human dentin.

The authors verified a decrease in human dentin microhardness after application of the following bleaching agents for 72 hours: sodium perborate+water, sodium perborate + 3% hydrogen peroxide, sodium perborate + 30% hydrogen peroxide, Endoperox (crystallized hydrogen peroxide), Proxigel (carbimide peroxide), and 30% hydrogen peroxide. Sodium perborate+water and sodium perborate + 3% hydrogen peroxide caused less of a decrease in dentin microhardness than Endoperox, Proxigel and 30% hydrogen peroxide which caused the greatest decreases in dentin microhardness. Sodium perborate + 30% hydrogen peroxide fell into a statistically intermediate position.

Analysis of Variance↗
PubMedDate not supplied

In vitro caries inhibition effects by conventional and resin-modified glass-ionomer restorations.

The ability of a material to inhibit recurrent caries formation is an important clinical therapeutic property. The objectives of this study were to develop an initial anticariogenicity profile (from fluoride release, to fluoride uptake, to resistance to an artificial caries challenge), testing the ability of conventional versus resin-modified glass-ionomer restorations to resist decay, and to study the effect of using intermediary dentin bonding agent components on the development of surface and wall carious lesions adjacent to a resin-modified glass-ionomer restoration. Cumulative fluoride release was measured from the immersion of disk-shaped specimens into deionized distilled water for 24 hours, 1, 2, 4, and 10 weeks. For the fluoride uptake and artificial caries test, standardized restorations were placed along the cementoenamel junction of extracted human molars. Secondary ion mass spectroscopy was used to determine the depth of fluoride uptake into the adjacent axial dentin from the restoration after 1 and 10 weeks. For the artificial caries test, the teeth were immersed into an acidified gelatin gel, pH 4.0, for 10 weeks. The development of recurrent decay was assessed using polarizing light microscopy. Statistical analyses were conducted using ANOVA and Fishers' LSD test (P < or = 0.05). There was generally greater fluoride release and uptake from the conventional glass ionomers, equivalent or less from the resin-modified glass ionomers, and none from the resin composite restorations. The use of an acid conditioner and primer from a dentin bonding system significantly increased the depth of fluoride uptake at 1 week. The additional use of an intermediary adhesive resin layer, however, significantly decreased the depth of fluoride uptake. The maximum depth of fluoride uptake into dentin was 300 microns at 10 weeks. Both conventional and resin-modified glass-ionomer restorations imparted resistance to dentin against the development of recurrent wall carious lesions in vitro. This was attributed to material fluoride release and uptake.

Cariostatic Agents↗