ABSTRACT
The purpose of this study was to compare the shear bond strength of a resin composite to air abraded and not air abraded enamel and dentin surfaces, and to evaluate the need for acid conditioning before the application of a single component adhesive. Enamel (E) and dentin (D) flat surfaces were obtained from a pool of recently extracted human teeth (30 incisors and 30 molars) and prepared with different treatments with and without the application of air abrasion (AA) and phosphoric acid (PA). Composite samples were bonded to the surfaces and stored in distilled water at 37 degrees C. After 24 hours, shear bond strength tests were carried out with an Instron machine and the results were subjected to statistical analysis. Maximum bond strength was obtained in the E + AA + PA group (34.74 MPa--2.70), followed by: E + PA (31.26 MPa--1.87); D + PA (24.09-1.72); D + AA + PA (20.61 MPa--1.79); D + AA (8.96 MPa--0.82) and E + AA (7.17 MPa--1.75). The results were significantly lower in those groups that were not acid conditioned (P < 0.01). The bond strength of composite to enamel was slightly increased as a result of the combination of AA with PA. However, the opposite effect was observed on dentin surfaces. Acid etching is a necessary clinical step even on air abraded surfaces.
ABSTRACT
The adherence of microorganisms to dentin that had been contaminated and then treated with conditioning substances was evaluated. The germicide effect of those products and their possible substantivity was also evaluated. Dentin slices were contaminated with Candida albicans, Streptococcus mutans and Actinomyces naeslundii and then treated with the following substances: 1. Experimental Blue Solution A, 2. Experimental Red Solution B; 3 Tubulicid Blue Label; 4. Tubulicid Red Label; 5 Scotchprep Dentin Primer; 6 ventura Dentin Bond Cleaner; 7 ventura Dentin Bond Primer, 8. Gluma dentin Bond; 9 Tenure Conditioner; 10. All Bond Dentin Conditioner; 11 Syntac Primer; 12. Clearfil New Bond acid + adhesive; 13 Prisma Universal Bond 3 Primer; 14. Denthesive Cleaner; 15. Control (Distilled water). Adherence was evaluated using scanning electron microscopy and viability tests were performed. Substances 1, 2, 3, 4, 5, 7, 8, and 11 impair adherence; the control and substances 6 and 9 produced no afforded intermediate results effect while substances 10, 12, 13 and 14. Viability tests afforded results similar to those obtained for adherence. Several substances that are used for dentin treatment or for dentin priming for adhesion could be useful in preventing microorganism viability and so contribute to the protection of pulp vitality.
ABSTRACT
Dentin treatment before adhesion of composites is performed both to enhance adhesion and to remove the microbial contents of the smear layer. The purpose of these experiments was to evaluate the germicide potential of several dentin treatments used in adhesive systems and of some cleansing solutions. Different germs involved in caries processes were used (Candida Albicans, Streptococcus mutans and Actinomyces naeslundii) to prepare suspensions. Half a milliliter of each of the suspensions was transferred to test tubes and an equal volume of the following substances was added: Scotch Prep Dentin Primer (P), Gluma Cleanser (G), Cleaner Sol. (C), Tubulicid Blue (TB) and Red Label (TR), Blue Experimental Solution (SB) and Red Experimental Solution (SR) and sterile distilled water (control). The preparation was incubated at 37 degrees C for seven days to test viability. P, TR, TB and SB produced complete inhibition of germs tested. The results reveal that, [quot ]in vitro[quot ], not all the substances tested exert a germicide effect on the microorganisms analyzed.
ABSTRACT
The object of this paper is to evaluate the marginal filtration occurring between restoration/teeth in cavities filled with silver alloy when using different cavity varnish and adhesives. In 50 teeth removed as a result of decay, cavities were prepaired on vestibular faces and were divided into 5 equal groups: Group A: with no caviti varnish; Group B: two coats of a linkin agent (Scotch Bond 3M); Group C: an amalgam liner base (Voco); Group D; two coats of copal varnish: Group E: an amalgam bond base (Carl San Remo, Germany). All groups were filled with a silver alloy. The teeth were inmersed in a fuchsin solution at different temperatures (17.37 degrees C and 50 degrees C) for 20 minutes. Longitudinal cuts were made for visualization under a stereoscopic magnifying glass. Each group was observed by five odontologists and was classified according to four categories: Grade I: no filtration: Grade II: less than 1/3 wall filtration; Grade III: more than 1/3 wall filtration; Grade IV: filtration in walls and floor. Teeth with pulp filtration were discarded. Total and percentage values were determined for each analysed group. The results revealed that: Group A: 100
of samples corresponds to Grade IV. Group B: 40
of sample falls within Grade II while the rest corresponds to the highest grade. Group C: 30
belongs to Grade II, 60
to Grade III and the remaining 10
falls within Grade I, while the remaining 20
correspond to Grades III and IV, respectively. Group E: 50
for Grade I and the rest in Grade II.(ABSTRACT TRUNCATED AT 250 WORDS)