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Biomedical subjects

F Barbakow

Publications and source records attributed to F Barbakow.

At least 55 records · Page 3Linked to original sources

Quality and durability of marginal adaptation in bonded composite restorations.

Excellent marginal adaptation extends the longevity of restorations. Unfortunately, polymerization shrinkage of composite restorations adversely affects this quality requirement. The residual stress within the cured resin compromises the material's properties, causes marginal openings, and flexes cavity walls. In this study, the wall-to-wall contraction in MOD cavities was measured for different placement techniques. In addition, the restoration margins were quantitated before and after thermo-cycling and mechanical stressing. Factors which enhanced adaptation also optimized marginal quality and reduced the amount of residual stress. The latter was expressed by intercuspal narrowing after the restoration was completed. Both quality and stress resistance of the marginal adaptation were inversely correlated to the intercuspal narrowing caused by the polymerization contraction of bonded and excellently adapted resin restorations. The most effective factors which optimized marginal quality included: guidance of the shrinkage vectors; reducing the ratio of bonded to free, unbonded restoration surfaces; and minimizing the mass of in situ-cured composite. The latter principle was followed best in the adhesive inlay technique. In medium-sized adhesive MOD composite inlays, the volume loss induced by the polymerization contraction of the composite cement was non-destructively compensated for by an inward flexing of each cavity wall of approximately 10 microM.

Composite Resins↗

Enamel remineralization: how to explain it to patients.

The term remineralization of initial enamel caries is frequently used, but mainly at research conferences and in lecture rooms. Clinicians avoid discussing remineralization and white-spot enamel lesion formation with patients because details of the processes are complex. Patients, therefore, incorrectly assume that cavitation occurs right at the onset of caries and that a restoration must be placed to halt further progression of the lesion. Although laboratory and clinical studies have shown that initial white-spot enamel lesions can remineralize, patients have little or no access to this information. The schematic diagrams in this paper explain the diffusion of organic acids from plaque between enamel crystals, the partial loss of mineral from enamel crystals, and subsequent demineralization and remineralization that produces the white-spot lesion. Further, these diagrams may help clinicians explain remineralization as simply as possible to patients who present with white-spot enamel lesions.

Dental Caries↗

CAD-CAM ceramic inlays and onlays: a case report after 3 years in place.

At least three different techniques are available for preparing computer-aided designed (CAD) and computer-aided manufactured (CAM) inlays and veneers. This paper details a clinical case in which 13 Cerec CAD-CAM inlays have been functioning for 3 years. Advantages and limitations of this system are discussed.

Adult↗

[Dental calculus-inhibiting tooth pastes and mouthwashes. A review of the literature of clinical trials].

Several brands of anticalculus dentifrices and mouthrinses claim to reduce the formation of supragingival calculus. These products contain soluble pyrophosphates (with or without Gantrez), zinc citrate trihydrate or zinc chloride which reduce the amount of supragingival but not subgingival calculus after a scaling. Most of the clinical anticalculus trials ran for 3 or 6 months and the calculus reductions were assessed using the Volpe-Manhold Index. This index assesses the coronal extension of supragingival calculus. Calculus reductions varied from 9% to 50% but no plaque scores were quantitated. However, the ADA has stipulated that dentifrices claiming anticalculus effects must clearly state that the products have not therapeutic effect on periodontal diseases. Some of the placebo dentifrices used in the clinical trials also reduced the calculus scores although they are not as yet advertised as anticalculus dentifrices.

Clinical Trials as Topic↗

Dentin abrasion (RDA), enamel abrasion (REA) and polishing scores of dentifrices sold in Switzerland.

Assessments of the abrasion of hard dental tissues produced by different dentifrices are usually carried out on extracted teeth in the laboratory. The tests most commonly used to measure dentifrice abrasion on dentin and enamel are the radiotracer (radio-active) and profilometry methods. The radiotracer dentin (RDA) and enamel (REA) abrasion scores of the 32 dentifrices were determined using the ADA specifications. RDA and REA scores are related to a standard abrasive, calcium pyrophosphate (Ca2P2O7), which is assigned a score of 100 for the RDA method and 10 for the REA method. The same abrasive was used as the standard in the enamel polish study and assigned a score of 100. The RDA scores of the dentifrices tested varied from 37 to 203, the REA scores from 1.0 to 11.7, and the polishing scores ranged from 19.63 to 96.88. Half the dentifrices tested had RDA scores below 100.

Dental Enamel↗

No effect of waxed dental floss on enamel fluoride uptake or on enamel dissolution changes.

Enamel specimens were flossed in vitro with "waxed" dental floss and then treated with water, Act, Meridol, or Elmex Gel to evaluate the effect of "waxed" floss on the enamel fluoride uptake and on the enamel dissolution rate. The flossed and treated enamel was etched 4 times successively in 2N HCl for 5, 10, 15 and another 15 s. The concentrations of fluoride, calcium and phosphorus were assayed in the etching solutions. The enamel fluoride concentration was significantly increased in only the first layer of the Elmex Gel group compared to the other 3 groups. Respective etching depths were similar for the water, Act and Elmex Gel groups. However, the first layer in the Meridol group was less etched than that in the 3 other groups. This study showed that "waxed" dental floss did not compromise the fluoride uptake by surface enamel after treatment with a concentrated acidic topical fluoridating agent. Moreover, previously reported results showing that Meridol solution containing SnF2 and amine fluoride 297 significantly decreased the in vitro dissolution rate of enamel were confirmed by the present study. Even though the enamel was first treated with "waxed" dental floss, the SnF2/amine fluoride 297 still produced a decreased enamel dissolution rate.

Acid Etching, Dental↗