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Biomedical subjects

L J Litkowski

Publications and source records attributed to L J Litkowski.

8 recordsLinked to original sources
PubMed1988

The effect of polishing pastes on composite resin surfaces. A SEM study.

CLINICALLY, COMPOSITE RESINS can be polished to a smooth surface at the time of placement using a variety of polishing methods. Subsequently maintaining the finish on recalls needs to be evaluated. The purpose of this investigation was to compare surface textures of a small particle composite resin (average particle size 5 microns) after polishing with prophylaxis and polishing pastes. Each specimen of the small particle composite resin, PrismaFil, was finished and polished to a smooth surface with Soflex discs. This was the control polish. The specimens were then polished with a rotating rubber prophylaxis cup with seven different prophylaxis and polishing pastes. All the samples were then prepared for scanning electron microscopy (SEM) evaluation and photographed at 750x to compare the effects of polishing on the surfaces of composite resins. SEM photographs were also made of a sample polished with Soflex discs (SF) and with a dry rubber cup (RC). The seven prophylaxis and polishing pastes were Command Ultrafine Lustre Paste (CULP), Coral Phosphate Prophylaxis Paste (CPPP), NuPro fine (NPF), NuPro medium (NPM), Prophydent (PD), Rembrandt Polishing Paste (RPLP) and Rembrandt Prophylaxis Paste (RPXP). The SEM photographs were rated by independent evaluators according to surface roughness from the smoothest to roughest surfaces. The results of the evaluator ratings determined that the composite resin surface gets rougher with the use of any polishing paste. The smoothest to roughest surface by groupings were: (SF)-(RPLP)-(CULP, RC)-(RPXP)-(NPF, CPPP, PD)-(NPM).

Composite Resins↗
PubMed1979

follicular fluid electrolytes and osmolality in cyclic pigs.

Sodium and osmolar concentrations of porcine folliclar fluid in the cyclic pig did not vary significantly during the oestrous cycle, and were similar to those in plasma. The K+ concentration was greater in small (Days 12-13) and medium-sized (Day 16) follicles than in plasma or large (Day 18-oestrus) follicles of cyclic sows. In contrast, follicular fluid obtained from slaughterhouse material had higher potassium and osmolality, and lower sodium values, which are assumed to be due to post-mortem changes.

Animals↗
PubMed1979

Effect of protein on titrimetry of bicarbonate, titratable acid, and ammonium in urine.

Measurement of bicarbonate, titratable acid (HTA+) and ammonium in the urine can facilitate clinical evaluation of acid-base status. Sequential measurement of these three components by titrimetric techniques is well established, but possible interference by proteinuria has not been examined. We report the influence on these analyses of albumin and globulin, two proteins commonly observed in urine in renal disease states. The presence of these proteins in urine affects the measurement of NH4+, and to a less extent that of HTA+. The magnitude of the effect depends on the concentration and the kind of protein present. Proteins do not influence the measurement of HCO3-.

Acid-Base Equilibrium↗
PubMedDate not supplied

Effect of two cavity designs on root surface marginal microleakage.

Current methods for bonding composite resins rely upon the etching of enamel to attain a bond that is strong enough to resist polymerization shrinkage and decrease the amount of marginal microleakage. Previously, modification of cavity designs have been evaluated that have enhanced retention. However, all these cavity designs have utilized methods to increase the surface area of enamel to bond thus resulting in a stronger enamel bond. This in vitro study evaluated the effect of one cavity design modification when the restoration is placed entirely on cemental surfaces and relied on only cementum and dentin.

Composite Resins↗
PubMedDate not supplied

Repair of porcelain/metal restoration with resin bonded overcasting.

Porcelain occasionally fractures from ceramometal fixed partial dentures following final cementation. Repair of these porcelain fractures can be a challenging task. When the problem occurs on anterior teeth, it is especially difficult because the repair must not only be durable, but esthetically pleasing as well. Although composite resins can be used for some repairs, it is often difficult to match the color and texture to the surrounding intact porcelain. In addition, the bonding between the resin and porcelain is susceptible to margin leakage, which may ultimately cause an esthetic failure. Techniques involving a cemented porcelain-fused-to-metal overcasting have often been successful in restoring the fixed partial denture to form and function. Although the esthetic result of a porcelain/metal overcasting can be quite successful, retention of the overcasting is sometimes poor. The compromised retention and resistance form is due to lack of interproximal walls on the underlying fractured unit. To improve the retention of the overcasting, the following technique of tin plating the overcasting and fractured unit prior to cementing with a composite resin cement is presented.

Dental Bonding↗
PubMedDate not supplied

Root surface marginal microleakage of composites: comparison of Cavosurface finishes.

The effect on microleakage of a modification of the cavosurface finish was evaluated using extracted thermalcycled teeth. Composite resin was placed in cavity preparations on root surfaces of teeth and finished to leave either a flash of material on the margin or finished flush to the margin. The teeth were thermalcycled for 10 days at 5 and 55 degrees C. The teeth were evaluated for microleakage using the silver nitrate staining procedure. Results showed a significant decrease in the amount of microleakage on the margins finished leaving a flash of composite resin. Clinical trials placing these restorations on root surfaces will be necessary to evaluate the impact on the periodontal health.

Composite Resins↗