Amalgam Strength Resistance to Various Contaminants.

PURPOSE:: The purpose of this study was to quantify the relative strength tolerance of 1-day and 30-day amalgam following saturation contamination with water, saliva, blood, and handpiece lubricant oil during condensation. METHODS AND MATERIALS:: Valiant PhD XT amalgam was tested with 300 shear-strength (N=15) and 120 compressive-strength (N=6) specimens, divided into 1-day and 30-day groups, each with control, water, saliva, blood, and lubricant oil contamination samples. Shear specimens were condensed in 4 × 4-mm anchor wells inundated with contaminant fluids before adding a ring mold with 3.5-mm-diameter central hole adapted immediately to the top for continued condensation under contaminant-submerged conditions. Compressive specimen samples were condensed while completely inundated by each contaminant using the American Dental Association Specification No. 1 amalgam mold apparatus. All specimens were tested with the Instron E3000 and E10000 at 0.5 mm/min, with data statistically evaluated using the Kruskal-Wallis procedure with IBM SPSS v25 and Wilcoxon signed ranks test. RESULTS:: Shear test values (mean±SD) following intracapsular and extracapsular contamination after 30 days under 100% humidity at 37°C were as follows: control, 30.97±5.41 MPa; water, 30.63 ±4.41 MPa; saliva, 27.54 ±4.56 MPa; blood, 24.92 ±3.48 MPa; lubricant oil, 26.06 ±4.06 MPa. Compressive strengths (±SD) of similarly contaminated samples were as follows: control, 447.7 ±76.3 MPa; water, 343.6 ±70.1 MPa; saliva, 307.7 ±24.0 MPa; blood, 281.6 ±35.2 MPa; lubricant oil, 227.8 ±16.9 MPa. CONCLUSIONS:: Saliva, blood, and handpiece oil diminish compressive strength significantly, but water shows no statistically significant effect ( p>0.05). Amalgam 30-day shear strength is significantly altered by contamination with water, blood, or handpiece lubricant oil ( p<0.05). Remaining amalgam strength after extensive contamination may still be clinically functional relative to a previous ADA recommendation and when compared with resin-based direct restorative materials.

Experimental initial partial polymerization method for Fuji II placement evaluated for microleakage with/without Fuji Coat.

PURPOSE: This laboratory study evaluated an experimental 1-second initial partial polymerization (IPP) technique using Fuji II LC vs the manufacturer's standard placement (control), both with and without Fuji Coat, relative to microleakage. METHODS: Class V restorative preparations were placed on the buccal and lingual aspects of 30 permanent, caries-free and restoration-free, third molar teeth. Fuji II LC restorations were placed either following manufacturer-specified guidelines or IPP for 1 second prior to contouring and full light curing. Half of the restorations were placed using the IPP experimental technique and half of the teeth were finished using Fuji Coat LC. Following thermocycling, specimens were sectioned and dye penetration was measured. SPSS 16 was used for statistical analysis (p<0.05). RESULTS: Mean microleakage results: experimental/varnish (0.08 ± 0.15 mm), control/varnish (0.17 ± 0.35 mm), experimental/nonvarnish (0.33 ± 0.33 mm), and control/nonvarnish (0.58 ± 0.47 mm). Univariate analysis of variance demonstrated significantly less microleakage for the experimental technique (p<0.001), use of finishing varnish (p<0.001), and the combination of experimental/varnish (p=0.013). CONCLUSIONS: The initial partial polymerization technique of Fuji II LC placement significantly reduces microleakage. Fuji Coat LC results in further diminished microleakage.

Choose a practical dental title slide film processing system.

The basic 35-mm camera equipped with a 90-, 100-, or 105-mm macro lens, which is already used in many dental offices, has the potential to create good title slide transparencies for use in study club presentations, table clinics, and academic lectures. Several photographic film products are now available that place this well regarded medium of dental education within the capability of the average motivated practitioner. In this overview, Kodalith, Versicolor SO-279, PolaBlue, Polachrome HCP, and Polagraph systems are analyzed and compared for time efficiency, cost effectiveness, and quality of slides produced.