Bond strength of compomers to human enamel.

The study evaluated the tensile bond strength between human enamel and seven compomer restorative systems under different bonding conditions. Seven compomers were bonded to human tooth structure with and without phosphoric acid etching of the bonding surface, with and without the use of their recommended combined primer and bonding agent and with both moist and wet bond interface environments. Overall, the highest bond strengths to human enamel were attained using phosphoric acid conditioning, primers and moist bonding surfaces.

Effect of finishing and polishing procedures on the surface roughness of packable composites.

This study examined the average surface roughness (Ra, micron) of three packable composites and one hybrid composite cured against mylar, before and after treatment with a fine finishing diamond bur, a resin finisher followed by fine and extrafine polishing paste, two silicone-based finishing and polishing systems, fine and super-fine aluminum-oxide polishing disks, a silicon carbide-impregnated polishing brush and a surface-penetrating composite sealant. Additionally, the Ra was examined for one of the packable composites before and after treatment with a finishing carbide, prior to the finishing and polishing procedures detailed above. The finishing diamond significantly increased the Ra for all composites (ALERT, SureFil, Solitaire and Z-100). The finishing carbide used with SureFil (SureFil + C) also increased the Ra; however, it also produced surfaces up to 3.5x smoother when compared to SureFil surfaces finished with the diamond. Overall, Sof-Lex Contouring and Polishing Discs were able to produce the smoothest surfaces, followed by the Jiffy Composite Polishing Cups, the Enhance Composite Finishing & Polishing System/Prisma-Gloss Composite Polishing Paste, the Diacomp Intra-Oral Composite Polishers and the Jiffy Composite Polishing Brushes, respectively. The smoothest surfaces were produced using Z-100, followed by SureFil + C (carbide finishing bur), Solitaire, SureFil and ALERT, respectively. In general, Protect-It Composite Surface Sealant had little effect on the Ra, except with ALERT, where a slight increase in Ra was observed.

Bond strength of compomers to dentin using acidic primers.

PURPOSE: To determine the in vitro bond strengths of seven compomer/bonding agent restorative systems to human dentin. MATERIALS AND METHODS: Seven compomer/bonding agents were bonded to human dentin, stored in water at 37 degrees C for 24 hours, and debonded in tension. Bonding conditions were with and without phosphoric acid etching, with and without the use of combined primer/bonding agents, and under moist and wet bond interfaces. RESULTS: Without phosphoric acid etching, F2000/F2000 Compomer Primer/Adhesive and F2000/Single Bond Dental Adhesive System were less sensitive to dentin wetness. With moist dentin, bond strengths of Dyract/Prime & Bond 2.1, Dyract AP/Prime & Bond 2.1, Hytac/OSB light-curing, one-component bonding agent, F2000/Single Bond, and Freedom/STAE single component light-cured dentin/enamel adhesive system, were improved with phosphoric acid etching. Also, with moist dentin, the bond strength of F2000/F2000 Compomer Primer/Adhesive in the 3M Clicker dispensing system was higher without phosphoric acid etching, whereas bonds of Compoglass/Syntac Single-component were not affected by phosphoric acid etching. Bonding did not occur without primer/bonding agent, regardless of surface condition or use of phosphoric acid etching.

Bond strength of composites to hybrid ionomers.

Tensile bond strengths among three different hybrid ionomers and two different hybrid composites were evaluated. With one exception, bond strength to a high-modulus composite (Z-100) was higher than that to a low-modulus composite (Charisma). Thermocycling lowered the bond strength of Charisma, whereas storage for 3 months increased the bond strength of Z-100 compared to storage for 24 hours. Etching the hybrid ionomers with phosphoric acid had no effect on bond strength.

Performance of composite finishing and polishing instruments after sterilization.

PURPOSE: To evaluate the performance before and after sterilization of Enhance and Min-Identoflex finishing and polishing systems on TPH and Z100 composites. MATERIALS AND METHODS: Finishing and polishing instruments consisted of a light-cured resin cup impregnated with an abrasive and a silicon dioxide impregnated rubber cup. Sterilization methods included microwaving and autoclaving. RESULTS: Performance of the finishing and polishing instruments were affected more by the composite being finished and polished than by autoclaving or microwaving.

Surface roughness of composites and hybrid ionomers.

This study examined the average surface roughness (Ra, micron) of two composites and three different hybrid ionomers before and after treatment with a 12-fluted finishing bur, two finishing and polishing systems, and a hybrid-ionomer glaze for the hybrid ionomers. The 12-fluted finishing bur produced a roughened surface with all materials compared to the initial surface formed and cured against glass. Both the Enhance Finishing and Polishing System and the Sof-Lex contouring and polishing disks produced smoother surfaces for the composites, Revolution and Charisma, compared to the hybrid ionomers, Fuji II LC, Variglass, and Vitremer. However, the Fuji II LC glaze and the Vitremer glaze created smoother surfaces compared to Revolution finished with the Enhance system. Overall, the Sof-Lex disk system produced the smoothest surfaces for all materials.

Disinfection and sterilization of composite polishing instruments.

PURPOSE: To evaluate the efficacy of several methods of sterilization and disinfection on two different types of composite finishing and polishing instruments. MATERIALS AND METHODS: The instruments consisted of a proprietary light-cured resin cup impregnated with an abrasive and a silicon dioxide-impregnated rubber cup. Chemical and physical methods included treatment with iodophor, synthetic phenol, glutaraldehyde, microwaving, autoclaving, and chemiclaving. RESULTS: Glutaraldehyde (Vital Defense-S) was an effective disinfectant; however, other chemical (cold) disinfectants overall, were not reliable. Autoclaving, chemiclaving, and microwaving all provided to be effective means of sterilization.

Surface roughness of opalescent porcelains after polishing.

Intraoral porcelain polishing is an important consideration in many restorative and esthetic procedures. Several porcelain polishing systems as well as improved ceramics are now commercially available. This study evaluated the efficacy of eight different intraoral polishing techniques on three opalescent porcelains. The surface roughness (Ra) of the opalescent porcelains were measured before and after the polishing procedures with a profilometer. These results were then compared to self-glazed and overglazed control groups. Five of the techniques tested produced surfaces smoother than glazing. The use of a 30-fluted carbide bur before diamond polishing paste produced the smoothest surfaces.

Bond strength of resin cements to microfilled composites.

The in vitro bond strengths of three resin cements and a light-cured and a laboratory-processed micro-filled composite were measured. Effects of two surface treatments, and three bond enhancers were analyzed. Resin cements were bonded to sandblasted composite substrates, stored at 37 degrees C in 100% humidity overnight, and debonded in tension. An analysis of variance revealed significant differences among bond strengths. Overall, the composite substrate had the largest effect on bond strength, followed by bond enhancer, cement and, finally, surface treatment. Mean bond strengths ranged from 0.9 to 13.6 MPa. A combination of Concept, Dual Cement, phosphoric acid and Silane produced the lowest mean bond strength (0.9 MPa), while EOS, Dual Cement, hydrofluoric acid, and Heliobond produced the highest recorded mean bond strength (13.6 MPa). In general, the highest bonds were produced using the light-cured composite (EOS), the acrylic monomer (Special Bond II) or the dimethacrylate monomer (Heliobond), the adhesive cement (CR Inlay Cement), and surface treatment with hydrofluoric acid (Comp-Etch). Most of the bond failures (86%) with the laboratory-cured microfilled composite were adhesive. With the light-cured composite, 69% of the failures were mixed adhesive-cohesive types.

Bond strength of resin cements to a hybrid composite.

Tensile bond strengths among three resin inlay cements and a light-cured and a post-cured hybrid composite prepared with two different surface treatments and three different bond-enhancing liquids were measured in vitro. The resin cements were bonded to sandblasted hybrid composite, stored at 37 degrees C in 100% humidity overnight, and debonded in tension. Interfacial bond strengths were affected most by the type of pre-bond surface treatment. Hydrofluoric acid produced weaker bond strengths than surface treatment with phosphoric acid. Post-cured Herculite XRV produced weaker bond strengths than the light-cured Herculite XRV. Porcelite cement produced the highest bond strengths. Of the surface enhancers, the acrylic monomer (Special Bond II) produced the highest bond strengths, regardless of which cement or surface preparation was used. Fracture analysis revealed mostly adhesive failures with hydrofluoric acid treatment in both light-cured and post-cured Herculite.

Quantitative analysis of six composite polishing techniques on a hybrid composite material.

Determining the best technique for finishing and polishing composite resins is important to ensure longevity of the restoration and prevention of recurrent decay and periodontal disease. This study quantitatively compared the surface roughness of a small particle hybrid composite material finished and polished using six different techniques. Five composite samples were randomly assigned to one of six polishing techniques. Uniform composite surfaces were prepared by finishing samples with a 600-grit carborundum disk prior to polishing. The unpolished surfaces were analyzed with the Taylor-Hobson Talysurf 10 surface texture measuring instrument. The surfaces were then polished and analyzed again. There were no statistical differences among treatment groups prior to polishing. There was a statistical difference between treatment groups after polishing. The smoothest surfaces were obtained using Centrix System rubber points alone, Centrix System rubber points plus Caulk's Prisma Gloss fine and super-fine pastes, and Caulk's Enhance disks plus Caulk's Prisma Gloss fine and super-fine pastes. There was no statistical difference between these methods and 3M Sof-flex disks alone. The roughest surface was produced by the Enhance disks only without using the Prisma Gloss pastes. There was no statistical difference between this method, however, and the use of Sof-flex disks plus Kerr's Lustre Paste. Lustre Paste, included with Herculite kits, did not improve a surface polished with Sof-flex disks.

A comparative study of fluoride release from glass-ionomer cements.

This study compared the amounts and patterns of fluoride release from 11 commercially available glass-ionomer cements into artificial saliva over an 84-day period. The results indicated that the materials differed in the amount of fluoride released, and that Miracle Mix released the highest cumulative total of fluoride over the test period. Along with old Fuji II, Miracle Mix also released the most fluoride during the last time interval (56 to 84 days). All of the materials released the greatest proportion of their cumulative total fluoride in the first 24 hours after mixing.

Fluoride release from light-cured liners.

This study compared the relative amounts and patterns of fluoride release from six commercially available light-cured liners in artificial saliva over a 28-day period. Cavalite and two Zionomer products released relatively small amounts of fluoride. Timeline and XR Ionomer released the highest cumulative total of fluoride over time. During the last time interval (14-28 days), Timeline released the greatest amount of fluoride. Patterns of fluoride release for all materials were similar with the largest proportion of the total fluoride release being in the first 24-48 hours, followed by a dramatic reduction in release rate.