Materials Testing

Aim  To evaluate marginal seal, water sorption, solubility and loss of mass after brushing of several temporary filling materials.Methodology  For marginal seal, Class I cavities, including endodontic access preparations, were made in human molar teeth and restored using one or other of several temporary filling materials (n = 10): zinc oxide/calcium sulphate-based cement (Cavit, 3M,ESPE, St. Paul, MN, USA), zinc oxide/eugenol cement (IRM, Dentsply Caulk, Milford, DE, USA), glass ionomer cement (Vidrion R, SSWhite, Rio de Janeiro, RJ, Brazil) or a dimethacrylate-based filling (Bioplic, Biodinâmica, Londrina, PR, Brazil). Dye penetration was assessed after thermocycling and immersion in 0.5% basic fuchsine solution. For water sorption, solubility and loss of mass analyses, disc-shaped specimens were made. Water sorption and solubility were evaluated by mass alteration after storage in distilled water for 7 days (n = 7). Loss of mass was calculated based on the difference of mass after abrasion with a toothbrush (n = 5), and surfaces were analysed by SEM. Data of water sorption, solubility and loss of mass were submitted to anova and Tukey’s test, and marginal sealing data to Kruskal–Wallis test (P < 0.05).Results  Statistically significant differences were observed for marginal sealing (P < 0.0001), water sorption (P < 0.01), solubility (P < 0.01) and loss of mass (P < 0.05). Bioplic had the best marginal seal. Cavit had the greatest water sorption and solubility. Vidrion R and Bioplic had the lowest solubility. Loss of mass after brushing was higher for Cavit, followed by Bioplic, IRM and Vidrion R. Cavit and Vidrion R were worn aggressively by brushing.Conclusions  The resin-based temporary filling Bioplic produced the best marginal seal, and was associated with the lowest water sorption, solubility and loss of mass.

Biological debris between modular components using Morse tapers in hip arthroplasty can lead to weakening of the implant construct. We conducted a study to determine the effect of blood and fat within the taper interface. Tapers were divided into groups 1 (clean), 2 (surface covered with blood and fat), and 3 (blood and fat wiped off). Each taper was impacted and disassembled 5 times. There was a difference in mean disassembly force between pulls within group 2. Thus, blood and fat contamination can have a significant effect on the potential for disassembly.

The aim of this study was to assess in vitro the influence of the CO2 laser and of the type of ceramic bracket on the shear bond strength (SBS) to enamel. A total of 60 enamel test surfaces were obtained from bovine incisors and randomly assigned to two groups, according to the ceramic bracket used: Allure (A); Transcend (T). Each group was divided into 2 subgroups (n = 15): L, laser (10W, 3s); C, no laser, or control. Twenty-four hours after the bonding protocol using Transbond XT, SBS was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. After debonding, the Adhesive Remnant Index (ARI) was evaluated at 10 x magnification and compared among the groups. Data were analyzed by one-way ANOVA, Tukey&#39;s, Mann-Whitney&#39;s and Kruskal-Wallis tests (α = 0.05). Mean SBS in MPa were: AL = 0.88 ± 0.84; AC = 12.22 ± 3.45; TL = 12.10 ± 5.11; TC = 17.71 ± 6.16. ARI analysis showed that 73% of the specimens presented the entire adhesive remaining on the tooth surfaces...

The aim of this study was to evaluate the accuracy of three implant transfer impression techniques. Four groups (n = 5) were defined, according to the technique: TC - tapered copings without splint; SC - square copings without splint; SCS - square copings splinted with dental floss and acrylic resin, and CG (control group) - master model with four external hexagonal implants and a superstructure. Individual trays and polyether were used for the impression. All casts were checked for their fit into the master superstructure; for this, all four screws were placed in the implants. Digital photos were taken and images were analyzed using UTHSCSA ImageTool software. Statistical analyses were performed using one-way analysis of variance and Student&#39;s t test (p &lt; 0.05). The means and standard deviation were (µm): CG = 2.03 ± 0.00, TC = 14.74 ± 3.41, SC = 12.08 ± 2.56, and SCS = 6.51 ± 0.09. The control group was found to be statistically different from the TC and SC groups. Within t...

ABSTRACTPurpose:: The purpose of this study was to determine the wear resistance of five different packable composites versus two different composite controls using a laboratory toothbrushing simulation test.The purpose of this study was to determine the wear resistance of five different packable composites versus two different composite controls using a laboratory toothbrushing simulation test.Materials and Methods: Twelve samples measuring 5 mm in diameter and 3 mm thick were prepared from the following resin composites: Packable resin composites SureFil® (Dentsply Ind. Com. Ltda, Petrópolis, Rio de Janeiro, Brazil), Alert® (Jeneric Pentron Incorporated, Wallingford, CT, USA), Filtek P60™ (3M ESPE Dental Products, St. Paul, MN, USA), Prodigy Condensable® (sds Kerr, Orange CA, USA), Solitaire® (Heraeus Kulzer GmbH, Wehrheim, Germany), and control resin composites Z100 Restorative™ (3M ESPE) and Silux Plus™ (3M ESPE). Finishing and polishing were conducted with Sof-Lex™ disks (3M ESPE), and baseline weight (grams) and surface roughness (measured with Hommel Tester® T 1000, Hommelwerke, GmbH, Alte Tuttinger Strebe 20. D-7730 VS-Schwenningen, Germany) were recorded. Specimens were aged for 2 weeks until they reached a weight that remained constant for 5 consecutive days, and then were subjected to 100,000 cycles of brushing (representative of 4.2 yr) using a toothbrushing testing machine. Toothbrush heads with soft bristle tips (Colgate Classic™, Colgate-Palmolive Co., Osasco, São Paulo, Brazil) with dentifrice suspension (Colgate MFP™, Colgate-Palmolive Co.) in deionized water were used under a 200 g load. Changes in weight and surface roughness were determined after toothbrushing cycles.Twelve samples measuring 5 mm in diameter and 3 mm thick were prepared from the following resin composites: Packable resin composites SureFil® (Dentsply Ind. Com. Ltda, Petrópolis, Rio de Janeiro, Brazil), Alert® (Jeneric Pentron Incorporated, Wallingford, CT, USA), Filtek P60™ (3M ESPE Dental Products, St. Paul, MN, USA), Prodigy Condensable® (sds Kerr, Orange CA, USA), Solitaire® (Heraeus Kulzer GmbH, Wehrheim, Germany), and control resin composites Z100 Restorative™ (3M ESPE) and Silux Plus™ (3M ESPE). Finishing and polishing were conducted with Sof-Lex™ disks (3M ESPE), and baseline weight (grams) and surface roughness (measured with Hommel Tester® T 1000, Hommelwerke, GmbH, Alte Tuttinger Strebe 20. D-7730 VS-Schwenningen, Germany) were recorded. Specimens were aged for 2 weeks until they reached a weight that remained constant for 5 consecutive days, and then were subjected to 100,000 cycles of brushing (representative of 4.2 yr) using a toothbrushing testing machine. Toothbrush heads with soft bristle tips (Colgate Classic™, Colgate-Palmolive Co., Osasco, São Paulo, Brazil) with dentifrice suspension (Colgate MFP™, Colgate-Palmolive Co.) in deionized water were used under a 200 g load. Changes in weight and surface roughness were determined after toothbrushing cycles.Results: Significant differences of weight loss and surface roughness were found (paired t-test, p < .05). Weight loss percentage (mean [SD]) ranged from 0.38 to 1.69% (analysis of variance and Tukey's least significant difference, p < .05); the weight loss of the materials ranked from least to most as follows: SureFil (0.38 [0.56]), Alert (0.52 [0.18]), Z100 (1.16 [0.27]), Filtek P60 (1.31 [0.17]), Solitaire (1.51 [0.45]), Prodigy Condensable (1.55 [0.47]), and Silux Plus (1.69 [0.66]). Regarding surface roughness, Prodigy Condensable (0.19 [0.08]), Solitaire (0.28 [0.06]), and Z100 (0.30 [0.07]) became less rough after toothbrushing, whereas all the others were rendered rougher: Alert (0.49 [0.29]), Filtek P60 (0.28 [0.08]), Silux Plus (0.39 [0.09]), and SureFil (0.81 [0.32]).Significant differences of weight loss and surface roughness were found (paired t-test, p < .05). Weight loss percentage (mean [SD]) ranged from 0.38 to 1.69% (analysis of variance and Tukey's least significant difference, p < .05); the weight loss of the materials ranked from least to most as follows: SureFil (0.38 [0.56]), Alert (0.52 [0.18]), Z100 (1.16 [0.27]), Filtek P60 (1.31 [0.17]), Solitaire (1.51 [0.45]), Prodigy Condensable (1.55 [0.47]), and Silux Plus (1.69 [0.66]). Regarding surface roughness, Prodigy Condensable (0.19 [0.08]), Solitaire (0.28 [0.06]), and Z100 (0.30 [0.07]) became less rough after toothbrushing, whereas all the others were rendered rougher: Alert (0.49 [0.29]), Filtek P60 (0.28 [0.08]), Silux Plus (0.39 [0.09]), and SureFil (0.81 [0.32]).Conclusion: SureFil and Alert were statistically more resistant to wear (less weight loss) than were the other materials. SureFil became significantly rougher than did all the others.SureFil and Alert were statistically more resistant to wear (less weight loss) than were the other materials. SureFil became significantly rougher than did all the others.