all-bond-2 and tytin

Flat rectangular tabs (n = 270) prepared from spherical (Tytin), admixed (Dispersalloy) or lathe-cut amalgam (ANA 2000) were subjected to aluminum oxide sandblasting with either 50-mu or 90-mu abrasive powder. Mandibular incisor edgewise brackets were bonded to these tabs. An intermediate resin was used, either All-Bond 2 Primers A + B or a 4-META product--Amalgambond Plus (AP) or Reliance Metal Primer (RMP)--followed by Concise. All specimens were stored in water at 37 degrees C for 24 hours and thermocycled 1000 times from 5 degrees C to 55 degrees C and back before tensile bond strength testing. The bond strength of Concise to etched enamel of extracted, caries-free premolars was used as a control. Bond failure sites were classified using a modified adhesive remnant index (ARI) system. Results were expressed as mean bond strength with SD, and as a function relating the probability of bond failure to stress by means of Weibull analysis. Mean tensile bond strength in the experimental groups ranged from 2.9 to 11.0 MPa--significantly weaker than the control sample (16.0 MPa). Bond failure invariably occurred at the amalgam/adhesive interface. The strongest bonds were created to the spherical and lathe-cut amalgams (range 6.8 to 11.0 MPa). Bonds to the spherical amalgam were probably more reliable. The intermediate application of the 4-META resins AP and RMP generally created significantly stronger bonds to all three basic types of amalgam products than the bonds obtained with the All-Bond 2 primers. The effect of abrasive-particle size on bond strength to different amalgam surfaces was not usually significant (p > 0.05). The implications of these findings are discussed in relationship to clinical experience bonding orthodontic attachments to large amalgam restorations in posterior teeth.

Topics: Analysis of Variance; Dental Alloys; Dental Amalgam; Dental Bonding; Dental Stress Analysis; Dentin-Bonding Agents; Materials Testing; Methacrylates; Orthodontic Brackets; Resin Cements; Silver; Statistics, Nonparametric; Surface Properties; Tensile Strength

The aim of this study was to compare the fracture strengths of three restorative materials, a lanthanide reinforced composite (Ti-Core Natural), a silver amalgam (Tytin), and a hybrid glass ionomer (Advance), supported by either a multitiered, threaded split-shank post (Flexi-Flange) or with a dentin spur without a post.. A total of 60 recently extracted single-rooted human teeth were divided into six groups of 10. All groups were stored at 100% humidity at room temperature for 1 week before testing. Each specimen was placed in a special jig at a 45-degree angle to the buccolingual axis and subjected to a load that was recorded in pounds and converted to Newtons on a universal testing machine, with a crosshead speed of 0.63 cm/minute until failure. Two-way analysis of variance followed by the Newman-Keuls pairwise multiple comparisons test were used to compare the results.. There was a statistically significant difference between core materials (p < 0.001), but not regarding post conditions. Ti-Core Natural material had a significantly larger mean failure threshold for fracture than either Tytin silver amalgam or Advance material and the letter two core materials (Tytin and Advance) do not differ from each other. There was no statistical difference between Ti-Core material supported by a post and Ti-Core material supported without a post.

Topics: Analysis of Variance; Cementation; Composite Resins; Dental Alloys; Dental Amalgam; Dental Prosthesis Design; Dental Restoration Failure; Dental Stress Analysis; Dentin-Bonding Agents; Glass Ionomer Cements; Humans; Materials Testing; Metals, Rare Earth; Methacrylates; Post and Core Technique; Stress, Mechanical; Zinc Phosphate Cement

To determine whether the use of microetching and bonding agents could improve the shear bond strength between aged and freshly added dental amalgam, simulating an amalgam repair.. Aged amalgam surfaces were treated with either a carbide bur or carbide bur + microetcher (Al2O3 abrasive). Five commercially-available adhesive systems were tested. Fresh amalgam was condensed through a split mold onto each prepared amalgam surface. Two control groups were included: a positive control consisting of non-repaired amalgam, and a negative control consisting of aged specimens which received neither carbide bur nor microetching preparation prior to the addition of fresh amalgam. In addition, one group received only carbide bur and another received only carbide bur and microetching treatments, without any adhesive. Following storage and thermocycling, each specimen was tested for shear bond strength.. The mean shear bond strength of the repaired samples treated with carbide bur alone (25.8 MPa) was not exceeded by any of the other treatments. Neither microetching nor use of an adhesive agent significantly improved amalgam-to-amalgam shear bond strength. In some cases, use of an adhesive agent significantly decreased the shear bond strength of repaired amalgam samples.

Topics: Aluminum Oxide; Analysis of Variance; Composite Resins; Compressive Strength; Dental Alloys; Dental Amalgam; Dental Bonding; Dental Cements; Dental Polishing; Glass Ionomer Cements; Materials Testing; Mechanics; Methacrylates; Microscopy, Electron, Scanning; Tensile Strength

The purpose of this in vitro study was to determine the shear bond strengths (SBS) of amalgam to dentine treated with the Amalgambond Plus System (AM) and All-bond 2 System (AL) after storage periods in physiological saline for up to 48 weeks.. The occlusal superficial dentine surfaces of 150 extracted human molars were exposed by wet grinding on 600-grit silicon carbide and the bonding area demarcated with a perforated adhesive tape. Freshly mixed Tytin amalgam was transferred to the opening in a split Teflon mold on the demarcated dentine surfaces treated with either AM or AL as directed by the manufacturers. The SBS of AM after 24 h (A), 4 weeks (B), 12 weeks (C), 24 weeks (D), and 48 weeks (E), and of AL after 24 h (F), 4 weeks (G), 12 weeks (H), 24 weeks (I), and 48 weeks (J), were determined with a knife-edged rod at a crosshead speed of 0.5 mm/min and expressed in megapascal (MPa). The data were analyzed by ANOVA and Student's t-test.. The mean +/- SD of SBS in MPa were: A: 14.6 +/- 4.0; B: 14.5 +/- 3.6; C: 15.3 +/- 4.8; D: 14.6 +/- 4.6; E: 13.9 +/- 4.0; F: 9.5 +/- 4.7; G: 12.1 +/- 1.7; H: 10.2 +/- 3.5; I: 12.0 +/- 3.9; J: 11.9 +/- 3.5. The SBS of the five groups treated with AM (A, B, C, D and E) were not significantly different (P > 0.05) and the SBS of the five groups treated with AL (F, G, H, I and J) were not significantly different (P > 0.05). The SBS of A vs. F, B vs. G, ad C vs. H, were significantly different (P < 0.05), but D vs. I and E vs. J were not significantly different (P > 0.05).. The SBS of amalgam to dentine treated with AM and AL were not adversely affected by the duration of storage.

Topics: Analysis of Variance; Dental Alloys; Dental Amalgam; Dental Bonding; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Humans; Methacrylates; Stress, Mechanical; Surface Properties; Time Factors

To evaluate the effectiveness of the dentin bonding systems (DBS) Tenure, Syntac, Amalgambond and All-Bond 2 using a resin-lined amalgam technique in preventing short-term microleakage in Class V cavity preparations restored with a spherical and an admixed alloy.. Class V cavity preparations were made on the mesial and distal surfaces of non-carious human mandibular molars with the occlusal margins in enamel and gingival margins in cementum. Prepared teeth were randomly assigned to 12 treatment groups (n = 10) consisting of each DBS, no liner and Copalite for both amalgam alloys. Samples were thermocycled, stained and sectioned to evaluate microleakage.. The DBS-lined restorations had significantly less microleakage at both occlusal and gingival margins than the Copalite and unlined restorations. Among DBS, Syntac had significantly more microleakage with both alloys than either All-Bond 2 or Amalgambond. These results do not totally correlate to a previous study which used the same experimental design but included viscous liners in addition to the same DBS, indicating a potential difference between resin-lined versus resin-bonded amalgam techniques in preventing microleakage.

Topics: Analysis of Variance; Dental Alloys; Dental Amalgam; Dental Bonding; Dental Cavity Lining; Dental Leakage; Dental Materials; Dentin-Bonding Agents; Humans; Methacrylates; Resin Cements; Resins, Plant; Statistics, Nonparametric