Comparison of the adhesive strength of a BIS-GMA cement to tin-plated and non-tin-plated alloys

Effect of Sulfur-Containing Primers for Noble Metals on the Bond Strength of Self-Cured Acrylic Resin

This study investigated the effect of sulfur-containing primers for noble metals on the shear bond strength of self-cured acrylic resin after thermal cycling (TC). Four pure metals (Au, Ag, Cu, and Pd) and type IV Au alloy were either untreated, or treated with one of the five sulfur-containing metal primers (V-Primer, Metaltite, Alloy Primer, Metal Link Primer, and Metal Primer Z). Afterwards, a brass ring was placed on the metal surface and filled with self-cured acrylic resin (n = 10). The bond strengths were measured after 24 h (TC0) and after 2000 thermal cycles at 4–60 °C (TC2000). Three-way ANOVA and Tukey compromise post hoc tests were used to analyze the data (α = 0.05). All of the sulfur-containing primers significantly improved the resin bond strength as compared to that of the non-primed group at TC0 regardless of the metal type (p < 0.05). However, at TC2000, the bond strengths between the resin and the five metals significantly decreased with respect to the values obtained at TC0 regardless of the primer (p < 0.05). The sulfur-containing metal primers, except for Metal Link Primer, were found to be more effective for improving the bond strength between the self-cured acrylic resin and Ag as compared to the other three pure metals (p < 0.05). The bond strengths between the resin and Au and type IV Au alloy at TC2000 were the highest ones when Metal Primer Z was used.

Evaluation of shear bond strength of composite resin bonded to alloy treated with sandblasting and electrolytic etching

Conservation of natural tooth structure precipitated the emergence of resin-retained fixed partial dentures. The weakest link in this modality is the bond between resin cement and alloy of the retainer. Various alloy surface treatment have been recommended to improve alloy-resin bond. This in vitro study was carried out to observe changes in the Nickel-Chromium alloy (Wiron 99, Bego) surface following sandblasting or electrolytic etching treatment by scanning electron microscope (SEM) and to evaluate the shear bond strength of a resin luting cement bonded to the surface treated alloy. 80 alloy blocks were cast and divided into four groups of 20 each. In groups-A & B, the test surfaces were treated by sandblasting with 50 and 250 μm sized aluminium oxide particles respectively. In groups-C & D, the test surfaces were first treated by sandblasting with 50 and 250 μm sized aluminium oxide particles respectively followed by electrolytic etching. Test surfaces were observed under SEM at 1,000× magnification. Two alloy blocks of each group were luted together by a resin luting cement (Rely X, 3M) and their shear bond strength was tested. The mean shear bond strength in MPa of groups-A to D were 6.44 (±0.74), 8.18 (±0.51), 14.45 (±0.59) and 17.43 (±1.20) respectively. Group-D showed bond strength that is more than clinically acceptable bond strength. It is recommended that before luting resin-retained fixed partial dentures, the fitting surface of the retainer should be electrolytically etched to achieve adequate micromechanical retention.

Synthesis of novel acryloyloxyalkyl and methacryloyloxyalkyl 6,8-dithiooctanoates and evaluation of their bonding performances to precious metals and alloys

This study investigated the bonding effectiveness of novel acryloyloxyalkyl and methacryloyloxyalkyl 6,8-dithiooctanoates (dithiooctanoate monomers) to precious metals and alloys. Eight kinds of dithiooctanoate monomers were synthesized in 16.09-39.34% yields. They were characterized and confirmed as new compounds using (1)H- and (13)C-NMR spectroscopy and mass spectral analysis. Eight experimental primers each containing 5.0 wt% of a novel dithiooctanoate monomer in acetone were prepared. After primer treatment and 2,000 thermal cycles, tensile bond strengths of MMA-PMMA/TBBO resin to seven metal adherends were measured. Results were as follows: 17.2-29.3 MPa (Au), 41.9-49.6 MPa (Ag), 36.8-47.6 MPa (Pt), 36.7-47.5 MPa (Pd), 34.0-48.9 MPa (Au alloy), 24.3-49.6 MPa (Ag alloy), 35.0-48.8 MPa (Au-Ag-Pd alloy). 10-Methacryloyloxydecyl 6,8-dithiooctanoate exhibited the highest mean bond strength to gold (29.3 MPa) and 12-methacryloyloxydodecyl 6,8-dithiooctanoate to Au alloy (48.9 MPa). Therefore, it was found that the novel dithiooctanoate monomers synthesized in this study exhibited excellent bonding to precious metals and alloys.

Shear bond strength between different materials bonded with two resin cements

BACKGROUND

The aim of this study was to compare the shear bond strength between Ni-Cr alloy specimens bonded to air-abraded Ni-Cr, bur-abraded Ni-Cr, etched ceramic and etched enamel substrates using the resin cements RelyX ARC or Enforce.

MATERIALS AND METHODS

Ni-Cr specimens were made and sandblasted with Al(2)O(3) airborne-particles. Disc-shaped patterns were made for each of the four experimental substrates: Ni-Cr treated with Al(2)O(3) airborne-particles, Ni-Cr treated with diamond bur abrasion, etched enamel and etched ceramic.

RESULTS

Significant differences in shear bond strength were found between the different materials and luting agents evaluated. The Ni-Cr alloy cylinders bonded to Ni-Cr surfaces sandblasted with 50 μm Al(2)O(3) particles and bonded with Enforce achieved the highest bond strength when compared with other substrates (28.9 MPa, p < 0.05). Bur-abraded metal discs had lowest values, regardless the cement used (2.9 and 6.9 MPa for RelyX and Enforce, respectively). Etched enamel and etched ceramic had similar shear bond strengths within cement groups and performed better when RelyX was used.

CONCLUSIONS

Bonding Ni-Cr to Ni-Cr and ceramic may result in similar and higher bond strength when compared to Ni-Cr/enamel bonding. For metal/metal bonding, higher shear bond strength was achieved with resin cement Enforce, and for metal/ceramic and metal/enamel bonding, RelyX had higher results.

Effect of the combination of dithiooctanoate monomers and acidic adhesive monomers on adhesion to precious metals, precious metal alloys and non-precious metal alloys

This study investigated the effect of the combination of a dithiooctanoate monomer and an acidic adhesive monomer on adhesion to precious metals, precious and non-precious metal alloys. From a selection of four dithiooctanoate monomers and six acidic adhesive monomers, 14 experimental primers containing a combination of 5.0 wt% of a dithiooctanoate monomer and 1.0 wt% of an acidic adhesive monomer in acetone were prepared. Tensile bond strengths (TBSs) of MMA-PMMA/TBBO resin to nine kinds of precious metals, precious metal alloys, and non-precious metal alloys after 2,000 thermal cycles were measured. Results showed that there were no significant differences in TBS among the primers to all the precious and non-precious metal adherends tested (p>0.05). Highest TBS values (46.5-55.8 MPa) for bonding to Au alloy, Au-Ag-Pd alloy, Co-Cr alloy, and Ni-Cr alloy were achieved with the primer which contained 5.0 wt% 10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT) and 1.0 wt% 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA). Therefore, 5.0 wt% 10-MDDT and 1.0 wt% 6-MHPA was determined as the optimal combination for bonding to precious metals, precious and non-precious metal alloys.

Surface characterization of precious alloys treated with thione metal primers

OBJECTIVES

To characterize the effect of two thione metal primers with phosphate groups on the surface morphology and composition of two noble prosthodontic alloys.

METHODS

Cast specimens from Argen 81(Au-Pd) and Argipal (Hi-Pd) alloys which were ground, polished and ultrasonicated in water, were divided in two groups (2 x 3) and treated with single layers of Alloy Primer (AP) and Metal Primer II (MP) primers respectively. The treated alloy surfaces were washed off with acetone and then examined by polarized light microscopy (PLM), reflection FTIR microspectroscopy (FTIRM) and X-ray photoelectron spectroscopy (XPS).

RESULTS

After AP treatment, PLM revealed a crystalline phase (VBATDT) dispersed in an amorphous phase (MDP plus soluble VBATDT) on both the alloys tested. MP demonstrated a fibrial arrangement with the most dense structure found on the Hi-Pd alloy. FTIRM failed to clearly resolve the presence of SH peaks on alloy surfaces. Moreover, NH and PS peaks were identified denoting the presence of original thione tautomers. In both primers, phosphates were detected in a dissociative state (-PO(3)(2-)). FTIR molecular mapping confirmed separation of VBATDT from MDP and MEPS from residual MMA. XPS showed that on alloy surfaces approximately 50% of sulphur was in the sulphide state, the rest being organic sulphur. AP showed higher sulphide percentage than MP on both alloys and higher sulphide percentage on the Au-Pd alloy (p<0.05).

CLINICAL SIGNIFICANCE

Phase separation of the primer components on alloy surfaces may adversely affect their clinical performance. Sulphide formation on alloy surfaces was confirmed only by XPS under ultra-high vacuum and not by environmental techniques like FTIR; this poses serious questions on the chemical bonding capacity of these primers with the noble alloys tested under environmental conditions.

Influence of metal cleaning methods on the resin bond strength to NiCr alloy

OBJECTIVES

The purpose of this laboratory study was to evaluate the influence of different metal cleaning methods on the bond strength of various resin bonding systems and its durability to a NiCr alloy. The hypothesis was that the resin bond strength and its durability is related to the cleaning method and to the bonding system used.

METHODS

Plexiglas tubes filled with composite resin were bonded to NiCr disks using three different bonding systems: tribochemical silica-coating and silanization of the alloy, acrylization of the alloy, or bonding with a phosphate monomer containing composite resin. For each bonding system, three cleaning methods were used after the last air abrasion step: cleaning with a stiff brush, ultrasonic cleaning in alcohol or in a neutral detergent. For each combination 20 samples were bonded. Subgroups of 10 bonded samples were tested for tensile strength following storage for either 3 or 150 days. In addition, the 150-day samples were thermal cycled 37,500 times. The statistical analyses were made by ANOVA, followed by multiple pair-wise comparison of the groups using Scheffe and t-tests with Bonferroni-Holm correction.

RESULTS

The mean tensile bond strengths ranged from 34.8 to 49.2 MPa after 3 days and from 2.1 to 43.1 MPa after 150 days. Acrylization of the alloy did not provide durable bond strength to NiCr alloy over storage time. Cleaning the alloy surface with alcohol provided statistically significant higher bond strength than the other cleaning methods after 3 days.

SIGNIFICANCE

Alloy cleaning methods after air abrasion have a significant influence on the resin bond strength.

An in vitro comparison of tensile bond strengths of noble and base metal alloys to enamel

STATEMENT OF PURPOSE

Many different surface treatments have been used to increase the bond strength of noble and base metal alloys to enamel, but only a few have been studied.

PURPOSE

The purpose of this in vitro study was to compare the tensile bond strength of a tin-plated noble alloy, an Alloy Primer-treated noble alloy, and an airborne particle-abraded base metal alloy, all bonded to enamel with a phosphate-methacrylate resin luting agent.

MATERIAL AND METHODS

Seventy noncarious molar teeth were extracted, cleaned, and embedded in autopolymerizing acrylic resin with the buccal surface of the teeth exposed. Seventy wax patterns (4-mm diameter x 2-mm thickness) were waxed, invested, and cast-50 with a noble alloy (Argedent 52) and 20 with a base metal alloy (Argeloy N.P.). Twenty of the noble alloy specimens were tin-plated (TP), 20 noble alloy specimens were treated with Alloy Primer (AP), and 20 base metal alloy specimens were airborne particle abraded (AA). All specimens were luted with a phosphate-methacrylate resin luting agent (Panavia F) and stored in 100% humidity at 37 degrees C, half for 24 hours and half for 7 days. Ten noble alloy specimens were tin-plated and stored in water for 48 hours (aged) before cementation and then stored in water for 24 hours after cementation. These specimens were used to test whether there is an advantage to aging the tin-plated surface in water before cementation. All specimens were thermocycled (5 degrees to 55 degrees C) for 500 cycles and then tested for tensile bond strength (TBS), measured in MPa, with a universal testing machine at a crosshead speed of 0.5mm/min. Various castings (n=6 per test group) were randomly selected from each group and inspected under a scanning electronic microscope to determine mode of failure. The mean values and standard deviations of all specimens were calculated for each group. A 2-way analysis of variance (ANOVA) was performed, and multiple pairwise comparisons were then completed with post hoc Tukey test (alpha=.05).

RESULTS

The TBS of the tin-plated noble alloy specimens bonded to enamel (24 hours: 9.33 +/- 1.31 MPa; 7 days: 11.65 +/- 1.55 MPa) was significantly greater than the Alloy Primer noble alloy specimens (24 hours: 6.11 +/- 1.01 MPa; 7 days: 5.45 +/- 1.22 MPa) (P <.001). The Alloy Primer noble alloy group showed the lowest TBS compared with the tin-plated noble alloy and airborne particle-abraded base metal alloy group (24 hours: 10.61 +/- 1.41 MPa; 7 days: 6.94 +/- 1.40 MPa). The tin-plated noble alloy specimens showed greater TBS after storage for 7 days in distilled water compared with storage for 24 hours (24 hours: 9.33 +/- 1.31 MPa; 7 days: 11.65 +/- 1.55 MPa). Aging the tin-plated noble alloy for 48 hours in 37 degrees C (9.17 +/- 1.68 MPa) prior to cementation did not increase the TBS to enamel. The airborne particle-abraded base metal alloy showed significantly lower TBS at the 7-day storage time compared to the 24-hour storage time (24 hours: 10.61 +/- 1.41 MPa; 7 days: 6.94 +/- 1.40 MPa) (P <.001). SEM examination of the debonded metal and enamel surfaces showed mixed (adhesive and cohesive) failures for all groups.

CONCLUSION

Tin-plating a noble alloy produced the highest bond strength to enamel. Storing the tin-plated noble alloy in 37 degrees C distilled water for 48 hours before cementation did not result in a change in TBS. Using an Alloy Primer with a noble alloy resulted in statistically significant lower TBS than tin-plating.

A comparison of 3 alloy surface treatments for resin-bonded prostheses

PURPOSE

The most frequent cause of clinical failure of resin-bonded fixed partial dentures is a debonding at the metal-cement interface. The purpose of this in vitro study was to compare the tensile bond strengths of 3 different alloy-surface treatments when cemented to human enamel with a resin cement.

MATERIALS AND METHODS

Cylinders of a nickel-chromium-beryllium (Ni-Cr-Be) and a gold-palladium (Au-Pd) alloy were fabricated and assigned to different surface treatment groups as follows: Group 1: Ni-Cr-Be, chemically etched; Group 2: Au-Pd, airborne particle-abraded and tin-plated; and Group 3: Au-Pd, airborne particle-abraded and treated with the Alloy Primer (Kuraray Co, LTD, Osaka, Japan). The cylinders were bonded to the enamel surfaces of extracted, human third molars and stored in normal saline at 37 degrees C for 48 hours. The tensile bond strength of 21 specimens from each group was measured on a Universal Testing Machine (Instron, Canton, MA). Three failed specimens of each group were evaluated using scanning electron microscopy and energy dispersive spectroscopy.

RESULTS

Statistically significant differences (p <.05) were found between all 3 treatment groups. The mean tensile bond strengths (+/- the standard error of mean) recorded as follows: Group 1: 10.6 MPa (+/-1.3), Group 2: 0.9 MPa (+/-0.2), and Group 3: 13.4 MPa (+/-1.0). Specimens from groups 1 and 3 revealed a trend towards mixture of cohesive, within the resin cement, and adhesive failures at the metal-cement interface. Group 2 specimens exhibited primarily adhesive failures at the metal-cement interface.

CONCLUSIONS

The tensile bond strength of Au-Pd alloy specimens was significantly increased with the Alloy Primer.

Effect of three adhesive primers on the bond strengths of four light-activated opaque resins to noble alloy

The effect of commercial adhesive primers for noble metals on the bond strength of light-activated opaque resin has not been determined. This study evaluated the effect of three adhesive primers on the shear bond strengths of each of the four light-activated opaque resins to silver--palladium--copper--gold (Ag--Pd--Cu--Au) alloy. The adhesive primers Alloy Primer (AP), Metal Primer II (MPII) and Metaltite(MT) were used. Four commercial light-activated opaque resins (Axis (AX), Cesead II (CEII), Dentacolor(DE) and Solidex (SO) were used to bond a light-activated resin-veneered composite to Ag--Pd--Cu--Au alloy. The specimens were stored in water at 37 degrees C for 24 h and then immersed alternatively in water baths at 4 and 60 degrees C for 1 min each for up to 20,000 thermal cycles before shear mode testing at a cross-head speed of 0.5 mm min(-1). All the primers examined improved the shear bond strength between opaque resin and Ag--Pd--Cu--Au alloy compared with non-primed specimens prior to thermal cycling. After 20,000 thermal cycles, the bond strengths of combined use of AP and DE and that of MT and each of AX, CE or DE were significantly greater than any other groups. Significant difference was observed between the bond strengths at thermal cycles 0 and 20,000, with the combined use of MT and DE. With the combination of appropriate adhesive metal primers and light-activated opaque resins, complicated surface preparations of metal frameworks of resin-veneered prostheses that are composed of casting Ag-Pd-Cu-Au alloy may be negligible.

Effectiveness of metal surface treatments in controlling microleakage of the acrylic resin-metal framework interface

STATEMENT OF PROBLEM

Microleakage at the junction between the metal alloy and acrylic resin in a removable partial denture may result in discoloration, fluid percolation, and acrylic resin deterioration. The junction between a metal alloy and acrylic resin is an area of clinical concern. Failure of a removable partial denture may be linked to this interface. Enhancing resistance to microleakage at this interface may improve the long-term union between the 2 materials.

PURPOSE

This investigation was designed to determine the effects of various metal surface treatment protocols on microleakage and bond strength between the metal alloy and acrylic resin used in the fabrication of a removable partial denture.

MATERIAL AND METHODS

Ninety-six nickel-chromium-beryllium alloy specimens were randomly divided into 8 groups. After adaptation of baseplate wax, each specimen was invested. Subsequent to wax removal, each specimen was divided into a control half and an experimental half. Air abrasion, tinplating/oxidation, and silanation were evaluated individually and in all combinations. Heat-polymerized acrylic resin was processed against all specimens before storage in distilled water at 37 degrees C for 72 hours. Each specimen then was thermocycled in distilled water (3000 cycles) before immersion in sodium fluorescein dye for 24 hours. Counting grids that exhibited dye penetration under ultraviolet light exposure allowed assessment of microleakage.

RESULTS

Air abrasion resulted in a significant decrease in microleakage when used individually and in all combinations (P<0.05). All experimental combinations that did not involve air abrasion demonstrated no significant reduction in measured microleakage between the experimental and control sides. Tukey's pair-wise comparison of the difference in the mean number of squares exhibiting microleakage between the control and treated sites for each experimental group revealed a significant difference, based on the involvement of air abrasion. Groups involving air abrasion did not differ significantly from each other (P<0.05). In addition, no significant difference was detected between groups not involving air abrasion (P<0.05).

CONCLUSION

Air abrasion, alone and in combination with tinplating/oxidation and with silanation, resulted in a significant reduction in microleakage between the metal alloy and acrylic resin.

Effect of a new metal primer on the bond strength between a resin cement and two high-noble alloys

STATEMENT OF PROBLEM

With the development of new adhesive resin cements, the question of surface treatment of noble metal castings with primers has become an important issue.

PURPOSE

This study compared the tensile bond strength and its durability of a new metal primer (Alloy Primer, Kuraray) to 2 noble metal alloys (Au-Ag-Cu-Pt and Au-Pt-Pd-Ag-In).

MATERIAL AND METHODS

Sixty cast disk specimens of each alloy were polished, grit blasted with 50 microm Al(2)O(3), and ultrasonically cleaned in 96% isopropanol. Then, they were either nonprimed or primed only with the Alloy Primer or Alloy Primer combined with ED Primer (Kuraray). Plexiglas tubes filled with self-curing composite resin (Clearfil FII, Kuraray) were bonded to the metal samples with the use of an alignment apparatus and a self-curing luting cement (Panavia 21 Ex). The samples were stored in water, either for 3 days with no thermal cycling or for 150 days with 37,500 thermal cycles. After the different storage conditions, the tensile bond strengths of the specimens were determined.

RESULTS

The mean bond strengths increased over storage time for all groups, except for the grit-blasted Au-Pt-Pd-Ag-In group. However, only in the grit-blasted and the primed groups for the Au-Ag-Cu-Pt alloy was this increase significantly different (P<.01). After 150 days of storage, the mean bond strength to Au-Ag-Cu-Pt alloy was 38.8 MPa without priming, whereas it was 40.6 to 40.8 MPa with the use of the primers. After the same time, the mean bond strength to the Au-Pt-Pd-Ag-In alloy was 20.6 MPa without priming, whereas it was 31. 9 to 37.8 MPa with the use of the primers. When comparing the different bonding methods and different storage times for the alloys, the superiority of the usage of both primers in combination was determined. Conclusion. The tested Alloy Primer significantly improved the bond strength of the dental adhesive resin cement (Panavia 21 Ex) to noble alloys. However, this effect depended on the alloy composition and was much greater for the Au-Pt-Pd-Ag-In alloy than for the Au-Ag-Cu-Pt alloy.

Strengths of composite bonded to base metal alloy using dentin bonding systems

STATEMENT OF PROBLEM

Many different bonding systems are currently available that may be used to bond composite to base metal alloy.

PURPOSE

This study measured and compared bond strengths of composite with a base metal alloy using 8 modern dentin bonding systems.

MATERIAL AND METHODS

Base metal alloy buttons were imbedded in acrylic and ground with 120, 400, and 600 grit sandpaper, respectively. Metal surfaces were air abraded for 5 seconds with 50 microm aluminum oxide, washed for 5 seconds under running tap water, then dried with compressed air. Specimens were arbitrarily divided into 8 groups of 10 specimens. Each group was treated with 1 of 8 dentin bonding regimens. A hybrid composite (Herculite) was placed onto the treated metal surface and light polymerized. Specimens were incubated at 37 degrees C in distilled water for 2 hours. Shear bond strengths were measured and the collected data subjected to an ANOVA, followed by multiple t -tests.

RESULTS

All-Bond 2 exhibited the highest mean shear bond strength and Panavia 21 with primer had the lowest in the tests conducted.

CONCLUSION

All-Bond 2 demonstrated significantly higher shear bond strengths over all materials tested, except 3M Single Bond and Optibond FL. No significant difference was noted between the single component and the multicomponent bonding systems.

New method for the in vitro evaluation of dental alloy bonding systems

STATEMENT OF PROBLEM

Bonding systems are used in some fixed prosthetic devices with base alloys. However, different studies of the same dental alloy bonding agents, under similar circumstances, have yielded disparate results in bond strength testing.

PURPOSE

This study compared directly 2 dental alloy bonding systems through a "duel" type of confrontation, which basically is a 2-way tensile force test.

MATERIAL AND METHODS

Ninety Wiron 88 base alloy cylinders (diameter of 8 mm length 15 mm) were sandblasted on both sides with Al(2)0(3) powder (particle size 50 microm) during 10 seconds at an approximate distance of 5 mm, at an air pressure of 60 psi determined before sandblasting procedures. The surface of each cylinder was cleaned from Al(2)0(3) powder with a strong burst of oil-free air from a chairside air syringe. Thirty cylinders were randomly assigned to 1 of 3 groups for direct bond strength comparison: (1) Panavia 21 to Panavia EX, (2) Panavia 21 to Metabond, or (3) Panavia 21 to a combination of a resin bonding agent plus Panavia 21. Each group was composed of 10 specimens that used 3 cylinders for each specimen. Each side of the sample cylinder received the same quantity of cement and 1 cylinder at a time was bonded to it. Cylinder alignment was verified with a Boley gauge during luting procedures. The bonded 3-piece block was held together for 24 hours under a compressive force of 2 kg/cm(2) using a hydraulic press. Excess cement was removed with a brush, and the pertinent air sealant was applied to allow for autocuring of the cement. Specimens were later stored in water at room temperature for 48 hours before thermocycling procedures. Each specimen was thermocycled for 100 cycles with a 5-minute dwelling time in water at 4 degrees C and 60 degrees C. Specimens were subject to tensile force testing until debonding in 1 of the cylinders.

RESULTS

The opposing pull duel test (OPDT) showed that the Panavia EX failed (40. 3 MPa) 10 of 10 duels against Panavia 21, whereas Panavia 21 failed (49.7 MPa) 9 of 10 duels against Metabond, and Panavia 1 failed (50. 1 MPa) 10 of 10 duels against Photobond+Panavia 21. ANOVA revealed significant differences (P <.05) between PAN-EX group and MET and PHB+P21 groups. However, no significant differences were found between MET and PHB+P21 groups.

CONCLUSION

The opposing pull duel test was a valid method to directly compare bond strengths of 2 bonding systems to dental base alloys. There was a small dispersion of the values even though cement mixing and thickness variables were difficult to control. Duel tensile testing provides meaningful information on the superiority of one bonding system over another in this controlled environment.

Effect of sandblasting and silicoating on bond strength of polymer-glass composite to cast titanium

STATEMENT OF PROBLEM

There is little information regarding the mechanical and chemical retention of polymer-glass composite to cast titanium.

PURPOSE

This study examined whether sandblasting in conjunction with silicoating improves the bond strength of the polymer-glass composite to cast titanium.

MATERIALS AND METHODS

Disk patterns (10 mm in diameter, 2.5 mm thick) were cast with commercially pure titanium (CP Ti) and Type IV gold alloy. Three pretreatments were applied: 50 microm Al(2)O(3) sandblasting (50 SB), 250 microm Al(2)O(3) sandblasting (250 SB), and 600-grit SiC paper polishing (600 SiC). After surface preparation, the Siloc system (silicoating) was applied on the disks. The 50 SB specimens without Siloc system were also prepared as controls. Then sticky tape with a circular hole (4.76 mm diameter) was placed onto the disk to define the bonding area. Artglass (polymer-glass) opaque, dentin, and enamel composites were applied using Teflon matrices and then light-polymerized. Shear bond strength (n = 8) was determined at a crosshead speed of 5 mm/min. Results were analyzed statistically with 2-way ANOVA and the Tukey-Kramer test (alpha=.05).

RESULTS

The Siloc system significantly (P <.05) improved the mean shear bond strength of Artglass to both metals in the 50 SB specimens. Statistical differences (P <.05) in shear bond strength were found among surface treatments for the silicoated CP Ti specimens, in which 250 SB specimens yielded the greatest bond strength. The Type IV specimens treated with Siloc system showed no significant differences in shear bond strength between the 50 SB and the 250 SB specimens.

CONCLUSION

Sandblasting with coarser alumina particles in conjunction with silicoating significantly enhanced bond strength of polymer-glass composite to cast titanium.

Effect of MMA-PMMA resin polymerization initiators on the bond strengths of adhesive primers for noble metal

OBJECTIVES

This study was conducted to investigate the effect of MMA-PMMA resin polymerization initiators on the bond strengths of two adhesive metal primers by evaluating the shear bond strengths of resins of silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy.

METHODS

Three types of MMA-PMMA resins for which the polymerization initiators were TBB, BPO-amine and CQ-amine, and two adhesive primers, Metal PrimerII and V-Primer, were used. A brass ring placed over the nonprimed or primed casting alloy disk surface was filled with each resin. The half specimens were stored in water at 37 degrees C for 24 h. In addition, another half specimens were then immersed alternately in water baths at 4 degrees C and 60 degrees C for 1 min each for 20,000 thermal cycles before shear mode testing at a crosshead speed of 0.5 mm/min.

RESULTS

There were no significant differences (p > 0.05) in bond strength between the three types of resins with or without thermal cycling when Metal PrimerII was used. However, when Ag-Pd-Cu-Au alloy was primed with V-Primer, the bond strength of CQ-amine resin was significantly weaker than that of TBB resin. Metal PrimerII was more effective for enhancing the bond strength and the bond strength was not affected by thermal cycling, in contrast to V-Primer.

SIGNIFICANCE

The effectiveness of Metal PrimerII to enhance the bond strength is not influenced by polymerization mode of MMA-PMMA resin, in contrast to V-Primer when the resin is bonded to Ag-Pd-Cu-Au alloy.

Current status of luting agents for fixed prosthodontics

STATEMENT OF THE PROBLEM

The long-term clinical outcome of fixed prosthodontic treatment depends, in part, on the use of adhesives that can provide an impervious seal between the restoration and the tooth. There are several types of available luting agents, each possessing unique properties and handling characteristics. No one product is ideal for every type of restoration.

PURPOSE

The purpose of this article is to review available dental luting agents, discuss improvements and drawbacks in newly formulated adhesives, and present the indications for their use.

RESULTS

Each cement type is physically and chemically unique. A single adhesive will not suffice in modern day clinical practice.

A simple method of increasing the adhesion between resinous cements and tinplated gold alloys: a pilot study

PURPOSE

This study: (1) tested 2 BIS-GMA resinous cements on tinplated gold alloy surfaces with shearing forces to record their bond strengths, and (2) determined whether storage of the tinplated surfaces in water before cementation affected initial bond strengths.

MATERIAL AND METHODS

The bond strengths of Panavia Ex and Panavia 21 resinous cements to tinplated Type III gold alloy were measured when subjected to shearing forces. Specimens were luted in pairs with these cements. In one group, the cementation was performed after tinplating procedures. In the other group, tinplated alloy surfaces were first stored in water at 37 degrees C for 48 hours before cementation.

RESULTS

A 3-fold increase in bond strength values was recorded for tinplated specimens stored in water before cementation with both cements, these differences were statistically significant. Storage of the specimen in water before cementation appeared to increase resistance of the alloy resin bond to failure with application of shearing forces.

CONCLUSION

This pilot study suggested that it would be advantageous to age tinplated gold alloy surfaces in water for 48 hours before cementation.

The effect of tin-electroplating on the bond of four dental alloys to resin cement: an in vitro study

STATEMENT OF THE PROBLEM

Nickel-chromium alloys are indicated for the construction of resin-bonded fixed partial dentures; however, the potential toxicity of nickel has been a source of concern. Composite cements do not develop an adequate bond to air abraded noble alloys, which cannot be electrolytically etched. Tin-electroplating of noble alloys appears to be an alternative treatment for resin bonding.

PURPOSE

This in vitro study investigated the effect of tin-electroplating on the bond of a composite cement to base and noble alloys.

MATERIAL AND METHODS

Tensile tests were made with disks of four alloys that were cemented to each other with an adhesive composite cement after (1) air abrasion with 50 microns aluminum oxide and (2) air abrasion plus tin-electroplating.

RESULTS

Tin-electroplating increased the bond strength of metal-ceramic gold alloy (Au,Pd,Pt) to a level comparable to the nickel-chromium alloy, but had a harmful effect on type IV gold alloy.

CONCLUSIONS

Despite the recommendation for tin-electroplating of type IV gold alloys, this procedure did not improve bond strength to composite in this study.

Effects of adhesive primers for noble metals on shear bond strengths of resin cements

OBJECTIVES

The purpose of this study was to evaluate the durability and shear bond strengths of the different combinations of two adhesive primers and three resin cements to two types of noble metal alloys, silver-palladium copper-gold and type IV gold alloys.

METHODS

The adhesive luting agents Imperva Dual, Panavia 21 and Super-Bond C&B, and the adhesive primers Metal Primer and V-Primer were used. Two sizes of casting alloy disks were nonprimed or primed and cemented with each adhesive luting agent. The specimens were stored in 37 degrees C water for one day and then immersed alternately in 4 degrees C and 60 degrees C water baths for 1 min each for up to 100,000 thermal cycles before shear mode testing at a cross-head speed of 0.5 mm/min.

RESULTS

The application of Metal Primer was effective for improving the shear bond strengths between each of the three resin cements and both noble metal alloys compared with nonprimed specimens. When each noble metal alloy was cemented with Super-Bond C&B, there were no significant differences between the bond strengths with the use of Metal Primer and those with the use of V-Primer at 100,000 thermal cycles. However, V-Primer was ineffective for enhancing the shear bond strengths of Imperva Dual and Panavia 21 to noble metals.

CONCLUSION

Metal Primer and V-Primer are clinically useful for strongly bonding adhesive resin cements to noble metal alloys.

Resin-bonded fixed partial dentures: a review of three decades of progress

The resin-bonded fixed partial denture has undergone significant changes in design, materials and tooth preparation since its development in 1973. The selection of resin cement and micromechanical retention have closely paralleled alloy-resin-bonding research. Despite impressive in vitro research results, only 74 percent of the prostheses are still functional at the end of four years. Understanding the limitations, indications and design of resin-bonded fixed partial dentures will result in improved longevity and patient satisfaction.

The bond strength of an adhesive resin luting cement to a variety of surface treatments of a high-palladium copper alloy

PURPOSE

This study evaluated the tensile bond strength of a bisphenol glycidyl methacrylate (Bis-GMA) resin luting cement with four different surface treatments of a high Pd-Cu alloy.

MATERIALS AND METHODS

For each surface treatment type (tin-plated, porcelain furnace oxide, air-abraded, and finished-only), 15 opposing half-dumbbell-shaped samples were cast and prepared in new Pd-Cu alloy. Samples were luted with a Bis-GMA resin luting cement at a film thickness of 80 microns using a custom alignment apparatus. Samples were stored in distilled water at 37 degrees C for 24 hours, thermocycled for 1,000 cycles, and then stored for 30 days in distilled water at 37 degrees C. Samples were then subjected to fracture in tension at a loading rate of 0.5 cm/min with the bond strengths calculated in megapascals (MPa). The fractured surfaces were examined using stereomicroscopy and scanning electron microscopy at various magnifications ranging from 5.5x to 500x to determine the type of bond failure (adhesive, cohesive, or mixed).

RESULTS

Tensile bond strengths (mean +/- SD MPa) were: tin-plated, 30 +/- 15.7; porcelain furnace oxide, 23 +/-n 8.6; air-abraded, 8 +/- 8.1; and finished-only, 4 +/- 4.5. Statistical analysis of the tensile bond values using an ANCOVA and Tukey's multiple comparison test at a significance level of 0.05 indicated that there was no difference between the tin-plated and the furnace oxide groups, as well as between the air-abraded and the furnace oxide groups. However, there was significant difference between the tin-plated, the air-abraded, and the finished-only groups. The observed bond failures were predominantly mixed and cohesive in nature with only one adhesive failure.

CONCLUSIONS

There was no significant difference in the tensile bond strengths between the tin-plated group or the porcelain furnace oxide surface group. This suggests that the less-technique-sensitive porcelain furnace oxide surface treatment offers an alternative for achieving high metal-resin bonds to a high Pd-Cu alloy.

The effect of metal surface treatment on the shear bond strengths of base and noble metals bonded to enamel

Adhesive resin luting agents provide a way for bonding metal surfaces to teeth through a combination of micromechanical retention to the rough metal surface and chemical adherence to metal oxides. The purpose of this study was to measure the effect of metal alloy surface treatments that would produce different textures and oxide layers on the shear bond strength of three alloys luted to etched enamel with one adhesive resin luting agent (Panavia). After a simulated porcelain firing sequence, high noble (Olympia), noble (Jelstar), and base metal (Rexillium III) alloy specimens were subjected to one of the following treatments: (1) sandblasting and simulated glazing, (2) simulated glazing only, (3) simulated glazing and sandblasting, or (4) simulated glazing, sandblasting, and tin plating. The specimens were bonded to extracted teeth and subjected to shear testing after water storage for 2 weeks, thermocycling for 500 cycles, and water storage for an additional 2 weeks. Data were analyzed with a two-way analysis of variance (alpha = 0.05). The base metal specimens and the tin-plated high noble and noble metal specimen groups exhibited similar mean shear bond strengths that were greater than the other groups. Those high noble and noble metal alloys sandblasted after simulated porcelain firing cycles and before the simulated glaze cycle exhibited nonsignificant increases in shear bond strengths compared with the groups that were either sandblasted after the simulated glaze cycle or not sandblasted at all.

In-vitro study of the adhesive strengths of brackets on metals, ceramic and composite. Part 2: Bonding to porcelain and composite resin

In addition to part 1 of the study, the present paper investigated more than 25 resin/conditioner combinations with respect to their bond strengths to porcelain and composite resin. For that purpose stainless steel lingual buttons were bonded with the various adhesives and their shear bond strengths and types of bond failure were determined after 24 hours. All specimens were air-abraded with 50 microns Al2O3 for 2 or 4 seconds by means of a Microetcher before bonding. Results show that, on the porcelain, and composite under investigation, several materials yield bond strengths which are similar to or higher than what is achieved with the conventional acid etch technique on enamel. Maximum adhesive strength is not always desirable, however, for bonding brackets. The type of bond failure and the risk of irreversible damage to the bonded material have also to be taken into consideration.

Shear bond strengths of three resin cements used with three adhesive primers for metal

This study compared the durability and shear bond strengths of combinations of three adhesive primers and three resin cements bonded to silver-palladium-copper-gold (Ag-Pd-Cu-Au) and cobalt-chromium (Co-Cr) alloys. The adhesive luting cements Imperva Dual, Panavia 21, and Super-Bond C&B and the adhesive primers Metal Primer material, V-Primer material, and Cesead Opaque Primer material were used. The application of Metal Primer material was effective in improving the shear bond strengths between each of the three resin cements and Ag-Pd-Cu-Au alloy compared with nonprimed specimens. Co-Cr alloy primed with Cesead Opaque Primer, followed by cementation with Imperva Dual or Super-Bond C&B luting cements yielded the strongest shear bond strengths after 50,000 thermocycles, and Panavia 21 cement did not reveal any significant differences in bond strengths between nonprimed specimens and those primed with Cesead Opaque Primer at all thermocycles.

Improving orthodontic bonding to gold alloy

Flat tabs of cast gold alloy (n = 156) were subjected to either of three surface treatments: (1) roughening with diamond bur, (2) aluminum oxide sandblasting, and (3) sandblasting plus tin electroplating. Mandibular incisor edgewise brackets were bonded with Concise (BIS-GMA resin) (Unitek, Monrovia, Calif.) or Superbond C&B (4-META metal bonding resin) (Sun Medical Co. Ltd., Kyoto, Japan), or with Concise after application of an intermediate resin. All-Bond 2 Primers A and B (Bisco Dental Products, Itasca, Ill.), or B alone. All specimens were stored in water at 37 degrees C for 24 hours, and 60 were then thermocycled 1,000 times from 5 degrees C to 55 degrees C and back. The tensile bond strength testing was performed in a Lloyd 1,000R machine (Fareham, Hants, England). Alignment and uniform loading during testing were secured by engaging a hook in a circular ring soldered onto the bracket slot before bonding. Similar control brackets (n = 24) were bonded with Concise to extracted human premolars and lower incisors according to a routine procedure. Bond failure sites were classified by a modified ARI system. The results showed that sandblasting produced significantly stronger bonds to gold alloy than roughening with diamond bur. Superbond C&B provided significantly stronger bonds to gold alloy than Concise. There were generally insignificant differences in bond strengths between the water stored and the thermocycled specimens. Bond failures of Concise to sandblasted plus tin-plated gold alloy invariably occurred at the gold/adhesive interface, whereas those of Superbond C&B occurred within the adhesive or in the adhesive/bracket interface.(ABSTRACT TRUNCATED AT 250 WORDS)

Tensile bond strength of a composite resin cement for bonded prosthesis to various dental alloys

The development of composite resin cements that chemically bond to dental alloys has improved the construction of resin-bonded prostheses. Composite resins can be selected for various situations, but specific clinical situations may require different alloys. This study evaluated the ability of a composite resin cement to bond to various dental alloys of different compositions. Ten pairs of disks for each alloy (two NiCr, two NiCrBe, one CuAl, one gold type IV, and one gold for metal ceramic) were bonded to a composite resin cement after air abrasion was performed with aluminum oxide. The disks were then rinsed in tap water and were ultrasonically cleaned in distilled water for 2 minutes. The tensile tests exhibited greater values for alloys ultrasonically cleaned, and the best results were recorded by NiCr and NiCrBe alloys.

Influence of saliva contamination and abrasion on resin to tin-plated alloy bond strengths

This investigation studied the effects of abrasion and salivary contamination on the shear bond strength of a composite resin bonded to tin-plated gold alloy. Experimental groups (n = 15) consisted of: group 1, no surface treatment; group 2, enamel abraded; and group 3, saliva-contaminated. After surface stressing and bonding, groups were thermocycled before shear testing. Fractured interfaces were analyzed by use of light microscopy and SEM. Specimens in group 3 (12.2 +/- 2.5 MPa) had significantly lower bond strengths than group 1 (17.9 +/- 6.8 MPa). The shear bond strengths of resin bonded to tin-plated metal were significantly affected by salivary contamination but not by abrasion.

Comparison of shear bond strengths of two resin luting systems for a base and a high noble metal alloy bonded to enamel

Researchers are investigating the use of noble metals for the fabrication of resin-bonded prostheses because of concerns about health hazards of nickel and beryllium in base metal alloys. Tin-plating has been advocated to improve the bond of resin luting agents to noble metal alloys. Some manufacturers have suggested that tin-plating is unnecessary to bond noble metal alloys to etched enamel with their products. In this study, Rexillium base metal and Olympia noble metal alloy specimens were bonded to extracted human teeth with the use of two resin luting agents (F21 and Panavia OP). One third of the noble metal specimens were tin-plated, one third were oxidized, and one third were oxidized and sandblasted. Each of the bonded specimens were thermocycled and subjected to a shear force until bond failure. The base metal specimens bonded with Panavia OP luting agent exhibited the greatest mean shear bond strengths. The tin-plating surface treatment significantly increased the mean shear bond strengths of Olympia noble metal specimens.

Influence of prolonged thermal cycling and water storage on the tensile bond strength of composite to NiCr alloy

OBJECTIVES

The purpose of this study was to evaluate the bond strength and bond durability of new adhesive systems (both micromechanical and chemo-mechanical) to a beryllium-free nickel-chromium alloy (NiCr).

METHODS

Plexiglass tubes filled with composite were bonded to NiCr alloy discs. Groups of 24 samples were bonded using six different bonding systems. Subgroups of eight bonded samples were stored in an isotonic artificial saliva solution (37 degrees C) either for 1 d, 30 d or 150 d. In addition, the 30 and 150 d samples were thermal cycled for 7,500 or 37,500 cycles, respectively.

RESULTS

The bond strength of a conventional BisGMA composite to sandblasted NiCr was statistically significantly lower than that of chemo-mechanical bonding systems and decreased continuously during the storage time of 150 d. The additional use of a silane on the sandblasted alloy resulted only in a slight, statistically insignificant increase in bond strength. Statistically significantly higher and more durable bonds to NiCr alloy were achieved either with the combination of silica coating and use of a conventional BisGMA composite or with the combination of sandblasting and the use of a composite modified with a phosphate monomer. In these systems, the bond strengths were limited by the cohesive strength of the resin composites. However, a newly developed composite containing the same active phosphate monomer showed a statistically significant decrease in bond strength (cohesive strength) over storage time.

SIGNIFICANCE

Longer-term storage times in a wet environment are needed in laboratory tests to examine the durability of bonding systems.