A qualitative study for the bond and color of ceramometals. Part I

A shear testing method was devised to study and evaluate the effect of various and repeated firing cycles, types of alloy, and brand of porcelain relative to the color and bond strength of ceramometal complexes specifically at the opaque porcelain-metal interface and the opaque-body porcelain juncture. Two alloys and two porcelain brands were chosen on the basis of their widespread clinical use and the marked contrast between them. An increase of the firing temperature significantly raised the bond strength for all alloy-porcelain combinations.     

Bond strength of porcelain to dental alloys - an evaluation of two test methods

Two methods for measuring shear strength of the porcelain-metal interface, a rod/disk-push test and a cube/cube-push test, were compared using the same metals and porcelain material. Both types of specimen showed evidence of complex stress distribution at the interface during loading and a fracture line located mainly in the opaque porcelain layer. Both methods were thus mainly a test of the "strength" of the porcelain at the interface. The "bond strength values" obtained with the rod/disk specimen seemed to depend on the geometry of the specimen and the values obtained with the cube/cube specimen seemed to depend on the quality of the porcelain work. It seems questionable whether "bond strength values" as obtained with these two methods can be the basis for requirements in a standard for porcelain-metal systems.     

Adhesive bonding of titanium with a titanate coupler and 4-META/MMA-TBB opaque resin

Adhesive bonding of titanium was evaluated with a titanate primer and adhesive opaque resin. The primer consisted of 2% isopropyl dimethacryloyl isostearoyl titanate in methyl methacrylate. The adhesive was 4-META/MMA-TBB opaque resin that contained 4-methacryloyloxyethyl trimellitate anhydride and was initiated by tri-n-butylborane derivative. Titanium discs were machined and blasted with aluminum oxide. They were primed and bonded together with the opaque resin. A shear test was performed after repeated thermocycles for investigation of the durability of the bond. The shear strength of the primed and 4-META resin-bonded specimens was 37.2 MPa after 50,000 thermocycles, with only a small decrease in bond strength. This was significantly higher than the control values. Thus, titanate primer and 4-META/MMA-TBB opaque resin may be used for the bonding of titanium in prosthodontic practice.     

Bond strength of porcelain to dental alloys – an evaluation of two test methods

Abstract – Two methods for measuring shear strengh of the porcelain-metal interface, a rod/disk-push test and a cube/cube-push test, were compared using the same metals and porcelain material. Both types of specimen showed evidence of complex stress distribution at the interface during loading and fracture line located mainly in the opaque porcelain layer. Both methods were thusmainly a test of the "strength" of the porcelain at the interface. The "Bond strength values" obtained with the rod/disk specimen seemed to depend on the geometry of specimen and the values obtained with the cube/cube specimen scemed to depend on the quality of the porcelain work. It seem questionable whether "bone strenghth values" as obtained with these two methods can be the basis for requirenments in a standard for porcelain-metal systems.     

Effect of electrodeposition of gold on porcelain-to-metal bond strength

The effect of electrodeposition of two different thicknesses of gold on porcelain-metal bond strength with three different base metal alloys was determined and compared to a control high gold alloy. The following conclusions can be drawn. Mean porcelain-metal bond strengths of all four alloys were in the same range when conventional porcelain application techniques were used. However, the base metal porcelain-metal bond is clinically suspect because of adhesive failure through the porcelain-metal interface. A thin 180A gold coat increased the porcelain-metal bond strength and generally resulted in cohesive failure through the porcelain. A thicker gold coat (720A) decreased the bond strength and generally resulted in adhesive failure. The mechanism of action of the gold coat on bond strength is likely its effect on the oxide layer on the surface of the base metal alloy.     

遮色瓷双层涂法对金瓷结合强度的影响

目的：比较Ｏｐａｑｕｅ双层涂法和Ｏｐａｑｕｅ一次法对金瓷结合强度的影响。方法：采用双轴弯曲实验,计算金瓷结合强度及金瓷界面剩瓷率。结果：Ｏｐａｑｕｅ双层涂法的结合强度及金瓷界面剩瓷率均显著高于Ｏｐａｑｕｅ一次法;９５０℃和９７０℃烧结的两种Ｏｐａｑｕｅ双层涂法对金瓷结合的影响无显著性差异。结论：Ｏｐａｑｕｅ双层涂法显著提高了金瓷复合体的结合强度。     

Effect of surface conditioning and restorative material on the shear bond strength and resin-dentin interface of a new one-bottle nanofilled adhesive.

OBJECTIVES: To determine the effect of different combinations of surface conditioning (DeTrey Conditioner 36, NRC, no etching) and restorative materials (Dyract AP, Spectrum TPH) on the shear bond strength of Prime and Bond NT to enamel and dentin, and to characterize the resin-dentin interface produced by these combinations. METHODS: Shear bond strength was tested on 30 enamel and 30 dentin flat labial surfaces of extracted bovine teeth. The enamel and dentin specimens were randomly assigned to six groups of five teeth each and treated using different combinations of surface conditioners and restorative materials with Prime and Bond NT. Scanning electron microscope (SEM) observation of argon-ion-etched specimens was done to evaluate the resin-dentin interface. RESULTS: The type of surface conditioning and restorative material had significant effects on dentin bond strengths. Etching the dentin prior to application of Prime and Bond NT significantly increased bond strength and caused formation of a hybrid layer for Spectrum TPH. For Dyract AP, dentin etching generally did not improve bond strength despite the formation of a hybrid layer. On enamel, Prime and Bond NT had consistently high bond strengths on etched specimens. SIGNIFICANCE: The results showed that Dyract AP and Spectrum TPH, when used with Prime and Bond NT have different bonding mechanisms and the effect of surface conditioning on their shear bond strength differs. Clinicians should be aware of these effects in order to optimize bonding.     

Sprayed opaque porcelain as a retentive surface for resin-bonded restorations

This study investigated the shear bond strength between etched enamel and 4-mm-diameter base metal castings cemented with Panavia EX. Four different methods of casting preparation were used: air abraded, salt crystals placed on the wax patterns, opaque porcelain sprayed on the metal surface, and sprayed opaque porcelain followed by a silane coupling agent. The prepared surfaces were examined before and after testing using SEM and electron dispersive analysis by x-rays. It was determined that there was no significant difference in the shear bond strength between the salt-crystal technique and the nonsilanated sprayed ceramic surfaces. The air-abraded surface was the least retentive, and the silanated opaque porcelain specimens had intermediate retention. The sprayed opaque porcelain technique seems to offer several advantages.     

The effect of surface treatments on the bond strength of a nonprecious alloy-ceramic interface

PURPOSE: The purpose of this study was to compare the effect of seven different alloy surface treatments on the bond strength of the porcelain-metal interface. MATERIALS AND METHODS: Three layers of opaque porcelain and a measured thickness of dentin porcelain were applied to nickel-chromium alloy. A tensile bond strength test was used. RESULTS: The alloy surface treatment that exhibited the highest bond strength was sandblast + surface grinding + sandblast + de-gas, whereas the alloy surface treatment that exhibited the lowest bond strength was sandblast + surface grinding + sandblast + steam cleaning + de-gas. There was a significant difference between the two methods (P < 0.05). CONCLUSION: It was concluded that de-gassing the alloy prior to porcelain application increased the bond strength and excess surface grinding of the alloy reduced bond strength; steam cleaning the alloy surface prior to de-gassing and porcelain application also significantly reduced the bond strength.     

To evaluate the variation in shade by a spectrophotometer of porcelain fused to metal samples with respect to repeated firing and variation in lot of ceramic – An in-vitro study

Shade matching is an integral part of esthetic dentistry. Thus, this study was done to compare the variation in shade of standardized porcelain fused to metal samples after 5th, 7th and 9th firing with no repeated firing (control group) using a spectrophotometer. It also compared the variation in shade by changing the lot of ceramic of same dentinal shade. For the study 120 samples were made in the form of discs and subdivided into four groups for the required grouping. All the samples were gauged by Vernier caliper. Layering was done of the samples for wash opaque, shade opaque and lastly ceramic layer of dentine. 1st firing was wash opaque firing, 2nd firing – shade opaque, 3rd firing – 1st dentine build up, 4th firing – 2nd dentine build up and 5th firing – autoglaze. Any firing after this was considered as repeated firing. The results were calculated by using ANOVA test and ‘F test.’ Thus, within the limitations of this study it was concluded that repeated firing did not significantly affect the shade of porcelain fused to metal samples and secondly variation in batch showed a statistical significant change but within the acceptable limits of an individual's color perception.     

Shear bond strength of dental porcelains to nickel-chromium alloys

The continuous technological advance and increasing availability of new base metal alloys and ceramic systems in the market, coupled to the demands of daily clinical practice, have made the constant evaluation of the bond strength of metal/porcelain combinations necessary. This study evaluated the metal/porcelain shear bond strength of three ceramic systems (Duceram, Williams and Noritake) in combination with three nickel-chromium (Ni-Cr) alloys (Durabond, Verabond and Viron). Thirty cast cylinder specimens (15 mm high; 6 mm in diameter) were obtained for each alloy, in a way that 10 specimens of each alloy were tested with each porcelain. Bond strength was measured with an Emic screw-driven mechanical testing machine by applying parallel shear forces to the specimens until fracture. Shear strength was calculated using the ratio of the force applied to a demarcated area of the opaque layer. Mann-Whitney U test was used for statistical analysis of the alloy/ceramic combinations (p<0.05). Viron/Noritake had the highest shear bond sregnth means (32.93 MPa), while Verabond/Duceram (16.31 MPa) presented the lowest means. Viron/Noritake differed statistically from other combinations (p<0.05). Viron/Duceram had statistically significant higher bond strengths than Verabond/Duceram, Verabond/Williams and Durabond/Noritake (p<0.05). It was also found significant difference (p<0.05) between Verabond/Noritake, Verabond/Duceram and Durabond/Noritake. No statistically significant difference (p>0.05) were observed among the other combinations. In conclusion, the Noritake ceramic system used together with Viron alloy presented the highest resistance to shear forces, while Duceram bonded to Verabond presented the lowest bond strength. Viron/Duceram and Verabond/Noritake provided intermediate results. The combinations between the Williams ceramic system and Ni-Cr alloys had similar shear strengths among each other.     

Shear bond strength of textured opaque porcelain.

Textured opaque porcelains have been introduced to improve the appearance of metal ceramic restorations by increasing light refraction. This investigation compared the shear bond strength of a textured opaque porcelain with that of a conventional opaque porcelain. Opaque and body porcelains were fired onto six different alloys and the specimens were loaded to failure by applying shear force at the alloy-porcelain interface. No significant differences in bond strength were found between the textured and conventional opaque porcelains for any of the alloys tested.     

The Effect of Surface Treatments on the Bond Strength of a Nonprecious Alloy–Ceramic Interface: An Invitro Study

The purpose of this study was to compare the effect of seven different alloy surface treatments on the bond strength of the porcelain-metal interface. Three layers of opaque porcelain and a measured thickness of dentin porcelain were applied to nickel–chromium alloy, A tensile bond strength test was used. The alloy surface treatment that exhibited the highest bond strength was sandblast + surface grinding + sandblast + de-gas, whereas the alloy surface treatment that exhibited the lowest bond strength was sandblast + surface grinding + sandblast + steam cleaning + de-gas. There was a significant difference between the two methods (P < 0.05). It was concluded that de-gassing the alloy prior to porcelain application increased the bond strength and excess surface grinding of the alloy reduced bond strength; steam cleaning the alloy surface prior to de-gassing and porcelain application also significantly reduced the bond strength.     

Shear Bond Strength of Two Chemically Different Denture Base Polymers to Reline Materials

Purpose: This study evaluated the shear bond strengths of light-polymerized urethane dimethacrylate (Eclipse) and heat-polymerized polymethylmethacrylate (Meliodent) denture base polymers to intraoral and laboratory-processed reline materials.
Materials and Methods: Thirty disks measuring 15 mm diameter and 2 mm thick were prepared for each denture base material following the manufacturers' recommendation. They were relined with Meliodent RR, Kooliner, and Secure reline materials after 1 month of water immersion. Ten additional Eclipse specimens were relined using the same Eclipse resin. A shear bond test was carried out on an Instron machine at a crosshead speed of 1.0 mm/min 24 hours after relining. Data were analyzed using two-way and one-way ANOVAs and post hoc Dunnett's T3 test ( p = 0.05). The nature of failure was analyzed under a stereomicroscope. The effect of dichloromethane adhesive on the two denture polymer surfaces and the failed interfaces of mixed and adhesive failures were analyzed under a SEM (scanning electron microscope).
Results: Two-way ANOVA showed significant differences in the shear bond strength values as a function of the denture base polymers, reline materials, and their interaction ( p < 0.05). One-way ANOVA showed significant differences in shear bond strength values among denture base-reline combinations ( p < 0.05) except for Meliodent-Kooliner and Eclipse-Meliodent RR relines. Meliodent showed the highest shear bond strength value when relined with Meliodent RR (14.5 ± 0.5 MPa), and Eclipse showed the highest value with Eclipse relining (11.4 ± 0.6 MPa). Meliodent denture base showed adhesive, cohesive, and mixed failure, while all Eclipse showed adhesive failure with various reline materials.
Conclusion: The two chemically different denture base polymers showed different shear bond strength values to corresponding reline materials.     

Effect of cooling rate on shear bond strength of veneering porcelain to a zirconia ceramic material

The purpose of the present study was to evaluate the effect of cooling rates after firing procedures of veneering porcelain on shear bond strength between veneering porcelain and a zirconium dioxide (zirconia; ZrO?) ceramic material. A total of 48 ZrO? disks were divided equally into three groups. Two veneering porcelains that are recommended for ZrO? material - Cerabien ZR (CZR), IPS e.max Ceram (EMX) - and one that is recommended for metal ceramics - Super Porcelain AAA (AAA) were assessed. Each group was then further divided into two subgroups (n = 8) according to cooling time (0 or 4 min) after porcelain firing. Specimens were fabricated by veneering the porcelain on the ZrO? disks, after which shear bond testing was conducted. Bond strength differed significantly by cooling time in ZrO?-AAA (P < 0.001) and ZrO?-EMX (P = 0.001) specimens. There was no significant difference in shear bond strength with respect to cooling time in ZrO?-CZR specimens (P = 0.382). The duration of cooling from firing temperature to room temperature may affect the shear bond strength of veneering porcelain to a zirconia material depending on porcelain material used.     

An evaluation of four variables affecting the bond strength of porcelain to nonprecious alloy.

Four variables that could possibly affect the bond strength of the porcelain to nonprecious alloy were investigated. The variables were directional variations of metal preparation using the Paasché Air Eraser with aluminum oxide fast-cut abrasive, atmosphere variations in the furnace from low to high temperature limits of the degassing cycle, time variations at normal atmosphere of 1,850 degrees F. (degassing upper-limit timing), and firing of the opaque layer of porcelain at different temperatures. A total of 162 Ticon alloy interfaces were prepared, from which 81 paired test samples were constructed. Porcelain was fused to the samples and tested under specified conditions of preparation utilizing an Instron Universal testing machine. It was determined that firing the opaque layer at 1,840 degrees F. at a rate of 75 degrees F. per minute more than doubled the mean bond strength of all samples. The time at the upper limit of the degassing cycle also had a significant effect on the bond. As the time increased, the bond strength decreased. Complete bonds between porcelain and nonprecious metals were demonstrated when the fracture occurred in the porcelain and not at the interface. It is recommended that the opaque firing and degassing be done in accordance with the foregoing findings.     

Effect of time on bond strength in indirect bonding

The purpose of this in vitro investigation was to determine the influence of a reduced time interval before debonding on shear bond strength of stainless steel brackets bonded with a custom base indirect technique. A total of 135 bovine permanent mandibular incisors was randomly divided into nine groups of 15 specimens each. Three base composite-sealant combinations were investigated: (1) Phase II base composite, Custom I.Q. sealant, (2) Phase II base composite, Maximum Cure sealant, and (3) Transbond XT base composite, Sondhi Rapid Set sealant. Shear bond strength was measured for three different debonding time intervals: (1) time of transfer tray removal as recommended by the manufacturer, (2) 30 minutes after bonding of the sealant, and (3) 24 hours after bonding of the sealant. For groups bonded with Maximum Cure or Sondhi Rapid Set sealants, no influence of debonding time on shear bond strength was found. The Custom I.Q. sealant groups showed significantly lower bond strength measurements when debonded at the recommended tray removal time, and the Weibull analysis indicated a higher risk of bond failure at clinically relevant levels of stress. All base composite-sealant combinations showed acceptable bond strength at 30 minutes and 24 hours after bonding of the sealant.     

Shear bond strength of indirect resin to NiCr with different metal surface preparations

This study sought to evaluate the shear bond strength of indirect resin to nickel chromium (NiCr) after different surface preparations. Sixty-four metal samples were divided into four groups, according to surface preparation, and two layers of opaque resin and three layers of body resin were applied. Each group was divided into two subgroups based on storage period in distilled water at 37 degrees C. Mechanical shear testing was performed using a universal testing machine with 0.5 mm/minute of cross-head speed. Debonded areas were analyzed and classified according to different failure types, such as cohesive, adhesive, and mixed. The storage periods were compared using a student T-test (alpha = 0.05); Group T (that is, the tin electroplating group) showed the highest average after 24 hours. The macro retentions showed higher shear bond strength than the sandblasted samples (p < 0.05). Tin electroplating did not improve the shear bond strength of metal-resin bonding. The results were not affected by 30-day storage, with the exception of group T (p < 0.05).     

Physical properties of light-cured opaque resin. (1) Influence of monomer composition

Light-cured opaque resins with excellent physical properties were prepared using five types of monomer liquid and titanium dioxide as the powder. The five opaque resin monomer liquid had the following monomer compositions. Methyl methacrylate (MMA)/di(methacryloxyethyl) trimethylhexamethylene diurethane (UDMA) = 70/30 (M-U), MMA/neopenthylglycol dimethacrylate (NPG)/UDMA = 45/45/10 (M-N-U), UDMA/MMA = 70/30 (U-M), 2,2-bis (4-methacryloxypolyethoxy phenyl) propane (2.6 E)/2,2-bis [4-(3-methacryloxy-2-hydroxy propoxy) phenyl] propane (Bis-GMA)/triethyleneglycol dimethacrylate (3 G) = 60/35/5(2.6-B-3) and 3 G/UDMA = 70/30 (3-U) by weight. The bond strength, photo-curability and handling properties of the opaque resin were improved. Three MMA-based opaque resins showed nearly the same values in Knoop hardness number, diametral tensile strength and shear bond strength. The depth of cure increased with the decrease in MMA content of monomer composition, while the amount of residual monomer decreased. The 2.6-B-3 opaque resin had nearly the same properties in depth of cure and Knoop hardness number as the 3-U opaque resin. However, the 2.6-B-3 and 3-U opaque resins had a diametral tensile strength more than twice as high as that of the U-M opaque resin. The bond strength of three MMA-based opaque resins showed 0MPa after 5,000 thermocycles, while the 2.6-B-3 opaque resin, about 16 MPa, and the 3-U opaque resin, about 25 MPa. Therefore, the bond strength of the opaque resin was influenced by monomer composition. 3G-UDMA opaque resin showed excellent physical properties and may be clinically acceptable to bond fixed prosthodontic composite.     

溶剂处理对钛-瓷结合强度的影响

目的 考察丙酮,乙酸乙酯,９５％乙醇及１５氢氟酸对钛－瓷结合产生的影响。方法 采用剪切实验法。结果 纯钛经丙酮、乙酸乙脂,９５％乙醇及１％氢氟酸处理后再烤瓷,太－瓷剪切强度分别为５３．２９ＭＰａ,５２．５４Ｍｐａ,５０．６９ＭＰａ,及２１．１８ＭＰａ,而未经任何清洗处理的对照组剪切强度值为２６．７５ＭＰａ。Ｔｉ－７５合金烤瓷前经丙酮,乙酸乙酯,９５％乙醇及１％氢氟酸处理后其钛－瓷剪切强度分别为５７