PANAVIA F
---IADR Abstracts ---
up-dated 27/7/2000
Kuraray Europe GmbH
The purpose of this study was to evaluate the effect of medicaments for root canal treatment on dentin bond strengths of resin cements. Freshly extracted bovine teeth were ground with #600-grit SiC to expose the dentin surface. The dentin surface was then treated with 3% hydrogen peroxide (H²O²), 5% sodium hypocholorite (NaOCl), the combination of H²O² and NaOCl (H²O²/NaOCl), formocresol (FC), or calcium hydroxide (Ca(OH)²) for 60s. then rinsed and air dried. The bonding area was demarcated with a vinyl tape (4mm diameter hole), and then one of two resin cements, Superbond C&B (SB, Sun Medical, Kyoto, Japan) or Panvia F Cement (PF, Kuraray, Osaka, Japan), was applied to the dentin surface according to the manufacturers' instructions. After storage in water for 1 day, tensile bond test was performed at a crosshead speed of 2mm/min using a universal testing machine. The data were analyzed with one-way ANOVA and Fisher's PLSD test at the 5% level. (n=10)
| Control | H²O² | NaOCl | H²O²/NaOCl | FC | Ca(OH)² | |
| SB | 16.0(5.8) | 4.9(1.3)* | 5.8(1.3)* | 7.1(1/7)* | 13.8(3.8)* | 8.2(2.3)* |
| PF | 10.9(3.5) | 3.8(2.4)* | 10.3(3.1) | 5.9(2.5)* | 8.9(1.8) | 7.5(1.7)* |
J Dent Res 79(IADR Abstracts) 2000, p273, #1037
In vivo Fluoride Uptake of Human Dentin Using PANAVIA F
T. Kashiwada, M.Morita, S.Kato
Keiai Dental Clinic (Japan), Takanawa Dental Office (Japan)
New dental adhesives have recently been developed. Sealing by adhesive materials could provide the long term preservation of tooth structure. Furthermore, fluoride-release function may be more effective against secondary caries. We reported that the adjacent tooth structure using gluoride-releasing adhesives showed fluoride-rich layer, and was strengthened in vitro ('99 IADR, #432). The purpose of this study was to evaluate in vivo fluoride uptake using fluoride-releasing adhesive resin materials "PANAVIA F (JPN Name: PANAVIA FLUORO CEMENT), Kuraray" [PNF]. Premolar and molar teeth that were destined to extract for a orthodontic treatment were used for the experiment. Under local anesthetic, occlusal enamel was removed to expose dentin using a high-speed diamond bur. With or without the dentin surface conditioning (10 sec etching with 40% H³PO4 followed by 2min cleansing with 10% sodium hypocholorite, that is expected to amprove adhesion) [P/S], a crown made of hybrid-ceramics (Estenia, Kuraray) was bonded to the tooth using PNF. 2 Months after bonding, the tooth was extracted and immediately submerged in a isotonic saline at 37? prior to test. The teeth samples were sectioned at the PNF area and the exposed dentin surfaces observed with EPMA. The findings were that a fluoride-rich layer of 20µm was found in case with P/S conditioning, and that of 20µm was also found in case without P/S conditioning, as same as in vitro. This study indicates that PNF supply fluoride to tooth structure for 2 months in vivo. The results indicate that the adjacent tooth structure using PNF could showed a resistance to decalcification in vivo, as found in vitro.
J Dent Res 79(IADR Abstracts) 2000, p283, #1116
Bonding strength of luting cements for dental metals treated by GDT
F. Hiroshima, A.Fujishima, M.Yamamoto, M.Suzuki, T.Miyazaki
Showa Univ. (Japan)
The authors already revealed that the flow discharge treatment (GDT) significantly increased the wettability of dental metals over a short time and enhance the bonding of resin composites for veneering to the crown and bridge. The aim of this study was to investigate the bonding strength of resin cements for dental metals treated by two types of GDT equipment with a power supply of direct and alternating current. Four kinds of resin cements (PF: Panavia fluoro cement, Kuraray, SB: Super bond C&B, Sunmedical, BS: Bistite II, Tokuyama, and ID: Imperva dual, Shofu) were used for the bonding test. The specimens of cp titanium (Ti) and silver-palladium-gold alloy (Ag) were polished with emery paper up to #1200 followed by sealing a tape with a hole of f6mm and bonding to a titanium rod with each cement. Tensile tests were performed with an universal testing machine (1125, Instron) at a cross-head speed of 1mm/min using the specimens stored in water at 37? for 24 hours (n=5). Bonding strengths were compared between the specimens with and without GDT by the Student's t-test. The result showed that bonding strengths of Ti were significantly (p<0.05) higher than those of Ag for all cements. The only PF cement containing a MDP monomer showed significantly (p<0.05) higher bonding strength for both Ti and Ag with GDT. Although Ti showed higher bonding strength with both GDT conditions, Ag showed higher strength only by GDT with a direct current condition. Therefore, we suggest GDT of dental metals definitely enhanced the bonding strength of PF. However, since the condition of GDT influenced differently on Ti and Ag, we need more investigation to clarify the suitable condition for each metal.
J Dent Res 79(IADR Abstracts) 2000, p453, #2477
Early bond strengths of dual-cured resin cement to resin-coated dentin
M.F.de Goes, T.Nikaido, P.N.R.Pereira, J.Tagami
UNICAMP (Brazil), Tokyo Med. & Dent. Univ. (Japan)
Low viscosity composite improves marginal seal and adhesion between tooth and restoration. The purpose of this study was to measure the early tensile bond strength 8TBS) of a dual-cured resin cement to dentin and resin-coated surface. Sixty bovine teeth were ground flat to expose dentin and covered with a vinyl tape containing a 4 mm diameter hole. The teeth were randomly divided into two groups as follows: Group 1, dentin was treated with ED primer (Kuraray Co., Japan) for 60 s. Panavia F (Kuraray) was applied on the dentin surface, to which a silanated resin composite rod was placed. The resin cement was light-cured from three directions for 20 s each. For Group 2, the dentin surface was treated with Clearfil Liner Bond 2V (Kuraray) and then coated with a low viscosity resin composite (Protect Liner F), and light-cured for 20 s. It was then conditioned with 37% phosphoric acid for 5 s, rinsed and dried. ED primer was applied over the etched surface and air-dried. Panavia F was used to fix the silanated resin composite rod, and light-cured from three directions for 20 s each. Bond strengths were tested at 1min, 10min, and 24f. The 24-hour samples were stored in water at 37?. The TBS were performed on an universal testing machine (Shimazu AG-500B) at a crosshead speed of 2mm/min. The fracture modes were visually inspected. The data were analyzed using ANOVA and Tukey's test (p<0.05). MPa (±SD), n=10
| 1min | 10min | 24hours | |
| Group 1 (Dentin) | 10.2 (±3.8) | 9.5 (±2.6) | 11.6 (±3.5) |
| Group 2 (Resin-coating) | 10.6 (±4.6) | 14.2 (±2.8) | 17.4 8±4.4) |
J Dent Res 79(IADR Abstracts) 2000, p597, #3630
Microtensile Bond Strength Test of Dental Adhesives to the Dentine of the Root Canal
F. Mannocci, M.Sherriff, T.F.Watson
Univ. of Siena (Italy), Guy's Hospital (UK)
The aim of the present study was to evaluate the bond strength of two dentine-bonding systems to the dentine of the root canal. 4 central incisors, extracted for periodontal reasons, were endodontically treated, no obturation of the root canal space was performed. The teeth were cut parallel to their long axis. One half of each tooth was randomly assigned to one of two experimental groups. The teeth of the first group were treated with All Bond 2 dental adhesive and those of the second with Panavia F. The dentine of the root canal was conditioned as suggested by the manufacturer and after the application of the dental adhesives, a layer of composite resin was polymerised on the adhesive layer. After the resin composite had completely set, the sections were prepared for the microtensile test and kept in a wet environment at a relative humidity of 90±2% measured with a digital relative humidity meter and at a temperature of 22? for 24 hours. Ten specimens were sectioned perpendicularly to the bonded surface, into alabs 1.5mm thick, ten sections were obtained for each experimental group. The slabs were then trimmed by super fine diamond burs for the microtensile bond test with the narrowest region located at the respective bonded interface to be tested. The thickness of the slab was then exactly established by three measurements performed in three points of each slab by a digital micrometer. The specimens were then subjected to a tensile force at a cross-head speed of 0.2mm/min. The test was observed under the confocal microscope. The load at failure was registered and the bonded area was measured under the confocal microscope at a magnification of 25 x by an image processing program. The failure modes were also observed under the confocal microscope. The failure data were analyzed using the Wilcoxon-Gehan test with exact non-parametric inference. The mean value at failure was the same for the two experimetal groups (17.1MPa). There was no statistically significant difference between Panavia F and All Bond 2 (p=0.9671). The results showed that the bond strength of the two bonding systems tested to the dintine of the root canal are similar to those obtained with the latest adhesive systems, in the coronal denitne.
J Dent Res 78 (IADR Abstracts) 1999, p147, #334
Characteristic of a New Fluoride-releasing Adhesive Resin Cement
M. Kawashima, M.Harada, K.Nakatsuka, J.Ohtsuki
Kuraray Co., Ltd. (Japan)
A new fluoride-releasing adhesive resin cement "Panavia Fluoro Cement" (PNF, Kuraray) has recently been developed as an advanced type of "Panavia21"(P21,Kuraray). The purpose of this study was to compare the adhesive properties of PNF with P21, and to examine the fluoride uptake of tooth structure from PNF. PNF cement is comprised of MDP (phosphate monomer), comonomers, fillers, and initiator as found in P21, and functionalized sodium fluoride. Adhesion tests for the materials were performed after the materials had been adhered to human enamel (E) and Dentin (D), and 70%Au Alloy (Casting Gold Type IV, GC). Tooth surfaces were treated with self-etching primer "ED Primer", which is aq. solution of MDP, HEMA and other compounds. Gold metal surfaced were sandblasted using alumina and then coated with a metal primer, "Alloy Primer", which contains MDP and triazine dithion monomer. Metal rods were adhered to the substrates with each type of cement. Shear bond strength [MPa, (SD)] after thermocycling 3000 cycles were (PNF/P21): (E)39.0(4.0) / 31.2(8.5), (D)22.0(5.9) / 20.9(3.5), (Au)42.3(7.4) / 36.3(2.6). Some dentin samples prepared with the same method as the adhesion test were immersed in phosphate buffer solution (pH7) for 2 months, then the cement was removed and the sample was tested for F uptake. For PNF samples, F was found at 10µm depth with concentration of 6000ppm and at 30µm depth with 3000ppm. Other samples were immersed into acetic acid buffer solution (pH4.6) for 1 month. Eluted calcium ion [mg/cm2] from dentin were : 15 (PNF) and 24 (P21). This study demonstrates that PNF provides a good adhesion as compared to P21. In addition, PNF shows an effective F uptake level at dentin surface to reduce demineralization.
J Dent Res 78 (IADR Abstracts) 1999, p 159, #432
Enhanced Caries Resistance Using Fluoride-releasing Resin Materials
T. Kashiwada, M.Morita, T.Hashimoto, S.Kato
Keiai Dental Clinic (Japan)
Several new dental adhesive shave recently been developed. These adhesive materials, when used as sealing materials, could play an important role in the long term preservation of tooth structure. An introduce of fluoride (F) release function into adhesive materials may be become more effective against secondary caries. The purpose of this study was to investigate the effectiveness of F-releasing resin materials in strengthening the adjacent tooth structure. Two F-releasing materials were used : "Teethmate F-1" (sealant : Kuraray, TMF) and "Panavia Fluoro Cement" (adhesive cement : Kuraray, PNF). Two non F-release control materials were also used : Teethmate A (sealant : Kuraray, TMA) and "Panavia21" (adhesive cement : Kuraray, P21). The sealants were applied to root surface dentin as materials for protecting root surface from caries, while the adhesive cements were applied to crown dentin. Phosphoric acid and sodium hypochlorite (P/S) were used to condition the dentin surfaces prior to applying the adhesive cements since this conditioning is known to improve adhesion. The teeth samples were sectioned at the material area and the exposed dentin surfaces observed with EPMA and EDS before and after immersion in the buffered citric acid solution (pH5.6). The findings were that a F-rich layer with TMF and PNF of 15 and 20µm respectively was formed, and a Ca residual layer corresponding to the F-rich layer was noted. TMA or P21 did not show a F-rich layer, nor a Ca residual layer. PNF with P/S conditioning showed a thicker F-rich layer and a greater Ca residual layer. This study indicates that F-releasing materials supply F to tooth structure, and the treated tooth structure can show a resistance to decalcification.
J Dent Res 78 (IADR Abstracts) 1999, p227, #970
An Evaluation of the Anti-cariogenicity of Adhesive Resin Cements
R. W.Ellis, M.A.Latta
Creighton Univ. (USA)
A number of modern fluoride releasing luting materials have shown the ability to inhibit demineralization in an in-vitro caries model. A newly developed luting agent cement has been formulated to provide fluoride release with the strength and adhesive properties of a resin cement. The purpose of this study was to determine the anti-cariogenicity of this prototype (PN200) compared to Panavia 21. All enamel surfaces were acid conditioned with 40% phosphoric acid for 60 seconds and both enamel and dentin surfaces were treated ED Primer in both cement groups. Equal amounts of each cement's base and catalyst were mixed and placed in the preparations, covered with Oxyguard II and allowed to set for 24 hours. The cements were polished flush to the cavo-surface margins with Enhance polishing points. All teeth were placed in ten Cate solution (pH4.5) for 96 hours. 100-micton longitudinal sections were obtained through all of the restorations. Polarized light images using a 20X apperature were captured and lesion depths at the tooth/material interface were quantitated using Visilog 5.1.1 image analysis software. Results demonstrated that the mean (±S.D.) depths on the enamel interface to be: Pn200 - 72 (±39)µm; Panavia21 - 196 (±42)µm. A two-way ANOVA factors- (cement, surface) and Fisher's LSD comparison were done on the results. A significant difference was demonstrated between the cement used and the surface evaluated. The dentin lesion sizes within cement groups were significantly greater (p<0.05) than the enamel lesions. Enamel lesions were smaller with PN200 as compared to Panavia 21 (p<0.05). However, there was not a significant difference in the size of the dentin lesions (p>0.05) in either of the cements. The results of this study indicate that anti-caries activity exists for PN200 in enamel making it an ideal cementing agent for Maryland Bridge and other enamel margin restorations. This study was funded in part by the Kuraray Co. Ltd and the Health Future Foundation.
J Dent Res 78 (IADR Abstracts) 1999, p227, #973
Laboratory Evaluation of a Fluoride-releasing Adhesive Cement
M. A.Latta, W.W.Barkmeier, R.M.Pitruzello, T.M.Wilwerding
Creighton Univ. (USA)
A goal of modern luting agents is to combine high adhesive bonding properties with fluoride release for a number of restorative applications. The purpose of this in-vitro study was to 1) evaluate the shear bond strength (SBS) of Ni-Cr-Be (Rexillium) to enamel, dentin, Ni-Cr-Be and noble metal (Olympia) and 2) to evaluate the enamel and dentin microleakage of a new adhesive fluoride releasing resin cement, PN200 (Kuraray Co.Ltd.). 40 rods of Ni-Cr-Be alloy were cast to a diameter of 3.2mm and cut to lengths of approximately 6mm. The ends of the rods were air abraded with 50 micron alumina (AB) and cemented using the adhesive cement to the following substrates: Group I - Ni-Cr-Be AB treated with MP-100 metal primer, Group II - High Noble alloy AB and treated with MP-100 metal primer, Group III - enamel wet ground to 600 grit and treated with ED PRIMER and Group IV - dentin wet ground to 600 grit and treated with ED PRIMER. Equal amounts of base and catalyst of the cement were mixed, applied to the end of the metal rod and placed on the substrate with finger pressure. Excess cement was removed with an explorer and Oxyguard II was placed to allow complete polymerization of the cement. Microleakage was determined by cutting V-shaped cavities on the facial and lingual surfaces of 15 molar teeth with the occlusal margin in enamel and gingival margin in cementum/dentin. The cavities were filled with the cement. After 24 hours and themocycling between water baths of 5? and 55? for 800 cycles the specimens were placed in a 50% by weight silver nitrate solution, sectioned and scored 0 (no leakage), 1 (leakage 1/3 along the cavity), 2 (leakage 2/3 along the cavity) or 3 (leakage to the apex of the cavity). Groups I-IV were stored in water at 37? for 24hr and debonded using a chisel shaped rod in an Instron machine at a crosshead speed of 5 mm/min. A one-way ANOVA and post hoc Tukey's test were used for statistical of SBS values. Enamel and dentin microleakage scores were compared with a Kruskall Wallace analysis. Mean SBS (MPa) were: Group I - 54.2±11.1, Group II - 50.4±9.7, Group III - 55.9±18.3, Group IV - 36.26±12.0. SBS of Group I, II and III were statistically equivalent (p>0.05) and greater than Group IV (p<0.05). The median leakage score for enamel was 0 and for dentin was 1 (p<0.05). The results of this study show high bond strength of non-precious metal to both metal and mineralized tooth surface. This cement in combination with ED PRIMER was effective in sealing an enamel margin from microleakage. This study was supported by The Health Future Foundation and Kuraray Co. Ltd.
J Dent Res 78 (IADR Abstracts) 1999, p284, #1431
Micro-tensile Bond Strength of Cerec Inlay Luted to Dentin
S. Uno, C.Kawamoto, J.Konishi, T.Tanaka, H.Sano
Hokkaido Univ. (Japan)
For Cerec inlays, the luting materials and procedures have a great influence on the longevity of restorations. The purpose of this study was to examine the bond strength of the Cerec inlay to dentin by micro-tensile test and to access the bond efficacy of the three luting materials. Material and methods: VitaMark II disc (2mm thick) treated with a coupling agent was bonded to the coronal dentin surface with Clapearl DC/Linerbond IIS (CL), AP-X/ Linerbond IIS (AX) or an experimental chemically cured resin cement/ED Primer(PN-200), After 24 hours storage in water, micro-tensile bond strengths (MTB) were measured. Additionally, Cerec inlays were luted to the MO cavities prepared in molars with the same materials. After themocycling (x 2000), the restorations were cut mesio-distally. Gap formation was microscopically examined along the cavity walls. Results: There was no significant difference in MTB (CL: 20.89±4.58 MPa, AX: 24.22±5.97 MPa, PN-200: 19.82±6.43 MPa) among the materials (Scheffe, p>0.05). The frequency of gap formation was higher in AX than in CL and PN-200 (?2-test, p<0.05). Debonding occurred more often at the interface of luting material/dentin than at the inlay/luting material. (Sign test, p<0.05). It was concluded that contraction and thermal stresses in the luting material might affect the adaptation of Cerec restorations as well as the bond capacity.
J Dent Res 80 (IADR Abstracts) 2001, #1084
Bond strength to zirconia Ceramic with Different Luting Cements
O. Loeffel1. Hilüthy 1, F. Filser2, L. Gauckler2, P. Schärer1 and CH. Hämmerle1
(University of Zurich1 and Eth2, Zurich, Switzerland).
Zirconia is a new esthetic all-ceramic crown and bridge material used in dentistry. The purpose of this study was to evaluate the efficacy of the 3 following luting cements for bonding zirconia: Ketac-Cem (KC, Espe), Nexus, (NX, Kerr) and Panavia 21 (PA, Kuraray). 120 shear test specimens were prepared by bonding small cylindrical steel rods (3 mm in height and diameter) treated with Rocatec (R, Espe) to ceramic disks (3 mm thick; 13 mm in diameter) made of tetragonal zirconia polycrystals stabilized with 3 mol% Y2O3. The disks were previously mounted with a cold curing resin, and the surface was first polished and then sandblasted with Al2O3 (110 µm, 4 bars, at distance of 1 cm). For one group (NX) theZrO2-surface was treated with R. A load of 4 N was applied to secure the rods to the disks and the excess cement was carefully removed. This load was kept constant for 8 min. Prior to testing all bonded specimens were stored in distilled water at 37°C for 48 h and half of them were additionally subjected to thermocycling TC (10,000 x) in water (%/55°C) during 333 h. Finally the specimens were placed in a jig for shear bond strength testing described in ISO/TR 11405 and loaded to failure with a crosshead speed of 0.8 mm/min. The results were analyzed by ANOVA (p<0.001). The mean strength values (N=15) before and after TC were MPa: for PA: 63.4 +/- 7.8, 73.8 ± 8.5; for KC: 5.6 ± 2.4, 1.4 ± 0.4; for NX: 7.3 ± 4.0, 2.5 ± 4.3 and for NX9R): 22.8 ± 7.1, 18.9 ± 8.7. This in vitro study showed that Panavia 21 achieved the strongest and most durable bond to zirconia.
J Dent Res 76 (IADR Abstracts) 1997, #1131
Fracture Toughness of Resin-Based Luting Cements
L Knoblauch, R.E. Kerby, J.S. Berlin and J. Lee
(The Ohio State University, College of Dentistry, Columbus, Ohio, USA).
The purpose of this investigation was to evaluate the relative fracture toughness (K) of two composite resin luting cements (Enforce and Panavia 21), three resin-modified glass ionomer luting agents (Advance, Fuji Duet and Vitremer Luting), a polymethyl methacrylate resin-based cement (C&B Metabond) and a conventional glass ionomer cement (Ketac Cem) at 24 hr and 7 day storage times. K was determined by preparing light-cured (80s exposure) mini-compact test specimens (n=8) with introduced prepacks as described by Kovarik et al (1991). Specimens were stored at 37° ± 2°C in distilled water and then tested on an Instron at 0.5 mm/mln displacement rate. Mean values and standard deviation (SD) are listed
below:
|
Kg im MPa. m 1/2 |
||
| Cement | 24 hr | 7 day |
| C&B
Metabond Enforce Panavia 21 Advance Fuji Duet Vitremer Luting Ketac Cem |
1.42
(0.20) |
1.07
(0.10) |
ANOVA
(p<0.001) and REGW Multiple Range Test (p<0.05) demonstrated
significantly higher fracture toughness for resin-based luting systems
when compared to the conventional glass ionomer cement.
J Dent Res 80 (IADR Abstracts) 2001, #1304
Resin
cement is currently the material most often recommended for bonding
ceramic restorations to tooth structure. The purpose of this study was to
compare the bond strengths of different resin modified glass ionomer
cements (RMGIC) and a composite resin cement for the luting of an aluminum
oxide core (Procera®, Nobel Biocare) to dentin. Thirty freshly extracted
caries-free human teeth, stored in physiologic saline were sectioned 5 mm
into dentin. The teeth were randomly divided into three groups of ten each.
Two groups were bonded with RMGIC: Group 1-RelyX Luting Cement (3M), Group
2 –ProtecCem (Vivadent); and Group 3 used a composite resin cement,
Panavia 21 (Kuraray). The ceramic buttons were bonded to the dentin in
three groups using the respective cements. The teeth were then placed in a
humidity chamber at 100% humidity at 37°C for 30 minutes and then
thermo-cycled between 5°C and 55°C for 500 cycles. The buttons were
shear tested with an Instron machine at a cross-head speed of 0.5 mm/minute,
and the strengths of the bonds recorded. The mean shear bond strength
results are as follows: Group 1 = 4.8 ± 2.7 MPa, Group 2 = 1.4 ±1.3 MPa,
Group 3 = 9.7 ± 3.5 MPa. A One-way ANOVA showed significance between
groups (p=0.001). Of the resin-modified glass ionomer cements tested,
Group 1 was significantly better in shear bond strength than Group 2
(Student t-test, t=3.3, p<0.01). Supported in part by 3M Corp.
J Dent Res 78 (IADR Abstracts) 1999, #1532
This
investigation evaluated the retention of complete cast restorations with
three different cements: adhesive resin (Panavia EX), glass ionomer (Ketac-Cem),
and zinc phosphate (Fleck’s) cement as control. Thirty standardized
preparations were made using a modified milling machine with diamond
rotary instruments to a total convergence of 5°. Crowns were made using
the indirect technique with type III dental gold alloy (Ney-Oro B-2). The
cast crowns were divested and air abraded with 50 -µm aluminum oxide for
10 seconds using a contra-angle micro etcher at 60 Psi. The thirty crowns
were divided into three groups of 10 and crowns in each group were
cemented with one of the three cements. Cements were mixed according to
the manufacturer’s specifications. Retention was evaluated by measuring
the tensile load required to dislodge the crowns from their respective
tooth preparations with a universal-testing machine. With 1000 N load cell
and 0.5 mm/min cross head speed, the tensile force was applied to the
crown until separation occurred. Results were subjected to ANOVA and Tukey’s
Studentized Range. Analysis of forces disclosed a statistical significant
difference between zinc phosphate cement and adhesive cements (P <
0.001). However no significant difference was recorded between resin
cement and glass ionomer cement. Panavia EX cement was the most retentive
(352 ± 29 N). Zinc Phosphate cement was the least retentive (214 ±24 N).
However, glass ionomer cement had an intermediate value (308 ± 51 N). Adhesive
cements offer more tensile resistance to crown dislodgment and should be
used for cementation of complete cast restorations when maximum retention
is desired. Manufacturers provided products.
J Dent Res 77 (IADR Abstracts) 1998, #2238
The
aim of this study was to evaluate the effect of three different surface
treatments on the bond strength of In-Ceram (Vita Zahnfabrik, Germany) to
four different luting cements; three Bis-GMA based resin cements (Panavia
21, Kuraray, Japan; Variolink Ultra, Vivadent, Liechtenstein; Sonocem,
Espe Germany) and a compomer cement (DyractCem, Dentsply De Trey , Germany).
In-Ceram samples were fabricated in discs that were 2 mm thick and 16 mm
in diameter according to manufacturer’s recommendations. Eighth samples
were used for each experimental group. The bonding surface of each sample
was ground to 1200 grit silicone carbide abrasive. The samples were
cleaned ultrasonically in ethylacetate for ten minutes and they were
randomly assigned to each of the following three treatment conditions: (1)
Etching for 90 sec. with 10% hydrofluoric acid gel, (2) Air abrading (110
µm AL2O3) (3) Tribochemical silicoating (Rocatec
system, Espe Germany). All samples were silanated following the surface
treatment. The luting cements were bonded to In-Ceram specimens using
Teflon tubes with internal diameter of 5 mm and 5 mm in height. All
samples were thermocycled for 5000 cycles alternating between 5 and 55°C
with 30 sec dwell times. The shear bond values were measured in an Instron
testing machine with the cross-head speed of 1 mm/min. The mean shear bond
strength values and standard deviation of each group are shown in the
following table:
In
Vitro Bond Strength Evaluation of Resin Modified Glass Ionomer Cements
N.N. Lokko, G Kugel, C. Habib, E. Doherty, W. Rand (Tufts Univesity
of Dental Medicine, Boston MA)
Retentive
Properties of Adhesive Luting Cements for Complete cast crowns
M.
Ayad, M Bahabri and S. Rosenstiel (Elite Medical and Surgical Center, Riyadh,
KSA and the Ohio State University, Columbus, OH, USA).
Effect
of Surface Treatment on the Bond Strength of Luting Cement to In-Ceram
H.N.
Alkumru, M. Özcan, I Negriz, D Gemalmaz, A. Akkaya (Marmars University,
Faculty of Dentistry, Istanbul, Turkey
and Medical and Dental
School of Köln, Germany)
| Panavia 21 | Variolink Ultra | Sonocem | Dyract Cem | |
|
Acid
etching |
10.6
(1.4) |
2.4
(2.1) |
2.6
(1.5) |
6.6
(1.5) |
J Dent Res (IADR Abstracts) 1997, #2391
Surface
Conditioning of Dental Alloys; Its Upon Adhesion
P.A. Burmann, P.E.C.
Cardoso; M Poloniato; J.F.F. Santos (U.F. Santa Maria & Dental Materials,
School of Dentistry USP, Sao Paulo, Brazil).
This
research deals with adhesive strength of a semi-noble alloy (Pors-on 4 – AgPd)
and a noble one (Degudent U – Au-Pd), promoted by means of two luting cements,
Panavia EX and Ketac Cem. The samples were cast in a button form with flattened
surfaces and divided in 2 groups: 1) 120 buttons with surfaces sandblasted by
means of Al2O3 (74 – 105 µm); 2) 120 buttons with
surfaces sandblasted by means of AL2O3 (74-105 µm); 2)120
buttons with surfaces that were first sandblasted with AL2O3
followed by microblasting with tin powder followed by oxidation at 300°C. Each
test specimen (120 in total) was composed by a pair of buttons bonded with one
of the adhesive cements, thermocycled 700xs in a water bath at 5 an 55°C and
stored during 2, 90 and 180 days in a saline solution at 37°C. After the
specimens had undergone these experimental conditions the adhesive strength of
each pair of metallic bonded buttons was measured in a Welpert testing machine.
The data were statistically analyzed (ANOVA) and the following conclusions could
be drawn: The
highest values of tensile bond strength were observed with the oxidation (tin
powder) of the alloys;The bond strngth values obtained with Panavia EX were
higher than those obtained with KetacCem;: The Ag-Pd alloy showed best results
than Au-Pd one. The age of the samples (storage in saline solution) had no
significance upon the bond strength values: SEM pictures suggest a
micro-mechanical bonding.
This
research was supported in part by CNPq and NAPEM
J Dent Res 76 (IADR Abstracts) 1997, #2439
Linear
Expansion of three RMGI Cements compared to three controls
R.A. Hollis, T.E.
Rasmussen & R.P. Christensen (Clinical Research Associates, Provo, Utah USA
Claims have been recently made that ceramic crowns have cracked when used in conjunction with resin modified glass ionomer (RMGI) cements. This in vitro investigation compared the long-term expansion of three recently introduced RMGI cements compared to representative brands of well-known cements of varying formulations. Materials tested are listed below. Ten samples, 20 mm diameter and 1 mm high, were made from each material. Each sample was built & allowed to cure at 37 °C. The diameter was then measured along the x and y axis, placed in a propylene vial with 10 ml of a 0.85% NaCL solution & stored at 37°C. All measurements were made with the sample submerged in 37°C distilled H2O. Each sample was subsequently measured at the times listed below for linear expansion. Data were analyzed using AOV & Fisher’s LSD (p< 0.05), Linear expansion (%) over three weeks were as follows:
| cement | material type | 1 hour | 24 hour | 2 days |
| Flecks Fuji 1 Panavia 21 Advance Vitremer Fuji Duet |
Zinc Phosphate Glass ionomer (GI)Resin ® RMGI RMGI RMGI |
-0.20 0.13 -0.16 0.30 2.79 3.51 |
-0.24 0.02 0.05 2.42 3.91 5.02 |
0.01 -0.13 0.56 3.18 4.03 4.99 |
| cement | material Type | 3 days | 1 week | 3 weeks |
| Flecks Fuji 1 Panavia 21 Advance Vitremer Fuji Duet |
Zinc Phosphate Glass ionomer (GI)Resin ® RMGI RMGI RMGI |
0.01 -0.17 0.64 3.11 3.88 4.81 |
-0.58 -0.20 0.53 3.49 4.14 5.21 |
-0.54 -0.27 0.53 4.18 4.31 5.40 |
Fleck’s
(ZP) shrunk slightly, which was attributed to a visible deterioration of
the samples over time. Fuji 1 (GI) was statistically not different over
the 3 weeks (p< 0.0563) however it did appear to be shrinking slightly
over the 3 week period. Panavia 21 ® expanded slightly & then
remained constant beyond 2 days. All three RMGI’s expanded significantly
more than the other three materials (p<0.0001). Vitremer & Fuji
Duet expanded for 24 hours but thereafter remained constant. Advance,
however, continued to expand throughout the three-week test. Conclusion:
Expansion of the three RMGI’s was significantly greater than the
controls: ZP, GI, & R. In vivo testing must be done to determine if
the expansion is large enough to critically affect a ceramic crown.
| Bistite (Tokuyama) |
Panavia
21 Kuraray |
FujiLute GC |
Advance (Caulk) |
|
| Wear loss | ||||
| (µm) | 3.28 | 7.22 | 12.72 | 13.14 |
| (SD) | 2.82 | 4.37 | 7.52 | 4.82 |
| Vitremer Luting (3M) |
Dyract
Cem (De trey) |
Fuji1 (GC) |
Resinomer (Bisco) |
|
| Wear loss | ||||
| (µm) | 14.27 | 15.81 | 16.82 | 16.93 |
| (SD) | 8.18 | 6.41 | 7.34 | 6.92 |
Means
(n=6) connected with the line are not significantly different (p >
0.05, Scheffer’s test). Bistite presented the last wear loss among the
eight luting cements. The wear resistance of the resin-modified glass
ionomer cements was not significantly different from Fuji1. The results
indicated that the wear resistance of resin-modified glass ionomers was
similar to conventional glass ionomer and one type of resin cement, but
inferior to another type of resin cement.