Efficacy of various cleaning solutions on saliva-contaminated zirconia for improved resin bonding

PURPOSE: This study aimed to investigate the efficacy of cleaning solutions on saliva-contaminated zirconia in comparison to air-abrasion in terms of resin bonding. MATERIALS AND METHODS: For saliva-contaminated airabraded zirconia, seven cleaning methods)-no contamination (NC), water-spray rinsing (WS), additional airabrasion (AA), and cleaning with four solutions (Ivoclean [IC]; 1.0 wt% sodium dodecyl sulfate [SDS], 1.0 wt% hydrogen peroxide [HP], and 1.0 wt% sodium hypochlorite [SHC])-were tested. The zirconia surfaces for each group were characterized using various analytical techniques. Three bonded resin (Panavia F 2.0) cylinders (bonding area: 4.5 mm2) were made on one zirconia disk specimen using the Ultradent jig method [four disks (12 cylinders)/group; a total of 28 disks]. After 5,000 thermocycling, all specimens were subjected to a shear bond strength test with a crosshead speed of 1.0 mm/minute. The fractured surfaces were observed using an optical and scanning electron microscope (SEM). RESULTS: Contact angle measurements showed that groups NC, AA, IC, and SHC had hydrophilic surfaces. The X-ray photoelectron spectroscopy (XPS) analysis showed similar elemental distributions between group AA and groups IC and SHC. Groups IC and SHC showed statistically similar bond strengths to groups NC and AA (P>.05), but not groups SDS and HP (P<.05). For groups WS, SDS, and HP, blister-like bubble formations were observed on the surfaces under SEM. CONCLUSION: Within the limitations of this in vitro study, some of the cleaning solutions (IC or SHC) were effective in removing saliva contamination and enhancing the resin bond strength.

Degree of conversion of two dual-cured resin cements light-irradiated through zirconia ceramic disks

PURPOSE: The aim of this Fourier transform infrared (FTIR) spectroscopic study was to measure the degree of conversion (DC) of dual-cured resin cements light-irradiated through zirconia ceramic disks with different thicknesses using various light-curing methods. MATERIALS AND METHODS: Zirconia ceramic disks (KT12) with three different thicknesses (1.0, 2.0, and 4.0 mm) were prepared. The light transmittance of the disks was measured using ultraviolet visible near-infrared spectroscopy. Four different light-curing protocols were used by combining two curing light modes (Elipar TriLight (standard mode) and bluephase G2 (high power mode)) with light-exposure times of 40 and 120 seconds. The DCs of the two dual-cured resin cements (Duo-Link and Panavia F2.0) light-irradiated through the disks was analyzed at three time intervals (3, 7, and 10 minutes) by FTIR spectroscopy. The data was analyzed using repeated measures ANOVA (alpha=.05).Two-way ANOVA and Tukey post hoc test were used to analyze the 10 minute DC results. RESULTS: The 1.0 mm thick disk exhibited low light transmittance (<25%), and the transmittance decreased considerably with increasing disk thickness. All groups exhibited significantly higher 10 minute DC values than the 3 or 7 minute values (P<.05), but some exceptions were observed in Duo-Link. Two-way ANOVA revealed that the influence of the zirconia disk thickness on the 10 minute DC was dependent on the light-curing methods (P<.001). This finding was still valid even at 4.0 mm thickness, where substantial light attenuation took place. CONCLUSION: The curing of the dual-cured resin cements was affected significantly by the light-curing technique, even though the additional chemical polymerization mechanism worked effectively.

Effect of Cobalt-Chromium Alloy Surface Treatment When Bonding With 4-Meta/mma-Tbb Resin / 대한치과보철학회지

The effects of pretreatment of Co-Cr alloy, including two adhesive primers that contain either MDP or MAC-10, and silicoating on the bond. The results obtained as follows : Strength of 4-META/MMA-TBB resin were investigated using FT-IR SEM, and EDAX. in the SEM observation of surface morphologies, the sandblasted specimen exibited a very rough surface, whereas the surfaces of the two groups primed with either MDR or MAC-10 were covered with a layer of primer, and the surface morphology of the silicoated specimen remained almost the same after sandblasting. Before the thermocycling tests, the group treated with MDP demonstrated the highest mean tensile bond strength and the sandblasted group showed the lowest bond strength. After 20,000 themocyling, the mean tensile bond strength of the sandblasted group exhibited a 50% reduction in bond strength, while the other showed a 20~30% reduction. Observation of the metal-resin interface revealed that in all groups the resin permeated the rough surface formed by sandblasting thereby producing a mechnical bond between the metal and the resin, It was also found that thermocycling resulted in a gap formation at the metal-resin interface of the specimens, and the sandblasted group exhibited a larger gap width than the other groups. in fracture mode, all specimens indicated a cohesive fracture within the resin before thermocycling. However, thermocyling produced adhesive failure at the edge of the resin-metal interface in most specimens, The sandblasted group, which exhibited the lowest bond strength after thermocycling, also demonstrated the largest area of adhexive failure.

The frictional resistance of tin ion-plated Co-Cr orthodontic wire / 대한치과교정학회지

The effectiveness of TiN ion-plating was examined with TiN ion-plated Co-Cr wires(016", 016"X.022") on three different types of bracket(TiN ion-plated metal bracket, ceramic bracket and plastic bracket). Maximum static frictional forces and characteristic curves obtained from the frictional characteristic graph, were compared and surface roughness of wires and bracket slots before and after friction experiment was observed by SEM. The obtained results were as follows. · The frictional forces of TiN ion-plated wires were significantly lower than those of non ion-plated wires(P<0.O5 ).· On the effect of wire shape, the frictional forces of round wires were significantly lower than those of rectangular wires(P<0.05). · As the result of the SEM observation on the wires and bracket slots after the friction experiment, the surface of non ion-plated wires was rougher than that of TiN ion-plated ones. · The difference between the static frictional forces and the kinetic frictional forces was not significant in case of the TiN ion-plated round wires, but the static frictional forces were a little higher than the kinetic frictional forces in the TiN ion-plated rectangular wires. · The static frictional forces were much higher than the kinetic frictional forces in the case of non ion-plated wires.

The effect of ligation method on the frictional force between orthodontic bracket and archwire / 대한치과교정학회지

The frictional force has been considered as an harmful factor in an active unit where tooth movement occurs, but as an advantageous factor in anchor unit that resist tooth movement. That is, efficient tooth movement is planned by using ligation methods that have low levels of bracket-wire frictional force and the anchorage control can be achieved by using ligation methods that have high levels of bracket-wire frictional force that result in binding of the bracket accompanied by little or no tooth movement. The purpose of this study was to evaluate the frictional force generated between bracket and wire in accordance with the methods of ligation, the material of ligation and the passage of time under artificial saliva. Tested were 0.017X0.022 inch stainless steel wires in standard edgewise twin brackets for upper central incisors in a 0.018-inch slot The wires were ligated into the brackets with elastomeric modules and stainless steel ligatures. Whole tie, half tie, twisting tie and double overlay tie were done with elastomeric modules. With 0.009-inch stainless steel ligature whole tie and half tie were done by needle holder and whole tie by ligature tying plier. With 0.012-inch stainless steel ligature whole ties were done by needle holder. Whole tie groups of elastomeric module were kept in artificial saliva bath at 37degress C for 28 days. The frictional force was recorded by means of an Instron universial testing instrument (4202 INSTRON, Instron Co., U.S.A.) at initial, 7, 14, 21, and 28 days. The results for ligated samples in a simulated oral environment revealed the following: In elastomeric module whole tie, 28 days group was significantly greater mean static frictional force than any other group but there were no significant differences among any other group (p>0.05). Elastomeric module twisting ties were significantly greater mean static frictional forces than any other ligation method but there were no significant differences between twisting tie and double overlay tie (p>0.05). Twisting tie, double overlay tie, whole tie, half tie showed differences in decreasing order. Stainless steel half tie produced lower mean static frictional forcee than whole tie, ligation by ligature tying plier produced greater mean static frictional force than by needle holder and ligation with 0.012-inch stainless steel ligature produced greater mean static frictional force than with 0.009-inch stainless steel ligature (p0.05).

The physical properties of tin ion-plated Co-Cr (elgiloy) orthodontic wires / 대한치과교정학회지

To estimate the possibility of clinical application of TiN ion-plated Elgiloy(Co-Cr wire), measurements of tensile strength and hardness were made on the four tempers on each of the manufactured Elgiloy, the (heat-treated) Elgiloy for 30 minutes at 250degrees C and the TiN ion-plated Elgiloy. For comparison, the tensile strength and hardness of Stainless Steel wires were also measured. The following are the results of the study: · In the 4 tempers, tensile strength was the greatest in the TiN ion-plated group, followed by the heat-treated Elgiloy group and the manufactured Elgiloy group, but no statistical difference was noticed between heat-treated and manufactured Elgiloy groups(P<0.05). · In each temper, tensile strength- of ion-plated Elgiloy increased- about l0kgf/mm` in comparison with the values of the manufactured Elgiloy. · In yellow, green and red tempers except the blue, hardness was the greatest in ion-plated group. In the blue temper, there was no statistical difference between heat: treated and manufactured Elgiloy groups(P<0.05). · In each temper, hardness of ion-plated Elgiloy increased about 50-90VHN in comparison with the values of the manufactured Elgiloy. · The tensile strength of Stainless Steel wire was similar to that of the red temper of manufactured Elgiloy and the green temper of ion-plated Elgiloy.

Biomechanical Study about Strength and Strain of Pretwist on Properties of Canine Central 1/3 Patellar Tendon / 대한정형외과학회잡지

Pretwisting the patellar tendon graft has been advocated hy many authors. Lambert has described a 90 degrees pretwist to benifit the fat pad vascular supply as well as to "" simulate the helicoid course of the ACL "". This technique has also been recommended to fascilitate fixation. Jackson has recommended a 90 pretwist to decrease the possibility of abrasive wear on the tunnel edge, and also to fascilitate fixation as much as a 180 degrees pretwist has heen recommended. However, in spite of all these recommendations, little work has been done on the effect of such pretwisting on the biomechanical behavior of patellar tendon grafts. The purpose of this study is to discover, by experiment, the effects of a 360 degrees external rotation pretwist on the following tensile mechanical properties of canine central 1/3 patellapatellar tendon-tibia complex : (a) ultimate stress, (b) ultimate strain, (c) average elastic modulus, and (d) strain energy density. Five groups of each S specimens were divided as group 1 (0 degrees external rotation), group 2 (90 degrees external rotation). group 3 (180 degrees external rotation), group 4 (270 degreesexternal rotation), and group 5 (360 degrees external rotation). The direction of pretwist meant the twist of tibia around patella. The effects of pretwist were analyzed using parameter one-way analysis of variance (ANOVA)(P1) and nonparameter Kruskal-Wallis one-way analysis of variance (ANOVA)(P2) with repeated measures followed by Scheff multiple comparison test. A p values of < 0.05 was considered statistically significant. Among each groups ultimate stress (P1=0.059, P2=0.095), ultimate strain(P1=0.154, P2=0. l65), and average elastic modulus(P1=0.814, P2=0.818) were not statistically significant. Only strain energy density was the statistically significant difference between group 2 and group 5(P1=0.008, P2=0.022). As a result, there were observed that the ultimate stress and strain energy density were decreased and ultimate strain was decreased but there were not statistically significant differences hetween groups because of the small number of samples, and there will be advantages for graft to avoid ahrasive wear on the tunnel edge and lateral femoral condyle. But, more studies are needed for human being in the future.

The effect of tin ion-plating on the bond strength of orthodontic bracket / 대한치과교정학회지

This study was conducted to see the effect of TiN ion-plating on the bond strength of orthodontic bracket. Three stainlesssteel brackets with different base types were chosen; when TiNTion-plated brackets and non ion-plated brackets were bonded to the teeth, initial and long-term bond strength were measured The observations of bonding surface and failure sites through the scanning electron microscope were analysed and compared. The summary of this study was as follows: When TiN ion-plating was not applied, the Micro-Loc type was the highest in bond strength atter 24 hours as 5.89+/-1.77 MPa, followed by 4.27+/-1.12 MPa for Foil Mesh type and 2.64+/-0.58 MPa for Undercut type(P<0.05). Under TiN ion-plating, the bond strength after 24 hours showed: Micro-Loc type - 6.26+/-1.51 MPa, Foil Mesh type - 7.45+/- 2.01 MPa, Undercut type - 2.93+/-0.84 MPa Unlike in the case of non ion-plating, Foil Mesh type showed a higher strength than Micro-Loc type, with Undercut type still showing the lowest bond strength(P<0.05). The bond strength, after 24 hours, increased in case of ion-plated in all 3 types, but a significant increase was shown only in Foil Mesh type(P<0.001). Under a long-term immersion, regardless of ion or non ion-plating, bond strength in general increased over the initial bond strength(one day), with more stability. Through scanning electron microscopic observation of bonding surface, it was found that, regardless of the bracket base type or the application of ion-plating, the resin was thoroughly spreaded into bracket base to form a solid bonding surface between the bracket and the tooth.. This was also true in case of a long-term immersion. The scanning electron microscopic observation of failure sites revealed diverse failure patterns.

Comparison of the frictional resistance between non-ion plated and Tin ion plated to the orthodontic appliance / 대한치과교정학회지

To estimate the possibility in the application of TiN ion-plating to the orthodontic appliance, this study investigated frictional force and frictional coefficient between non-ionplated and TiN ion-plated to the orthodontic appliance. The obtained results were as follows: 1. For each group, the frictional force between metal bracket and arch wire in the wet condition was exhibited lower than that in the dry condition. 2. In the dry condition, the frictional force was lowest with fourth group, and it increased in the order of the 3rd, 1st, and 2nd group. Same situation happened in the wet condition. 3. Experimental results using ceramic & plastic bracket showed that group B was lower than group A, and group D was similar to group C. 4. The surface texture after experiment showed that the scratch due to a friction with bracket was observed in an arch wire of dry contition. Also the surface of bracket was rougher than before. 5. We observed that a specimen surface processed with the TiN ion plating was smoother than that of without the TiN ion plating. 6. The surface texture of a metal bracket and an arch wire in the wet condition was observed smoother than that in the dry condition. 7. In the dry condition, the friction coefficient of each specimen was very similar to each other, but in the wet condition, the friction coefficient of specimen processed with the TiN ion plating showed lower values.

Application of tin ion-plating to the orthodontic appliance / 대한치과교정학회지

To estimate the possibility of the application of TiN ion-plating to the orthodontic appliance, colorimetric properties, and characteristics of ion-plated film as well as adhesive strength of TiN film to the substrate and mechanical properties of ion-plated orthodontic appliance were investigated. The obtained results were as follows: 1) TiN ion-plated film had the colorimetric properties which were the hue of about 2.5 Y, the brightness of about 6, and the chroma of about 4 by the standard color chip of JIS. 2) TiN ion-plated film was 2micrometer in thickness and its deposition pattern was rather irregular. 3) TiN phase was confirmed on the X-ray diffraction pattern. 4) Critical load for delamination of ion-plated film from stainless steel band was 10N. 5) Tensile and yield strength of ion-plated specimen was increased about 10Kg,f/mm2 , while elongation was decreased 1% com pairing to the values of the non ion-plated specimen.