负压对多晶颗粒表面改性氧化锆与树脂粘接强度的影响

目的:探讨负压对多晶颗粒表面改性氧化锆陶瓷与树脂粘接强度的影响。方法:制备120个预烧结氧化锆圆片,用随机数字表法随机分成对照组和喷砂组以及30、50、70 s酸蚀组（每组24个）。对照组、喷砂组试件致密烧结前无额外处理;30、50、70 s酸蚀组分别浸入氢氟酸溶液30、50、70 s,再置于CaCl 2溶...     

义齿基托软衬材料的研究进展

义齿基托软衬材料能缓冲压力，增加义齿的固位和稳定。近年来随着材料的改进和临床研究的深入，对其临床应用的意义又有了新的进展。本文从软衬材料的分类、性能、临床意义及适应症和使用注意事项等方面进行综述。     

树脂表面粗糙度对丙烯酸树脂与硅橡胶粘接强度的影响

高并不利于提高丙烯酸树脂与硅橡胶间的粘接力,用较小粗糙度的600目砂纸打磨丙烯酸树脂表面可提高丙烯酸树脂与硅橡胶间的粘接强度.     

不同表面处理对义齿软衬树脂黏结强度的影响

目的:探讨4种不同表面处理对义齿软衬树脂与硬质树脂之间黏结强度影响。方法:制作热凝硬质基托树脂试件(直径8mm,长度15mm)和热凝义齿软衬树脂试件(厚4mm,直径10mm),然后将2个硬质树脂试件黏结在软衬树脂正反两面的中心。采用4种不同表面处理方式——第1组,对照组,不加任何处理;第2组,喷砂粗化处理;第3组,专用黏结剂涂布表层;第4组,表层涂布 喷砂粗化。每组各10个试件,分别测定黏结强度,采用SPSS10.0软件进行单因素方差分析。结果:第1、2、3、4组的平均黏结强度分别为3.518、2.834、4.077和3.852MPa。F=6.40,P<0.0014。表层涂布组的黏结强度最高,而喷砂组的黏结强度最低。结论:使用专用黏结剂表层涂布,可显著增强义齿软衬树脂的黏结强度;而进行喷砂处理,反而会使黏结强度下降。     

热固化义齿软衬材料与基托树脂粘结的实验研究

测试了不同底胶、软衬材料中ＥＤＭＡ的含量及ＰＭＭＡ表面预处理对软衬材料与ＰＭＭＡ粘结强度的影响。结果表明，底胶Ｃ粘结效果最好，含有５％ＥＤＭＡ的软衬料与ＰＭＭＡ粘结强度最大，ＰＭＭＡ表面经处理后，粘结强度有明显提高。     

树脂表面形态处理对义齿软衬材料粘结性能的影响

目的：探索一种增进硅橡胶软衬材料和基托粘结力的可靠方法,促进软衬材料的临床应用。方法：利用模具制作两组树脂基托板：平面基托板和有凸起的基托板,以silagum硅橡胶软衬材料为夹心,平板对平板、凸板对凸板分别制作＂三明治＂样结构,采用改良的＂L＂形拉伸撕脱试验测试两组试件的粘结功并记录撕脱方式,所得试验数据经统计学分析（a=0.05）。结果：凸起组的的粘结功明显大于平面组的粘结功,二者间的差异具有统计学意义（P〈0.05）。平面组的破坏形式以粘结性破坏为主;凸起组的破坏形式以内聚性破坏和混合性破坏为主。结论：改变树脂基托表面的形态增大接触面积及嵌合力可以增大硅橡胶软衬材料和丙烯酸树脂之间的粘结强度。     

提高塑料牙与基托树脂结合强度的实验研究

测定了３种塑料牙盖嵴面经４种预处理方法处理后塑料牙与基托树脂的剪切粘接强度，结果表明，涂氯仿组的粘接强度明显大于对照组，而且，氯仿的效果更优于单体。     

喷砂结合化学处理对软衬材料粘结效果的影响

[摘要]目的：研究喷砂结合化学处理对硅橡胶软衬材料与基托树脂间粘结强度及基托树脂挠曲强度的影响。方法：制备48块30mm×10mm×7．5mm热凝聚甲基丙烯酸甲酯树脂块,每2个树脂块配成一个试件,24个试件随机分为4组,每组6个试件,即：（1）喷砂组：喷嘴与试件轻接触,采用250txm的氧化铝,在0．62MPa压力下喷砂30S;（2）喷砂＋丙酮组：粘结面喷砂处理同前,喷砂后的粘结面浸泡在丙酮溶液中30S;（3）喷砂＋甲基丙烯酸甲酯单体组（后简称单体）：粘结面喷砂处理同上,喷砂后的树脂块粘结面浸泡在甲基丙烯酸甲酯溶液中180S;（4）对照组：表面不处理。每个试件的两树脂块间衬以3mm厚的软衬材料,冷热循环5000次后,置于万能测试机上,以5mm／min的加载速度测试其拉伸粘结强度。另制备24块65mm×10mm×3．3mm长方体树脂块,分组及表面处理同前,涂布软衬材料粘结剂后测试挠曲强度。结果：喷砂组、喷砂＋丙酮组、喷砂＋甲基丙烯酸甲酯组及对照组试件的拉伸粘结强度分别为（1．31±0．45）MPa、（1．75±0．34）MPa、（1．96±0．50）MPa及（0．90±0．17）MPa。喷砂组与对照组间差别无统计学意义（P〉0．05）。喷砂＋丙酮组及喷砂＋单体组的拉伸粘结强度与对照组相比有统计学差异（P〈0．05）;喷砂＋丙酮组与喷砂＋单体组组间比较无统计学差异;四组间挠曲强度均无统计学差异（P〉0．05）。结论：喷砂结合化学处理树脂表面能增强硅橡胶软衬材料与基托树脂间的粘结强度,且对基托树脂挠曲强度没有影响。     

分光光度法与目测法测量义齿基托树脂色稳定性的比较研究

Objective To explore the relationship between the spectrophotometric and visual methods in evaluating the color stability of denture base resin, and determine the threshold color difference of denture base resin in the spectrophotometric method. Methods Two kinds of denture base resin were respectively fabricated into 33 specimens whose color differences varied from indistinguishable to obvious.Each of the specimens was assessed respectively by 30 human observers and a SP62 spectrophotometer. The results of visual assement were recorded as "indistinguishable change", "light change" or "severe change",while the spectrophotometric color differences ( △ E) were calculated. In each group, a logistic curve was explored to determine the relationship between the color difference ( △ E) and the ratio of "severe change".Results The R squares of logistic curves were 0. 93 and 0. 94 respectively. The threshold color differences in the spectrophotometric method were 2. 87 and 2. 82 respectively. Conclusions A high relevance between the spectrophotometric and visual methods in evaluating the color stability of denture base resin was found.The threshold color differences for different color denture base resins were similar.     

含氟复合树脂释氟对材料挠曲强度的影响

目的：研究含氟复合树脂释氟对材料本身机械性能的影响。方法：选择不同氟含量的含氟树脂,以氟电极法连续30d测定含氟复合树脂体外释氟量。万能试验机测定含氟复合树脂释氟30d前后的挠曲强度。结果：含氟树脂氟含量越高（重量比分别为0％、0．3％、0．6％和1．2％）,初期释氟量越大（分别为0、21．98、43．98和99．91μg.cm^-2),相应挠曲强度越低（分别为101．70、94．29、82．03和79．84MPa）。随着含氟复合树脂释氟量的增加,材料的挠曲强度相应降低。结论：含氟树脂释氟对其机械性能有一定影响。     

Effect of silica coating and silane surface treatment on the bond strength of soft denture liner to denture base material

Objective

This study investigated the effects of different surface treatments on the tensile bond strength of an autopolymerizing silicone denture liner to a denture base material after thermocycling.

Material and Methods

Fifty rectangular heat-polymerized acrylic resin (QC-20) specimens consisting of a set of 2 acrylic blocks were used in the tensile test. Specimens were divided into 5 test groups (n=10) according to the bonding surface treatment as follows: Group A, adhesive treatment (Ufi Gel P adhesive) (control); Group S, sandblasting using 50-µm Al₂O₃; Group SCSIL, silica coating using 30-µm Al₂O₃ modified by silica and silanized with silane agent (CoJet System); Group SCA, silica coating and adhesive application; Group SCSILA, silica coating, silane and adhesive treatment. The 2 PMMA blocks were placed into molds and the soft lining materials (Ufi Gel P) were packed into the space and polymerized. All specimens were thermocycled (5,000 cycles) before the tensile test. Bond strength data were analyzed using 1-way ANOVA and Duncan tests. Fracture surfaces were observed by scanning electron microscopy. X-ray photoelectron spectrometer (XPS) and Fourier Transform Infrared spectrometer (FTIR) analysis were used for the chemical analysis and a profilometer was used for the roughness of the sample surfaces.

Results

The highest bond strength test value was observed for Group A (1.35±0.13); the lowest value was for Group S (0.28±0.07) and Group SCSIL (0.34±0.03). Mixed and cohesive type failures were seen in Group A, SCA and SCSILA. Group S and SCSIL showed the least silicone integrations and the roughest surfaces.

Conclusion

Sandblasting, silica coating and silane surface treatments of the denture base resin did not increase the bond strength of the silicone based soft liner. However, in this study, the chemical analysis and surface profilometer provided interesting insights about the bonding mechanism between the denture base resin and silicone soft liner.     

Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties.

Objective

This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply).

Material and Methods

Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37ºC for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers'' instructions and stored in distilled water at 37ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (α=0.05) and the failure modes were visually classified.

Results

No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups.

Conclusions

Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents.     

Effect of denture base surface pretreatment on microleakage of a silicone-based resilient liner

STATEMENT OF PROBLEM: Microleakage between resilient liner and denture base resins is a significant clinical problem, often responsible for debonding of the resilient liner from the denture base resin. PURPOSE: This study investigated the effect of 2 surface treatments, airborne-particle abrasion (APA) and wetting with methyl methacrylate monomer (MMA), on microleakage between a silicone-based resilient liner and denture base resin using a gamma camera imaging technique. MATERIAL AND METHODS: Thirty-three specimens, each having 2 plates measuring 40 x 40 x 2 mm, were prepared by packing and processing an acrylic denture base resin (QC-20) into square plates following manufacturer's instructions. Specimens were divided into 3 groups (n=11) as APA-, MMA-, and control-treatment groups. For the APA group, the inner surfaces of both plates were airborne-particle abraded with 250-microm Al 2 O 3 particles and, for the MMA group, surfaces were treated with monomer (QC-20). Control specimens were not surface treated. Following application of an adhesive (Ufi Gel P-specific), a silicone lining material (Ufi Gel P) was prepared and applied to the inner surfaces of all 33 specimens. Eleven size-matched polymethyl methacrylate (PMMA) specimen blocks (40 x 40 x 6 mm) were prepared to calculate the level of residual radioactivity for the denture base itself, the entire outer surface count (OSC). All specimens and PMMA blocks were immersed in a radioactive solution (thallium-201 chloride) for 24 hours. Specimen activities (gamma-ray cts/sec, representing thallium-201 concentration) were then measured using a high-resolution gamma camera. The amount of OSC-subtracted total specimen counts was a direct indicator of the quantity of inward diffusing tracer. The subtracted values were analyzed using a 1-way analysis of variance (ANOVA) and Bonferroni multiple comparison tests (alpha=.05). RESULTS: OSC levels averaged 754 +/- 110 gamma-ray cts/sec. OSC-subtracted APA, control, and MMA values were 5,546 +/- 1,534, 3,392 +/- 738, and 1,405 +/- 392 gamma-ray cts/sec, respectively. All 3 groups were significantly different ( P <.05) from each other. Surface wetting with MMA showed the lowest microleakage values among all specimen groups. CONCLUSION: In terms of microleakage, surface treatment with MMA monomer preceding the adhesive application demonstrated lower values than adhesive application alone. APA pretreatment resulted in 4 times the microleakage found in MMA-treated specimens, and 1.5 times the microleakage of the untreated control. None of the surface pretreatments completely prevented microleakage. Microleakage between the silicone-based resilient liner and denture base resin can be quantitatively determined using the gamma camera imaging technique.     

The evaluation of microleakage and bond strength of a silicone-based resilient liner following denture base surface pretreatment

STATEMENT OF PROBLEM: The failure of adhesion between a silicone-based resilient liner and a denture base is a significant clinical problem. PURPOSE: The purpose of this study was to examine the effects of denture base resin surface pretreatments with different chemical etchants preceding the silicone-based resilient liner application on microleakage and bond strength. The initial effects of chemical etchants on the denture base resin in terms of microstructural changes and flexural strength were also examined. MATERIAL AND METHODS: Forty-two polymethyl methacrylate (PMMA) denture base resin (Meliodent) specimens consisting of 2 plates measuring 30 x 30 x 2 mm were prepared and divided into 7 groups (n = 6). Specimen groups were treated by immersion in acetone for 30 (A30) or 45 (A45) seconds, methyl methacrylate monomer for 180 (M180) seconds, and methylene chloride for 5 (MC5), 15 (MC15) or 30 (MC30) seconds. Group C had no surface treatment and served as the control. Subsequently, an adhesive (Mollosil) and a silicone-based resilient denture liner (Mollosil) were applied to the treated surfaces, and all specimens were immersed in the radiotracer solution (thalium-201 chloride) for 24 hours. Tracer activity (x-ray counts), as a parameter of microleakage, was measured using a gamma camera. For bond-strength measurement, 84 rectangular PMMA specimens (10 x 10 x 40 mm) were surface-smoothed for bonding and treated with the different chemical etchants using the same previously described group configurations. The adhesive and the silicone-based denture liner were applied to the treated surfaces. Tensile bond-strength (MPa) was measured in a universal testing machine. Flexural strength measurement was performed with 49 PMMA specimens (65 x 10 x 3.3 mm according to ISO standard 1567) in 7 groups (n = 7), with 1 flat surface of each treated with 1 of the chemical etchants preceding adhesive application. The flexural strength (MPa) was measured using a 3-point bending test in a universal testing machine. The data were analyzed by 1-way analysis of variance and the Tukey HSD test (alpha = .05). RESULTS: Significant differences were found between the groups in terms of microleakage (P < .0001). The lowest microleakage was observed in group M180 (30,000 x-ray counts) and the highest in the control group (44,000 x-ray counts). The mean bond strength to PMMA resin ranged from 1.44 to 2.22 MPa. All treated specimens showed significantly higher bond strength than controls (P < .01). The flexural strength values all significantly differed (P < .05). All experimental specimens that had chemical surface treatments showed lower flexural strength than controls (P < .05). CONCLUSION: Treating the denture base resin surface with chemical etchants increased the bond strength of silicone-based resilient denture liner to denture base and decreased the microleakage between the 2 materials. Considering the results of both tests together, the use of methyl methacrylate monomer for 180 seconds was found to be the most effective chemical treatment.     

义齿基托树脂PMMA的化学改性研究

目的通过对义齿基托复合树脂PMMA的改性来提高其自身机械性能,解决长期以来义齿基托尤其是上颌总义齿基托容易断裂的问题.方法用不同浓度的活性单体二甲基丙烯酸一缩乙二醇酯(DD)与MMA接枝共聚.在Instron1125和Instron3365万能测试机上测量其弯曲强度、拉伸强度、弹性模量和断裂伸长率,用SPSS进行统计学分析.用示差扫描量热法(DSC)分析研究其热性能,结合扫描电镜(SEM)分析研究其结构性能.并且与未改性的义齿基托树脂进行对比研究.结果在MMA中加入25%的活性单体DD共聚后的基托树脂的弯曲强度增加了9.36%;拉伸强度提高了9.02%;弹性模量提高了13.12%;断裂伸长率提高了44.87%,统计学分析有显著性差异(P＜0.05).DSC分析显示玻璃化转变温度提高了3.54%.SEM观察断裂面为韧性断裂.结论用25%的活性单体DD改性的基托树脂力学性能和热稳定性都有一定的提高.     

The effect of denture base surface pretreatments on bond strengths of two long term resilient liners

PURPOSE

Purpose of this study was to evaluate effect of two surface treatments, sandblasting and monomer treatment, on tensile bond strength between two long term resilient liners and poly (methyl methacrylate) denture base resin.

MATERIALS AND METHODS

Two resilient liners Super-Soft and Molloplast-B were selected.Sixty acrylic resin (Trevalon) specimens with cross sectional area of 10×10 mm were prepared and divided into two groups of 30 specimens each. Each group was surface treated (n = 10) by sandblasting (250 µ alumina particles), monomer treatment (for 180 sec) and control (no surface treatment). Resilient liners were processed between 2 poly(methyl methacrylate) surfaces, in the dimensions of 10×10×3 mm. Tensile strength was determined with Instron Universal testing machine, at a crosshead speed of 5 mm/min; and the modes of failure (adhesive, cohesive or mixed) were recorded. The data were analyzed using one-way ANOVA, followed by Tukey HSD test (α = 0.05).

RESULTS

Monomer pretreatment of acrylic resin produced significantly higher bond strengths when compared to sandblasting and control for both resilient liners (P < .001). Sandblasting significantly decreased the bond strength for both the liners when compared to monomer pretreatment and control (P < .001). Mean bond strength of Super-Soft lined specimens was significantly higher than Molloplast-B in various surface treatment groups (P < .05).

CONCLUSION

Surface pretreatment of the acrylic resin with monomer prior to resilient liner application is an effective method to increase bond strength between the base and soft liner. Sandblasting, on the contrary, is not recommended as it weakens the bond between the two.     

分光光度法与目测法测量义齿基托树脂色稳定性的比较研究

目的 探讨分光光度法与目测法测量义齿基托树脂色稳定性的相关性,以期确定分光光度法中的界值色差.方法 选取A、B两种红色义齿基托树脂(牙科丽义齿基托聚合物BQ-1,色号分别为2和3),各制作33个圆形试片,对试片一侧进行不同时间的光照处理,使其变色.30名色觉正常且具有1年以上口腔修复临床经验的口腔医学研究生分别对试片进行目测判定,结果计为"不变色"、"轻微变色"或"严重变色".用SP62分光光度仪测量试片两侧的色度值L*、a*、b*,计算色差△E.以色差△E为横坐标,以目测观察判定为"严重变色"的人数比例为纵坐标,绘制两种树脂的Logistic曲线.以50%观察者判定为"严重变色"时所对应的色差值,作为分光光度法的界值色差.结果 A、B树脂Logistic曲线的R2值分别为0.93和0.94;界值色差分别为2.87、2.82.结论 义齿基托树脂色稳定性评价中,分光光度仪数值测色方法与目测方法具有较好的相关性,不同色号的红色义齿基托树脂的界值色差相近.

Abstract：

Objective To explore the relationship between the spectrophotometric and visual methods in evaluating the color stability of denture base resin, and determine the threshold color difference of denture base resin in the spectrophotometric method. Methods Two kinds of denture base resin were respectively fabricated into 33 specimens whose color differences varied from indistinguishable to obvious.Each of the specimens was assessed respectively by 30 human observers and a SP62 spectrophotometer. The results of visual assement were recorded as "indistinguishable change", "light change" or "severe change",while the spectrophotometric color differences ( △ E) were calculated. In each group, a logistic curve was explored to determine the relationship between the color difference ( △ E) and the ratio of "severe change".Results The R squares of logistic curves were 0. 93 and 0. 94 respectively. The threshold color differences in the spectrophotometric method were 2. 87 and 2. 82 respectively. Conclusions A high relevance between the spectrophotometric and visual methods in evaluating the color stability of denture base resin was found.The threshold color differences for different color denture base resins were similar.     

Shear bond strength between light polymerized hard reline resin and denture base resin subjected to long term water immersion

Statement of the problemThe effect of long-term water immersion on the shear bond strength between denture base resin and Triad visible-light-polymerized (VLP) direct hard reline resin is not known.PurposeThe aim of this study was to investigate the bonding characteristics of Triad VLP direct hard reline resin to heat-polymerized denture base resin subjected to long-term water immersion.Material and methodsNinety circular disks, 15 mm in diameter and 3 mm thick, of denture base resin were polymerized from a gypsum mold. Sixty specimens were subjected to water immersion and 30 were stored at ambient room temperature for 4 months. Thirty water-immersed specimens were dried with gauze (group 1), while the other 30 water-immersed specimens were dried with a hair dryer (group 2). The dry specimens (n = 30) represented the control group (group 3). All specimens were air abraded and painted with bonding agent before packing Triad VLP direct hard-reline resin. Specimens in each group were subjected to thermal cycling for 50,000 cycles between 4 °C and 60 °C water baths with 1-min dwell time at each temperature. The bond strength at which the bond failed under stress was recorded using a universal testing machine. One-way ANOVA and Tukey post hoc comparison were applied to find significant differences between groups (α = 0.05).ResultsSignificant differences in mean shear bond strength among the specimens existed because of variable water content in the denture base resin (P < 0.05). Group 3 (dry) was higher than group 2 (desiccated), and the lowest was group 1 (saturated).ConclusionThe shear bond strength of Triad VLP direct hard reline resin to denture base resin depended on the water content in the denture base resin. The dry denture base resin demonstrated superior bond strength compared with the desiccated and water-saturated denture base resins.     

温度循环老化对复合树脂间粘接强度的影响

目的 探讨复合树脂和粘接界面老化后树脂间粘接强度的变化,以期为临床工作提供实验依据.方法 纳入甲基丙烯酸酯类复合树脂(Clearfil AP-X,树脂A)及其配套粘接剂(Clearfil SEBond,粘接剂a)和环氧树脂(Filtek P90,树脂B)及其配套粘接剂(Filtek P90 System Adhesive,粘接剂b).将树脂A、B分别制作基底树脂块各24块,各分为3组,每组8块:①对照组,基底树脂块表面涂布粘接剂,充填固化新树脂后切成条状试样;②粘接界面老化组,基底树脂块粘接新树脂后切成条状试样,行温度循环老化;③基底树脂老化组,将基底树脂块行温度循环老化后打磨表面,再粘接新树脂,最后切成条状试样.每组中由基底树脂(A、B)-粘接剂(a、b)-新树脂(A、B)构成8种粘接组合,每一组合设2个平行样.体视显微镜下筛选条状试样,每个粘接组合获得15条微拉伸试样,用微拉伸测试仪检测微拉伸强度,对不同粘接组合中粘接界面老化组与对照组、基底树脂老化组与对照组的微拉伸强度行独立样本t检验.结果 粘接界面老化组中,由粘接剂a粘接新树脂A或B的粘接组合[A-a-A:(45.0±3.2)MPa,B-a-A:(41.7±3.3) MPa,A-a-B:(28.6±3.9) MPa,B-a-B:(47.7±6.6) MPa],及由粘接剂b粘接新树脂A的粘接组合[A-b-A:(44.2±4.7) MPa,B-b-A:(38.0±3.2) MPa],微拉伸强度均显著低于各自对照组[A-a-A:(70.7±5.5) MPa,B-a-A:(60.3±5.1) MPa,A-a-B:(44.2±1.6) MPa,B-a-B:(54.1±3.2) MPa,A-b-A:(65.6±7.2) MPa,B-b-A:(59.1±4.1) MPa](P＜0.05);而由粘接剂b粘接新树脂B的粘接组合A-b-B及B-b-B的微拉伸强度与各自对照组相比差异均无统计学意义(P＞0.05).基底树脂老化组中,各粘接组合的微拉伸强度均显著低于各自对照组(P＜0.05).结论 复合树脂和粘接界面的老化均可对复合树脂间的粘接强度产生影响.