金-瓷修复体瓷折裂及剥脱原因分析

收集了59例金-瓷修复体瓷折裂、剥脱病例，分析其造成的可能原因及机制，并对控制不良因素。保证金一瓷间良好结合，避免修复后瓷折裂、剥脱的正确有效的操作方法进行了探讨。     

The influence of interfacial surface roughness on bilayered ceramic specimen performance.

OBJECTIVES: The aim of the current study was to assess the influence of interfacial surface roughness on the performance of bilayered ceramic composite disc-shaped specimens. METHODS: Specific surface flaw distributions were introduced to a series of standard aluminous core porcelain disc specimens (12 mm diameter, 1.7 mm thickness) prior to bilayering with dentin porcelain. Mean flexure strengths, standard deviations and associated Weibull moduli (m) were determined using bi-axial flexure (ball-on-ring) for each series of 30 bilayered specimens. RESULTS: The mean bi-axial fracture strengths of bilayered specimens resulted in significant differences between specimen groups with the smoothest interfacial roughness recording the highest strength and fracture strength reliability. Specimen delamination was identified in five of the bilayered group with the smoothest interfacial roughness compared with no specimen delaminations in the rougher interface groups. However, fracture occurred in the weaker dentin layer rather than along the interface between the dentin and core porcelain for specimens in these rougher interface groups. CONCLUSIONS: A smoother interfacial surface roughness resulted in increased performance, namely increased strength and reliability amongst the bilayered dental ceramic composite specimens examined in the current investigation. The incidence of complete or partial delamination of the reinforcing core and aesthetic dentin was increased for these specimens since the reduced tortuosity of the interface between porcelain layers fails to restrict propagation of a crack front along the interface.     

Effect of brushing and thermocycling on the shade and surface roughness of CAD-CAM ceramic restorations

Statement of problem

The effects of toothbrushing (B) and thermocycling (TC) on the surface texture of different materials with various fabrication processes have been investigated. However, studies of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramic restorations are limited.

氧化锆陶瓷表面粗糙度对微生物附着的影响

目的 分析牙科氧化锆陶瓷表面粗糙度对微生物附着的影响. 方法 使用碳化硅砂纸将氧化锆陶瓷表面逐级打磨为粗糙、中等粗糙和平滑表面,使用原子力显微镜和光学接触角测量仪测定表面粗糙度、形态及接触角,通过使用变异链球菌UA159处理的探针检测其与不同粗糙度氧化锆陶瓷表面的粘附力;并将氧化锆陶瓷与变异链球菌共培养,通过扫描电镜和激光共聚焦显微镜观察生物膜形成情况. 结果 不同粗糙度表面的氧化锆陶瓷,由粗糙到平滑,接触角逐渐减小,表面能逐渐增大,表面生物膜厚度逐渐减小,变异链球菌与氧化锆陶瓷表面的粘附力减小,但生物膜细菌量差异无统计学意义(P>0. 05). 结论 随着氧化锆表面粗糙度增加,变异链球菌的粘附力增加;随着粗糙度减小,生物膜厚度与微生物数量相应减小,但表面粗糙度减小至一定数值后,生物膜厚度与微生物数量无显著变化.     

The influence of resin infiltration system on enamel microhardness and surface roughness: An in vitro study

Objective

To investigate the effect of a resin infiltrant on the surface microhardness and roughness of healthy enamel and, as a subsidiary aim, to compare it with a fissure sealant.

Materials and methods

Twenty freshly extracted premolars were used. Sound enamel surfaces were treated with a resin infiltrant (Icon) or fissure sealant (Seal-Rite). The average roughness (R_a, μm) of the specimens was measured with a profilometer (Surtronic 10 Tylor Hobson). Surface hardness was determined by utilizing Vicker’s surface hardness (VHN) with a Micromet II Microhardness tester. Each specimen acted as its own control. Data were analyzed with 2-way analysis of variance (ANOVA), and mean values were compared with independent t-test. All analyses were performed with the SPSS program version 16 (USA). Differences with a P-value of ⩽0.05 were considered statistically significant.

Results

Comparison of enamel surfaces before and after application of resin infiltrant revealed no significant differences in surface hardness; however, enamel surfaces treated by infiltrant showed significantly higher VHN (244.0 ± 79.8) values than those treated with fissure sealant (37.5 ± 14.2). Surface roughness did not differ before and after application of either material to sound enamel. Enamel surfaces treated with fissure sealant (5.3 ± 1.4) were significantly smoother than those treated with infiltrant (6.9 ± 2.0).

Conclusion

Within the limitations of the study, the results showed that enamels treated with the resin infiltrant showed approximately the same microhardness and surface roughness as sound enamel, indicating that this material might be suitable for the treatment of enamel subsurface lesions.     

三种复合树脂表面粗糙度的实验研究

目的：比较3种牙体充填材料的表面用在粗糙度。方法：抛光过程中以粗糙度测试仪分别测试3M Filtek Supreme XT、Venus、ceram XMono试件表面经0.5、1.0、1.5、2.0、2.5、3.0、3.5、4.0min抛光头抛光后的粗糙度值并进行统计学分析。结果：3种充填材料的表面粗糙度程度不等,Venus〉ceram XMono〉3M Filtek Supreme XT。结论：充填材料的表面粗糙度以3M Filtek Supreme XT为最佳。经统计分析,与其他两组充填材料相比有显著性差异。     

纳米陶瓷与普通陶瓷表面粗糙度的对比研究

目的比较纳米陶瓷与普通陶瓷的表面粗糙度并探讨烧结次数对每种陶瓷的表面粗糙度的影响。方法根据瓷粉种类及烧结次数不同分为10组,每组5个。A～E组为普通陶瓷组,烧结次数依次为4、6、8、10、12次。A'～E'组为纳米陶瓷组,烧结次数分别与A～E组相对应。各组的烧结次数中均包括不透明瓷烧结2次,自身上釉烧结1次,其余为体瓷的烧结次数。采用2205型表面粗糙度仪分别测定每个试件的表面粗糙度值,求取每组试件的平均值。结果体瓷不同烧结次数处理后,纳米陶瓷的表面粗糙度值均明显小于普通陶瓷(P0.001),而每种陶瓷的表面粗糙度值均与体瓷烧结次数无关(P0.05)。结论纳米陶瓷较普通陶瓷表面光滑,经自身上釉烧结处理后,纳米陶瓷和普通陶瓷的体瓷烧结次数对其表面光滑度均无影响。     

Comparative study on the surface roughness of nano-ceramic and traditional ceramic

目的 比较纳米陶瓷与普通陶瓷的表面粗糙度并探讨烧结次数对每种陶瓷的表面粗糙度的影响.方法 根据瓷粉种类及烧结次数不同分为10组,每组5个.A～E组为普通陶瓷组,烧结次数依次为4、6、8、10、12次.A′～ E′组为纳米陶瓷组,烧结次数分别与A～E组相对应.各组的烧结次数中均包括不透明瓷烧结2次,自身上釉烧结1次,其余为体瓷的烧结次数.采用2205型表面粗糙度仪分别测定每个试件的表面粗糙度值,求取每组试件的平均值.结果 体瓷不同烧结次数处理后,纳米陶瓷的表面粗糙度值均明显小于普通陶瓷(P＜0.001),而每种陶瓷的表面粗糙度值均与体瓷烧结次数无关(P＞0.05).结论 纳米陶瓷较普通陶瓷表面光滑,经自身上釉烧结处理后,纳米陶瓷和普通陶瓷的体瓷烧结次数对其表面光滑度均无影响.     

Influence of surface roughness on mechanical strength of resin composite versus glass ceramic materials.

OBJECTIVES: Clinical polishing leads to reduction of surface flaws sizes and thus to increased mechanical strength. The aim of the present work was to assess fracture strength of a resin composite and of a glass ceramic as a function of surface roughness and to relate the strength data to flaw sizes, microstructural and fractographic examinations. METHODS: Specimens have manufactured out of a resin composite (Tetric EvoCeram, TEC) and out of glass ceramic material (IPS E.max Press, EMP). Different surface roughness levels have been induced using cutting, grinding and polishing techniques and quantified under CLSM. Fracture strength was measured in four-point bending and analyzed using Weibull statistics. Indentation fracture method was used to calculate fracture toughness. Critical flaw sizes were calculated and related to microstructure. Microstructural and fractographic examinations have been performed under SEM. RESULTS: Fracture strength upon the glass ceramic material decreased from 441.4 to 303.3 MPa (R(a)=150 nm-1.5 microm) and upon the resin composite from 109.8 to 74.0 MPa (R(a)=300 nm-50 microm). EMP exhibited a fracture toughness of K(Ic)=4.14 MPam(0.5) and TEC of K(Ic)=1.89 MPam(0.5). Calculated crack lengths for EMP ranged from 28.1 microm (441.4 MPa) to 59.6 microm (303.3 MPa) and for TEC from 94.3 microm (109.8 MPa) to 207.0 microm (74.0 MPa). SIGNIFICANCE: Dependency of fracture strength on surface roughness is neither determined by crystallite size of the glass ceramic material nor by filler sizes of the resin composite. No significant increase in fracture strength has been observed below 0.65 microm (1000 grit) in EMP. For TEC a threshold value might be determined below 2.1 microm (320 grit). Optimal polishing of a restoration right after placement is strongly recommended to keep an optimum strength performance through the whole clinical lifetime.     

Effect of different luting materials on the marginal adaptation of Class I ceramic inlay restorations in vitro.

OBJECTIVES: The aim of this in vitro study was to assess the marginal adaptation of prefabricated Class I ceramic inlay restorations placed with various luting materials. METHODS: Forty-two standardized occlusal cavities were prepared in extracted human molars with diamond burs exactly corresponding to the dimensions of prefabricated glass ceramic inlays. The prepared teeth were randomly assigned to seven groups of six teeth each and restored using (1). the composite resin Tetric Ceram in increment technique [Group I] or (2). ceramic inlays (Cerana) luted with: the composite based materials Dual Cement [Gr. II] and Panavia 21 [Gr. III], the compomer material Dyract Cem [Gr. IV], Dyract Cem with additional use of Prime & Bond 2.1 [Gr. V], the silicophosphate cement Trans-Lit [Gr. VI], or the ethylcyanoacrylate Cyano-Veneer [Gr. VII]. Marginal adaptation was evaluated by SEM-analyses before and after thermal cycling (2500 cycles; 5-55 degrees C) and mechanical loading (100N; 500000 cycles) using replica models. Kruskal-Wallis H-test and Mann-Whitney U-test were used for statistical analyses. RESULTS: Group I (increment technique) as well as Groups II-V (inlay technique) revealed high percentages of perfect marginal adaptation in over 95% of the analyzed margins, both before and after thermo-mechanical loading. Statistical significant differences could not be detected within these groups. All inlays luted with silicophosphate cement (Group VI) and four of six inlays applied with Cyano-Veneer (Group VII) fractured under occlusal load. SIGNIFICANCE: A stable bonding to the enamel and to the ceramic inlay was achievable with the composite luting resins Dual Cement and Panavia 21 as well as with the compomer based luting material Dyract Cem but not with the use of the silicophosphate cement Trans-Lit or the ethylcyanoacrylate Cyano-Veneer.     

Evaluation of surface roughness and polishing techniques for new ceramic materials

The surface roughness of crown and bridge materials should be minimized to obtain optimal biocompatability. This study used scanning electron microscopy to evaluate the effect of polishing procedures on two all-ceramic crown materials (Dicor and Cerestore). The "as formed," unpolished specimens of both Dicor and Cerestore materials presented a rough surface. It was found that any attempt to polish the Cerestore coping material resulted in an extremely rough surface. Finishing of the Dicor ceramic resulted in a smoother but pitted surface. Polishing of both ceramic materials resulted in a surface that was rougher than the glazed metal ceramic controls. The smoothest finish was obtained when the glazed veneer (Cerestore) and shading porcelain (Dicor) were applied to the all-ceramic materials.     

钴铬合金表面粗糙度对口内常见细菌黏附的影响

目的:观察并分析口腔常见菌种在不同表面粗糙度的钴铬合金修复体表面黏附和定植的数量,为临床制作良好的修复体和尽可能减少细菌在修复体表面附着和定植提供参考.方法:所有钴铬合金样本按不同步骤打磨抛光后,应用表面粗糙度仪MAHR M1测试其表面粗糙度,按不同粗糙度分为6组.将6组试件放入含有变形链球菌(Ua)、内氏放线菌(An)和牙龈卟啉单胞菌(Pg)的混合培养基中作厌氧培养,24h后分别定量检测各组试件表面黏附的细菌数量以及液体培养基中的细菌数量,将结果采用SPSS6.0软件包进行方差分析.结果:各组试件的表面粗糙度有显著差异(P<0.05).各组试件表面及液体培养基中均检测不到Pg,24h后,Ua和An在钴铬合金各组表面黏附定植的数量均有显著差异(P<0.05),细菌定植总数也有显著差异(P<0.05).结论:3种细菌混合培养时,Pg受到强烈的抑制.钴铬合金不同的表面粗糙度导致细菌黏附定植数量显著差异,粗糙度越大,细菌黏附量越多.临床应采用高度抛光的钴铬合金修复体,以尽量减少修复体表面的细菌黏附.     

Effect of toothbrushing on the material loss,roughness, and color of intrinsically and extrinsically stained porcelain used in metal-ceramic restorations: an in vitro study

PURPOSE: Because of abrasion by toothbrushing, dental materials in the oral cavity are subjected to substance loss to a different extent depending on the hardness of the material. This study investigated the color-change effect of substance loss and change of roughness resulting from toothbrushing of internally and externally stained metal ceramic. MATERIALS AND METHODS: Metal-ceramic specimens 15 mm in diameter and 2 mm thick were made. Blue colorant suspension was applied over the enamel porcelain (enamel-stained), in the body porcelain (dentin-stained), and over the opaque porcelain (opaque-stained). One group was not stained. Each group was made up of seven samples. All specimens were brushed in an experimental device. Material loss, roughness measurements, and spectrophotometric evaluations were made before and after brushing. Overall color change, chroma change, and value change were calculated with the use of the CIE-LAB uniform color scale. RESULTS: Significant substance loss as a result of brushing was observed. No significant differences between chroma changes, between value changes of different groups, or between overall color changes of dentin- and enamel-stained groups were found. The difference between overall color changes of opaque-dentin and opaque-enamel stained groups was statistically significant. CONCLUSION: Staining should be done as deeply as possible to obtain durable color appearance.     

Spectrometric analysis of the influence of metal substrates on the color of metal-ceramic restorations

The development and use of ceramic alloys have created the potential for variation in the color of dental porcelain. In order to define the nature of the alterations, it is necessary to examine quantitatively the color of dental porcelain baked onto ceramic alloys. The purpose of this study was to examine spectrometrically where color differences occur in the fabrication process. One shade of Vita porcelain was baked onto coupons of three ceramic alloys (high gold, palladium-silver, base metal). Eight replications were made in each alloy at seven fabrication steps: prepared metal, oxide, first opaque, second opaque, first dentin, second dentin, and glaze. Spectrometric analyses were performed for each replication at each step. Data were tabulated every 10 nm over the recorded 380-750-nm range, for conversion to the CIE color measurement system. Tristimulus values X, Y, and Z and chromaticity coordinates x and y were calculated. Differences from spectrographic inspection were seen among the metal substrate series. The greatest variation appeared at the first dentin step between the palladium-silver and high-gold alloys and between the palladium-silver and base metal alloys. Mean tristimulus values were significantly different (p less than 0.0001) for all steps and alloys. The distribution of plotted values followed the same pattern of spectral changes throughout the seven fabrication steps. Analysis of these data shows that color differences of metal-ceramic coupons based on dissimilar metal substrates can be quantified, and that spectral reflectance values can be converted to CIE notation. As depicted spectrally, notable color differences appeared with the first dentin porcelain layer.     

烤瓷表面抛光和上釉对其表面粗糙度及细菌黏附的影响

目的比较不同抛光方法对烤瓷表面粗糙度的影响,以及不同粗糙度烤瓷表面对口腔变异链球菌黏附的影响。方法采用原子力显微镜测量不同抛光方法对瓷表面粗糙度的影响,并通过细菌实验观察不同粗糙度的瓷表面对细菌黏附的影响。结果用抛光膏抛光或者上釉后,瓷面平整且有光泽。无论是表面粗糙度还是表面黏附的细菌数,橡皮轮组都大于抛光膏组和上釉组（P<0.05）。结论建议调改过的瓷表面进行抛光膏抛光或上釉以恢复瓷表面的光滑度和减少口腔致龋菌的黏附。     

洁治及抛光对釉质表面粗糙度影响的实验研究

目的:评价不同洁治及抛光方法对牙釉质表面粗糙度及形态的影响.方法:选择6 颗人离体中切牙,切除牙根.在唇面中心点将牙冠分别水平及垂直切割成4 个釉质块,制得唇面釉质块共24 个,再用自凝塑料包埋每个釉质块,打磨抛光暴露的釉面.将24 个试样均分为8 组,分别作如下处理, A组:无处理(空白对照);B组: 超声洁治;C组:超声洁治后抛光膏抛光;D组: 超声洁治后牙膏抛光;E组:超声洁治后喷砂抛光;F组:喷砂洁治;G组:喷砂洁治后抛光膏抛光;H组:喷砂洁治后牙膏抛光.之后用粗糙度仪测定釉面粗糙度, 并进行扫描电镜观察.结果:超声洁治后釉面粗糙度大幅度增加(P<0.01),经3 种方法抛光后,釉质表面粗糙度均有显著下降(P<0.05),其中牙膏抛光后粗糙度下降幅度显著大于喷砂抛光和抛光膏抛光(P<0.05).喷砂洁治后釉面粗糙度明显增加(P<0.05),进一步用抛光膏抛光使得釉面更加粗糙(P<0.05),而用牙膏抛光,虽未进一步增加粗糙度,但也未能降低釉面粗糙度(P>0.05).结论:超声洁治能使釉质表面形成凹陷性缺损,粗糙度增加,应当抛光.喷砂洁治后不必再抛光.抛光材料及方法明显影响抛光效果.     

瓷修复技术的临床应用Ⅶ.牙科全瓷材料的分类与应用

按照国际ISO6872牙科陶瓷标准,牙科陶瓷分为两种类型,Ⅰ型是以粉体形式构成的材料,其以用途再细分为8个类别,并有国际ISO6872推荐的颜色标识以鉴别瓷粉类别,见表1.Ⅱ型是以其他形式构成的材料,可再细分为2个类别:第1类用于制作冠、贴面、嵌体和高嵌体的支持结构,第2类直接用于制作贴面、嵌体和高嵌体.     

Evaluation of clinical methods for assessing the surface roughness of restorations.

Using four different clinical methods to assess the surface roughness of Concise and Spheraloy samples finished with four different treatments, two dentists untrained as evaluators found the following: 1. Although the control profile measurements showed significant differences both between the two materials and the four surface treatments (p less than .001), no clinical assessment method differentiated clearly between all treatments, especially for Concise. 2. Differentiation between the surface treatments was shown best for Spheraloy by the clinical criteria, abraded glass blocks, and ranked photographic negatives. For Concise the best results were shown by the clinical criteria and abraded glass blocks. However, evaluator agreements were highest for Spheraloy with the ranked replica profiles and photographic negatives. For Concise the highest agreements were with the ranked replica profiles. 3. Differentiation between pairs of each material finished with the same surface treatment was shown best by the ranked replica profiles and photographic negatives. These two methods also gave the highest evaluator agreements. 4. Where possible, the use of suitable visual ranking assessment methods rather than clinical ratings or scores to assess surface roughness is preferred for dentists untrained as evaluators.