Tooth wear against ceramic crowns in posterior region: a systematic literature review

The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was conducted to identify studies on tooth wear against ceramic crowns in posterior region. The selected studies were analyzed in regard to type of crowns, natural antagonist, measuring protocol and outcome. From a yield of 1 000 titles, 43 articles were selected for full-text analysis; finally, no in vitro and only five in vivo studies met the inclusion criteria. As there is heterogeneity in design, used measuring method, ceramics and analysis-form, a meta-analysis was not possible. Results of these studies are very controversial which makes a scientifically valid comparison impossible. This review indicated that some all-ceramic crowns are as wear friendly as metal-ceramic crowns. Up to now, it has been impossible to associate tooth wear with any specific causal agent. The role of ceramic surface treatment that might be responsible for the changing in rate of tooth wear seems undetermined as yet through clinical trials. The literature reveals that studies on this topic are subject to a substantial amount of bias. Therefore, additional clinical studies, properly designed to diminish bias, are warranted.

Diminished fracture initiation sites in ceramic layers bonded to glow-discharge treated substructure

A mechanically retentive structure and meticulous surface cleanliness are critical factors in providing fracture resistance and clinical success of metal ceramic restorations. This investigation compared the porcelain/metal interfaces of deliberate compressive fractures of ceramic crowns between conventional preparation and application of the Radio Frequency Glow Discharge Treatment (RFGDT) before each bonding step. It evaluated RFGDT’s capacity to improve wetting effectiveness and minimize porosity. Twelve metal ceramic crowns were fabricated identically. RFGDT was applied to the metal substructures of half the specimens before the ceramic layering process. All specimens were fractured in the same manner by an applied compressive force to simulate dental occlusive failure. Fracture surfaces were inspected by light and scanning electron microscopy. Quantitative analyses of images were performed to identify numbers, locations of cracks, porosity patterns, and other morphological correlates of the fracture zones. There were significantly fewer voids per millimeter at the interfaces in the RFGDT group than in the non-RFGDT group (t = 2.377, df = 9, p = 0.021). There was a significant difference in the number of horizontal cracks per millimeter between the groups (t = 2.132, df = 7, p = 0.035), with more cracks occurring in the non-RFGDT group. RFGDT can improve the integrity of metal ceramic crowns by increasing the substratum surface energy, improving porcelain wetting and spreading and thereby diminishing the numbers of interfacial voids available for initiation of fracture. Routine application of RFGDT should result in fewer cracks along metal/ceramic interfaces in all restorative preparations.

Subsolidus Conceptual Design of CaO-AI_2O_3-TiO_2-SiO_2 System and Its Significance for Manufacturing Advanced Ceramics

The article deals the structure of the CaO -Al2O3 - TiO2 -SiO2 system as a basis for obtaining advanced ce- ramics with a complex of high-operational characteris- tics. As a result o[＇investigations the phase charctcteristics are represented trod the graph of the relationship of the elementaory tetrahedra has been plotted. The most techno- logical system area ,for the production of heat resistant advanced ceramics has been determined. The batches for producing heat and chemical resistant dense advanced ceramics made of natural, technical and technogenic raw materials have been developed.

The 4th International Exhibition on Refractories, Industrial Ceramics and Furnaces(RCF Expo'2003)Beijing, China, April 15-17, 2003In conjunction with China Refractories Seminar' 2003-Technology and Markets

Organizers and Sponsors: China Association of Refractories Industry The Chinese Society for Metals The Chinese Ceramic Society

The Influence of Ceramic Coating on Fatigue Crack Growth Behaviour of X17CrNi15-2 Stainless Steel

Fatigue crack growth tests were carried out on the SEN B3 precracked specimens, with dimensions in accordance with ISO 12108 requirements. The specimens were made of martensitic stainless steel, X17CrNi15-2, and some of them were modified by the ceramic coating deposition surface treatment. The effects of ceramic coating, on the fatigue crack growth behaviour of hollow shaft specimens, were experimentally investigated. Fatigue crack growth rates, da/dN, were characterised, using the power law relationship between da/dN (in mm/cycle) and the stress intensity factor range, ΔK (in MPa∙m0.5). The two constants of the correlation are 7.9768 × 10−9 and 2.8107 for the parent material, and those for the coated material are 2.4391 × 10−9 and 3.1990, respectively. Microstructural analyses were carried out on the tested specimens, which shows that the maximum hardness of the ceramic coating is higher than that of substrate by a factor of ~3.2. The dimple fracture dominates the final fracture mechanism for the parent material, and the combination of fatigue, ductile fracture and cleavage dominates the final fracture mechanism for the coated material, based on the SEM analyses. EDS tests’ results reveal that the parent material specimen shows higher levels of C at matrix regions along with Fe- and O-rich regions, compared with the coated material specimen.

CAD-CAM氧化锆全瓷冠与金属烤瓷种植体牙冠的修复效果和临床性能比较

目的:比较计算机辅助设计与计算机辅助制作(CAD-CAM)氧化锆全瓷冠与金属烤瓷种植体牙冠的修复效果和临床性能。方法:选取2021年1月—2023年1月江门市新会区新会第二人民医院收治的100例全冠单冠修复患者,按随机数字表法分为A组(n=50)与B组(n=50)。A组行金属烤瓷种植体牙冠修复,B组行CAD-CAM氧化锆全瓷冠修复,比较两组患者修复效果及并发症发生情况,比较两组患者修复前、修复后6个月牙周袋深度(PD)、附着丧失(AL)、龈沟出血指数(SBI)、牙龈指数(GI)水平。结果:B组患者牙冠修复总有效率高于A组,差异有统计学意义(P<0.05)。修复前,两组患者PD水平、AL水平、GI评分、SBI评分比较,差异无统计学意义(P>0.05);修复后6个月,B组患者PD水平、AL水平、GI评分、SBI评分均低于A组,差异有统计学意义(P<0.05)。B组患者牙冠修复并发症总发生率低于A组,差异有统计学意义(P<0.05)。结论:CAD-CAM氧化锆全瓷冠对全冠单冠修复效果好于金属烤瓷种植体牙冠的修复,可降低并发症发生率,帮助患者改善牙周健康问题。

In-Ceram氧化铝全瓷冠与氧化锆全瓷冠在前牙修复中的临床效果比较

目的比较In-Ceram氧化铝全瓷冠与氧化锆全瓷冠在前牙美容修复中的临床综合修复效果。方法选择需要前牙修复的患者74例,随机分为两组。治疗组采用氧化铝全瓷冠修复,对照组采用氧化锆全瓷冠修复,修复后12个月,根据美国公共健康协会的修正标准对修复体的边缘着色、密合度、形态、颜色、周围龋坏等情况进行评价。结果两组病例修复效果在所检查指标中差异无统计学意义(P>0.05)。结论 In-Ceram氧化铝全瓷冠与氧化锆全瓷冠在边缘密合性、美观性及抗折强度等方面,均能满足临床要求。

In-Ceram全瓷冠与金属烤瓷冠对成纤维细胞株L929细胞活力及相关基因表达的影响

目的:研究In-Ceram全瓷冠与金属烤瓷冠对成纤维细胞株L929细胞活力及相关基因表达的影响。方法:培养成纤维细胞株L929,分别用In-Ceram全瓷冠、镍铬合金烤瓷冠、钴铬合金烤瓷冠的浸提液处理,检测细胞活力、血清细胞因子含量以及细胞中Fas、FasL、Apo-1、mTOR、P70S6k的mRNA含量。结果:镍铬合金组、钴铬合金组细胞的OD值低于阴性对照组;In-Ceram组细胞的OD值高于镍铬合金组、钴铬合金组;镍铬合金组、钴铬合金组细胞培养基中TNF-α、IL-6、IL-8的含量明显高于阴性对照组,In-Ceram组细胞培养基中TNF-α、IL-6、IL-8的含量明显低于镍铬合金组、钴铬合金组且与阴性对照组无差异;镍铬合金组、钴铬合金组细胞中Fas、FasL、Apo-1的mRNA含量高于阴性对照组,mTOR、P70S6k的mRNA含量低于阴性对照组,In-Ceram组细胞中Fas、FasL、Apo-1的mRNA含量低于镍铬合金组、钴铬合金组且与阴性对照组无差异,mTOR、P70S6k的mRNA含量高于镍铬合金组、钴铬合金组且与阴性对照组无差异。结论:In-Ceram全瓷冠具有良好的组织相容性,不会影响成纤维细胞株L929的细胞活力以及炎性因子的生成、凋亡和增殖相关基因的表达。

反复烧结对In-Ceram全瓷冠适合性的影响

【目的】研究体瓷的反复烧结对In Ceram全瓷冠适合性的影响。【方法】制作In Ceram后牙全瓷冠试件 5 0个。试件分为 5组。对照组为氧化铝底层冠 ,实验组依体瓷烧结次数分为 4组 ,即烧结 3次、5次、7次和 9次。采用片切法 ,用万能工具显微镜测量冠边缘 ,轴壁和牙合面与代型之间的粘固剂厚度。【结果】对照组和实验各组 (烧结 3次、5次、7次和 9次 )冠边缘粘固剂厚度分别为 6 9μm、74μm、6 4μm、6 8μm和 6 5 μm ;各组的平均粘固剂厚度依次为 6 1μm、6 3μm、5 8μm、6 3μm和5 9μm。实验各组与对照组各测量点之间的粘固剂厚度的差异无显著性 ;实验各组与对照组之间的平均粘固剂厚度的差异无显著性。【结论】在实验条件下 ,体瓷的反复烧结对In Ceram全瓷冠的适合性无影响。In Ceram全瓷冠在瓷烧结热循环中的尺寸稳定性较好。

上颌第一磨牙基牙不同聚合度对Inceram-Z全瓷冠应力分布影响的三维有限元研究

目的:探讨上颌第一磨牙基牙不同聚合度对全瓷冠和牙本质应力分布的影响。方法:通过有限元方法建立三组基牙不同聚合度的有限元模型,并对模型垂直施加600N的作用力。结果:随着基牙聚合度的减小,全瓷冠的应力值呈下降趋势,同时牙本质的应力值呈上升趋势,所有应力峰值均小于材料本身的抗压强度。结论:基牙不同聚合度对全瓷冠及牙本质的应力分布是有影响的,本实验为全瓷修复体的优化设计提供实验和理论依据。

In-ceram全瓷冠前牙修复的临床研究

目的 :探讨和评价In -ceram全瓷冠在前牙修复中的应用及其临床牙科美学特征 .方法 :用金刚砂车针进行常规的全瓷冠牙体预备 ,取印模、灌制模型 ,自然光线下用Vita比色板比色、选色 ,用VitaIn -ceramAlumina系列烤瓷粉制作修复体 ,临床试戴、调改、粘结 .结果 :94 %的病人对In -ceram全瓷冠修复非常满意 ,6 %满意 .结论 :In -ceram全瓷冠修复前牙无论从维护牙龈组织的健康还是从临床牙科美学的角度都不失为一种满意的修复手段 .

In-Ceram氧化铝全瓷冠在牙齿美容修复中的应用效果及对牙龈炎发生的影响

目的:探讨In-Ceram氧化铝全瓷冠在牙齿美容修复中的应用效果及对牙龈炎发生的影响。方法:选择2018年1月-2019年7月本院接诊的84例拟行牙齿美容修复患者,按随机数字表法分为对照组和研究组,各42例。对照组行氧化锆全瓷冠牙齿美容修复,试验组行In-Ceram氧化铝全瓷冠牙齿美容修复。比较两组修复效果、咀嚼功能、牙周健康状况、牙龈炎发生率。结果:试验组边缘着色、边缘密合度、美观度和形态颜色评分均较对照组高,差异均有统计学意义(P<0.05);试验组治疗12个月后咬合力、咀嚼效率均较对照组高,差异均有统计学意义(P<0.05);试验组治疗12个月后BI与PD均较对照组低,差异均有统计学意义(P<0.05);试验组牙龈炎发生率低于对照组,差异有统计学意义(P<0.05)。结论:In-Ceram氧化铝全瓷冠牙齿美容修复效果好,能够有效提高患者咀嚼功能,改善牙周健康状况,减少牙龈炎发生。

In-ceram氧化锆基全瓷冠的适合性评价

目的评价3种In-ceram氧化锆基全瓷冠的边缘和内部间隙。方法制作In-Ceram YZ全瓷冠、In-Ceram Zirconia全瓷冠和Wolceram全瓷冠各12个,采用树脂粘接剂粘固于人工预备的离体上颌前磨牙上,经过温度循环试验后,沿近远中向和颊舌向片切试件,用扫描电镜观察并测量全瓷冠组织面与牙体组织之间的间隙,3组试件的数据用SPSS12.0软件进行统计学分析。结果 3种全瓷冠的间隙宽度中,均是边缘间隙宽度最小,牙合面间隙宽度最大。In-Ceram YZ全瓷冠的边缘间隙宽度为(19.86±1.81)μm,肩台间隙宽度为(92.66±0.64)μm,牙合面间隙宽度为(128.06±1.38)μm,在3种全瓷冠中最小;Wolceram全瓷冠的边缘间隙宽度为(29.43±0.84)μm,肩台间隙宽度为(117.89±1.73)μm,轴壁间隙宽度为(112.50±1.71)μm,牙合面间隙宽度(168.11±1.33)μm,在3种全瓷冠中最大。结论 3种In-Ceram氧化锆基全瓷冠的间隙宽度均在临床可接受范围内,其中In-Ceram YZ和In-Ceram Zirconia全瓷冠的边缘和内部间隙较Wolceram全瓷冠小。

不同玻璃渗透方法对In-Ceram氧化铝全瓷冠基底适合性的影响

目的:研究快、慢速玻璃渗透方法对In-Ceram氧化铝全瓷冠基底适合性的影响。方法:制做上颌第一前磨牙铝合金代型,翻制耐火石膏代型后按标准的快速与慢速玻璃渗透方法制作In-Ceram氧化铝全瓷冠基底试件共10个,粘结、包埋、片切。采用体式显微镜测量咬合面(A、A′)、轴壁(B、B′)和冠边缘(C、C′)与代型之间的间隙。结果:慢速玻璃渗透组咬合面间隙为:A(41.23±4.22)μm,A′(39.85±6.26)μm,轴壁间隙为:B(37.94±3.90)μm,B′(33.51±6.71)μm,边缘浮出量为:C(35.87±7.99)μm,C′(36.49±8.73)μm。快速玻璃渗透组咬合面间隙为:A(41.47±11.81)μm,A′(34.71±8.52)μm,轴壁间隙为:B(38.21±5.55)μm,B′(34.03±6.29)μm,边缘浮出量为:C(35.36±5.69)μm,C′(32.10±6.59)μm。通过单因素方差进行统计学分析,快速玻璃渗透组和慢速玻璃渗透组各测量点之间的间隙无显著性差异(P>0.05),各组的边缘适合性均在临床要求范围内。结论:经快、慢速玻璃渗透法制作的In-Ceram氧化铝全瓷冠基底均具有良好的适合性,能满足临床应用要求。

前牙In-Ceram全瓷冠与金属烤瓷冠修复临床疗效对比

目的:评价In-Ceram全瓷冠在前牙修复的临床效果。方法:对30例58颗前牙进行全瓷冠修复(全瓷冠组),以加利福尼亚牙科协会(CDA)评价标准对戴用0.5～2年后的冠边缘完整性、解剖外形、表面及颜色等进行临床观察评价,结合美观效果、牙龈刺激及失败率等指标,与同期制作的金属烤瓷修复体(金属烤瓷冠组)进行对比。结果:全瓷冠在颜色(满意率:全瓷冠91.4%,烤瓷冠75.8%)及解剖外形(满意率:全瓷冠91.4%,烤瓷冠77.3%)满意度方面优于烤瓷冠组(均P<0.05)。全瓷冠出现牙龈炎的概率小于烤瓷冠,2组在1.5年以后差别有统计学意义(P<0.05)。全瓷冠组不会出现龈缘灰线,金属烤瓷冠组在1年后就会有龈缘灰线出现,2组差别有统计学意义(P<0.05),在修复失败率及边缘完整性方面,2组差别无统计学意义(P>0.05)。结论:In-Ceram全瓷冠用于前牙修复可取得良好效果。

In-Ceram全瓷冠的临床疗效评价

目的 :研究In Ceram全瓷冠的修复效果。方法 :追踪观察 4 0位采用In Ceram全瓷冠修复的患者 ,共 5 0件 ,其中前牙 2 8件 ,后牙 2 2件。看全瓷冠的边缘适合性、形态、颜色、基牙是否有继发龋 ,冠有无折裂 ,综合评价In Ce ram全瓷冠的临床效果。结果 :全瓷冠中 92 %的边缘适合性良好 ,94 %的形态良好 ,98%的颜色良好 ,基牙没有出现继发龋 ,也没有冠折裂的情况出现。结论 :全瓷冠修复效果良好 ,适于临床推广。

Preparation and properties of dental zirconia ceramics

Y2O3-stabilized tetragonal zirconia polycrystalline （Y-TZP） ceramics with high-performance were prepared for dental ap- plication by use of the micro-emulsion and two-step sintering method. The crystal phase, morphology, and microstructure of the reaction products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron mi- croscopy （TEM）. XRD results show that the ceramics mainly consist of tetragonal zirconia. Physical and mechanical properties test results show that the bending strength, fracture toughness, and the density of full sintered Y-TZP ceramics are 1150 MPa, 5.53 MPa.m1/2, and 6.08 g/cm3, respectively, which suggest that the material is relatively suitable for dental restoration. The dental base crown machined with this material by CAD/CAM system exhibits a verisimilitude configuration and the material＇s expansion coefficient well matches that of the glaze. These results further indicate that the product can be used as a promising new ceramic material to fabricate dental base crowns and bridges.

In-Ceram氧化铝全瓷冠与氧化锆全瓷冠在前牙修复中的临床效果比较

目的评价分析In-Ceram氧化铝全瓷冠与氧化锆全瓷冠在前牙美学修复中的五年临床效果。方法以我院在2011年3月—2011年8月期间接收的70例前牙修复患者为研究对象,随机分为观察组和对照组,各35例,对照组InCeram氧化铝全瓷冠,观察组采用氧化锆全瓷冠,分析两组的五年临床修复效果。结果在前牙修复对应的指标参数方面,观察组和对照组之间差异无统计学意义(P>0.05)。结论在前牙修复中采用In-Ceram氧化铝全瓷冠与氧化锆全瓷冠均能取得较好效果,临床上可根据患者的实际情况加以应用。

Crack patterns corresponding to the residual strength plateau of ceramics subjected to thermal shock

The formation strength plateau of ceramics is addressed. A set of of 99A1203 are conducted, mechanism of the residual subjected to thermal shock thermal shock experiments where the thin specimens of 1 mm× 10 mm×50 mm exhibit parallel through edge cracks, and thus permit quantitative measurements of the crack patterns. The cracks evolve with the severity of ther- mal shock. It is found that there is a correlation between the length and density of the thermal shock cracks. The increase of crack length weakens the residual strength, whereas the increase of crack density improves it. In a considerably wide temperature range, the two contrary effects just counteract each other; consequently a plateau appears in the variation curve of the residual strength. A comparison between the numerical and experimental results of the residual strength is made, and they are found in good agreement. This work is helpful to a deep understanding of the thermal shock failure of ceramics.

生物活性陶瓷iRoot BP Plus^(■)在儿童年轻恒前牙复杂冠折牙髓切断术中的应用

目的:观察生物活性陶瓷材料iRoot BP Plus^(■)(Innovative BioCeramix Inc,Vancouver,BC,Canada)在儿童年轻恒前牙复杂冠折牙髓切断术中的应用,并对其预后进行分析,为该术式的更广泛应用提供临床参考。方法:收集2017年3月至2022年9月因恒前牙复杂冠折就诊于北京大学口腔医院急诊科,行以生物活性陶瓷iRoot BP Plus^(■)为盖髓剂的牙髓切断术患者。根据患者术前根尖片和初诊病历显示为年轻恒牙者,纳入97颗年轻恒牙进行研究。收集患者初诊及复查时的临床及影像学检查资料,临床检查包括根尖孔形成情况、松动度、牙冠颜色、牙髓活力测试(冷测)、有无脓肿和瘘管,影像学检查包括根周膜连续性、根尖周低密度影像、复诊时盖髓剂下方牙本质桥形成情况、髓腔及根管钙化情况,并对上述结果进行分析。结果:最终纳入有复诊记录的64例患者共75颗患牙,其中男性37例(57.8%),女性27例(42.2%),就诊时平均年龄为9.1岁,平均随访时长19.3个月。采用iRoot BP Plus^(■)盖髓的牙髓切断术后6个月成功率为96.0%,术后1年成功率为94.7%。术后复查2年以上者共23例,累计失败6例。成功率在患牙就诊时距外伤的时间是否超过24 h组中(P=0.61)以及是否松动组中(P=0.28)的差异无统计学意义。结论:对无移位性损伤的年轻恒牙复杂冠折患牙,采用iRoot BP Plus^(■)盖髓的牙髓切断术1年成功率很高,该术式具备广泛推广价值。