金沉积烤瓷冠的临床评价

目的：评价金沉积烤瓷冠临床修复效果。方法：选择金沉积烤瓷冠、贵金属烤瓷冠、镍铬合金烤瓷冠各50颗牙,观察修复体颜色、牙龈染色、边缘适合性、牙周组织健康状况、瓷裂、瓷崩等情况。结果：对临床修复病例进行6个月至1年的随访观察,在颜色、牙龈染色、牙周组织健康方面金沉积烤瓷冠与贵金属烤瓷冠差异无显著性（P〉0.05）,明显优于镍铬合金烤瓷冠（P〈0.01）;在边缘适合性方面,金沉积烤瓷冠优于贵金属烤瓷冠（P〈0.05）,明显优于镍铬合金烤瓷冠（P〈0.01）,三者在瓷崩瓷裂方面差异无显著性。结论：在烤瓷修复体中金沉积烤瓷冠是良好的修复体。     

Influence of core material on fracture resistance and marginal adaptation of restored root filled teeth

Aim To investigate ex vivo the influence of direct placement core materials on the fracture strength and marginal adaptation of root filled maxillary central incisors restored with glass fibre‐reinforced posts, various core materials and all‐ceramic crowns. Methodology Forty‐eight human maxillary incisors were root filled. Posts were placed and teeth restored with composite cores and crowns (n = 8). Six core materials were examined after thermal cyclic and mechanical loading (TCML). Fracture force was determined under static loading. The marginal adaptation at the interfaces between cement‐tooth and cement‐crown were categorized as ‘intact margin’ or ‘marginal gap’ using scanning electron microscopy. Statistical analysis was undertaken with the Mann–Whitney U‐test (α = P ≤ 0.05). Results Median fracture strength varied between 204 N (low viscous experimental core) and 1094 N (Multicore). No difference in fracture resistance was found with varying viscosity of the core material. The layering technique improved the fracture performance (P = 0.059) to a minor degree. Crowns with dedicated core materials (Rebilda 1063 N; Multicore 1094 N) had a significantly higher fracture resistance than crowns with a conventional restorative material (Tetric Ceram 509 N). Significantly poorer marginal adaptation before TCML was found for the layering technique at the tooth–cement interface and for all experimental cores after TCML. At the crown–cement interface significant differences in marginal adaptation could be determined between Multicore‐layered core (P = 0.002) and Multicore‐Rebilda (P = 0.001) after TCML. Conclusions The fracture strength of post and core restorations was dependent on the core material and bonding system. Marginal adaptation was influenced by the method of application of the core material and by TCML.     

In vitro study of mean loads and modes of failure of all-ceramic crowns cemented with light-cured or dual-cured luting cement, after 1 and 30 d of storage

This study compared the mean loads and modes of failure of teeth restored with all-ceramic crowns (ACCs) cemented with dual-cured (RelyX ARC; 3M ESPE) or light-cured (RelyX Veneer; 3M ESPE) luting cements. Clinically, there are advantages of light-cured cements over the recommended dual-cured cements, namely increased working time, improved handling, colour stability, and a homogenous mix. Forty, sound, extracted, human, premolar teeth underwent a standardized preparation for ACCs. IPS Empress (Ivoclar-Vivadent) crowns of standard dimensions were fabricated and 20 were cemented with each cement. The crowns were stored for 1 or 30 d in water and subjected to a compressive load to failure at 0.017 mm s⁻¹. There were no significant differences in loads at failure, between each cement group, at each storage period, and there were no significant differences in loads at failure, for each cement, at 1 and 30 d of storage. There were also no significant differences in modes of failure between each cement group. Before recommending light-cured cement as an alternative to dual-cured cement for the cementation of all-ceramic crowns, further research is required to establish the depth of ceramic at which light-cured lutes fail to polymerize completely.     

前牙铸瓷全冠、金铂合金烤瓷全冠与镍铬合金烤瓷全冠临床效果评价

目的观察E.MAX三代CAD-CAM铸瓷全冠、金铂合金烤瓷全冠与镍铬合金烤瓷全冠辅以纤维桩、树脂核,修复前牙残根、残冠的临床效果。方法对240例需桩核修复的前牙,经完善根管治疗后,以纤维桩、树脂核修复,并分别制作铸瓷全冠、金铂合金烤瓷全冠与镍铬合金烤瓷全冠各80件,进行多项指标2年临床的追踪观察。结果铸瓷冠在颜色方面优于金铂合金和镍铬合金烤瓷冠（P〈0.05）;金铂合金烤瓷冠在边缘密合度方面优于铸瓷冠和镍铬合金烤瓷冠（P〈0.05）;镍铬合金烤瓷冠在颜色、边缘着色、牙龈健康状况方面不及铸瓷冠和金铂合金烤瓷冠（P〈0.05）。结论 E.MAX三代CAD-CAM铸瓷全冠在美学效果方面优于其它两种修复体;金铂合金烤瓷全冠在边缘密合度方面优于其它两种修复体,两者在牙龈健康和边缘着色方面也优于镍铬合金烤瓷冠。     

采用分光光度计比较种植支持式氧化锆全瓷和贵金属金瓷修复的牙冠颜色

目的 应用一种小型分光光度计对上前牙区种植支持式氧化锆全瓷修复与贵金属金瓷修复的牙冠颜色进行比较,为临床选择修复材料提供参考依据。方法 纳入 18例（男 7例,女 11例）行口腔种植修复后复查患者的上前牙区种植支持式单冠 29颗进行研究,其中氧化锆全瓷修复单冠 11颗,贵金属金瓷修复单冠 18颗。采用小型反射型分光光度计型比色仪 SpectroShadeTM采集图片并输入计算机,应用相关软件测量每个种植牙冠体 1/3与对照天然牙的CIE L﹡a﹡b﹡颜色差异。应用统计学软件 SPSS 17.0进行统计分析。结果 氧化锆全瓷修复和贵金属金瓷修复的牙冠明度均高于天然牙,全瓷修复引起的明度差异（ 4.5±3.2）大于金瓷修复引起的明度差异（ 1.0±2.6）,具有统计学意义（ P=0.004）;色相差异和饱和度差异均无统计学意义。全瓷修复和金瓷修复与天然牙的颜色差异（ 7.0±2.8和4.0±1.9）均高于人眼的分辨阈值（ 3.7）,且前者差异大于后者,具有统计学意义（ P=0.002）。氧化锆全瓷和贵金属金瓷两种修复方式的临床主观评分无统计学差异（ P=0.977）。上前牙天然牙色由前向后明度渐低,色相变红黄。结论 就本试验所选用的修复材料而言,分光光度计测量显示氧化锆全瓷修复与天然牙的牙冠颜色差异大于贵金属金瓷修复与天然牙的颜色差异,但两种修复方式的临床效果无明显区别。     

牙周维护在金属顶盖加覆盖义齿修复中的临床应用

目的 评价牙周维护在金属顶盖加覆盖义齿修复残根残冠伴牙列缺损中的临床意义。方法 选择我科就诊的残根残冠伴牙列缺损患者20例,按顶盖基牙牙周情况分为对照组10例（28颗患牙）：基牙无牙周炎;试验组10例（24颗患牙）：基牙牙周炎较重但还可以保留的。修复前对试验组进行口腔卫生指导、牙周基础治疗以及必要的牙周手术治疗,金属顶盖加覆盖义齿修复后认真牙周维护,定期复查;对照组修复后不进行牙周维护,3个月复查后处理同试验组,检测修复后3、6、12个月顶盖基牙周围菌斑指数（plaque index,PLI）及龈沟出血指数（sulcus bleeding index,SBI）,观察牙周维护效果。结果 试验组修复后3、6及12个月时PLI及SBI较基线水平均有明显的下降（P<0.05）;对照组修复后3个月时PLI及SBI较基线水平显著升高（P<0.05）,且与试验组3个月时的PLI及SBI相比具有统计学差异（P<0.05）;两组3个月后各指数间无统计学差异性（P>0.05）。结论 牙周维护在金属顶盖加覆盖义齿修复中是不可或缺的重要组成部分。     

Dental visits, teeth remaining, and prosthetic appliances in a Norwegian urban population

Abstract Of a random sample (177 persons) of 35-year-old Oslo citizens, 117 subjects (66.1 %) attended a dental examination. Questionnaires were returned by mail from 28 of the non-respondents. The most common reason for not attending was “difficulty in finding time for an appointment.” About 89% of the respondents had visited a dentist regularly. Regular dental care seemed to be more common among people with a high level of education than among those with a low level of education. The most common treatment performed at the last dental visit was filling of cavities. The mean number of remaining teeth was 25.7. Females in the lower educational group had significantly less teeth than those in the higher educational group. No subjects were totally edentulous, but five persons had one edentulous jaw. Nine full or partial dentures were found. Twelve percent of the subjects had one or more fixed bridges, and 29.9% of the persons had one or more crown restorations. There seemed to be no differences between the sexes or educational levels in this respect.     

Fabricating Crowns to Fit Existing Removable Partial Dentures: An Illustration of Two Techniques

The prosthetic treatment of a structurally compromised abutment tooth supporting a removable partial denture may present a variety of restorative modalities. Ideally, a surveyed crown is made for the individual tooth, which is later followed by a new removable partial denture fit to the contours of the crown. Frequently, however, the removable partial denture is clinically acceptable, and remaking the prosthesis is not indicated. In these cases, the crown can be made to fit the existing removable partial denture. Fabricating crowns to fit existing removable partial dentures can be accomplished using a direct method, an indirect method, or combinations of these techniques. Direct techniques traditionally use acrylic resin and inlay wax intraorally to develop a custom pattern that captures the contours of the clasp assembly. Indirect techniques use a pick-up impression to allow the crown pattern to be waxed against the denture framework on a cast in the laboratory. Combination methods use either a direct-indirect or indirect-direct approach. The direct-indirect method develops the preliminary resin pattern directly on the tooth and finalizes the contours in wax on a master cast. The indirect-direct technique initiates a crown pattern on a die and completes it either intraorally or on the die after the intraoral refinements. This article reviews the literature for methods of fabricating surveyed crowns under existing removable partial dentures. Additionally, two cases are presented that illustrate an indirect and combination direct-indirect technique for making the restorations.     

预成根管钉或铸造桩核修复老年人残根残冠的临床分析

目的：比较预成根管钉和铸造桩核在老年人前后牙修复时的操作时间及成功率。方法：随机选择需做桩核或根管钉修复的老年病人，记录操作时间，随访观察成功率。结果：后牙的桩核修复操作时间均长于预成根管钉（P〈0．001）；前牙桩核与根管钉操作时间2组差异无显著性（P〉0．05）；前牙桩核修复成功率高于预成根管钉（P〈0.05）；后牙桩核修复和预成根管钉修复2组差异无显著性（P〉0.05）。结论：在老年患者前牙首选桩核，后牙首选根管钉。     

A comparison of fracture strength of yttrium-oxide- partially-stabilized zirconia ceramic crowns with varying core thickness, shapes and veneer ceramics

The fracture strengths of stylized all-ceramic crowns manufactured using an yttrium-oxide-partially-stabilized (Y-TZP) zirconia ceramic core (Denzir) veneered with lithium disilicate glass-ceramics (IPS Empress 2 or IPS Eris) were evaluated. The Denzir cores were manufactured in two ways: either with different thickness in different parts of the restoration, called an 'adapted Denzir core'; or with a uniform core thickness of 0.5 mm. IPS Empress 2 all-ceramic crowns served as reference. There was no significant difference between the crowns with an 'adapted Denzir core' veneered with the two brands of glass-ceramics. No significant difference was seen between the crowns with a 0.5 mm Denzir core veneered with the two brands of glass-ceramics. The crowns with an 'adapted Denzir core' exhibited significantly higher values than those with a 0.5 mm Denzir core and than the IPS Empress 2 crowns used as reference. No significant differences were seen among the IPS Empress 2 crowns used as reference and the crowns with a 0.5 mm Denzir core. The mode of failure varied among the Empress 2 crowns and the crowns with a core of a Y-TZP zirconia ceramic. Long-term studies are necessary to assess the clinical performance of this restorative system.