Marginal fit of leucite-glass pressable ceramic restorations and ceramic-pressed-to-metal restorations

STATEMENT OF PROBLEM: Fabricating a feldspathic porcelain margin on a metal-ceramic restoration with a clinically acceptable marginal fit has proven to be a technique-sensitive procedure. Pressable ceramics are advocated to solve this problem. PURPOSE: The purpose of this in vitro study was to compare the marginal adaptation of a pressable ceramic system when used with both all-ceramic and metal-ceramic crowns, with a traditional metal-ceramic restoration. MATERIAL AND METHODS: A 1.5-mm, 360-degree chamfer margin was prepared on a typodont maxillary central incisor. Polyether impressions were made and poured in a Type IV dental stone, and the following crowns were fabricated on individual dies: 15 metal ceramic restorations (MCR) (Ceramco II, Ceramco, and Argelite 60), 15 pressed-to-metal restorations (PTM) (CPC-MK, and Argelite 60), and 15 pressed ceramic restorations (PCR) (CPC-MK). The marginal fit of the crowns was evaluated every 90 degrees around the crown margin circumference under a microscope at original magnification x 45. A 1-way analysis of variance (ANOVA) was used to compare data (alpha=.05). RESULTS: The mean marginal discrepancy for MCRs was 94 +/- 41 microm, for PTMs, 88 +/- 29 microm, and for PCRs, 81 +/- 25 microm. The 1-way ANOVA showed no significant difference between groups ( P =.568). CONCLUSION: The marginal fit of pressed-to-metal (PTMs) and pressed all-ceramic crowns (PCRs) was similar to that of traditional metal-ceramic crowns (MCRs).     

CAD/CAM氧化锆全瓷冠修复临床疗效评价

目的：探讨CAD／CAM氧化锆全瓷冠的修复效果。方法：选择82例（192颗患牙）,分别在CAD／CAM氧化锆全瓷冠粘接后1、3、6、12个月进行随访观察。采用美国公共健康协会的修订标准对修复体的临床效果进行评价。结果：观察期间失访4例,随访78例共181件修复体,结果显示CAD／CAM全瓷冠颜色达到好以上91．2％,CAD／CAM氧化锆全瓷冠的崩瓷率2．76％,与修复体部位有明显相关性（P〈0．01）,在粘接12个月后有1个修复体的边缘密合度欠佳,所有复诊患者在12个月的临床观察中均未见边缘着色,继发龋和基牙松动。结论：氧化锆全瓷修复体具有良好的稳定性和生物相容性,近期临床效果满意。     

CAD/CAM氧化锆全瓷冠桥随访4年的临床分析

目的:回顾分析评价CAD/CAM氧化锆全瓷冠桥的修复效果.方法:为267位患者制做CAD/CAM氧化锆全瓷冠或桥681件,随访了205例患者的562件全瓷冠桥,随访时间2-6年.对修复体的崩瓷、全瓷冠的颜色与修复体的边缘密合度进行评价.结果:CAD/CAM氧化锆全瓷冠的崩瓷率3.31%,与修复体部位有明显相关性(P＜0.01),不同技术员完成的CAD/C氧化锆全瓷冠的颜色效果有明显不同(P＜0.001),不同颜色预备体的修复体后颜色效果没有明显差异(P＞0.05),CAD/CAM全瓷冠颜色达到好以上90.8%,CAD/CAM全瓷修复体的边缘密合度达到好的99.2%,长桥边缘密合度欠佳,修复体松动脱落0.35%,随访期间没有发现CAD/CAM全瓷修复体基底冠或桥支架折断.结论:CAD/CAM全瓷冠颜色接近天然牙,特别是预备体变色时是115床旨选的美学修复体,CAD/CAM全瓷冠边缘密合度好,整体崩瓷率可接受,但长桥边缘密合度需进一步提高,且磨牙的崩瓷率须进一步研究降低.     

Marginal Discrepancy of All-Ceramic Crowns Cemented on Implant Abutments

Purpose The purpose of this investigation was to determine the mean marginal discrepancy of all-ceramic crowns cemented on implant abutments. Materials and Methods Five Brånemark CeraOne abutments were connected to implant fixtures embedded in acrylic resin blocks. The marginal discrepancy was measured using a video camera connected to a digitizing board at four locations on each abutment for five samples in each of the following groups: all-ceramic caps (caps), all-ceramic crowns (crowns), and all-ceramic crowns cemented with zinc phosphate cement (cemented crowns). Results The mean marginal discrepancies were as follows: caps, 99.0 μm (SD, 16); crowns, 117.8 μm (SD, 20); and cemented crowns, 168.8 μm (SD, 23). Statistically significant differences were found between all three groups at the 99% level of confidence. In addition there were two significant differences between abutments. Conclusions Subgingival marginal discrepancies of the magnitude measured in this study have been shown to cause periodontal problems. It is probable that the marginal discrepancy of CeraOne restorations, as tested, can be improved. Efforts should be made to enhance the marginal accuracy of these restorations.     

Evaluation of the fit and strength of an all-ceramic fixed partial denture

A laboratory investigation of the fit and strength of three-unit all-ceramic FPDs was performed with a metal-ceramic FPD control. The conclusions were: 1. No difference was found between the marginal seal of the metal-ceramic and all-ceramic FPDs. 2. The all-ceramic FPDs had a more uniform cement space and their occlusal seat was significantly (99.9%) better than the metal-ceramic restorations. 3. The metal-ceramic FPDs were significantly stronger than the all-ceramic FPDs. 4. Load calculations suggest that short-span all-ceramic FPDs may be strong enough to resist normal masticatory forces for selected patients. However, generalized usage will probably result in an unacceptable failure rate.     

肩台瓷在金瓷冠中的临床应用及与其他修复方法的比较

目的 分析肩台瓷金瓷冠修复的临床效果。方法 根据统一标准对92个肩台瓷金瓷冠、36个金沉积烤瓷冠及50个普通金瓷冠的一年后修复效果进行复查，对比评价复查结果。结果 三组间，在颜色、边缘适合性及牙龈健康情况方面无差别，外形方面差异无统计学意义。肩台瓷金瓷冠和金沉积烤瓷冠之间边缘变色方面无差异；牙龈灰线方面差异无统计学意义。肩台瓷金瓷冠或金沉积烤瓷冠与普通金瓷冠之间边缘变色和牙龈灰线方面有显著统计学差异。结论 应用肩台瓷可以提高金瓷冠的美观效果，达到较好的边缘适合性和边缘形态。     

氧化锆全瓷冠与贵金属烤瓷冠修复体生物相容性比较的回顾性研究

目的：对比分析氧化锆全瓷冠与贵金属烤瓷冠修复的临床疗效。方法：60例患者的98颗牙齿进行全冠修复,其中,观察组30例（49颗）采用氧化锆全瓷冠修复,对照组30例（49颗）采用贵金属烤瓷冠修复。修复1年后按照美国加州牙科协会的全瓷修复临床标准对两组修复体的临床效果进行评价。结果：修复1年后检查,氧化锆全瓷冠的周围牙龈状况及颜色匹配优于贵金属烤瓷冠（P〈0．05）。结论：氧化锆全瓷冠修复体相比贵金属烤瓷冠具有更好的美学效果及生物相容性。     

氧化铝渗透陶瓷底瓷全瓷冠2年临床观察

目的 探讨氧化铝渗透陶瓷作为全瓷修复体底瓷的修复效果,为临床推广应用提供参考。方法 61例门诊患者,修复体159件,其中上颌98件,下颌61件。前牙全冠132个,后牙全冠27个。通过12～24个月的观察,采用美国加利福尼亚牙科学会的质量评价体系对氧化铝渗透陶瓷作为底瓷所做的前、后牙全冠修复进行临床效果评价。结果 对61例患者159颗全冠的临床观察结果 表明,氧化铝渗透陶瓷作为底瓷所制作的全瓷修复体具有良好的的边缘密合性,色泽稳定,强度高,其失败率为1.25%,效果满意。结论 氧化铝渗透陶瓷作为底瓷的全瓷冠修复是一种效果良好的全瓷修复方式。     

Removable partial denture abutments restored with all-ceramic surveyed crowns.

All-ceramic crowns are used as alternatives to conventional metal-ceramic crowns for the restoration of single teeth. Traditionally all-ceramic restorations possessed physical properties that contraindicated their use in many treatment situations. The strength that zirconia ceramics exhibit seems to support the hypothesis that, in specific situations, an all-ceramic crown may be used to restore removable partial denture (RPD) abutments in areas previously reserved for metal or metal-ceramic restorations. Abutments for RPDs may now be fabricated with Procera AllZirkon with the classically prepared guide planes and rest seats. This article provides an overview of a technique for the fabrication of a zirconia-based crown to be used in conjunction with removable partial dentures using the Procera CAD/CAM technology.     

Procera AllCeram crowns followed for 5 to 10.5 years: a prospective clinical study

PURPOSE: This is a report on Procera AllCeram crowns in a prospective multicenter study. The aim of the study was to evaluate AllCeram crowns in dental practice over a 5- to 10.5-year period. Some of the AllCeram crowns were among the very first that were placed. MATERIALS AND METHODS: The crowns were placed between 1989 and 1995. Twelve clinicians at nine clinics placed 87 crowns in 50 patients. The California Dental Association quality evaluation system was used for assessment of marginal integrity and esthetics. RESULTS: After 5 and 10 years a cumulative survival rate of 97.7% and 93.5%, respectively, and a cumulative success rate of 97.7% and 92.2%, respectively, was recorded. Six crowns (7%) were recorded as failures; five of these crowns (6%) had to be remade. The marginal integrity was considered excellent or acceptable for 92% of the crowns. Bleeding was somewhat more often recorded at teeth with AllCeram crowns (39%) than at contralateral teeth (27%). Endodontic treatment was performed for a low number (2%) of the AllCeram crowns. The patients found the esthetics to be excellent. CONCLUSION: The results of this study demonstrate about the same clinical outcome as has been reported by similar studies on all-ceramic crowns built on a core of alumina. The outcome is also in agreement with that reported for metal-ceramic crowns. The results indicate a good prognosis for Procera AllCeram crowns also for posterior teeth.     

The influence of different cements on the fracture resistance and marginal adaptation of all-ceramic and fiber-reinforced crowns

PURPOSE: This in vitro study investigated the marginal adaptation and fracture resistance of heat-pressed glass-ceramic and fiber-reinforced composite molar crowns luted with resin, resin-modified glass-ionomer, or zinc-oxide-eugenol-free cements. MATERIALS AND METHODS: A total of 24 heat-pressed all-ceramic and 24 glass fiber-reinforced composite crowns were constructed and cemented using the above-mentioned luting agents (eight crowns per cement). The restorations were thermocycled and mechanically stressed, and fracture resistance was determined. Marginal adaptation was evaluated before and after stress application using semiquantitative analysis in a scanning electron microscope. RESULTS: All-ceramic and fiber-reinforced composite crowns reached the highest fracture resistance after stress application in combination with the resin cement. When luted with resin-modified glass-ionomer or zinc-oxide-eugenol-free cements, the fracture resistance of all-ceramics decreased significantly, while the fiber-reinforced composite crowns maintained their fracture resistance level; the lowest values were found for zinc-oxide-eugenol-free cements. The marginal adaptation remained unchanged after stress for all-ceramics and fiber-reinforced composite restorations if they were luted with resin cements. Luting with resin-modified glass-ionomers significantly deteriorated the marginal adaptation after stress application, with the exception of the crown-cement interface of all-ceramics. CONCLUSION: The highest fracture resistance and marginal adaptation were found for all-ceramic and glass fiber-reinforced composite molar crowns if they were luted with resin cement.     

In vitro fracture strength of teeth restored with different all-ceramic crown systems

STATEMENT OF PROBLEM: There is insufficient knowledge of the strength of all-ceramic crowns bonded to natural teeth to warrant the use of all-ceramic crowns in place of metal-ceramic crowns. PURPOSE: The purpose of this study was to evaluate and compare fracture resistance of crowns made of 3 different types of 2 all-ceramic crown systems-0.4-mm and 0.6-mm aluminum oxide coping crowns and zirconia ceramic coping crowns-and metal-ceramic crowns. MATERIAL AND METHODS: Forty intact, noncarious human maxillary central incisors were divided into 4 groups (n=10): Group MCC (control), metal-ceramic crown (JRVT High Noble Alloy); Group AC4, crown with 0.4-mm aluminum oxide coping (Procera AllCeram); Group AC6, crown with 0.6-mm aluminum oxide coping (Procera AllCeram); and Group ZC6, crown with 0.6-mm zirconia ceramic coping (Procera AllZirkon). Teeth were prepared for complete-coverage all-ceramic crowns so that a final dimension of 5.5 +/- 0.5 mm was achieved incisocervically, mesiodistally, and faciolingually. A 1.0-mm deep shoulder finish line was used with a rounded internal line angle. All restorations were treated with bonding agent (Clearfil SE Bond) and luted with phosphate-monomer-modified adhesive cement (Panavia 21). Fracture strength was tested with a universal testing machine at a crosshead speed of 2 mm per minute with an angle of 30 degrees to the long axis of the tooth after restorations were stored in 100% relative humidity of a normal saline solution for 7 days. The mode of fracture was examined visually. Means were calculated and analyzed with 1-way ANOVA and Tukey's HSD (alpha=.05). RESULTS: The means of fracture strength were: Group MCC, 405 +/- 130 N; Group AC4, 447 +/- 123 N; Group AC6, 476 +/- 174 N; and Group ZC6, 381 +/- 166 N. There was no significant difference between groups ( P =.501). The mode of failure for all specimens was fracture of the natural tooth. CONCLUSIONS: There was no significant difference in the fracture strength of the teeth restored with all-ceramic crowns with 0.4- and 0.6-mm aluminum oxide copings, 0.6-mm zirconia ceramic copings, and metal ceramic crowns.     

Vita In-Ceram全瓷修复体2年临床观察

目的 探讨Vita In-Ceram Alumina渗透陶瓷全瓷修复体的修复效果,为临床应用提供参考。方法 45例门诊患者,修复体共194件,其中上颌124件,下颌70件。前牙全冠165个,后牙全冠21个,前牙固定桥8个。通过3－24个月的观察,采用美国加利福尼亚科学会的质量评价体系对Vita In-Ceram Alumina渗透陶瓷前、后牙全冠与前牙固定桥修复进行临床效果评价。结果 对45例患者186颗全冠与8个前牙固定桥的临床观察结果表明,Vita In-Ceram Alumina渗透陶瓷全冠具有良好的边缘密合性,色泽稳定,强度高,其失败率为0．01％。应用Vita In-Ceram Alumina渗透陶瓷制作的前牙固定桥,效果满意。结论 Vita In-Ceram Alumina渗透陶瓷修复是一种效果良好的全瓷修复方式。     

全瓷修复与烤瓷修复临床效果比较的Meta分析

目的：：通过Meta分析系统评价全瓷修复与烤瓷修复的临床效果。方法：计算机检索PubMed、Cochrane Library、EMbase、SinoMed、中国知网和万方、维普数据库,按标准纳入比较全瓷与烤瓷修复临床效果的随机对照研究,进行资料提取及偏倚评价,采用RevMan 5.3软件进行Meta 分析。结果：最终纳入15篇文献,其中全瓷修复体768例,烤瓷修复体1386例。 Meta分析结果显示：相比于烤瓷修复,全瓷修复能显著降低牙龈炎症(RR=0.30,95%CI=0.10-0.90,P=0.03)的发生风险。还能减少基牙继发龋、改善修复体的龈缘着色及边缘适合性,但无统计学差异。二者颜色匹配及修复体崩瓷状况相当。全瓷修复易导致牙髓炎症及牙髓失活,且固定桥修复时全瓷桥支架断裂(RR=6.24,95%CI=1.20-32.41,P=0.03)的危险性显著增高。结论：现有的有限证据表明,全瓷修复的临床效果要优于烤瓷修复,在临床应用中占有一定优势,但全瓷桥的强度有待提高。     

All-ceramic surveyed crowns for removable partial denture abutments

All-ceramic restorations may have limitations when used in combinations with other treatment modalities. Removable partial denture (RPD) abutment crowns are typically shaped to provide guide planes, rest seats, and retentive areas. Porcelain-to-metal crowns are routinely fabricated with retentive contours in the veneering porcelain, but until recently, the contours of the other portions of the restoration were developed in metal. This article describes the fabrication of all-ceramic crowns for RPDs with rest seats and guide planes in densely sintered aluminum oxide and retentive areas in veneering porcelain. Within the limitations outlined, this procedure allows the practitioner to use all-ceramic crowns in situations previously reserved for metal or metal-ceramic restorations.     

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目的    探讨Vita In-Ceram Zirconia渗透陶瓷全瓷修复体的修复效果 ,为临床应用提供参考。方法    对2008年3—5月广东省深圳牙科医疗中心门诊收治的59例接受全瓷修复的患者,共使用Vita In-Ceram Zirconia渗透陶瓷全瓷修复体81件 ,其中上颌61件 ,下颌20件;前牙全冠44个 ,后牙全冠27个 ,前牙固定桥4个, 后牙固定桥6个。通过3～24个月的观察 , 采用美国加利福尼亚牙科学会的质量评价体系对Vita In-Ceram Zirconia渗透陶瓷前、 后牙全冠与前、后牙固定桥修复进行临床效果评价。结果    观察期间失访2例患者4件修复体,对剩余57例患者77件修复体的临床观察结果表明 , Vita In-Ceram Zirconia 渗透陶瓷全冠具有良好的边缘密合性 ,色泽稳定 ,强度高 ,其失败率为0.030 %。结论    在严格选择适应证的前提下,Vita In-Ceram Zirconia渗透陶瓷修复是一种效果良好的全瓷修复方式。     

不同粘固剂对全瓷冠边缘完整性影响的研究

目的研究不同粘固剂粘固的全瓷冠边缘完整性。方法全瓷冠修复24颗离体上颌第三磨牙,随机分成3组,每组8个,分别用自酸蚀树脂粘接系统、Compomer粘固剂和磷酸锌粘固剂粘固,用扫描电镜观测标本牙疲劳试验前后边缘完整性及粘固剂表面质量。结果自酸蚀树脂粘接组试验前后完整边缘率均高于95%,Compomer组和磷酸锌粘固剂粘固组完整边缘率分别为16%~19%和5%,组间均有显著性差异（P〈0.001）;自酸蚀树脂粘接组边缘区粘固剂缺损显著小于其它两组（P〈0.05）。结论用自酸蚀树脂粘接系统粘固全瓷冠有优良的边缘完整性和边缘区表面质量。     

Marginal discrepancies and leakage of all-ceramic crowns: influence of luting agents and aging conditions

PURPOSE: This study evaluated the marginal discrepancies and leakage of all-ceramic crowns cemented with different luting agents after fatigue tests. MATERIALS AND METHODS: Forty-eight all-ceramic crowns were cemented onto natural molars. Zinc-phosphate cement, compomer cement, and an adhesive composite resin luting system were used in 16 specimens each. Sixteen metal-ceramic crowns were cemented with zinc-phosphate cement as a control. Half of the specimens in each group were fatigued in a chewing simulator for 600,000 loading cycles with 3,500 thermocycles. The others received the 3,500 thermocycles only. An impression-replica technique and SEM were used for evaluation of the marginal discrepancies. Leakage of the specimens was microscopically assessed. RESULTS: There were no significant differences between marginal discrepancies of the groups, with the exception of porcelain shoulder margins in the metal-ceramic group, which had significantly larger discrepancies (P < .01). There was no significant effect of the fatigue tests on marginal discrepancies. However, significant differences of leakage were found between the groups cemented with the different luting agents after both fatigue tests. The adhesive composite resin luting system demonstrated the least leakage. The compomer cement showed an intermediate level of leakage, and the zinc-phosphate cement showed severe leakage that extended through the dentinal tubules to the pulp chambers. No significantly different effect of the two fatigue tests on the leakage was found. CONCLUSION: The adhesive composite resin luting system showed clinically acceptable marginal discrepancies and an excellent ability to minimize leakage of all-ceramic crowns.     

Influence of firing cycles on the margin distortion of 3 all-ceramic crown systems

STATEMENT OF PROBLEM: Although all-ceramic restorations are widely used, there is a lack of information about how the fit is affected by fabrication procedures. The adequacy of the fit of all-ceramic restorations has been questioned. PURPOSE: This study examined the effect of porcelain and glaze firing cycles on the fit of 3 types of all-ceramic crowns. MATERIAL AND METHODS: Ten standardized all-ceramic crowns were fabricated on a metal die from each of 3 systems: conventional In-Ceram, copy-milled In-Ceram, and copy-milled feldspathic crowns. Copings of the conventional and copy-milled In-Ceram crowns and nonglazed copy-milled feldspathic crowns served as the control. A device was used to apply a uniform load on specimens during measurement and to reposition the specimens on the measurement device after each manufacturing process. The specimens were not cemented and were measured on the metal die using a profile projector. Measurements were recorded at 18 points selected along horizontal and vertical planes. The crown systems were compared by use of the Student t test and 1-way analysis of variance (ANOVA). Data of measurements repeated at identical locations were analyzed with a multivariate repeated-measures ANOVA. The Bonferroni post hoc test was used for multiple comparisons (alpha=.05). RESULTS: The conventional In-Ceram (57 +/- 24 microm) and copy-milled In-Ceram (57 +/- 32 microm) crowns demonstrated nearly identical marginal discrepancy values, followed by the copy-milled feldspathic crowns with a mean of 17 +/- 12 microm in the vertical plane. The copy-milled In-Ceram crowns had a mean horizontal discrepancy value of -12 +/- 4 microm, followed by the copy-milled feldspathic crowns with a mean of -4 +/- 5 microm and the conventional In-Ceram crowns with a mean of -6 +/- 4 microm. Statistical analyses demonstrated no significant differences in the marginal discrepancy values among the 3 all-ceramic crown systems, except for the horizontal discrepancy values between the conventional and copy-milled In-Ceram crowns after the porcelain firing cycle. Results indicated that the addition of porcelain to the copings caused a significant change ( P <.05) in the marginal fit of the crowns, except for the fit in the horizontal plane of the conventional In-Ceram crowns. However, no significant changes occurred in the fit of the 3 all-ceramic crowns after the glaze firing cycle. There were significant differences in the marginal discrepancy values among the measurement locations ( P <.05), and the discrepancy value at each location was independent of the mean of the entire crown. CONCLUSIONS: Within the limitations of this study, it was concluded that the 3 all-ceramic crown systems demonstrated a comparable and acceptable marginal fit. The porcelain firing cycle affected the marginal fit of the all-ceramic crowns. However, the glaze firing cycle had no significant effect on fit. The conventional and copy-milled In-Ceram crowns demonstrated medial deformations at the labial and palatal surfaces that might result in occlusal displacement of the crown.     

An overview of treatment considerations for esthetic restorations: a review of the literature

Controversy persists regarding the treatment planning criteria for esthetic restorations. This article reviews the literature regarding the biocompatibility, marginal adaptation, color matching, patient selection, technique sensitivity, and mode and rate of failure of tooth-colored restorations. A Medline search was completed for the period from 1986 to 2006, along with a manual search, to identify pertinent English peer-reviewed articles and textbooks. The key words used were amalgam, posterior composite resin, ceramic inlays/onlays, CEREC, porcelain laminate veneers, all-ceramic crowns, and all-ceramic fixed partial dentures.