Dogan Sami, Raigrodski Ariel J, Zhang Hai, Mancl Lloyd A
Assistant Professor, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash.
Professor, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash.
J Prosthet Dent. 2017 Feb;117(2):226-232. doi: 10.1016/j.prosdent.2016.07.019. Epub 2016 Oct 17.
Studies evaluating anterior zirconia-based crowns are limited.
The purpose of this prospective cohort clinical study was to assess the efficacy of zirconia-based anterior maxillary crowns with 0.3-mm customized copings at the cervical third and anatomical design elsewhere for up to 5 years of service.
Eighteen participants who required an anterior maxillary crown (n=20) and who had signed a consent form approved by the University of Washington Health Sciences Center Human Subjects Division were enrolled. All preparations were standardized and prepared with an occlusal reduction of 1.5 to 2 mm and an axial reduction of 1 to 1.5 mm with 10 degrees of convergence angle. All finish lines were located on the sound tooth structure. Zirconia copings (Lava; 3M ESPE) were custom designed and milled to a 0.3-mm thickness at the cervical third and with selective thickness elsewhere to support the veneering porcelain. All restorations were luted with self-etching self-adhesive composite resin cement. Recall appointments were at 2 weeks, 6 months, and 12 months, and annually thereafter for 5 years. Modified Ryge criteria were used to assess the clinical fracture measurements, esthetics, marginal discoloration, marginal adaptation, radiographic proximal recurrent caries, and periapical pathoses. Descriptive statistics and 95% confidence intervals were used to describe the number and rate of complications and self-reported satisfaction with the crowns.
Twenty crowns with a mean follow-up of 58.7 months were evaluated. All crowns were rated as Alfa for fracture measurements (smooth surface, no fracture/chipping). Twelve crowns were rated esthetically as Romeo (no mismatch in color and shade) and 8 as Sierra (mismatch in color and shade within normal range). Twelve crowns were rated as Alfa (no visible evidence of crevice) and 8 as Bravo (visible evidence of crevice, no penetration of explorer) for marginal integrity. Nineteen were rated as Alfa (no discoloration) and 1 as Bravo (superficial discoloration) for marginal discoloration. No proximal caries or periapical pathoses were detected in 5 years. Participants were highly satisfied with their crowns after 5 years (mean ±SD: 9.8 ±0.4 on 0 to 10 scale).
Zirconia-based anterior maxillary crowns with customized copings with 0.3-mm thickness at the cervical third and zirconia margins performed well after 5 years of service.
评估基于氧化锆的前牙冠的研究有限。
这项前瞻性队列临床研究的目的是评估在颈部三分之一处采用0.3毫米定制内冠、其他部位采用解剖学设计的基于氧化锆的上颌前牙冠长达5年的使用效果。
招募了18名需要上颌前牙冠（n = 20）且签署了华盛顿大学健康科学中心人类受试者部门批准的知情同意书的参与者。所有预备体均标准化，咬合面降低1.5至2毫米，轴向降低1至1.5毫米，聚合角为10度。所有边缘线均位于健康牙体结构上。氧化锆内冠（Lava；3M ESPE）采用定制设计，并在颈部三分之一处研磨至0.3毫米厚度，其他部位选择性加厚以支持贴面瓷。所有修复体均用自酸蚀自粘结复合树脂水门汀粘结。复诊时间为2周、6个月、12个月，此后每年复诊一次，共5年。采用改良的Ryge标准评估临床折断情况、美观度、边缘变色、边缘适合性、X线片显示的邻面继发龋和根尖周病变。使用描述性统计和95%置信区间来描述并发症的数量和发生率以及患者对牙冠的自我报告满意度。
评估了20颗平均随访58.7个月的牙冠。所有牙冠在折断情况评估中均评为Alfa级（表面光滑，无折断/崩瓷）。12颗牙冠在美观度方面评为Romeo级（颜色和色调无不匹配），8颗评为Sierra级（颜色和色调在正常范围内不匹配）。12颗牙冠在边缘完整性方面评为Alfa级（无可见缝隙迹象），8颗评为Bravo级（有可见缝隙迹象，但探针未穿透）。19颗牙冠在边缘变色方面评为Alfa级（无变色），1颗评为Bravo级（表面变色）。5年内未检测到邻面龋或根尖周病变。5年后参与者对其牙冠高度满意（0至10分制，平均±标准差：9.8±0.4）。
在颈部三分之一处采用0.3毫米厚度定制内冠且边缘为氧化锆的上颌前牙冠在使用5年后表现良好。
