Statement of problem

Long-term clinical data are lacking on the comparison of the survival of adhesively luted pressed e.max lithium disilicate glass-ceramic complete and partial coverage restorations in posterior dentitions and the effect that different technical and clinical variables have on their survival.

Purpose

The purpose of this clinical study was to examine and compare the 16.9-year survival of posterior pressed e.max lithium disilicate glass-ceramic complete and partial coverage restorations and associated clinical parameters on the outcome.

Material and methods

Patients requiring either single-unit posterior defect-specific partial coverage or complete coverage restorations were recruited in a clinical private practice. The participants were offered the options of direct restorations, partial coverage cast gold, or glass-ceramic (lithium disilicate) restorations. Those requiring complete coverage restorations were given the options of complete cast gold, metal-ceramic, or glass-ceramic restorations. Only participants who chose glass-ceramic partial and complete coverage restorations were included in the study. The overall survival of the glass-ceramic restorations was assessed by the clinical factors determined at recall. The effect of various clinical parameters (type of restoration, dental arch, tooth position in the dental arch, age and sex of participant, and ceramic thickness) was evaluated by using Kaplan-Meier survival curves to account for attrition bias and other reasons for failure. The statistical significance of differences between parameters was determined using the log rank test (α=.05).

Results

A total of 738 participants requiring 2392 lithium disilicate restorations in posterior teeth were evaluated. The mean age of the participants at the time of restoration placement was 62 (range: 20-99 years, 302 men and 436 women). Of 2392 units, 1782 were complete and 610 were partial coverage restorations. A total of 22 failures (bulk fracture or large chip) requiring replacement were recorded with the average time to failure 3.5 (0.02-7.9) years. The total time at risk computed for these units was 13227.9 years, providing an estimated failure risk of 0.17% per year. The 16.9-year estimated cumulative survival was 96.49%. The estimated cumulative survival of posterior complete (n=1782) and posterior partial coverage restorations (n=610) was 96.75% at 10.5 years and 95.27% at 16.9 years (P<.05). Of the 22, 16 failures were recorded for the complete coverage restorations. The total time at risk for these restorations was 10144.5 years, providing an estimated risk of 0.16 per year. The other 6 failures recorded occurred for the partial coverage restorations. The total time at risk for these restorations was 3083.5 years, providing an estimated risk of 0.19% per year. No statistically significant difference was found in the survival of posterior complete and partial coverage restorations among men and women, different age groups, or posterior tooth position in the dental arch (P>.05). The thickness of the restoration also had no influence on the survival of glass-ceramic posterior restorations (P>.05).

Conclusions

Pressed e.max lithium disilicate complete and partial coverage restorations showed high survival rates in posterior teeth over a 16.9-year period, with an overall failure rate of 0.17% per year. Risk of failure at any age was low for both men and women. No statistically significant difference was found in the survival of complete and partial coverage restorations, and none of the confounding variables, including the thickness of the restoration, appeared to have a significant effect on survival.

中文翻译：

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后牙压制酸蚀 e.max 二硅酸锂微晶玻璃完全和部分覆盖修复体 16.9 年生存率的比较：性能和结果作为牙齿位置、年龄、性别和陶瓷材料厚度的函数

问题陈述

缺乏长期临床数据来比较后牙列中粘合压制的 e.max 二硅酸锂微晶玻璃完全和部分覆盖修复体的存活率以及不同技术和临床变量对其存活率的影响。

目的

本临床研究的目的是检查和比较后压 e.max 二硅酸锂微晶玻璃完全和部分覆盖修复体的 16.9 年存活率以及与结果相关的临床参数。

材料与方法

在临床私人诊所招募需要单单位后部缺损特定部分覆盖或完全覆盖修复的患者。参与者可以选择直接修复、部分覆盖铸金或微晶玻璃（二硅酸锂）修复。那些需要完整覆盖修复体的人可以选择完整的铸金、金属陶瓷或玻璃陶瓷修复体。本研究仅包括选择微晶玻璃部分和完全覆盖修复体的参与者。微晶玻璃修复体的总体存活率通过召回时确定的临床因素进行评估。各种临床参数（修复体类型、牙弓、牙弓中的牙齿位置、参与者的年龄和性别、和陶瓷厚度）是通过使用 Kaplan-Meier 生存曲线来评估的，以考虑磨损偏差和其他失败原因。使用对数秩检验 (α=.05) 确定参数之间差异的统计显着性。

结果

对需要 2392 颗后牙二硅酸锂修复体的 738 名参与者进行了评估。修复体植入时参与者的平均年龄为 62 岁（范围：20-99 岁，302 名男性和 436 名女性）。在 2392 个单位中，1782 个是完整的，610 个是部分覆盖修复。总共记录了 22 次需要更换的故障（大块断裂或大芯片），平均故障时间为 3.5 (0.02-7.9) 年。为这些单元计算的总风险时间为 13227.9 年，估计每年的故障风险为 0.17%。16.9 年的估计累积生存率为 96.49%。后路完全修复（n=1782）和后路部分覆盖修复（n=610）的估计累积存活率在 10.5 年时为 96.75%，在 16.9 年时为 95.27%（P<.05）。在 22 次中，记录了 16 次完全覆盖恢复的失败。这些修复体的总风险时间为 10144.5 年，估计风险为每年 0.16。记录的其他 6 次故障发生在部分覆盖恢复中。这些修复体的总风险时间为 3083.5 年，估计风险为每年 0.19%。男性和女性、不同年龄组或牙弓中后牙位置的后牙完全和部分覆盖修复的存活率无统计学差异（P > .05）。修复体的厚度也对微晶玻璃后修复体的存活率没有影响（P > .05）。

结论

压制的 e.max 二硅酸锂完全和部分覆盖修复体在 16.9 年的时间里显示出后牙的高存活率，每年的总体失败率为 0.17%。男性和女性在任何年龄失败的风险都很低。完全覆盖修复体和部分覆盖修复体的存活率没有发现统计学上的显着差异，并且包括修复体厚度在内的任何混杂变量似乎都没有对存活率产生显着影响。