Statement of problem

Long-term clinical data on the survival of pressed lithium disilicate glass-ceramic when used with partial coverage restorations and the effect that different technical and clinical variables have on survival are sparse.

Purpose

The purpose of this clinical study was to determine the 10.9-year survival of pressed lithium disilicate glass-ceramic partial coverage restorations and associated clinical parameters on outcomes.

Material and Methods

Individuals requiring single unit defect-specific partial coverage restorations in any area of the mouth were recruited in a clinical private practice. Participants were offered the options of partial coverage cast gold or glass-ceramic (lithium disilicate) restorations. Only participants that chose glass-ceramic partial coverage restorations were included in the study. The overall survival of the glass-ceramic restorations was assessed by the clinical factors (participant’s age, sex, dental arch, tooth position in dental arch, type of partial coverage restoration, and ceramic thickness) determined at recall. The effect of this clinical parameters was evaluated by using Kaplan-Meier survival curves accounting for attrition bias and other reasons for failure. The statistical significance of differences between parameters was determined by using the log rank test (α=.05).

Results

A total of 304 participants requiring 556 lithium disilicate restorations were evaluated. The mean age for the participant at the time of restoration placement was 62 with a range of 20 to 99 years, 120 were men and 184 were women. A total of 6 failures (bulk fracture or large chip) requiring replacement were recorded with the average time to failure of 2.4 (0.8-9.2) years. The total time at risk computed for these units was 1978.9 years providing an estimated failure risk of 0.3% per year. The 10-year estimated cumulative survival was 95.6%.

The estimated cumulative survival of inlays (n=246) and onlays (n=305) were 93.9% and 98.3%, at 9.9 and 9.8 years, respectively (P<.05). Of the 6, there were 3 failures recorded for the partial coverage inlay restorations. The total time at risk for these inlays was 786.79 years providing an estimated risk of 0.38% per year. The other 3 failures recorded occurred for the partial coverage onlay restorations. The total time at risk for the onlays was 1032.17 years providing an estimated risk of 0.29% per year. The failures occurred in the molar region only. There were no failures recorded for the anterior partial coverage inlays (n=5). The total time at risk computed for the anterior units was 21.55 years providing an estimated risk of 0% per year.

There was no statistically significant difference in the survival of partial coverage restorations among men and women, different age groups, or position in the dental arch. The thickness of the restoration had no influence on the survival of glass-ceramic partial coverage restorations.

Conclusions

Pressed lithium disilicate defect-specific partial coverage restorations reported high survival rate over the 10.9-year period with an overall failure rate of 0.3% per year and limited to the molar teeth. Risk of failure at any age was minimal for both men and women.

中文翻译：

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压制酸蚀整体 e.max 二硅酸锂微晶玻璃陶瓷部分覆盖修复体的 10.9 年存活率：作为牙齿位置、年龄、性别和部分覆盖修复体类型（嵌体或高嵌体）的函数的性能和结果

问题陈述

关于压制二硅酸锂微晶玻璃与部分覆盖修复体一起使用时的存活率以及不同技术和临床变量对存活率的影响的长期临床数据很少。

目的

本临床研究的目的是确定压制二硅酸锂微晶玻璃局部覆盖修复体的 10.9 年存活率以及相关的临床参数对结果的影响。

材料与方法

需要在口腔任何区域进行单一单位缺陷特定部分覆盖修复的个人是在临床私人诊所中招募的。参与者可以选择部分覆盖铸金或玻璃陶瓷（二硅酸锂）修复体。该研究仅包括选择微晶玻璃部分覆盖修复体的参与者。通过召回时确定的临床因素（参与者的年龄、性别、牙弓、牙弓中的牙齿位置、部分覆盖修复体的类型和陶瓷厚度）评估微晶玻璃修复体的总体存活率。该临床参数的影响是通过使用 Kaplan-Meier 生存曲线来评估的，这些曲线考虑了磨损偏倚和其他失败原因。

结果

对需要 556 个二硅酸锂修复体的 304 名参与者进行了评估。植入修复体时参与者的平均年龄为 62 岁，范围为 20 至 99 岁，其中男性 120 人，女性 184 人。总共记录了 6 次需要更换的故障（大块断裂或大芯片），平均故障时间为 2.4 (0.8-9.2) 年。为这些装置计算的总风险时间为 1978.9 年，提供每年 0.3% 的估计故障风险。10 年估计累积生存率为 95.6%。

嵌体（n=246）和高嵌体（n=305）的估计累积存活率分别为 93.9% 和 98.3%，分别为 9.9 和 9.8 年（P <.05）。在 6 个中，部分覆盖嵌体修复体记录了 3 个失败。这些嵌体的总风险时间为 786.79 年，估计风险为每年 0.38%。记录的其他 3 次故障发生在部分覆盖高嵌体修复体中。高嵌体的总风险时间为 1032.17 年，估计风险为每年 0.29%。故障仅发生在磨牙区域。前部部分覆盖嵌体 (n=5) 没有记录失败。前牙单位的总风险时间为 21.55 年，估计风险为每年 0%。

男性和女性、不同年龄组或牙弓位置的部分覆盖修复的存活率在统计学上没有显着差异。修复体的厚度对微晶玻璃部分覆盖修复体的存活率没有影响。

结论

压制二硅酸锂缺陷特定部分覆盖修复报告在 10.9 年期间的高存活率，每年总失败率为 0.3%，仅限于磨牙。男性和女性在任何年龄失败的风险都是最小的。