Qualtrough A J, Cawte S G, Wilson N H
Unit of Operative Dentistry and Endodontology, University of Manchester Dental Hospital, Higher Cambridge Street, Manchester M15 6FH.
Oper Dent. 2001 May-Jun;26(3):267-72.
Controversy exists over the most favorable material and type of restoration to be used to transitionally restore teeth destined to be crowned. This in vitro study uses fracture resistance testing to compare eight different transitional restorations in maxillary premolars. Ninety sound maxillary premolars were randomly selected and allocated to nine groups, each comprising 10 teeth. One group remained unrestored and was used as the control. Teeth in the remaining groups were prepared to a standard cavity form using: a copy milling process removing the palatal cusp. Restorations were placed using amalgam with dentin pins and cavity varnish; amalgam with an amalgam bonding agent; resin composite with dentin pins and a dentin bonding agent; resin composite with a dentin bonding agent only; resin-modified glass ionomer with dentin pins; resin-modified glass ionomer cement alone and cermet with dentin pins and cermet alone. Each restored tooth was then subjected to axial loading via a bar contacting the buccal and restored palatal cusps until failure of the restored tooth occurred. The mean load-to-fracture values were statistically compared and the modes of failure recorded. It was found that the choice of restorative material and type of restoration had little effect on the fracture resistance of the restored tooth with the exception of those teeth restored with reinforced glass ionomer cement alone, which exhibited a significantly lower resistance to fracture than the other restored teeth. However, the choice of restorative material/technique did influence the mode of failure. Failure in teeth restored with resin-modified glass ionomer cement alone produced the least damage to the remaining tooth tissue when failure occurred. Consequently, this material may offer the most favorable range of properties for the transitional restoration of extensively broken-down maxillary premolar teeth destined to be crowned. Furthermore, the findings of this study fail to support the use of dentin pins in the placement of bonded build-up restorations.
对于用于过渡性修复准备进行牙冠修复的牙齿的最适宜材料和修复类型，目前仍存在争议。这项体外研究采用抗折性测试，比较了上颌前磨牙的八种不同过渡性修复体。随机选取90颗健康的上颌前磨牙并分为九组，每组10颗牙。一组不做修复作为对照。其余组的牙齿采用以下方法制备成标准洞形：使用复制铣削工艺去除腭尖。修复体的放置方式如下：使用汞合金加牙本质钉和洞漆；汞合金加汞合金粘结剂；树脂复合材料加牙本质钉和牙本质粘结剂；仅使用树脂复合材料加牙本质粘结剂；树脂改性玻璃离子体加牙本质钉；仅使用树脂改性玻璃离子水门汀；金属陶瓷加牙本质钉以及仅使用金属陶瓷修复体。然后，通过一根接触颊尖和修复后的腭尖的杆对每颗修复后的牙齿施加轴向载荷，直至修复后的牙齿发生折断。对平均抗折载荷值进行统计学比较，并记录折断模式。结果发现，修复材料和修复类型的选择对修复后牙齿的抗折性影响不大，但仅用增强型玻璃离子水门汀修复的牙齿除外，其抗折性明显低于其他修复后的牙齿。然而，修复材料/技术的选择确实会影响折断模式。仅用树脂改性玻璃离子水门汀修复的牙齿折断时，对剩余牙齿组织造成的损伤最小。因此，这种材料可能为注定要进行牙冠修复的广泛龋坏的上颌前磨牙的过渡性修复提供最适宜的性能范围。此外，本研究结果不支持在粘结性堆塑修复体放置过程中使用牙本质钉。
