Francis A V, Braxton A D, Ahmad W, Tantbirojn D, Simon J F, Versluis A
Oper Dent. 2015 Sep-Oct;40(5):515-23. doi: 10.2341/14-235-L. Epub 2015 Mar 5.
To investigate a bulk-fill flowable base composite (Surefil SDR Flow) in terms of cuspal flexure and cure when used in incremental or bulk techniques.
Mesio-occluso-distal cavities (4 mm deep, 4 mm wide) were prepared in 24 extracted molars. The slot-shaped cavities were etched, bonded, and restored in 1) two 2-mm increments Esthet-X HD (control), 2) two 2-mm increments Surefil SDR Flow, or 3) 4-mm bulk Surefil SDR Flow (N=8). The teeth were digitized after preparation (baseline) and restoration and were precisely aligned to calculate cuspal flexure. Restored teeth were placed in fuchsin dye for 16 hours to determine occlusal bond integrity from dye penetration. Extent of cure was assessed by hardness at 0.5-mm increments through the restoration depth. Results were analyzed with analysis of variance and Student-Newman-Keuls post hoc tests (α=0.05).
Surefil SDR Flow, either incrementally or bulk filled, demonstrated significantly less cuspal flexure than Esthet-X HD. Dye penetration was less than 3% of cavity wall height and was not statistically different among groups. The hardness of Surefil SDR Flow did not change throughout the depth for both incrementally and bulk filled restorations; the hardness of Esthet-X HD was statistically significantly lower at the bottom of each increment than at the top.
Filling in bulk or increments made no significant difference in marginal bond quality or cuspal flexure for the bulk-fill composite. However, the bulk-fill composite caused less cuspal flexure than the incrementally placed conventional composite. The bulk-fill composite cured all the way through (4 mm), whereas the conventional composite had lower cure at the bottom of each increment.
研究一种大块充填可流动型复合树脂（Surefil SDR Flow）在采用分层或大块充填技术时的牙尖挠曲和固化情况。
在24颗拔除的磨牙上制备近中-咬合-远中洞（深4 mm，宽4 mm）。将槽形洞进行酸蚀、粘结，然后分别用以下材料修复：1）分两层每层2 mm充填Esthet-X HD（对照）；2）分两层每层2 mm充填Surefil SDR Flow；3）一次性充填4 mm Surefil SDR Flow（每组n = 8）。修复前（基线）和修复后对牙齿进行数字化处理，并精确对齐以计算牙尖挠曲。将修复后的牙齿置于品红染料中16小时，通过染料渗透来确定咬合面粘结完整性。通过在修复体深度上以0.5 mm的增量测量硬度来评估固化程度。结果采用方差分析和Student-Newman-Keuls事后检验进行分析（α = 0.05）。
无论分层充填还是大块充填，Surefil SDR Flow的牙尖挠曲均显著小于Esthet-X HD。染料渗透小于洞壁高度的3%，且各组间无统计学差异。对于分层充填和大块充填修复体，Surefil SDR Flow在整个深度的硬度均无变化；Esthet-X HD在每层底部的硬度在统计学上显著低于顶部。
对于大块充填复合树脂，分层充填或大块充填在边缘粘结质量或牙尖挠曲方面无显著差异。然而，大块充填复合树脂引起的牙尖挠曲小于分层放置的传统复合树脂。大块充填复合树脂能完全固化（4 mm），而传统复合树脂在每层底部的固化程度较低。
