Frankenberger Roland, Zeilinger Inka, Krech Michael, Mörig Gernot, Naumann Michael, Braun Andreas, Krämer Norbert, Roggendorf Matthias J
Department of Operative Dentistry and Endodontics, Medical Center for Dentistry, University Medical Center Giessen and Marburg, Campus Marburg, Georg-Voigt-Str. 3, D-35039 Marburg, Germany.
Department of Operative Dentistry and Endodontics, Medical Center for Dentistry, University Medical Center Giessen and Marburg, Campus Marburg, Georg-Voigt-Str. 3, D-35039 Marburg, Germany.
Dent Mater. 2015 Nov;31(11):1312-20. doi: 10.1016/j.dental.2015.08.160. Epub 2015 Sep 26.
Aim of the present study was to evaluate fracture strength of endodontically treated molars with different preparations/restorations after thermomechanical loading in vitro.
264 extracted human third molars were used. Beside the control group, 256 teeth in 32 test groups (n=8) received root canal treatment (MTwo #40/.6) and root canal obturation with AH Plus and Guttapercha. After postendodontic sealing and build-up (Syntac, SDR), specimens were additionally prepared MO or MOD. Postendodontic restorations were: Direct restorations (Tetric EvoCeram Bulk Fill bonded with Syntac; as filling or direct partial crown (PC) after reducing the cusps 3mm; amalgam as filling or direct pin-retained partial crown (PC)), vs. indirect adhesive restorations (I: Inlay vs. PC; IPS Empress I/PC; Celtra Duo I/PC; e.max CAD I/PC; Lava Ultimate I/PC; Enamic I/PC - all inserted with Syntac/Variolink) vs. cemented cast gold I/PC. After 300,000 thermocycles (5/55°C) and 1.2 Mio. 100N load cycles, specimens were loaded until fracture.
Whereas IPS Empress showed no difference between I and PC (p>0.05), in all other groups PC were significantly more stable than fillings/inlays (p<0.05), this effect was more pronounced after MOD preparations. Cast gold PC exhibited the highest fracture strengths (p<0.05), inlays the lowest (p<0.05). IPS Empress was generally inferior to the other bonded materials under investigation (p<0.05) which as PC almost reached the level of control specimens. Amalgam fillings showed the worst outcome (p<0.05).
Less invasive preparation designs were not beneficial for the stability of postendodontic restorations. Except for IPS Empress, PC were generally more successful in restabilization of weakened cusps after endodontic treatment and preparation. Cast gold PC remain the ultimate stabilization tool for ETT in terms of fracture resistance.
本研究的目的是评估体外热机械加载后不同预备/修复方式的根管治疗磨牙的抗折强度。
使用264颗拔除的人类第三磨牙。除对照组外，32个试验组中的256颗牙齿（n = 8）接受根管治疗（MTwo #40/.6）并用AH Plus和牙胶进行根管充填。根管治疗后进行封闭和堆塑（Syntac，SDR），标本再额外预备MO或MOD。根管治疗后的修复方式为：直接修复（用Syntac粘结的Tetric EvoCeram Bulk Fill；作为充填物或在牙尖降低3mm后作为直接部分冠（PC）；汞合金作为充填物或直接针固位部分冠（PC）），与间接粘结修复（I：嵌体与PC；IPS Empress I/PC；Celtra Duo I/PC；e.max CAD I/PC；Lava Ultimate I/PC；Enamic I/PC - 均用Syntac/Variolink粘结）与粘结铸造金I/PC相比。经过300,000次热循环（5/55°C）和120万次100N加载循环后，对标本加载直至折断。
IPS Empress的嵌体和部分冠之间无差异（p>0.05），在所有其他组中，部分冠比充填物/嵌体显著更稳定（p<0.05），这种效应在MOD预备后更明显。铸造金部分冠表现出最高的抗折强度（p<0.05），嵌体最低（p<0.05）。IPS Empress总体上劣于其他研究中的粘结材料（p<0.05），其作为部分冠几乎达到对照标本的水平。汞合金充填物结果最差（p<0.05）。
侵入性较小的预备设计对根管治疗后修复体的稳定性无益处。除IPS Empress外，部分冠在根管治疗和预备后对薄弱牙尖的再稳定通常更成功。就抗折性而言，铸造金部分冠仍然是根管治疗牙齿的最终稳定工具。
