Department of Prosthodontics, Section of Material Sciences, University of Heidelberg, Heidelberg, Germany.
Int Endod J. 2010 May;43(5):436-42. doi: 10.1111/j.1365-2591.2010.01705.x.
The hypothesis of this study was that the fracture load of incisor teeth restored using short, threaded, parallel-sided posts (TMP) is, under special conditions, not inferior to that of teeth restored using long TMPs or fibre-reinforced posts (FRP).
Seventy-two maxillary incisors and 72 mandibular incisors were collected. Sixty-four in each group were root filled; in half of these FRPs were cemented, and in the other half TMPs were used. Half of the FRPs were pretreated; the others were not pretreated. In the TMP-group, half of the teeth received a long post (10 mm), the other half a short post (3 mm). Crowns were fabricated and cemented with Ketac-cem or Panavia. Eight maxillary incisors and eight mandibular incisors with intact natural crowns were used as control groups. All specimens were loaded until fracture.
Fracture loads were higher for pretreated FRPs than for untreated FRPs. If the FRPs were not pretreated, fracture loads for maxillary incisors after use of short metal posts were significantly higher (248 N compared with 133 N, P = 0.027). Fracture loads for teeth restored using long TMPs were not higher than for teeth restored using short TMPs (277 N compared with 266 N). Fracture loads for mandibular incisors restored using long (10 mm) pretreated FRP were higher than for mandibular incisors restored using short (3 mm) metal posts (436 N compared with 285 N). Cementation of the crowns using an adhesive resin cement did not increase the fracture load for mandibular incisors, whereas for maxillary incisors, this cementation technique tended to increase fracture loads in teeth restored with FRP, although this increase was not significant at the P < 0.05 level (P = 0.06). In both groups, fracture loads were higher for mandibular incisors.
Short, threaded, parallel-sided metal posts might be an alternative to fibre- reinforced posts for maxillary incisors, for teeth with short roots or when FRP cannot be pretreated.
本研究的假设是，在特殊条件下，使用短螺纹平行侧柱（TMP）修复的切牙的断裂负荷并不低于使用长 TMP 或纤维增强柱（FRP）修复的切牙。
收集了 72 颗上颌切牙和 72 颗下颌切牙。每组 64 颗进行根管填充；其中一半用 FRP 粘结，另一半用 TMP。FRP 组的一半进行预处理，另一半不进行预处理。在 TMP 组中，一半的牙齿使用长柱（10mm），另一半使用短柱（3mm）。牙冠用 Ketac-cem 或 Panavia 粘结。8 颗上颌切牙和 8 颗下颌切牙作为天然牙冠完整的对照组。所有标本均加载至断裂。
预处理 FRP 的断裂负荷高于未预处理 FRP。如果 FRP 未预处理，使用短金属柱后上颌切牙的断裂负荷明显更高（248N 比 133N，P=0.027）。使用长 TMP 修复的牙齿的断裂负荷并不高于使用短 TMP 修复的牙齿（277N 比 266N）。使用预处理长（10mm）FRP 修复的下颌切牙的断裂负荷高于使用短（3mm）金属柱修复的下颌切牙（436N 比 285N）。使用粘结树脂粘结牙冠不会增加下颌切牙的断裂负荷，而对上颌切牙而言，这种粘结技术往往会增加 FRP 修复牙的断裂负荷，尽管在 P<0.05 水平上这种增加并不显著（P=0.06）。在两组中，下颌切牙的断裂负荷均较高。
对于上颌切牙，短螺纹平行侧金属柱可能是纤维增强柱的替代品，适用于牙根较短或 FRP 无法预处理的情况。
