【摘要】：目的:研究在人工老化的條件下,不同形態(tài)的牙本質(zhì)肩領(lǐng)與樁核系統(tǒng)對(duì)樁核冠修復(fù)后的牙體抗折性能的影響。方法:收集三個(gè)月內(nèi)因正畸治療拔除的下頜單根管第一前磨牙64顆,隨機(jī)分成8組(n=8),各組離體牙預(yù)備成不同的牙體缺損形態(tài),設(shè)計(jì)為不同的牙本質(zhì)肩領(lǐng)及樁核類型。A1組:360°牙本質(zhì)肩領(lǐng)+玻璃纖維樁樹脂核。A2組:360°牙本質(zhì)肩領(lǐng)+鑄造鈷鉻合金樁核。B1組:180°頰側(cè)牙本質(zhì)肩領(lǐng)+玻璃纖維樁樹脂核。B2組:180°頰側(cè)牙本質(zhì)肩領(lǐng)+鑄造鈷鉻合金樁核。C1組:180°舌側(cè)牙本質(zhì)肩領(lǐng)+玻璃纖維樹脂樁核。C2組:180°舌側(cè)牙本質(zhì)肩領(lǐng)+鑄造鈷鉻合金樁核。D1:180°頰、舌側(cè)牙本質(zhì)肩領(lǐng)+玻璃纖維樁樹脂核。D2:180°頰、舌側(cè)牙本質(zhì)肩領(lǐng)+鑄造鈷鉻合金樁核。牙本質(zhì)肩領(lǐng)高度均設(shè)為2mm,厚度設(shè)為(1.2±0.2)mm。樁核粘接就位后所有離體牙均按照全冠預(yù)備標(biāo)準(zhǔn)進(jìn)行鈷鉻合金鑄造金屬全冠修復(fù)。將8組樣本全部進(jìn)行冷熱循環(huán)(5℃-55℃)處理5000次。在電子萬能試驗(yàn)機(jī)上以與牙長軸成150°于頰尖頂處加載,加載速度設(shè)置為1.0mm/min,直至試件任何一處出現(xiàn)斷裂,對(duì)各組折裂強(qiáng)度進(jìn)行方差分析、t檢驗(yàn)統(tǒng)計(jì)分析;觀察折裂模式的區(qū)別,并進(jìn)行卡方檢驗(yàn)(α=0.05)。結(jié)果:1各組試驗(yàn)牙齒的牙根長度、釉牙骨質(zhì)界處近遠(yuǎn)中徑、頰舌徑均無統(tǒng)計(jì)學(xué)上的差異(P0.1)。2纖維樁樹脂核組及鑄造金屬樁核組抗折強(qiáng)度最高值都出現(xiàn)在360°環(huán)形組,統(tǒng)計(jì)結(jié)果顯示與其他組間存在明顯差異(P0.05)。其余各組間未見明顯差異。3鑄造金屬樁核組的抗折強(qiáng)度高于纖維樁樹脂核組,但在保留舌側(cè)肩領(lǐng)類型組的差異無意義,其余三組間差異均有統(tǒng)計(jì)學(xué)意義(P0.05)。4纖維樁核組可修復(fù)性折裂例數(shù)明顯高于鑄造金屬樁核組�？ǚ綑z驗(yàn)顯示差異具有統(tǒng)計(jì)學(xué)意義(P0.05)。結(jié)論:1牙本質(zhì)肩領(lǐng)的完整性對(duì)樁核冠修復(fù)后牙體抗折性起著決定性作用,因此臨床上應(yīng)盡量多地保留牙本質(zhì)肩領(lǐng)來提高修復(fù)后牙體的抗折性能,牙本質(zhì)肩領(lǐng)位置形態(tài)對(duì)牙體抗折性能的影響較小。2鑄造金屬樁核抗折強(qiáng)度高,但易造成牙體的不可修復(fù)性根折,纖維樁核雖抗折強(qiáng)度較低,但能滿足臨床需求,且更有利于牙根的保護(hù)。
[Abstract]:Objective: to study the effect of different dentin shoulder collar and post core system on the fracture resistance of dentine crown after artificial aging. Methods: 64 mandibular first premolars extracted by orthodontic treatment within three months were randomly divided into 8 groups (n = 8). Different dentin shoulder collar and post core type. A1 group: 360 擄dentin shoulder collar glass fiber post resin core. A2 group: 360 擄dentin shoulder collar cast cobalt-chromium alloy post core. B1 group: 180 擄buccal side shoulder collar glass fiber post resin core .B2 Cast cobalt-chromium alloy post core. C1 group: 1% 180 擄tongue side dentin shoulder collar fiberglass resin post core. C2 group: 1 180 擄tongue side dentin shoulder collar casting cobalt-chromium alloy post core. D1: 180 擄cheek. The resin core of glass-fiber post. D2: 180 擄on the shoulder collar of lingual dentin, and the cobalt-chromium alloy post core cast on the shoulder collar of lingual side dentin. The height of dentin shoulder collar was 2 mm and the thickness was (1.2 鹵0.2) mm.. All the isolated teeth were repaired with cobalt-chromium alloy cast metal crown according to the standard of full-crown preparation. All 8 groups of samples were treated with cold and hot cycles (5 鈩，

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