華西口腔修復(fù)理想橋基牙ppt課件

1、Ideal abutment The ideal abutment tooth contains a vital pulp. If most not be inferred from this that a treated tooth with a properly filled root canal is not suitable as a bridge abutment; clinical evidence indicates that in properly selected cases such treated teeth have rendered years of valuable

2、 service to the patient without any harmful effects. Nevertheless, the first requisite in preparing vital teeth for the reception of bridge retainers is pulp conservation. 理想的基牙應(yīng)該是活髓牙。大多數(shù)情況下不能這樣推斷：完善根管治療后的牙齒不適宜作基牙。臨床證聽(tīng)闡明合理選擇的病例中這樣的牙齒可以在患者體內(nèi)服役很多年，沒(méi)有任何危害。但對(duì)作為承當(dāng)橋固位體的活髓牙來(lái)講，首先要必需思索的就是保管活髓。 Every effort s

3、hould be made during the cutting operations to avoid overheating or irritating the pulp in order to prevent its future degeneration or death. Those preparations are contraindicated which bring the retainer too close to the pulp, thus exposing it to continuous thermal shocks; if existing conditions i

4、ndicate the probability of such an occurrence, every percaution should be taken to reduce the danger to a minimum. 在牙體預(yù)備時(shí)應(yīng)該盡一切努力來(lái)防止過(guò)熱或激惹牙髓，其目的是預(yù)防以后的牙髓變性或壞死。這些牙體預(yù)備是不當(dāng)?shù)模构涛惑w過(guò)于接近牙髓，這樣就使牙髓會(huì)受延續(xù)的熱刺激；假設(shè)存在的景象闡明有能夠會(huì)出現(xiàn)這樣的情況，應(yīng)該非常的小心來(lái)將這種危險(xiǎn)減少到最小。 To be suitable for use as a bridge abutment, a tooth must have suf

5、ficient bulk to withstand the forces to force it will be subjected after the bridge is attached to it. This physical requirement is frequently compromised in the effort to conserve the pulp of a tooth which is extensively decayed. 要想成為理想的橋基牙，固定橋戴上之后，在接受力的時(shí)候，牙齒必需求有足夠的體積來(lái)抵抗外力。這種物理方面的要求經(jīng)常會(huì)影響到大面積齲壞的牙齒保管

6、牙髓的活力。 As previously indicated, abutment teeth sustain forces of a type and magnitude which the unattached tooth is not required to bear; hence, the type and amount of periodontal membrane attachment are items of importance and should be determined separately for each abutment tooth. 正如前面談到的那樣，基牙接受了

7、單個(gè)牙齒本身不用接受的特定類型和大小的力；因此，每個(gè)基牙附著的牙周膜的種類和牙周膜面積是很重要的，并且都應(yīng)該分別被評(píng)價(jià)。Although the ideal abutment is one which has normal amount of periodontal attachment, many teeth lacking one-third to one-half of the normal amount, when indiciously selected, it is questionable whether such a tooth should be used as an abu

8、tment. The amount of alveolar bone is determined by the extent of periodontal attachment and the type of bone present reflected its degree of function.雖然理想的橋基牙有正常的牙周附著，但很多牙齒的牙周附著是正常量的2/3到1/2，在進(jìn)展明智的選擇的時(shí)候，這樣的牙齒能否應(yīng)該用作基牙仍是一個(gè)問(wèn)題。牙槽骨的牙由牙周附著的程度來(lái)決議，并且骨的類型表現(xiàn)出的它所反響的功能的情況。 In operative dentistry cavities are pr

9、epared primarily to receive fillings which restore that part of the tooth lost be caries or accident. In fixed partial denture prosthesis a large proportion of the teeth receiving bridge retainers are sound and noncarious; occasionally a monocarious tooth is used. Polycarious teeth, those with more

10、than one carious lesion, are often restored with a complete crown instead of with the intracoronal or partial veneer type of retainers. The location of a cavity in an abutment tooth is also a determining factor. 有效的牙齒洞型被預(yù)備主要是放充填物，而充填物那么用來(lái)修復(fù)因齲壞或不測(cè)緣由而喪失的部分牙體組織。在固定義齒修復(fù)體中很多粘接橋固位體的牙齒是完好無(wú)齲壞的；多齲的牙齒有不止一個(gè)的齲損

11、，通常用全冠而不是冠內(nèi)或部分的貼面類型的固位體?；郎淆x洞的位置也是一個(gè)決議性的要素。Questionable abutmentWhile most abutments can be restored with complete crowns, the employment of intracoronal or partial veneer type of retainers has definite limitations. Before approving a tooth to serve as an abutment, its degree of calcification should

12、 be established; enamel that has not been properly calcified, but that is soft and chalky, will not furnish a suitable wall against which the margin of the casting may be finished. Some teeth have opalescent dentin; these are questionable for use as abutments to carry retainers of ther than complete

13、 crowns. In polycarious teeth the suitability of an abutment is determined to a large degree by the amount and distribution of healthy tooth structure that is left after the carious parts have been removed. 雖然大部分的橋基牙可以用全冠來(lái)修復(fù)，但冠內(nèi)或部分貼面的固位體有一定的局限。在決議一個(gè)牙齒用作橋基牙之前，它的鈣化程度應(yīng)該被評(píng)價(jià)。假設(shè)釉質(zhì)礦化不全或者是軟的，白堊色，就不能提供一個(gè)適宜的壁

14、來(lái)抵抗完成的鑄造體的邊緣。一些牙齒有乳光牙本質(zhì)，用作一些非全冠固位體的橋基牙就有一些問(wèn)題。多齲的牙齒能否適宜作為基牙在很大程度上由將齲壞去除掉后余留下的安康的牙齒構(gòu)造的量和位置來(lái)定。 The construction of a bridge retainer, other than a complete crown, frequently offers serious mechanical and biological problems on a badly abraded tooth. Due to the reduced coronal height of such a tooth, li

15、ttle opportunity is found to develop sufficient mechanical retention and still not endanger the pulp. It is much better, when such teeth are encountered, to employ the complete veneer type of retainer. 非全冠的橋固位體的構(gòu)造經(jīng)常會(huì)在一個(gè)重度磨損的牙齒上引起嚴(yán)重的機(jī)械或生物學(xué)問(wèn)題。過(guò)度磨損的牙齒由于降低了冠的高度，很難獲得足夠的機(jī)械固位，也會(huì)累及牙髓。當(dāng)遇到這樣的牙齒時(shí)，用全貼面類型的固位領(lǐng)會(huì)更好

16、。At times teeth egress beyond their normal occlusal plane to a point where, to use them as bridge abutments, it is necessary to grind down a considerable portion of the occlusal third of the crown. Such teeth are not usually in occlusal contact with the opposing arch. The amount of such vertical dis

17、placement varies from 1mm. to a point where the teeth touch the mucosa of the opposite arch. 有時(shí)牙齒會(huì)伸長(zhǎng)超越了他們所在的正常的合平面，用他們作為橋基牙時(shí)，必需將牙冠合1/3磨去相當(dāng)多的一部分。這樣的牙齒通常和對(duì)合牙沒(méi)有咬合接觸。這樣的垂直移位的量會(huì)從1mm到牙齒接觸到對(duì)合牙弓的粘膜。 Where the egression of such a tooth has exceeded one-fourth the normal height of its crown, its use as an abu

18、tment usually requires that the pulp be removed. Where the necessary amount of reduction can be made without encroaching upon the pulp, the same physical and biological handicaps prevail as in the case of an abraded tooth. An egressed tooth is further handicapped since it does not have a periodontal

19、 membrane of normal, functional width; neither does it possess a supporting bone of normal structure. Such teeth are of questionable value when used as bridge abutments. 當(dāng)牙齒伸長(zhǎng)超越了牙冠高度的1/4，用它作為基牙時(shí)通常要進(jìn)展殺髓。減少的量要求不累及牙髓，和牙齒過(guò)度磨損的情況一樣，也存在同樣的物理和生物學(xué)方面的妨礙。伸長(zhǎng)的牙齒還有其他問(wèn)題，由于它沒(méi)有正常的牙周膜，生物學(xué)寬度；也不具備正常的支持骨的構(gòu)造。這樣的牙齒用作橋基牙時(shí)

20、是有問(wèn)題的。A malposed or malrelated tooth is not necessarily contraindicated as an abutment. The deciding factors are whether a suitable can be prepared for it and whether the forces which will be transmitted to the tooth after the bridge is placed will be of a magnitude and direction which can be tolera

21、ted by the tooth and its investing tissues. The malpositions may be varied, such as a tilting of the tooth mesiodistally or buccolingually; a rotation of the tooth about its own axis and a migration bodily of teeth into new positions and malrelations in the arch.錯(cuò)位的或錯(cuò)合的牙齒不是作為基牙的忌諱癥。其決議要素是看它能否可以預(yù)備出適宜

22、的外形，固定橋就位后傳送到牙齒上的力量的大小和方向能否超越出了牙齒及牙周組織的耐受范圍。錯(cuò)位可以糾正過(guò)來(lái)，如近遠(yuǎn)中或頰舌向傾斜的牙齒、改動(dòng)的牙齒其本身的長(zhǎng)軸和整體的移位可以到新的位置，及牙弓中的錯(cuò)合。 There is no objection to the use of anomalies as abutments, provided that they have a sound biological relationship with the investing and supporting tissues and that their coronal contour is such as

23、 to afford sufficient mechanical retention. Such teeth, however, rarely are employed for intracoronal or partial veneer types of retainers; the complete crown is preferred.并不反對(duì)用畸形牙作為基牙，只需他們和周圍及支持組織有一個(gè)正常的生物學(xué)的關(guān)系，并且他們的冠的外形可以提供足夠的機(jī)械固位力。但這樣的牙齒，很少用作冠內(nèi)或部分貼面類型的固位體，通常采用全冠來(lái)冠位。 When an abutment is loose, the e

24、tiology for the existing condition should be determined. If it is due to periodontal infection, excessive bone destruction, or other similar causes, its use as bridge abutment should not be considered until the existing conditions have been corrected and their causes removed. 當(dāng)基牙松動(dòng)時(shí)，存在這種情況的緣由應(yīng)該被確定。假

25、設(shè)是由于牙周感染，過(guò)多的骨破壞，或其他類似的緣由，直到存在的情況得以改善或他們的病因被去除，才可以思索將其作為橋基牙。 Occasionally there is the possibility of using a tooth with a resected or a fractured root as an abutment. While such a condition curtails the probable life of a bridge, there are times when such a procedure is justified. The prognosis is m

26、ore favorable in those cases where the root is used to carry only an individual crown. 有時(shí)能夠會(huì)用殘根作為基牙。當(dāng)遇到這種情況的時(shí)候會(huì)減少固定橋的實(shí)際壽命。當(dāng)這樣的治療方案是合理的時(shí)候仍可以維持一段時(shí)間. 在殘根只用作獨(dú)立的單冠修復(fù)的時(shí)候，預(yù)后更好。Root length of abutmentIn the ideal abutment a proportionate relationship exists between the lengths of the crown and the root. Whe

27、re the root is excessively short, either congenitally or due to a resorption, it cannot furnish the necessary support to the crown or resistance to the forces of mastication developed during the various movements of the mandible. The additional forces inherent in a bridge will cause such teeth to fail as abutments.理想基牙應(yīng)有一個(gè)恰當(dāng)?shù)墓诟?。無(wú)論是先天的牙根過(guò)短，還是由于再吸收導(dǎo)致的牙根過(guò)短，它都不能給牙冠提供足夠的支持力，或