第15章 P335-349

PROFESSIONAL CLEANING OF THE TEETH




Preventive treatment by the dentist in the United States consists, at least as is reported for income purposes (Table 13- 8), primarily of annual or biannual tooth cleanings administered by the hygienist. As this procedure, when given to children, is often followed by topical application of fluorides, the caries preventive efficacy of the mechanical component cannot be assessed. However, one may deduce that an annual cleaning in the absence of fluoride will not be a particularly effective preventive caries procedure. In particular, there is the potential to select in the recolonization process for organisms buried within pits, fissures and other inaccessible anatomic sites. This has been beautifully demonstrated by means of scanning electron photomicrographs taken at various intervals following a dental cleaning. In Figure 15-1A a tooth surface containing a crack is shown immediately after a dental prophylaxis. No bacteria are observed on the flat tooth surfaces nor on the visible walls of the crack. However, four hours later a line of dense microbial growth is observed along the entire length of the crack (Fig. 15-1B). The appearance of the growth indicates that the bacteria left behind in the crack had quickly recolonized the vicinity of the crack and had established dominance in that site. If these bacteria contained S. mutans, then a cariogenic plaque was selected for. If these bacteria contained noncariogenic organisms, then a noncariogenic plaque would occupy this caries-prone site and could serve to exclude cariogenic organisms from the niche. The identity of the recolonizing bacteria thus would be decisive in determining the eventual caries outcome of the site. If the professionally administered mechanical debriding procedures are repeated at two or three-week intervals and are supplemented with a fluoride paste as was done in the Karlstad studies (Fig. 13-3, Table 13-11), there is the possibility that the fluoride could sterilize or greatly reduce the number of organisms left behind in pits, fissures and cracks. In this event, recolonization of these retentive sites would come from organisms in the saliva and would lead to a repopulation of these caries-prone sites with noncariogenic organisms, as was illustrated in Figure 14-1. If this is so, then fluoride was essential for the efficacy of these Swedish studies.





專業潔牙

對美國的牙醫師而言，預防治療是建議一年有一次到兩次的專業潔牙，這樣潔牙動作是讓衛教師來執行，有報導部分是基於收入的因素。這樣的專業潔牙到最後都會給與局部塗氟，用這種機械方法來預防蛀牙的效率是不可被評估的。然而，可能會有人說這樣專業潔牙若不給以氟，不會被視為一有效的預防蛀牙方法。特別來說，藏在溝縫裡或是其他不可接觸的地方，對於細菌而言是有潛力可以去選擇再次聚集的過程。這可以經由在潔牙時不同階段所拍攝的微電子照片美麗地呈現出來。如圖15-1，牙齒經過專業潔牙後可看出有一個裂縫，在平滑表面或是裂縫的強壁上都未發現任何細菌。然而經過四小時後，在整條縫隙處可見密集地細菌成長，可見圖15-1 B。被藏在縫隙裡的細菌很快地又再次聚集成菌落，並且成為此處的主要菌落者。若這些細菌包含S. mutans，則這些形成的菌落會是易蛀牙的細菌。若這些細菌包含的是非蛀牙性細菌，則非蛀牙細菌則會佔滿這容易蛀牙的地方，並排除那些易蛀牙的細菌。所以再次聚集細菌的種類會是決定這地方是否蛀牙重要因素。在Karlstand 所做的研究，每兩到三個禮拜所做的專業機械性潔牙並佐用氟膏，研究顯示氟可以消毒或是大量地減少在溝縫、或裂痕裡的細菌。在這個事件裡，重新聚集在這些地方的細菌是從唾液中來的，在這些容易引起蛀牙的地方重新聚集非蛀牙的細菌，像圖14-1所示。若真如這個所說，對於這些瑞典研究所顯示，氟是最重要的。



A Danish group consisting of Poulsen, Agerbaek, Melsen, Glavind and their colleagues have conducted a series of clinical experiments in which the various components of the Karlstad regimen have been isolated and individually studied. They observed that oral hygiene instructions and dietary and bacteriological information had no effect on caries reduction (Table 15-2). In a separate study they evaluated the effect that frequent toothcleaning using a nonfluoridated paste would have on caries increment. Seven-year-old children were stratified according to the presence or absence of smooth-surface lesions and then children within each of the two strata were randomly assigned to an experimental and a control group. The experimental group was given careful professional cleaning of the teeth every second week during the two years of the study. Both groups received biweekly 0.2 percent sodium fluoride rinses and were given complete restorative dental treatment before the baseline examinations and another course of treatment at six-month intervals.

有一群丹麥研究員包含Poulsen, Agerbaek, Melsen, Glavind和其他成員進行了以Karlstad研究裡不同的因素應被隔離或是個別研究進行的一系列實驗。他們發現口腔衛教、飲食還有細菌的資訊對於降低蛀牙是不會有幫助(表15-2)。在另一個實驗中他們評估經常用不含氟的牙膏刷牙對於蛀牙的增加率。一群七歲的小朋友以有無平滑面的蛀牙病炤來分層，所以當小朋友有在兩層以下的就被平均分配到實驗組和控制組。在這兩年的實驗中，實驗組每兩個禮拜就給予專業潔牙一次。這兩組每兩個禮拜都給予0.2%鈉化氟的漱口水。而且在實驗開始前所有蛀牙都有填補，且每六個禮拜會定期檢查。



After one year the experimental group averaged one less decayed permanent surface than the control group, and after two years the experimental group had 1.7 fewer decayed surfaces (Table 15-6). This difference was low compared to the reduction of 5.5 surfaces observed after two years in the seven to eight-year-old children treated by the Karlstad regimen (Fig. 13-3). These findings indicate that repeated professional cleaning with a nonfluoridated paste decreased caries incidence, but that the treatment effect is only about 30 to 40 percent of that which was obtained when a fluoridated paste and motivational programs were also used. Motivational programs by themselves were without a noticeable treatment effect (Table 15-2), whereas topical fluorides alone yielded about a 70 percent reduction (See Table 18-8). This would suggest that the dramatic success of the Swedish studies had both a fluoride and a mechanical component. The fluoride most likely, via its antimicrobial and remineralizing actions, enhanced the ability of the mechanical debriding procedures to change the plaque flora from a cariogenic to a nondisease-associated flora (See "Fluoride" in Chap. 18).

經過一年後，實驗組在恆牙上蛀洞的面比起控制組平均少一面。過兩年後，實驗組則少1.7面(見表15-6)。這樣的差距比起Karlstad研究裡，觀察七到八歲的小朋友共兩年，降低5.5面的蛀牙所得的數據是些微的(圖13-3)。這樣觀察的結果是指使用不含氟的牙膏反覆潔牙是會降低蛀牙發生率。但是有用含氟牙膏和提高行動力下，其治療較率只有百分之三十到四十。提高行動力並不會有影響不同的治療結果(表15-2)；然而局部圖氟給予百分之七十的蛀牙降低率(表18-8)。這樣結果表示在瑞典研究裡用氟和機械性方法造成引人注目的成功，這是因為氟藉由抵抗微生物再礦化的作用，進而增加機械性移除的程序，並將這群菌落由蛀牙細菌改變成不會造成細菌的組合。



SEALANTS



The occlusal fissures are the most caries-prone sites in the dentition (Table 11-1). The bacteria contained therein subside into a micro-environment which is virtually inaccessible to mechanical debriding procedures (Figure 15-2). In the 1920s Hyatt recommended eradication of fissures by replacing them with Class I amalgam restorations, and Bodecker advocated reshaping of the fissure morphology to produce wide, non-retentive, self-cleaning grooves. In the latter procedure, called a prophylactic odontotomy, there was the problem that the extreme depths of some fissures would lead to dentinal exposures during the reshaping process. Neither procedure was subsequently adapted because of its invasive nature and its cost effectiveness relative to the placement of a dental restoration only after caries had developed. However, these procedures conceptualized a valid treatment strategy in preventive dentistry, namely the recontouring of the fissure anatomy, that was to become a reality in the 1970s with the introduction of plastic sealants. Only now the recontouring was achieved by an onlay of an adhesive resin which occluded the natural fissures so as to provide, in plastic, the same wide, non-retentive grooves that Bodecker recommended.

溝隙封填劑

在牙齒表面的縫隙是最容易蛀牙的地方(表11-1)。藏在溝縫裡的細菌是不可經由機械性移除的過程而被清除(圖15-2)。在1920年代，Hyatt建議以Class I 汞齊填補的方式來移除溝縫。Bodecker則提倡將溝縫的形狀重新塑形成較寬、無故持性，可以自行清潔的溝縫。在Bodecker的發法裡，又稱作預防性修行齒質，若有個極深的溝縫經過重新塑形後有可能會造成牙本質的暴露，這會造成問題。不管這些步驟是因為其侵略性的特質，或是在蛀牙發生後放上牙科填補材料之成本效益的考量。然而，這些步驟將在預防醫學有效的治療方法概念化，重新塑形溝縫，在1970年代開始有溝隙封填劑的引進。只有在現，用有黏性的樹脂做為一嵌體，封閉溝縫來重新塑形。



The technical knowledge of polymer chemistry which led to the development of the cyanoacrylates, polyurethanes and bisphenol A-glycidyl methacrylates (bis-GMA) plastics for clinical usage in dentistry are beyond the scope of this monograph. Suffice it to say that complex problems dealing with the binding of the resin to the inorganic tooth structure, control of setting time and exclusion of an aqueous environment have been solved to the extent that two generations of bis-GMA sealants have been evaluated clinically and been found to significantly reduce decay on fissure surfaces. The ability of these resins to reduce decay was initially demonstrated by Buonocore in a study in which a single application of bis-GMA was applied to one member of a contralateral pair of either permanent or primary teeth. The teeth were carefully dried and after pretreatment with a phosphoric acid etching solution, the adhesive was painted onto the fissure and then its polymerization was activated by means of an ultraviolet light. After either one or two years in vivo, the sealant was removed and the caries status of the underlying surface was determined and compared to the unsealed control teeth.

In plastic由Bodecker所介紹同樣較寬、無故持性的溝縫。

在化學上聚合物的知識增加，進而發明了氰基丙烯酸酯、聚氨酯和雙酚甲烷甘油基甲基丙烯酸酯(bis-GMA)塑膠，這些在牙科臨床上的運用遠超過此篇所討論的範圍。已有足夠能力去處理將樹脂黏到無機牙齒的表面，控制行成時間，並排除含水的環境，隨著這些問題的克服以有兩代的bis-GMA溝隙封填劑已在臨床運用評估過，且成功地降低溝縫的蛀牙。這些樹酯可降低蛀牙的發生，最先被Buonocore在研究中發現，將bis-GMA塗一次在任一恆牙或乳牙上。牙齒很小心被吹乾，接著用磷酸酸蝕，再塗上adhesive，接著用紫外光聚合。經過在人體一年或兩年的時間，溝隙封填劑被移除，來評估其下面的蛀牙，並和未封閉的牙齒來比較。



In the permanent teeth the adhesive was retained on all surfaces after one year and on 87 percent after two years (Table 15-7). The adhesive was not as well retained on the primary teeth. This was attributed to the prismless enamel layer found on these teeth which apparently did not dissolve upon acid etching, thereby preventing the formation of interprismatic voids which could be occupied by the resin. After two years only one sealant-treated permanent tooth had become carious, whereas 68 of 113 or 60 percent of the control teeth had become carious (Table 15-7). Over the same time period two sealant-treated primary teeth had become carious compared to 15 control teeth (Table 15-7).

在經一年後黏著劑仍全部保存在所有的恆牙牙齒表面上，經兩年後剩百分之87(表18-7)。黏著劑也沒有完全保存在乳牙表面上。這是因為牙齒上的無錐狀體的牙釉質，在酸蝕時沒有被溶解，如此就無法和樹脂形成錐體間的裂縫(interprismatic voids)。經兩年後只有一顆購隙封填劑處理的恆牙有蛀洞，然而在控制組中，113個牙齒中有68顆，或是百分之六十有蛀牙(表15-7)。經過相同的時間，有兩顆放有溝隙封填劑的牙齒有蛀牙，而控制組則是15顆。



Reductions in dental decay of this magnitude are impressive and have ushered in an era where preventive treatment of occlusal fissure decay is a distinct reality. However, other investigators have not achieved the same degree of success with sealants and have raised important practical questions concerning the retention of the sealant and the cost benefit of a procedure that requires exacting clinical conditions in regard to the dryness of the operating field, and which may need to be repeated several times during the caries-prone years of the patient. The great success of the Ypsilanti study in reducing occlusal fissure decay probably was related to the repeated applications of the sealant as needed (Table 13-12), but this vigilance contributed appreciably to the cost of the study.

溝隙封填劑這樣大量地降低蛀牙是令人印像深刻的，並帶領我們進入溝隙封填劑可以有效預防咬合面的蛀牙時代。然而其他的研究結果並不能完全達到這樣一般的成功率，並且還有許多實際的問題，如有關溝隙封填劑的故持力，還有在臨床操作上為了要保持有個乾燥的工作區域所需的成本效益，或是對於高蛀牙率的牙齒會需要重複治療。在Ypsilanti研究裡，在降低咬合面溝縫的蛀牙有很高的成功率，是因為能重複地放置溝隙封填劑(表13-12)，但這樣會影響到整個實驗的花費。



Some have raised questions concerning leakage along the sealant-enamel margin that could lead to decay beneath the sealant, as well as questions concerning the survival of the bacteria that were left beneath the sealant during placement. It would also be of interest to know whether the absence of a retentive surface had any effect on the ability of S. mutans to successfully colonize the occlusal surface. These bacteriological issues will comprise the remaining sections of this chapter.

有關溝隙封填劑和牙本質的交界可能會產生裂縫，並可能會在封填劑下產生蛀牙，或是在放溝隙封填劑時藏在底下細菌的存活率，這些問題都有被注意到。對於缺乏故持性的表面，會影響到S. mutans是否會成功聚集在咬合面上，是很有趣的一點。有關於細菌這方面的爭議在這章節剩餘的部分會繼續討論。



Bacterial Leakage Beneath Sealants

In-vitro tests employing extracted teeth demonstrated minimal if any leakage of water-soluble dyes or radioactive compounds between the resin-enamel junction. These results indicated that the resin bound so intimately to the enamel surface that it effectively "sealed" off the underlying fissure surface from the oral environment. When this "seal" was challenged in vitro with a bacterial system however, bacteria had no difficulty in penetrating methyl-2-cyanoacrylate or bis-GMA sealants.

在溝隙封填劑下細菌的滲透

一個在口外的實驗，用水溶性的染料或具放射性化合物去測試拔下來的牙齒在樹脂牙釉質交界處是否有任何裂縫。這結果說明樹脂可以和牙釉質非常緊密的黏合，所以這樣可以緊密地將溝縫和口外環境隔絕起來。在體外實驗時，這個封閉性面對細菌系統是很具挑戰性的，然而細菌對於穿透甲基二氰基丙烯酸酯或bis-GMA溝隙封填劑沒有困難的。



Extracted molars were prepared so as to have an open connection between the occlusal fissure and the root apex. The occlusal end was then closed by the placing of a cyanoacrylate sealant. The teeth were embedded in plastic petri dishes in such a way that their crown surfaces were bathed in a medium inoculated with either S. mutans or F. nucleatum (acidogenic and nonacidogenic organisms, respectively), while their roots extended into a second petri dish containing sterile medium. Growth occurred in the sterile medium in 47 of 48 teeth, indicating that the sealant posed no barrier to bacterial penetration. This model because of the gravity drop between the fluid levels bathing the crowns and the roots introduced an unrealistic sink condition that would exploit any defects in the adequacy of the sealant-enamel bond.

有一實驗把拔下來的臼齒用來做在咬合溝縫上和牙根尖的一開放連結。在咬合面放上氰基丙烯酸酯的溝隙封填劑。並將牙齒浸泡在有蓋培養皿裡，且牙冠的部分是泡在含有S. mutans 或F. nucleatum的容易裡(分別是酸性和非酸性的細菌)。而牙根的部份則是浸泡在第二層的培養皿中，期中包含無菌的培養液。而在無菌培養皿裡48個有47個發現有生長，這結果指出溝隙封填劑並不能阻止細菌的穿透。因為在牙冠和牙根間培養液有受重力影響，這樣不像現實的下沉現象會發現溝細封填劑和牙釉質黏合的任何缺陷。



The system was modified by obturating the apices of the extracted teeth with epoxy resin so as to minimize the influence of hydrostatic pressures. Sterile endodontic paper points were aseptically placed in the pulp canals, covered with a cotton pellet and followed by the placement of a bis-GMA sealant. The teeth were placed, as before, in a medium inoculated with S. mutans and F. nucleatum. Forty two of 68 paper points were contaminated with the test organisms indicating that the tested adhesive resins were not sealants in the literal sense. However, the fact that in 26 teeth the paper points were sterile suggested that the sealants, while not a perfect barrier to bacterial penetration, were indeed a formidable barrier.

這系統藉由用樹脂來阻塞拔下來牙齒的根間孔，這樣是用來降低流體淨力的壓力。將消毒過的指針無菌地放入根管內，用棉花覆蓋起來，接著放入bis-GMA溝隙封填劑。接著將牙齒放在像之前一樣的培養液裡。68隻指針裡有42隻受到測試的細菌所感染，這表示受測試的樹脂並不是如實的溝係封填劑。然而實際上26隻消毒的指針指出溝隙封填劑對於細菌並不是一個完美的阻隔，但的確也可算上一傑出的阻隔。



Subsequent studies were performed in vivo using noncarious primary teeth that were within months of exfoliation. A narrow preparation, 3 mm long, 1 mm wide and 2 mm deep was made in the central groove of the occlusal surface and filled with sterile paper points in 23 teeth and with paper points saturated with the patient's saliva in 21 teeth. All experimental points were sandwiched between two sterile paper points to avoid direct contact with the sealant. The experimental teeth were extracted at four to 16-week intervals after application of the sealant. The teeth were disinfected, carefully entered from the pulp chamber and the experimental points aseptically removed and cultured. Nine of 19 points in which the point had been initially sterile and in which the sealant had been retained were still sterile at the conclusion of the experiment (Table 15-8). The average CFU count for the ten contaminated points was 11,600, but this count reflected primarily the contribution of one point with a count of 92,000 CFUs. From this data it would appear that bacterial leakage can occur in about half the teeth but that the amount of leakage is low judging from the magnitude of the bacterial recoveries. If the fluid which seeps in has the same bacterial density as saliva, i.e., 10,000,000 CFU/ml, then the cumulative volume which could account for 11,000 CFUs is only 0.1 ml.

接下來的實驗是在人體內進行，是利用在幾個月內脫落下未蛀的乳牙。在咬合面的中央溝上做出一狹長的修行，3釐米長，1釐米寬，2釐米深，在23顆牙齒上修行的窩洞內放消毒過的指針，在21顆牙齒上則用沾滿病人的口水指針。在實驗組裡的指針是放在兩個消毒過指針的中間，去避免和溝係封填劑接觸。而實驗組裡的牙齒是在放溝係封填劑後四到十六週後再拔除。而拔下來牙齒被消毒過，小心地從牙髓腔進入，而實驗的指針小心低被取出並培養細菌。十九個一開始就被消毒過的指針，其中有九個其溝隙封填劑仍維持在上面，在實驗結尾後仍是維持無菌的(表15-8)。十個受污染指針的平均菌落數是11,600 CFU，這樣的數據反映出每個指針上大約有92,000 CFU。從這資料裡可得知約一半的牙齒其細菌會滲透，但從細菌中重新再覆蓋的觀點來看，這樣滲透的量是很低的。若滲透進來的液體和唾液裡細菌的有相同的密度，換言之每毫升有10,000,000 CFU，則累積的量可以達到僅0.1毫升就有11,000 CFU。



It is possible that somewhat larger volumes than 0.1 ml penetrated the sealant-enamel interface, but that the amount of nutrients available for bacterial growth was so low that some bacterial cells could not survive, let alone grow. This was suggested by the second experiment in which 18 paper points were inserted after they had been purposely contaminated with saliva to the extent that they contained about 733,000 CFUs (Table 15-8). When these points were examined after being in vivo beneath the sealant for 30 to 73 days, nine points showed a decrease in bacterial counts and two of these were sterile. This would indicate that the available nutrients were barely able to sustain the size of the initial inoculum.



對於稍微大於0.1毫升是可能滲入溝隙封填劑和牙釉質的交界面，但是對於剩餘可供細菌生長的養分是很低的，有時低到有些細菌細胞不可生存，更別說生長了。這一點可被第二個實驗證實，當18個指針被口水故意污染再放入，內含有733000 CFU。當這些指針在放入口中後，在溝係封填劑下30到73天，九個指針在細菌量上有減少，有兩個仍是無菌。這顯示出剩餘的養分幾乎可以維持一開始接種的量。



These bacterial studies demonstrate that some leakage occurred in about half the sealant-treated teeth, but that the magnitude was so low as to make questionable its biological significance. This incidence of leakage is probably no more than occurs with any dental restorative material. However, the question has been raised as to whether if incipient lesions were present, would this leakage sustain further bacterial growth and enlargement of the lesion. The answer appears to be no, as will be discussed in the next section.

這些細菌的研究顯示出部分的滲漏是發生在約一半有放溝隙封填劑的牙齒。但所改變的量是非常低，在生物重要性上是一個疑問。這樣的滲漏可能是不會發生在任何填補的材料上。然而，不知是否出初期蛀牙是否存在是一問題，是否滲露是否會讓更多的細菌生長，並將病炤擴大。這答案是否定的，會在下個部份來討論。



Survival of Bacteria Beneath the Sealant

In the previous study (Table 15-8) a small Class I cavity preparation was filled with contaminated paper points prior to being covered by an occlusal sealant. The topography of the cavity preparation bore little resemblance to the fissure surface and while the bacterial levels tended to decrease, this could have been an artifact due to the inability of paper points to provide the same nutritive support as the enamel. These objections have been eliminated by studies in which carious teeth were covered with a sealant, and by a study which used a modification of the artificial fissure model (See "Fissure Colonization" in Chap. 6). In this latter investigation, Theilade et al. removed blocks of enamel containing the occlusal fissure from unerupted third molars and inserted them into specially-prepared recesses in occlusal amalgam fillings. The molar fissures were allowed to become colonized by the oral flora and then some were sealed with an adhesive resin. Immediately thereafter both the sealed and unsealed molar fissures were removed and cultured. The viable anaerobic count in the sealed teeth was reduced about 50-fold compared to the unsealed teeth. This killing effect was attributed to the 50 percent phosphoric acid solution used to condition the enamel surface. The ultraviolet light used for sealant polymerization probably had no antibacterial effect because penetration was unlikely beyond the thickness of the sealant. Thus the procedures used to apply the sealant will exert a marked antibacterial action upon the organisms embedded in the fissure.

在溝隙封填劑下細菌的存活

在前一個實驗裡(15-8)，Class I 窩洞裡在放溝隙封填劑前放入受污染的指針。而修行的窩洞和溝縫是很相似的，而當細菌量是傾向降低的，這有可能會是加工的因素，因為指針不能像牙釉質一樣供應相同的營養。而這樣的缺點以被本實驗中有放溝隙封填劑給消除，還有另一實驗中用人造溝縫的模型(可見第六章”溝縫處的菌落”)。在後者的實驗中，Theiland 等學者移除未萌發的第三大臼齒上部份牙釉質包含咬合面的溝縫，將他們放入在咬合面上汞齊填補處特製的一個地方。而臼齒的溝縫有口內細菌的聚集，有部分牙齒是用樹脂將溝縫封閉起來。在封閉或是沒封閉的臼齒被立刻移除且被培養。在封閉牙齒上無菌細菌的數量是未封閉牙齒降低的50倍。而用於將溝係封填劑聚合的紫外光可能是沒有抑菌的效用，因為紫外光的穿透力是不可能透過溝縫的厚度。因此這樣放溝隙封填劑的步驟會對於藏在溝縫裡的細菌有很大抑制的效用。



The studies involving the placement of sealants over carious lesions demonstrated a definite decline in bacterial viabilities over time that would be independent of the acid etch procedure. Handelman et al. in two separate studies showed that both an ultraviolet polymerizing and an autopolymerizing bis-GMA sealant caused about a 1000-fold reduction in bacterial counts per mg of carious dentin (Table 15-9). The study involving the autopolymerizing sealant Delton“ extended only one month and included unsealed control teeth that had or had not been acid etched. The acid etch reduced the bacterial counts four-fold, but the sealant decreased the counts 35-fold after one to two weeks, and 925-fold after one month. When the ultraviolet polymerized sealant was used, the counts decreased 20-fold after one to two weeks, l95-fold after six months and about 1900-fold after 24 months (Table 15-9). The longer the sealant remained in place the lower the bacterial counts became. The bacterial density of 600 bacteria per mg of dentin observed after 24 months was extremely low, being approximately one millionth the bacterial density found in plaque. The amount of metabolic activity that this small level of bacteria could muster would be minuscule compared to plaque and would be more comparable to that of sterile tissue. Thus it was no surprise that the clinical appearance of this formerly carious dentin was dry and leathery, resembling the texture of an arrested carious lesion.

在蛀牙上放溝係封填劑表現出細菌量上的下降，這和酸蝕的步驟是獨立的。Handelman等人在兩個不同的實驗中顯示出用紫外光聚合或是自行聚合的bis-GMA溝係封填劑，造成在蛀牙牙本質的每毫克細菌量約減少一千倍(表15-9)。這實驗包含自行聚合的溝係封填劑Delton，只維持了一個月，並包含那些有或是沒有被酸蝕的未封閉牙齒。而酸蝕降低四倍的細菌量。而溝隙封填劑經一到兩個禮拜會降低細菌量35倍，而過一個月後會降低925倍的細菌量。當使用紫外光聚合的溝係封填劑時，經一到兩個禮拜會降低細菌量20倍，而過六個月後會降低細菌量195倍，過兩年後則將低1900倍(表15-9)。當封閉劑停留在牙齒上月久，則得到的細菌數越低。在經兩年後牙本質的細菌密度是每毫克600隻，這是非常低，大約是在聚落裡所得細菌量的百萬分之一。這樣微小的細菌和聚落的細菌量比較起來是渺小的，而這樣的量是比較能和無菌的細菌量做比較。而且臨床上這些之前形成的蛀牙是乾燥且向皮革般的，和那已停止的蛀牙病炤的質地是相似的。



 The arrest of dentinal decay after being covered with a sealant was shown by Going et al. Teeth that were clinically carious or suspected to be carious had been sealed in 1972 with a single application of an ultraviolet polymerized bis-GMA sealant. In 1977 the carious and bacteriological status of these fissures was evaluated. The fissure site was carefully encircled by drilling and then an islet of tooth structure containing the fissure plus associated dentin was fractured off, weighed and immediately cultured. The remaining dentinal surface was examined for caries status Of 30 occlusal sites judged in 1972 to be either carious (18 sites) or suspected to be carious (12 sites), only four were deemed to be carious in 1977 (Table 15-10). Of 21 control sites judged in 1972 to be either carious (7 sites) or caries free (14 sites), all were carious in 1977 (Table 15-10). Thus the sealant had arrested caries in 87 percent of the previously carious surfaces, at the same time that the control teeth in the same mouth were developing new decay.


由Going等人有研究用溝係封填劑去覆蓋以停止的牙本質蛀牙。這些牙齒在臨床上評估為蛀牙或是疑似蛀牙，在1972年時，單次用紫外線聚合的bis-GMA溝係封填劑將牙齒封閉起來。等到1977年再去評估這些牙齒溝縫裡蛀牙及細菌分布的情況。在溝縫處用鑽針將含有溝縫和牙本質的齒質小心地分切割來，秤重並立即培養細菌。檢查剩餘齒質的蛀牙狀況。在1972年有放溝係封填劑的30顆牙齒，其中被認定18顆被任定為有蛀牙，12顆為疑似蛀牙。到1977回診時只有四顆有蛀牙 (Table 15-10)。在1972年沒放溝隙封填劑的21顆牙齒，其中被認定7顆被任定為有蛀牙，14顆為無蛀牙。到1977回診時全部都有蛀牙 (Table 15-10)。因此溝隙封填劑可以抑制８７％的咬合面蛀牙，而同個時間在對照組上卻是有蛀牙在發生。



The bacteriological findings confirmed the clinical diagnosis. In 9 of 18 teeth judged to be carious in 1972, no bacteria could be cultivated in 1977. Six of 12 teeth suspected of being carious in 1972, were also found to be sterile in 1977 (Table 15-10). No sterile teeth were found among the unsealed teeth. The 14 actively carious teeth in the control group in 1977 had significantly more bacteria per mg of dentin than any of the other groups, including the four carious teeth in the sealant group (Table 15-10). This suggested that while these four teeth were still considered to be carious, they could well be in a transition stage on their way to caries arrest.

從細菌分布上也證實其臨床診斷。在1972年18顆被認定為蛀牙的牙齒，其中9顆到1977年未有細菌生存。在1972年12顆被認定疑似為蛀牙的牙齒，其中6顆到1977年仍是無菌的(表 15-10)。在未封閉的牙齒上不能找到沒有無菌的牙齒。在控制組裡14顆有活耀蛀牙的牙齒，到了1977年，每毫克的牙本質比起其他組有顯著更多的細菌，包含在溝隙封填劑組的那四顆牙齒也有相同的狀況(表 15-10)。這也表示這四顆牙齒仍被認定為有蛀牙，可以說是在轉換的過程中朝向蛀牙停止caries arrest的方向進行。

These studies, in which carious teeth were purposely sealed with an adhesive resin, indicate that if leakage occurs, the amount of nutrients that become available to these buried bacteria is so minimal that bacterial viability in most instances cannot be sustained. In fact, the nutrient supply may be even less than that which can occur when sealants are placed on caries-free surfaces, because of the increased retention of the sealant to the caries-demineralized enamel. Over time the bacterial counts drop to such low levels that an acid metabolism capable of continued tooth demineralization ceases and the decay arrests. In many instances the majority of the bacteria die, as is illustrated in Figure 15-3. Thus instead of concern over continued progression of the carious lesion beneath the sealant, the reality appears to be that the sealant can abort this progression and actually lead to caries arrest. The improved retention of the sealant on a carious surface plus the decreased viability of the bacteria in the carious lesion suggests that sealants may have some therapeutic applications.

這些研究裡，蛀牙的牙齒以樹脂封閉起來，若是有漏洞發生，則可以供給給底下細菌的營養量是很有限的，所以細菌在大部分的情況下是不能生存的。事實上，可供給的營養會比在無蛀牙表面上放上溝隙封填劑來得更少，因為溝隙封填劑在去礦物質的牙本質固持力上會增加。

經過一段時間細菌量掉至一個較低的基準時，酸蝕會造成牙齒脫鈣的狀況停止而且蛀牙也趨於停緩的狀態。在大多數情況下，如圖15-3所示，大部分的細菌已死亡。事實上溝隙封填劑可以將蛀牙過程中斷使蛀牙停止。因著封填劑在蛀牙表面上固持力的增加，加上變少的細菌量，可以說溝隙封填劑有治療的用途。



Change in S. mutans Percentages on Sealant-Treated Occlusal Surfaces

The placement of the sealant over the fissure changes the topography of the occlusal surface from one which provides retentive sites for bacterial colonization, to one in which the surface is relatively smooth and has great access to the saliva. Under these conditions the micro-environment on the occlusal surface might not select for S. mutans. We have cultured occlusal fissures in children participating in the Ypsilanti study (Table 13-11) before and after the placement of an ultraviolet polymerized sealant. These treated children were also given restorative dental treatment and periodic topical fluoride applications, whereas the untreated group received none of these modalities. Thus if a difference existed between the treated and untreated groups in regard to S. mutans proportions, it would not be possible to assign this difference to the sealants alone. However when the groups were compared, after eight and 12 months there was no apparent difference in the percent of S. mutans found in plaque samples taken from the sealant-enamel margin (Table 15-11). By 12 months the S. mutans/S. sanguis ratio had increased in the untreated group suggesting that an acidic environment had selected for S. mutans at the expense of S. sanguis.

在溝隙封填劑處理過咬合面S. mutans百分比的變化

溝隙封填劑的放置改變了咬合面的型態，將有溝縫易讓細菌群聚的地方改變成相對較平滑且口水有較大的接觸。在這樣的狀況下，咬合面可能不會有S. mutans存在。在Ypsilanti 研究裡(表13-11)，我們收集在放封填劑前、後咬合面溝縫的細菌。這些有放封填劑的小朋友同時給予補牙及定期局部塗氟，然而未放封填劑組則未接受任何治療。因此這兩組若有關於S. mutans比例上的不同，不會是僅僅和有無放溝隙封填劑有關。然而經過8和12個月後，從封填劑和牙釉質邊緣取出的S. mutans細菌量並無顯著的不同(表 15-11)。 經過12個月後，S. mutans/S. sanguis比例在未治療組裡是增加的，顯示出酸性環境對於S. mutans是有利的。



These finding indicate that the conditions which promoted S. mutans colonization on the treated children's teeth had not been appreciably changed by the various treatment modalities used. Some variable(s) other than fissure-retentive sites was operating in regard to S. mutans colonization in these patients. This could be sucrose availability. Despite the persistence of S. mutans on the sealant-treated teeth, the treated children experience a caries reduction of about 70 percent on the occlusal surfaces compared to the untreated group.。Obviously microbial metabolic activity on the sealant surface has very little demineralizing activity due to the barrier function of the sealant and the availability of the salivary protective functions.

這個結果表示會使S. mutans 聚集在治療過的牙齒表面上增加的情況，並不會經由改變治療的形式而增加。有些變異除了有關S. mutans聚集的溝縫處。也有可能是有過多的蔗糖。除了S. mutans持續在有封填劑處理過牙齒上，治療過的小朋友比起未治療有70%咬合面蛀牙的下降。明顯地可看出細菌在封填劑表面只有些微去礦物質化作用，因為封填劑的阻隔功能還有唾液有保護的功能。



Sealant Evaluation

The sealants represent a major breakthrough in the preventive treatment of caries-prone retentive surfaces such as pits and fissures. Leakage beneath the sealant is minimal and not adequate to sustain bacterial viability of most organisms left beneath the sealant. Because of this nutrient blockage phenomenon, the sealant apparently can be placed over incipient fissure lesions without causing progression of the lesion. In fact, the lesions tend to arrest, and the numbers of surviving bacteria in the lesion approach zero with time. (Obviously in such a situation the tooth should be carefully followed radiologically). Cariogenic organisms can colonize the sealant surface, but their acid waste products are unable to penetrate the sealant and therefore do not cause tooth demineralization.

封填劑的評估

封填劑在易蛀牙區域(如溝縫)上的預防治療是一大突破。在溝縫下的漏洞是很小的，並不會讓底下的細菌維持生存。因為隔絕營養的來源，封填劑可以放在起初的蛀牙上且不會讓蛀牙在發展。事實上，蛀牙傾向停止，在病灶上細菌的存活量趨於零(因此在這個情況下牙齒必須用x光片定期追蹤觀察)。易蛀牙的細菌可以聚集在封填劑的表面，但是其產酸的廢物卻不能透過溝隙封填劑，因此不會造成牙齒去礦物質化。





SUMMARY

Mechanical debriding procedures such as brushing and flossing were unable to reduce caries incidence when performed by patients under supervision. These debriding procedures were able to reduce plaque and gingivitis scores, indicating that the failure to reduce decay was not due to the patient's inability to debride those tooth surfaces of their supragingival plaque. Rather the failure reflects the weakness of the NSPH's main contention that plaque mass per se is the prime etiologic agent in caries development. In fact, an argument can be made that flossing and brushing can be counterproductive in caries prevention in that they can serve as a vehicle for the spreading of an S. mutans infection about the dentition. However, if the mechanical debridement is rigorously applied, as was done by professional personnel either by daily flossing or frequent tooth cleanings with rotary dental turbines, then caries can be reduced. In these instances, the thoroughness of the debriding apparently can change a cariogenic plaque to a noncariogenic plaque by repeatedly selecting for rapid plaque-forming organisms and discriminating against those species like S. mutans, which need a stagnant environment in order to gain ascendancy. Part of the success of the Karlstad and Danish professional cleaning studies can be explained in this manner. Studies which employ sealants are successful because they remove caries-prone sites from colonization and exploitation by aciduric organisms. Organisms left beneath the sealant are effectively cut off from their nutrient supplies and tend to die off.



結論

機械性移除方法如刷牙、用牙線是由病人在監督下使用不能降低蛀牙。這些移除方法可以減少plaque和gingivitis score，所以不能降低蛀牙不是因為病人無法將牙齦上的plaque清潔乾淨。因此這樣的失敗指出NSPH的缺失，plaque mass per se對於蛀牙發展是很重要的。

事實上有爭議認為牙線和刷牙會造成將S. mutans傳遞出去的媒介。然而，若機械性移除被嚴厲執行，就像是由專業人員每天用牙線和經常的使用rotary器械，蛀牙會下降。以這些例子來說，完整的清除，可以明顯的將易蛀牙的plaque改變為不易蛀牙的plaque，經由反覆選擇快速形成plaque的微生物，並區辨S. mutans需要遲鈍的環境以取得優勢。

Karlstad 和Danish的專業潔牙研究有成功可以用下面來解釋。封填劑的成功是因為他們移除易蛀牙的區域，有酸性細菌群聚。對於在封填劑下的微生物很有效的切斷其養分來源，然後就會死亡。

Mechanical procedures that are frequently applied by dental personnel can be caries preventive, but this labor intensive approach is expensive. In the following chapters we will examine preventive treatment strategies and tactics which are inherently less costly.



機械性清潔方法經常被牙科來做蛀牙預防的動作，但是這樣卻是很貴。在接下來的章節裡會介紹一些較省錢的方法