Though we use primarily photos for evaluating the patient’s smile, they are sometimes not the best reference because the patient expressions are sometimes forced and stiff. Therefore, we make sure to observe our patient during our conversations to take additional notes on their tooth display. For Sofia, her old prostheses, however faulty, did have a redeeming quality: the incisal contours are at least very close to her lower lip line.

Crown lengthening procedure was performed with a waterlase. The old prostheses were used as a starting reference for the amount of soft and hard tissue reduction. Finally, the desired tooth length and zenith positions for the centrals were established.

Sofia was about to taking her wedding photos and had a tight schedule, so the final restorations were placed one week after crown lengthening procedure. The abutment of tooth 21 was discolored due to prior root canal treatment and metal post placement. For monolithic full-ceramic crowns, the discolored abutments can be detrimental to the shade of the final crown. Therefore, I applied a thin layer of opaque resin to mask the grayish hues.

Having sufficient reduction is always a difficult thing to check for, especially on a tooth previously prepared by another dentist. From our experience, cervical third of buccal and palatal sides are usually under-prepared. In the next image, the light blue bubble show the minimal thickness as configured within the software. On the right side, the this bubble penetrated into the opposing teeth, which means that the reduction on palatal side is not enough.

For anterior restoration design, lateral profile photos and biocopy scans are two useful pieces of information to have. The precision with which the biocopy can match with the prepared abutment has to do with the coverage of the scanned immovable tissue. More advanced design on alignment and morphology of anterior restorations are covered in Esthetic Courses at CEREC Asia.

As for the CAD/CAM ceramic, considering the shade distribution of adjacent teeth, we chose Triluxe Forte from VITA.

At one-month follow up, the gingiva had acceptable healing.

Summary

We were able to achieve the optimal outcome with Sofia through her acceptance of the crown lengthening procedure. One limitation of this case is time set by the patient, so ideally we would wait a bit longer between follow-ups until crown placement. This simple clinical case showcases a few of our routinely procedures combined with a digital workflow.

李萌

李萌 is a member of Sweet Space Dental Clinic and CEREC Asia Training Center.

The post CEREC Restoration with CLP <br/><div class='secondary-title'>Countdown to Wedding Photography. CDT: Bonnie Huang (黃思璇)</div> appeared first on CEREC Digest.

微笑照並不是唯一參考，因為有時候會得到一個很僵硬、尷尬，或是自拍時的標準微笑，因此訪談時必須多觀察病人說話與自然微笑的狀況。

以水雷射輔助牙冠延長手術，重新建立牙齦 high-low-high 的 contour，並改善 gummy smile。

Sofia 馬上就要拍婚紗，因此牙冠延長一個禮拜後就拆除舊牙橋並重新製作，無法等到牙齦、骨頭完全穩定。#21 abutment 根管治療完成多年而且有金屬釘柱，顏色較深，使用遮色樹脂。

因為本來就是 prep 過的牙齒，拆 crown 後較難確認 reduction 的量，尤其 palatal 、 buccal cervical 等處最容易發生厚度不足的狀況，因此我反覆檢查 palatal side 的 clearance (如左圖)，口內看似足夠但看看右圖就會發現空間仍然不足。右圖的藍色半透明區域為最小厚度，就是從 abutment 往外再加上各個區域分別設定的最小厚度得到的結果，可以看到些微穿過下排的牙齒。

設計前牙時除了參考 lateral profile 、 biocopy (無論是病人治療前的狀態或是 mock-up)，若掃描時能取得足夠的軟組織資訊，能設計出更和諧的角度。在 CEREC Asia 的美學精煉級課程中，就有提到如何根據軟組織來設計理想的型態與角度。

由於 #21 已使用樹脂遮色，且厚度只有稍微不足，因此選用接近鄰牙顏色的 Triluxe Forte 長石瓷塊。

術後一個月追蹤，牙齦癒合狀況良好，Sofia 也順利拍完婚紗，希望下次能爭取幾張婚紗照和大家分享。

結語

感謝 Sofia 願意接受我們的建議，除了換掉三顆舊牙橋還做了牙冠延長，使得結果更加理想。當然如果有充裕的時間，能多觀察一段時間會比較保險。 而材料厚度會影響強度、遮色能力、透光表現等等，因此確認空間是很重要的。

李萌

李萌 is a member of Sweet Space Dental Clinic and CEREC Asia Training Center.

The post #11-#22 牙冠延長與牙套更新 <br/><div class='secondary-title'>婚紗告急! CDT: 黃思璇 (Bonnie)</div> appeared first on CEREC Digest.

上週末是 CEREC Asia 的年會，在這個年會中我們展示了整個團隊 2017 年的成果。

在我們分享的幾個主題中，有一個特別受到關注的題目： non-prep CAD/CAM 超薄貼片。

就我個人來說，我對這種 non-prep 或是 minimal-prep 的方式並不是太有興趣，一來運用範圍比較狹窄，二來需要較高的牙齒結構完整性要求。他們同時也需要比一般貼片更大量的技師工作以及技巧；在醫師端， delivery 的前後處理也更具挑戰性且費時。而且老實說吧，我是一個懶惰的傢伙。

另外，大家都知道，陶瓷的研磨有它的極限，是吧？

然而，在那個命運之日，我在 Facebook 上看到了這個友善的挑戰。 這出自於台灣的一位贋復大師，儘管不是使用 CAD / CAM，他經常展示一些令人驚嘆的作品。

「你知道你做了什麼嗎…」
在我看到這些字的同時，我的心就沉了下去。也許是因為我認識某位牙醫，他總是很低調，不會隨便接受挑戰，他叫作曹醫師。
開玩笑的，於是隔天我馬上被自願接下這個「用 CAD/CAM 作出一樣成果」的不可能任務。理論上，我能對我的老闆說不，但我還是希望能有份工作過活。

於是，在距離年會不到兩個月的時間內，我們必須找出作出這種超薄貼片的方法。但多薄才叫薄？

「150 µm 就可以了啦！」

「…………………….」

如果你曾仔細觀察瓷塊研磨的過程，粗糙的鑽石用難以置信的速度猛烈撞擊在脆弱的陶瓷上，你會驚訝它竟然可以成功完成最終的贋復物；但並不是所有的陶瓷都能作到，所以第一件事，我們必須知道每種陶瓷在多薄的邊緣下，仍然不會發生 chipping。

經過一連串的散盡家產，該選擇哪種陶瓷種類？以及邊緣該怎麼設計才是最合適的？

我們終於得到了結論。

儘管還沒經過嚴謹縝密的科學驗證，我們測試了十幾種不同的瓷塊，發現 Enamic 的表現最為穩定，對於 200 µm 以下的贋復物尤其如此。

那現在該是把我們的理論付諸實踐的時候了。

不瞞你說，發現 non-prep 貼片竟然也可以是 CEREC 當天完成的項目之一，這點我們也非常驚訝。

我們的教育中心主要任務之一，就是標準化以及優化這些新的工作流程。 因此，儘管這個第一個案例花了我們整整一天來嘗試與失敗，下一個案例我們已經成功地減少了一半以上的製作時間。

從一個挑戰開始，變成一種偏執，再投入團隊的努力，最後成為現實。

我謹代表 CEREC Asia，感謝所有為這個有趣專題貢獻的瘋狂牙科相關人士們。

Lucky, Li 李承翰

– Adjunct Attending physician of Taipei Veterans General Hospital Prosthetic Dentistry Department
– Member of The Academy of Prosthetic Dentistry, ROC TAIWAN
– Specialist of Taiwan Academy of Digital Dentistry
– Lecturer at CEREC Asia Training Facility

The post 我們的超薄挑戰旅程 <br/><div class='secondary-title'>The story of our single-visit ultrathin veneer challenge.</div> appeared first on CEREC Digest.

Amidst the various special topics on digital dentistry, there was one clinical case that was of particular interest: the non-prep CAD/CAM ultrathin veneer.

Personally, I’m not too fond of these non-prep (or minimal-prep) principles because they either have very niche applications or require a balance of structural integrity. They also take a hell of a lot more work than typical veneers both before and after delivery, and frankly, I’m a pretty lazy guy.

Besides, everybody knows that milled ceramics have their limits, right?

Then on that fateful day, I saw this on my Facebook feed. It was a friendly jab from a master dentist who does some amazing restorations, albeit without CAD/CAM.

What have you done… As soon as I saw those simple words, my heart sank. Perhaps because I knew a certain dentist, who will remain anonymous (it’s Michael), who will not take these challenges lightly, jokes or not. Sure enough, the next day he volunteered me to take on the seemingly impossible task of replicating the same result but with CAD/CAM. In theory, I could’ve said no to the boss, but then I like having a job.

So with less than two months left to our annual event, we had to somehow figure out a way to create a milled ultra-thin veneer. But just how thin is ultra-thin?

“150 microns ought to be enough”

“…………………….”

If you’ve ever taken a close look at how ceramic milling works, you might be surprised that it works successfully at all; coarse diamonds strike violently at brittle glass, all at incredible speeds. But not all ceramics are created equal, so the first thing we needed to figure out is how thin each type of ceramic can be milled without chipping at the margins.

After bleeding a mountain of cash, we got a pretty good idea of what each type of ceramic is able to handle, and which of their corresponding marginal designs are optimal.

Our results have not yet gone through rigorous scientific validation, but of more than a dozen different ceramic blocks that we tested, we found that Enamic performed the most consistent. This was especially true for sub-200 micron restorations. It was time to put our theory to the test.

Not gonna lie, it was a big surprise to find that non-prep veneers are actually quite doable as a single-visit CEREC treatment option.

At our training center, one of our primary tasks is to standardize and optimize new workflows. So while this first case took an entire day due to trials and errors, we have already cut down the time needed by more than half in subsequent cases.

So what began as a challenge, became an obsession, became a team effort, and then eventual reality. On behalf of CEREC Asia, I would like to thank all the crazy dental professionals who contributed to this fun project.

Hsuan

Hsuan is a lecturer at CEREC Asia Training Facility. He is from Vancouver, Canada, and is a big fan of prosthodontics and profanity.

toothfaerie.club/

The post How Thin is Thin? <br/><div class='secondary-title'>The story of our single-visit ultrathin VITA ENAMIC® veneer challenge.</div> appeared first on CEREC Digest.

So this 90-year-old male had a minor chewing mishap, and his tooth #21 (with previous endodontic treatment) snapped off quite cleanly as shown in the following photo.

The patient was over 90 years old and completely uninterested in fixing his multiple non-carious cervical lesions. After some back and forth, my final treatment plan was to simply restore #21.

The only remaining tooth structure was on the palatal side, but the patient also had a very deep bite, so really not the best combination of circumstances. After a precarious act of balancing occlusal clearance and tooth structure removal, the abutment was ready for gingival retraction and scanning.

There was a lot of design flexibility for this restoration, thanks to the severity and angle of fracture. With sufficient space to play around with, a physical indentation near the cervical region was possible to mimic the cervical lesion. We chose the Triluxe Forte due to the large shade gradient between cervical and incisal regions.

After cementation, I noticed that the cervical areas on the natural teeth are slightly less reflective, so I de-glazed the cervical regions with a twist polisher. Unfortunately, the instrument slipped a bit and lacerated the gingiva. My bad.

Luckily, things seemed to have healed over decently after a couple of weeks.

Remarks

Of course, this wouldn’t have been possible without Sharon, one of our wonderful in-house dental technicians. The reference shade used for this crown was 4R2.5, and with such an unusual color, we were fairly fortunate to get the color very close in one try; for a case like this, I typically set aside enough chair time for two attempts. The total chair time for this patient is about 90 minutes, not including endodontic re-treatment.

We are still getting the hang of CEREC! So while this case may not be perfect, it was definitely an interesting learning experience.

Hsuan

Hsuan is a lecturer at CEREC Asia Training Facility. He is from Vancouver, Canada, and is a big fan of prosthodontics and profanity.

toothfaerie.club/

The post Fun with Staining and Glazing <br/><div class='secondary-title'>CDT: 周星妤 (Sharon)</div> appeared first on CEREC Digest.

CDT: 林彥妤 (Joanna)

The flaring of the #12 crown is such that its palatal aspects traces exactly the protrusive and lateral movements of #42 and a bit of #41. How did this result come about is anybody’s guess, but the lack of contact with #11 told me that this current design was not originally intended. Surprisingly, the PFM is not loose, but rather securely seated into this position with cement.

Typically when restoring lateral incisors, I try to color-match closer to the centrals while also taking symmetry into consideration. The discolored canine in this case had me a bit worried, and so I squeezed a few more shade guides into the photo.

Although the old crown flared outward, the actual abutment was lingually displaced. This means that we might have to shape the recessed gingiva a bit with cervical contouring.

In addition, with thicker ceramic the interplay between translucency and reflectance can be a bit tricky at times, causing the occasional grayish appearance. While the biocopy of the original PFM is not explicitly shown here, its palatal scan was used to determine the palatal limits of our restoration design. This is especially imperative for patients with habitual parafunction, if the aim is to minimize chairside occlusal adjustment. The efficiency with which this can be achieved is yet another advantage of doing digital impressions.

Believe it or not, this tooth was vital. Fortunately, most of the preparation was already done by the previous dentist. The preparation was already pretty aggressive, however, so I didn’t want to risk pulp irritation by doing even more rounding for CAD/CAM milling. The fact that the tooth was in lingual version meant that I had extra space for over-milling anyway.

Although no adjustments were needed in static and dynamic occlusion, I would be lying if I wasn’t a bit apprehensive over the fact at the patient was clearly a rigorous bruxer. Who knows what strange ways the teeth may traumatize each other in his sleep. Anyway, the position of the old crown was so strange that I scheduled him back after only three days for a check up, which turned out to be redundant.

-END-

Hsuan

Hsuan is a lecturer at CEREC Asia Training Facility. He is from Vancouver, Canada, and is a big fan of prosthodontics and profanity.

toothfaerie.club/

The post #12 Crown Removal and Restoration appeared first on CEREC Digest.

本案例使用漸層的 Triluxe Forte 長石瓷塊，搭配使用外染及表面特徵處理，在不回切堆瓷的情況下盡可能的達到接近鄰牙的外型以及顏色分布。

技師：CDT 謝怡珣

患者為 20 歲女性，牙位 11 於數年前接受過根管治療，本次因牙齒變色前來求診，經評估後以全瓷冠復型。

圖一. 正面拉勾照，可見 11 變色，尤其以齒頸 1/3 最為明顯，主體色和21相比也略顯灰暗，外型無明顯不對稱。

圖二. 先用比色機初步判定顏色，再經過醫師、技師與病患三方溝通後，選擇以 2M1 做為主體色，並拍攝比色照片方便技師製作。

圖三.由於患者希望保留 11 原本的型態，因此設計時以 Biocopy (修磨前掃描的外型)為主要參考依據。

圖四. 設計適當的近遠心鄰牙接觸區域與咬合，鄰牙接觸強度參數設定為 25 微米，咬合強度參數設定為 0 微米，並調輕其 MI ( Maximum Intercuspation )時的咬合以達到 Mutual Protection。

圖五. 為了配合鄰牙的顏色以及透明度，選用含四層漸層的長石瓷塊：VITA Triluxe Forte。

圖六. 使用漸層瓷塊時，可將贋復體在瓷塊中的軸向、高低擺至理想位置，以調整各種漸層的分布與比例。

圖七.

調整贋復體在瓷塊中的高低位置，可以讓贋復體整體顏色偏深或偏淺；例如：若希望深色部份較少，切端較白，可將贋復體往瓷塊上方移動。

圖八. 若將贋復體的軸向調至較傾斜的角度，將使色塊在頰側變寬，漸層較不明顯。

圖九.

研磨出來後，進行表面特徵加強與外染：用直機修出表面的發育紋路以及Transition zone，外染時以比色照輔助，模擬鄰牙的色澤分部以及透明層。

最終達到下圖的臨床成果，外型複製了原本的前牙，顏色雖可觀察到在 Hue 上有輕微偏移，但仍在臨床可接受範圍內，最後在同一診次內 Delivery。

李萌

李萌 is a member of Sweet Space Dental Clinic and CEREC Asia Training Center.

The post Case report: 11 crown with Triluxe Forte <br/><div class='secondary-title'>Software: Cerec Premium 4.4.4</div> appeared first on CEREC Digest.

圖一. 患者未修形前的牙齒型態(Biocopy)

圖二. 移除完原本填補物後，因主要的缺損在近心側，齒質結構足夠
因此選擇以Overlay形式的Endocrown復形
Occlusal reduction為2 mm使材料達到足夠強度

圖三. 繪製Margin後，軟體運算出贋復體的Proposal，接著進行型態調整

圖四. 調整出理想的鄰牙接觸範圍與咬合，鄰牙接觸強度設定為25微米，咬合強度設定為0微米

圖五.

瓷塊選擇： Ivoclar Emax Cad LT A3.5
選擇LT是為了符合後牙Enamel的低透明度，避免過度透光導致牙齒灰暗

圖六.
 Delivery時鄰牙接觸因sprue的位置無法避免，有進行調整
調整完接觸後，咬合無須調整
最後以 3M ESPE RelyX Ultimate黏著
總共耗費診療時間約為十分鐘

圖七.

術後一週追蹤X光，可看見其邊緣完整，患者無明顯不適

李萌

李萌 is a member of Sweet Space Dental Clinic and CEREC Asia Training Center.

The post Case report: 26 overlay with e.max LT <br/><div class='secondary-title'>Software: Cerec Premium 4.4.4</div> appeared first on CEREC Digest.