It's controversial - let's wait for the research on this design. Most of us in Academics are concerned because it results in a knife edge of zirconia, and zirconia doesn't perform well when thin...
Hi Dr. Stevenson -- I'm wondering if you might share your dental CV. I would love to learn more detail about your continuing education efforts and career. The link on your website, re: Biosketch pdf, does not currently work. The videos and tips are excellent!
Thank you for your great videos. Do you have a video on preparations for a fixed partial denture? How to check for path of insertion, how to reduce, etc. Thank you.
Thanks doctor Stevenson, it was really helpful! Can we just creat a shoulder finishline in buccal side at the begining; I mean not creatjng the chamfer at first??
Very informative and so very well made. I just had 2 questions: 1) How do you maintain the anatomy of the triangular ridges when doing the plane reduction? I usually end up with pretty flat looking triangular ridges 2) When you are reducing the "B plane" are you are angling the burr parallel to the inclinations of the cusps like you did the in the "A plane" or is it perpendicular to the occlusal surface (making it flat)? Thank you!
I try to preserve the most prominent triangular ridges, like the maxillary buccal cusps and the lingual mandibular cusps. If the triangular ridge is fairly flat, I usually respect that form. As for the B plane, it would ideally parallel the triangular ridge declination angle - about 35º. When you respect the inclination angles, the prep will have more uniform clearance and preserve more tooth structure.
@@StevensonDentalSolutions Dr. Stevenson, how might the operator chair position change for each occlusal plane when doing this prep on #19 rather than #30?
I usually work from 7 O'clock to start the planes with direct vision, then swing around to 11 to refine with the patient's head turned towards me or away to facilitate the prep access
Hi Dr! What a nice & precise prep! I would like to ask, if there’s no RGS instrument to check on the clearance, what other ways we can make sure that we are cutting at the exact depth? Thank you
Great like always doc my question is for breaking contact we should keep the bur parallel to line of draw ? Bc for the distal you leaned the bur a little bit ? Is that something you for distal or its the camera angle thanks alit doc
Good observation! When breaking contact I use a very narrow diamond - the tipping is done to protect the adjacent tooth. After the contact is broken, you may start by holding the bur parallel to the line of draw, however, this will only provide about 6-7 degrees of Total Occlusal Convergence - not practical. The finest preps usually have 10-12 degrees of TOC and are completely acceptable with up to 20 degrees of TOC. Also, it is important to tip walls to obtain clearance with the proximal tooth contour...Thank you
They are very strange. Whenever there is an "8" in front of the three numbers, it means fine grit (30 microns) Otherwise, the system of numbering makes little sense! KS was named after Kois and Spear. KR burs have rounded corners. It's a mess!
Bjr dr. Pouvez vous me montrer l'orientation de la fraise sur la face vestibulaire svp ? Comment pousser la limite en sous gencive sans créer de contre dépouille ?
Fantastic and indepth explaination for every step including the bur size. Every video i see has new information in it. Thank you Sir for this commendable videos. Just had a doubt. As for shamfer using 8877 o09 it has max width is 0.9 and we need shamfer of 0.5 - 0.7 so when we use half of the bur it will give only 0.45 max. Going further deep won't it create a lip on the outer rim ??
Great Question! It may if you don't manage it. All burs will create a lip if they go deep enough axially and are allowed to move gingivally. If you can plane the finish line by moving the diamond axially and outwardly, the lip will be corrected. If you'd prefer, you can use an 878K-014 or -016 as these will create taper and avoid lips if used less than half of their diameters. Alternatively use an 8877-010 - these will create a 0.5 mm axial depth at the finish line.
Dr Stevenson, on your FGC preparation video (FULL GOLD CROWN in 7 STEPS ), you reduced the B plane after the C plane, whereas in this video you reduced the A plane after the B plane. I'm wondering does the order matter?
I like to show different approaches so dentists may make there own decisions...It really doesn't matter, as long as you keep your depth planes controlled and follow the original inclines. Thank you!
Hi Dr. Stevenson, Thank you so much for another great video! When you used 8847KR to create a shoulder, do you think the tip of the bur might create a sharp buccal cervical line angle that can potentially cause additional stress on the tooth's structure?
Not the KR - this has a rounded end, but PFMs need this axial depth, so there isn't much we can do. With all-ceramic preps, the KR burs are too aggressive and a fillet margin, using an 856-016 or KS type would be better as you mention.
Beautiful doc …. Any recommendations for lower first premolar bc once you cut 1.5 mm and supraginguval margin you end up about 2 mm crown prep length is that ok ? Any advice ??
6x or a microscope with up to 30x but I started with 2.5x, then increased to 4.5x after a year or so. I usually recommend 3.5x Univet Prismatics with a light.
Hi doc. Please can you explain what does the 016 refer to on the 847kr 016 bur? You mention 1.2mm tip but I was under the impression the 016 referred to 1.6mm diameter at the tip.
Thanks for the video, from buccal aspect we can't appreciate the distal cusp unlike your previous videos of FGC. This is the issue usually I face as as well. Any comments on how important is it from examination point of view?
It was not an issue Ankur, it was as required. If you reduce the occlusal properly, and then you prepare the proximal and develop the taper - and if the distal cusp is prepped away, it was meant to be. With the FGC video, it was on a Columbia typodont, which has a much larger distal cusp. This prep was done as dictated by the environment. This is what's important from an examination point of view...
I am right handed. I was preparing tooth no.15. It is very difficult to get accessibility and the buccal mucosa is fat, bulbous and difficult in retraction. Any advise!?
Rubber dam helps for some of the prep - then remove the dam - use a W3 or W2 clamp and do as much as possible, then remove the dam. Or...try an Isolite - they work great. If neither of these is working, then have the mirror slid between the tissue and the handpiece and have the patient perform a mandibular LEFT border movement which should open the area slightly.
What if skill tests like NDEB dont have needle burs to break contact. What would be our options? They only provide round end taper and flat end taper both 16 C.
If you can place a matrix between the teeth this might help - otherwise the entire batch will be prepping deeper axial walls and the examiners will be expecting it.
@@StevensonDentalSolutions Thanks for your advice. This NDECC exam in Canada for foreign dentist is really challenging. Hope the more relaxed grading criteria make it easier.
Hi Dr, for buccal and lingual axial walls reduction, should the 878k-012 bur be inserted completely (entire diameter of the bur)? And how much should the buccal and lingual axial walls reduction be? 1.5mm?
Beautiful work. Can I use 847 bur for porcelain shoulder instead of the 847KR you have in the video? And the axial reduction bur too, I’m using 878 bur instead of the 878K you have in the video. Thankyou very much.
Hi, dr You used the red bur refining chamfer, is it possible to reduce the tooth with the red band bur? You used the FG low speed angle handpiece or electric motor, creating shoulder.
@@StevensonDentalSolutions Thank you very much for your attention. I am lecturer, so we worry about that more dental faculties (US, EU) recommend dental student use electric handpiece (and air) during preclinical training (also in clinic). It is correct?
Hi Dr, When reducing the buccal and lingual walls, do we hold the bur parallel to the long axis of that particular wall or do we tilt it towards the tooth to create that tapered effect? or does the tapered effect come with the design of the bur?
The bur will give you 6 degrees of total occlusal convergence, but this is the absolute minimum taper and if not done without flaw, you can easily have undercuts. My recommendation is to tip the bur slightly more than the inherent taper to create a TOC of about 12 degrees. This will provide you with adequate retention and ease of visualization. The secondary planes at the occlusal 1/3 of the facial and lingual are done at a great taper to follow the adjacent tooth contours.
@@StevensonDentalSolutions for the lower molar the lingual wall is tipped lingually..so the bur inclination is parallel to the long axis of that wall or do we tilt the bur inwards towards the tooth for taper?
Hello Dr.Stevenson, Please correct me if I am wrong..for a PFM, after axial reduction all around the tooth with 878k-012 the next step is to use 8877-009 only on the lingual wall and 8847KR-016 only on the buccal wall.Is that right?
Oh, really? Hmm - try a block out to full counter and prep from there - it's possible doc! You don't know what you don't know...as Dr. Tucker would say.
@@StevensonDentalSolutions bloack out before prep !!!! , nice idia but we are in 3rd world and take 50$ for pfm and we pay more than half price to the lab
What bur I need to use to get a chamfer margin of width between 0.3 to 0.7 doc? And can I use half of the round end taper bur or need to use only torpedo bur? Please advise. Thank you in advance
The 877-010 is a parallel pointed diamond 1.0 mm in diameter and this will give you a 0.5 mm modified chamfer. If you would prefer a tapered chamfer bur, use the 878K-016 which will give you a 0.55 mm chamfer if using half of the tip diameter. Round ended diamonds don't give chamfer margins - they create fillet finish lines, which are more like a rounded shoulder.
A plane = functional cusp bevel B plane = interior incline reduction C plane = non-functional cusp incline reduction Maxillary Posterior teeth: A plane is on the lingual of the lingual cusps and parallels the C plane, with is on the facial cusps, lingual inclines. The B plane is on the facial incline of the lingual cusps. Mandibular Posterior teeth: A plane is on the facial of the facial cusps and parallels the C plane, with is on the lingual cusps, facial inclines. The B plane is on the lingual incline of the facial cusps.
Thank you Doctor, I watched this video may be ten times and the interesting thing is that every time when I watch I found a new thing to learn. By the way I had a chance to be one of your courses and can say that your fingers work just like a drils in CAD/CAM machin chamber. Highly recomend to attend his courses.
