Townie Clinical: A Saturday Morning Emergency By: Robert Henkel, DDS

My experience with high-tech dentistry began 2.5 years ago when I purchased a CEREC 3 for my office. The ability to prepare and deliver an all ceramic restoration in one visit had always intrigued me. Learning how to use the CEREC 3 was easy, but as with everything, there is a learning curve before you can easily obtain great results. To shorten the length of my learning curve, I took as many courses as I could fit into my schedule while devouring whatever information I could find. I highly recommend if you decide to add the incredible capabilities of the CEREC to your dentistry that you find as many hands-on courses as possible to get up to speed.

Once I had the basics of the CEREC technology mastered, I continued toward my quest of providing patients with an entire tooth restoration in one visit. I decided to purchase a Waterlase laser from Biolase. I must admit the Waterlase has given me that added dimension and provided a very valuable piece of the puzzle in obtaining my mission—to provide one visit full tooth reconstruction.

Learning advanced techniques on the use of rotary and/or reciprocating endodontics has allowed me to make short work of root canal therapy. One of my biggest challenges was navigating through the challenges of periodontal tissues and osseous structures when a cusp is fractured below the gingival or osseous crest. I was trained in classical periodontal surgical technique, flap design, osseous recontouring, apical repositioning, when needed, and suturing. All of these are required in order to achieve and maintain the best result for our patients. These classical procedures still guide me in my decision process to go forward with a procedure or look in another direction.

I recently had the opportunity to pull out all the stops on a patient who had fractured a tooth. This gentleman was a 41-year-old engineer and was scheduled to leave for an extended stay in England just two days later. He was a very good patient of record, so I wanted to do everything I could to insure this tooth wouldn’t be a problem during his trip.

		Fig. 1: Preoperative view of tooth #4 from the buccal
		Fig. 2: Preoperative view of occlusal surface, lingual cusp fractured to below gingival crest, recurrent decay on lingual

The patient called me on Friday evening and I asked him to meet me in the office on Saturday morning. Upon examination I found that tooth #4 had fractured, the lingual cusp gone, about 2mm below the gingival crest, and the remaining MODF amalgam was in jeopardy of being lost.

I anesthetized the patient with 2% Carbocaine with neocobefrin, buccal and lingual infiltration at approximately 9 a.m. The remaining old restoration was removed with a high-speed handpiece in order to evaluate what was remaining of the tooth.

		Fig. 3: Preoperative view of the lingual surface. The fracture extended below the gingival crest toward the distal of #4
		Fig. 4: Amalgam restoration and decay removed. Didn't know what to expect due to amount of recurrent decay from the lingual. Once excavated, it was very clear endodontics was necessary
		Fig. 5: Lingual view after excavation
		Fig. 6: Buccal view after excavation

No pain or sensitivity in #4 along with the recurrent decay, led me to initiate root canal therapy and place a post and core, to ensure adequate retention. After sounding to bone in the area of the fracture, I observed less than 1mm of tooth structure was above the osseous crest. I used the Waterlase, with a G6 tip, set at 1.75W and 11% air and 6% water to remove gingival tissue on the distal and lingual. I then began to remove and contour the osseous structure starting near the distofacial line angle of #4, continuing interproximally until I was wrapping around the lingual. I decreased my setting to .5W 15% air 0% water and troughed around to the mesial in soft tissue only. This allowed for excellent isolation with a rubber dam and I was able to initiate and complete the endodontics, with a combination of the AET system from Ultradent and my Waterlase.

The canal was accessed with Gates-Glidden drills used in a crown down approach. Starting with a #4 Gates-Glidden, working down to a #1 with a gentle pecking motion in the canal, stopping the advance and withdrawing when slight resistance was met. I have become dependent on the use of an apex locator to determine working length, and the #15 file which I was able to easily work as the apex gave me the working length within only a minute. Then the #1, #2 and #3 AET files were used to quickly cleanse and shape the coronal 2/3 of the canal, with the use of File-Eze and sodium hypochlorite(full strength). Hand instrumentation was used to finish the apical 1/3 up to a #30 file. Usually I would irrigate and dry the canal at this time, but with the use of the Waterlase, I was able to use a Z3 tip to within 2mm of the working length at 1.0W 36% Air and 25% with water activating the tip on the out stroke only, 6-8 times, each time orienting the fiber in a new direction. The Waterlase enables me to be able to thoroughly debride the canal, and remove the smear layer left after instrumentation. The canal was dried with paper points and obturated with EndoRez and a #30 gutta percha point from Ultradent.

Even though it may seem to be overkill during obturation, I still prefer to laterally condense a few accessory points next to the master cone. The excess is burned out and post space made with a hot plugger.

A small amount of Ultra-Blend (light cured calcium hydroxide liner from Ultradent) is placed over the top of the gutta percha/EndoRez fill and light cured for 30 seconds.

The canal was enlarged with a #3 and #4 Parapost drill, and a #4 Parapost cemented into the canal with a combination of Simplicity 1 and 2 and Core Paste (shade B67). The buildup was prepared for the crown and the optical impression was taken with the CEREC 3, using Scan Spray and Vita powder to enhance the image of the preparation.

		Fig. 7: It was at this point I became more concerned with the patient than photo documententation but this is a post-op shot of rubber dam isolation after crown lengthening with the Waterlase
		Fig. 8: You can clearly see the amount of isolation achieved with no clamp on the premolar
		Fig. 9: This is the post operative picture after crown lengthening with the Waterlase. The RCT had been completed, and a parapost buildup, with Fuji IX placed. the white residue is Scan Spray and Vita powder for the optical image with the CEREC 3. I removed approximately 3mm of bone on the distal and lingual, and recontoured the gingival tissues so they wouldn't be so bulbous

I then began the design and milling process with the CEREC 3. The CEREC crown was made from Vita Mark II porcelain, and the Vita Shading pastes and glaze were applied and fired in a porcelain oven. Beginning temperature is 6000 F and raises to 9400 F at the rate of 75 degrees per minute, held for one and a half minutes and taken out of the oven to cool. It took me approximately 20 minutes to complete.

Initial try-in revealed a crown, which, was too opaque, and darker than the adjacent teeth.

		Fig. 10: Buccal view of prep. Note this tooth is rotated toward the distal by about 30 degrees
		Fig. 11: This is the post-op film from the buccal with the AcuCam

The following is my bonding protocol:

• Etch the porcelain with 5% hydrofluoric acid for one minute, rinse for 30 seconds and dry.

• Apply Monobond (Silane coupler) and allow to dry.

• Apply Simplicity 2 to the etched and silanated porcelain, air thin and set aside

• Scrub the prep with alcohol or Therasol, rinse and lightly dry

• Apply Simplicity 1 for 10-15 Seconds with a Microbrush or sponge, Dab off the excess.

• Apply Simplicity 2, three coats, air thin

• Mix Variolink II base and catalyst, apply to crown and seat.

• Clean off excess, floss through contact and light cure for only one to two seconds to tack the Variolink

• Floss through contact again, scale off excess and final cure.

• Finish and Polish with fluted carbides and diamonds and a Jilly brush from Ultradent impregnated for porcelain, with Diaglaze polishing paste

I am particularly proud of this case simply because it shows how much is possible when technologies merge. In addition, I think it’s noteworthy to add I performed this case entirely on my own without an assistant. I used the Waterlase for the crown lengthening, and to assist in the endo. I used the CEREC 3 to make the final crown. My patient was really in great spirits when he left the office, because he was able to get this all completed in just one visit. The use of the CEREC and Waterlase allowed me to provide my patient with quality dentistry at a reasonable cost to everyone.

		Fig. 12: Lingual view of inserted CEREC crown with AcuCam. Gingival bleeding was induced while finishing and polishing. This was three hours after the only injection given to the patient 2% polocaine with levonordefrin. Patient was no longer numb, and no post op sensitivity from the osseous and soft tissue surgery
		Fig. 13: This is the final picture at the end of our marathon visit. I stained and glazed the Cerec crown on #4 to better match the hypocalcified areas on #5

itrtgums 5/5/2003 8:52:58 AM		I would like to know how you remove 3mm of bone and not get a trough around the distal and lingual. Aren’t you just creating a 3mm defect then? I know when I do conventional crown lengthenings, I make sure the bone is blended for a smooth transition and then let it heal for at least 4 weeks prior to final impression and for re-establishment of the sulcus. This prevents the dentist from putting the crown on too soon, such that recession could occur and end up with an unaesthetic result, or have him place the margins subgingival and leave the patient with a non-maintainable situation. How come you didn’t just leave him in a temp for the month so the tissue could heal properly and then your crown could still be done in an appointment when he got back from his trip?
rhenkeldds 5/5/2003 10:04:08 AM		I gave the patient the option of putting on a temp, or going forward with the Cerec. He chose the Cerec. As far as the crown lengthening, using the G6 tips and T4 tips we are able to ablate tissue and bone and direct the laser to adequately contour in these areas. The Waterlase is used after determining patency, up to a 25 file and used in the cleansing and shaping phases.
jasonteeth 5/6/2003 6:40:46 PM		Two questions. First is: I feel that you could have done the crown without the endo. I know, I know no ferrule the crown will come off. I have several pancake preps that are still holding in strong. Most Cerec docs will bond to flat surfaces. So, curious why the endo? Second, why not endocrown with the Cerec?
rhenkeldds 6/9/2003 7:07:18 PM		On a molar I would probably have not hesitated to place a crown with very little remaining tooth structure, due to the surface area afforded by the molar. But a premolar is a different animal, far too thin in the mesiodistal dimension. As far as doing an endocrown on a premolar with the CEREC, it is very much a hit or miss with milling the post. The program has a “failsafe” which won’t allow it to eat into a margin, so the post usually suffers the most. Premolar endocrowns generally have incredibly thin posts which do nothing for the strength and retention of the restoration. I did the endo because of a previous pulp cap which was placed years ago. The pulpal tissues were necrotic on entering the canal.

Dr. Henkel maintains a private practice in Woburn, Massachusetts concentrating on computerized and laser dentistry. Dr. Henkel is a graduate of Northwestern University Dental School (1990) and completed an Anesthesiology Residency from Medical College of Pennsylvania. He is also recognized as a clinical assistant to Dr. Stewart Rosenberg, teaching the use of the Waterlase, as well as providing hands-on instruction in the use of CEREC 3D in his own office. He can be contacted by email at rhenkeldds@comcast.net, as well as on the message boards at DentalTown.com.