Is packing cord required for crown prep?

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A friend of mine is getting two crowns done. During the first prep, the dentists put the packing cord around the tooth to lower the crown margin below the gum line. After the temporary was placed she went home. She has complained about the soreness of her gums for over a week now, and is not looking forward to getting the second prep done (due to gum pain following packing cord) She claims that "she knows somebody" that has had crowns done WITHOUT any packing cord.

I have never observed a crown prep without packing cord. Is it possible to do a prep with no packing cord? And if so, when is that indicated?

I don't know if and when it is needed but I got a crown on #2 about 6 months ago and they didn't use any cord. I then followed a different dentist and he did a prep on #2 also and he used cord. He said he like to use it because it made for better margins. Then again my crown only cost $375 (total price, no insurance involvement) and the other guy charged $850 I think.

I'm wondering the same thing. I recently went to a new dentist to have a crown replaced. He prept and packed the cord, took the impression and placed a temporary over the tooth. Long story short he left the packing cord in for so long during the procedure that my gumline is pulling away from the tooth. I return to him the other to show him my gumline and he said that he'd never seen something like that. He put one stich in the gumline---which fell out a few hours after my visit---and told me to come in next week before the crown is finished. My gum still looks swolen and will not attack to the tooth like it use to. I wonder there is something I can do?

You use retraction cord when the margin of the crown needs to extend below the gingiva. Packing cord displaces the gingiva away form the tooth allowing the dentist to gain access for preparation and impression. It is usually soaked in epinephrine so it causes the tissue to contract and physically keeps it out of the way.

Retraction cord is almost always used on anterior crowns where esthetics dictate that the margin be subgingival to avoid a black or white line at the neck of the tooth. It is also frequently needed on posterior teeth. A dentist who is only charging $380 for a crown is not going to be bothered with packing cord because at that rate he doesn't have time to do things right. He's got to run the patients through like an assembly line just to stay afloat. ...or maybe it just wasn't needed.

It usually isn't required unless the prep goes gingivally or sub-gingivally. Depending on the prep you can get a better final impression to send to the lab if you use the cord or a better temporary. But as seen above too big of a cord for too long will lead to gingival recession.

In private practice there are ways to get around using cord (expansyl retraction paste, modified impression techniques (H&H), etc) so it is not always necessary. Often at my school, the instructors tell you to pack two cords when one barely fits. "Just ram it in there." I can see now where a lot of dentists have learned this behavior. I love that they tell me to bury the margin for esthetics- then they have you traumatize the tissue so six months from now it will have receded and there's the margin staring at you. Regardless, I try to be as gentle as possible and pack a single 00 or 000 cord.

Originally Posted by UTDental

In private practice there are ways to get around using cord (expansyl retraction paste, modified impression techniques (H&H), etc) so it is not always necessary. Often at my school, the instructors tell you to pack two cords when one barely fits. "Just ram it in there." I can see now where a lot of dentists have learned this behavior. I love that they tell me to bury the margin for esthetics- then they have you traumatize the tissue so six months from now it will have receded and there's the margin staring at you. Regardless, I try to be as gentle as possible and pack a single 00 or 000 cord.

Do any instructors advocate using the H&H technique in clinic? I've read about it's use but from what they've told us using a 00 or 0 cord is what they reccomend.

I've probably packed cord less than 5 times in the last 3 years First off, if possible, all my finish lines are supra gingival, even anteriors(with a good lab tech and a 90 degree butt joint margin, you can make any anterior ceramic disapear , plus with a supragingival margin you've just made it much, much easier for your patients to keep that margin clean, and easier for you to examine it at recall visits!

Now if I have to go sub gingival, it's either Kerr's Expa-syl (just inject it into the sulcus and then go do a couple of hygiene checks/read the paper/check your e-mail, etc for about 5 minutes, rinse copiously, and voila a wide open, clean, dry margin ready for some impression material) or more often than not nowadays, I just fire up my soft tissue laser and in less than a minute after "walking" the tip of the laser around my prep where it's sub gingival, I've got a coagulated, clear sulcus with limited(very often no) post op pain

Cord is such a rarity due to new materials in my office, that my partner and I now have had our assistants take the cord out of our regular operatories and keep it in the backroom storage area along with such things as the half dozen or so bottles of various bonding agents that we've tried and don't like, the 3 or 5 types of composite that we've tried and don't like, the 7 or 8 types of cement that we've tried and don't like, etc, etc, etc. To be honest with you, if I had to look for a cord packing instrument, I'd have no clue where to look in my office

In the office where I work I have seen cord packed twice maybe three times in the past year. If the doctor can not keep the margins dry he will use H&H but in general he uses superoxol to stop any bleeding and the air/water syringe to wash and dry. This technique works wonders.

In the clinic, I try my best to keep the margin slightly supragingival (especially for posterior teeth) so I dont have to use the cord. If the margin is subgingival, I pack it with a cord, but also make sure you pack it at an angle of 45 degrees towards the tooth to minimize trauma to the gingiva.

Originally Posted by CJWolf

Do any instructors advocate using the H&H technique in clinic? I've read about it's use but from what they've told us using a 00 or 0 cord is what they reccomend.

I would venture to say most instructors at our school don't know what H and H is. I had one tell me not to use triple trays for single units- that a custom fabricated tray was necessary. LOL. These guys are old school, 18th century old school that is.

Originally Posted by UTDental

These guys are old school, 18th century old school that is.

Come on now, that isn't fair or nice.













I believe you meant to say 17th century.

I just had a packing and cord last week and I am in SO much pain a week later. I went to a periodontist and he put me on 2000mg of antibiotic for inflamation and possible infection. I am very angry because my dentist who is prepping me for a final 5 tooth bridge did not tell me anything about this procedure. I went home with vicodin and the pulsating pain in my gums behind my front teeth was incredible. I hate this procedure. I wondered if it was necessary.

Originally Posted by BarbieK1211

I just had a packing and cord last week and I am in SO much pain a week later. I went to a periodontist and he put me on 2000mg of antibiotic for inflamation and possible infection. I am very angry because my dentist who is prepping me for a final 5 tooth bridge did not tell me anything about this procedure. I went home with vicodin and the pulsating pain in my gums behind my front teeth was incredible. I hate this procedure. I wondered if it was necessary.

In general, cord is packed around a tooth when the dentist NEEDS to momentarily displace the adjacent gum tissue for certain clinical needs (i.e. to capture the entire prepared margin of a tooth for a crown impression, to facilitate the placement of a filling where the decay required that the edge of the prepared tooth structure extend below the gumline, etc). If the tissue isn't displaced during certain instances, it could very well lead to a final restoration where the edge of the restoration doesn't properly meet the tooth or potentially allow for moisture to "contaminate" the restoration-tooth interface thus leading to premature failure of the bond between the tooth and the restoration.

Packing cord and/or other means of momentarily displacing gum tissue to gain clinical access is just as much a part of certain dental procedures as local anesthesia is

Either there was an error in cord placement (aggressive placement = ripped attachment of gums to teeth) or your friend's pain threshold is extremely low. I have had cord packed before and it should not bother you for more than a day.

Originally Posted by DrJeff

plus with a supragingival margin you've just made it much, much easier for your patients to keep that margin clean, and easier for you to examine it at recall visits!

I would think this is the biggest reason to stay supragingival, if possible.

Originally Posted by txaggie03

I would think this is the biggest reason to stay supragingival, if possible.

That would be the key phrase!

Which is why I made sure not to leave it out.

I am still in school, but I am curious about what percentage of your crown cases are you able to keep supragingival?

Originally Posted by txaggie03

Which is why I made sure not to leave it out.

I am still in school, but I am curious about what percentage of your crown cases are you able to keep supragingival?

I'd say that 75-80% of my crown cases will have atleast a portion of the prepped margin ending up subgingival. The vast majority of the time the sub gingival margin will be at an interproximal location, very often due to a previous restoration with an existing subgingival margin.

I will say though that I am growing to really love the performance of 3M's new retraction capsule injectable retraction paste/hemostatic agent. I've been using it for about 2 months now, and have been really impressed with its ease of delivery (it has a much smaller diameter and flexible tip that expa-syl does) and it rinses out easier than expa-syl with very good clinical results. Very often if i'm prepping a subgingical crown margin, i'll do a little "micro gingevectomy" with a fine grit flame shaped finishing diamond bur in that area as essentially my last step of the crown prep, inject the retraction capsule paste, go do a hygiene check, and then 2 or 3 minutes later, i'm looking at a clean, dry sulcus in that subgingival area for an easy and predictable final impression without having to pack cord

I haven't tried the expansyl or other pastes, partially because the first time I looked up the instructions for the use of one of these pastes I saw that the "proper" technique according the the company was to place the paste, wash it out, then place a 00 cord, place more paste, and the wash it out again and then take the impression with the 00 cord in place. I thought it was the most ridiculous thing I ever heard and just continued using my 1 cord, H&H technique.

Originally Posted by msf41

A friend of mine is getting two crowns done. During the first prep, the dentists put the packing cord around the tooth to lower the crown margin below the gum line. After the temporary was placed she went home. She has complained about the soreness of her gums for over a week now, and is not looking forward to getting the second prep done (due to gum pain following packing cord) She claims that "she knows somebody" that has had crowns done WITHOUT any packing cord.

I have never observed a crown prep without packing cord. Is it possible to do a prep with no packing cord? And if so, when is that indicated?

The sole purpose of packing cord is to expose the margin to be captured in the impression. If you prep #19 and your margin is .5 mm supragingival all around, do you need to pack the cord then? Unless the crown is in the esthetic zone, I place all my crown margins supra and heck with cords. DP