Monday, November 28, 2011

Who Cares About the Periodontal Ligament?

Congratulations to the manufacturers and marketers of dental implants! We now have patients with perfectly good teeth considering removal and replacement with implants on their very own! We are actually seeing patients that are convinced that an implant is better than a natural tooth!

I was once at a seminar where a specialist was discussing implants to a group of endodontists, when I asked a question regarding the periodontal ligament, the lecturer replied, "Who cares about the periodontal ligament?". Perhaps that is a good questions to ask?

The periodontal ligament is the difference between a natural tooth and an implant.
While implants are an ideal way to replace a missing tooth, an implant will never be able to replace the periodontal ligament.

I think perhaps we overlook the benefit of having a periodontal ligament in our haste to condemn a tooth and replace it with an implant.

The periodontal ligament is the dense, fibrous connective tissue that connects the tooth to the bone. It is vital in the transmission of masticatory force from the tooth to the bone. It acts like a shock absorber, giving the tooth some movement in the socket. It provides proprioception, or feeling to the tooth. Without proprioception, we can have traumatic occlusion and have no sense of it (ie. fractured porecelain). The periodontal ligament also has an important interaction with the adjacent bone. If you loose the ligament, you will also lose bone. The periodontal ligament is the home to important cells such as osteoclasts, osteoblasts, fibroblasts, cementoblasts, cementoclasts, undifferentiated mesenchymal cells (stem cells). These cells are all important in the dynamic relationship between the tooth and the bone. These cells are important in orthodontic movement or extrusion. The periodontal ligament and its associated cells may be the only real consistant way to stimulate bone growth.

Consider the long term effects of losing a tooth (and its periodontal ligament) and replacing it with an implant...
1. The implant cannot be moved in any direction from its integrated position.
2. There WILL be crestal bone loss initially.
3. There WILL be crestal bone loss over time - up to 0.2mm/year
4. There will be loss of proprioception
5. With loss of crestal bone come loss of gingival height and esthetic issues.

As I mentioned, implants are a great way to replace MISSING teeth. But they are not alternative treatment for restorable teeth.

This patient was seen over 3 years ago. Tooth #8 was diagnosed as necrotic w/ acute apical abscess. She had swelling and pain at the time. Antibiotics were prescribed and RCT recommended.

Patient has returned again today with swelling and pain. She reports that she did not have RCT done because the swelling and pain went away. There is no mobility, despite the increased size of the lesion. The RCT has been recommended again. Unfortunately, due to previous experience with root canals, she is convinced that they are less successful than an implant.

Proper understanding of the role of the periodontal ligament with this tooth should help her decide the only acceptable way to treat this tooth is with endodontic treatment.

Thursday, November 17, 2011

This, Not That.

Short one today.

This is what a maxillary second molar root canal treatment should look like:

Rethink what you are doing if your cases look like this:

Wednesday, November 9, 2011

Consult Along: A Day at Alpharetta Endodontics

Rather than try to have an overarching theme to this post, I will present each of today's patients as each case was complex and each illustrate rather important points. For the sake of brevity, I will only post significant findings (and I apologize for poor consistency and errors in grammatical tense) . Unless otherwise stated, assume medical history is non-contributory. I would love for readers to post feedback, alternate treatment plan ideas, or other approaches to these cases.

Patient 1:
This patient presented with a history of root canal treatment on #20 by an endodontist 1-2 years ago. #19 was treated by her general dentist ~8 months ago, and #18 was fractured and replaced with an implant within the last two years. The crown came loose and was replaced with a post 1 month ago. Following this treatment, she described severe pain upon chewing and swelling on her tongue side of the tooth. There is no extraoral sign of swelling or lymphadenapathy. No intraoral swelling or sinus tract. Around #19, the gingiva is edematous and inflamed with bleeding on probing. The crown margins are open and overextended. The probing depths on #19 are 3 mm interproximally and 8-9mm mid buccal and mid lingual. The radiograph reveals a laterally widened PDL with a hint of an apical radiolucency. The restoration on the mesial is into the furcation and associated with horizontal bone loss. #20 displays an apical radiolucency as well. The implant on #18 is bulbous and overcontoured to the mesial with some signs of horizontal bone loss.

Unfortunately, I recommended extraction of #19 due to the likelihood of a vertical root fracture and a poor restorative prognosis. I recommended she return to her previous endodontist for reevaluation/recall of #20. I also provided her some proxibrushes to maintain oral hygiene around #18. Would you rather have that root canal/crown or that implant...or neither?

Patient 2:
This patient is referred by her general dentist for evaluation of #3 and initially presented two weeks ago. She reports having root canal therapy a year and a half ago by another local endodontist, no microscope. Since the time of treatment, she has had spontaneous "shooting" pain that is localized to tooth #3. It is worse in the morning and with mastication. A history of symptoms indicates that the tooth was likely vital preoperatively and so persistent bacteria is not a feasible etiology. No extraoral swelling or lymphadenopathy. No intraoral swelling or sinus tract. Probing depths 2-3mm, crown margins are in tact. Occlusion is light in MI with no interferences. No palpation tenderness, no swelling, no sinus tract, no percussion tenderness, no mobility. Slight bite pressure tenderness on the MB cusp and P cusp only.

Preop, no radiolucency, slight ligament widening in the palatal, short palatal obturation, overenlarged mesial obturation in the cervical third, undermined/weakened mesial tooth structure. Diagnosis: previous treatment/acute apical periodontitis. Possible etiology: restorative recontamination, root fracture, strip perforation of MB/MB2. I recommended retreatment but cautioned that a finding of a root fracture would indicate a need for extraction.

Upon access, blood was found on the palatal canal, and, in spite of anesthesia, the GP was tender to pressure with fluid built up around it. No fractures were found. Additionally, a strip perforation was found in the cervical third of MB2. It was repaired with MTA and the palatal canal was retreated. The patients symptoms resolved immediately, and the case was finished this morning.

Patient 3:
This patient went to her new dentist for a broken restoration on #30. Decay was found encroaching on the pulp chamber and she was referred for root canal therapy. She is asymptomatic. #31 was treated 2 years ago by another endodontist, no microscope. The anatomy appears to be very challenging. A history of symptoms of cold sensitivity and throbbing pain prior to the previous treatment indicate that #31 was likely diagnosed as irreversible pulpitis preoperatively.

Treatment on #30 was completed at today's visit and treatment options for #31 were discussed. Restoratively, the case is compromised with a crown on a buildup with voids. Additionally, retreatment of the mesial root is going to be challenging if not impossible. If, as it appears, the distal root is the primary source, retreatment may be successful. One alternative, if retreatment is not successful, is to place spacers to loosen the tooth and then try an intentional reimplantation. Apical surgery is difficult to impossible in this location with such long roots (25mm working length on #30).

Patient 4:
Asymptomatic, original treatment over 15 years ago. Her crown and posts came off and extensive recurrent caries was found beneath. Her dentist cleaned the area and placed a temporary crown before referring her for evaluation. While radiographically, the ligament is in tact, her history indicates bacterial contamination and retreatment was recommended.

Case #5:
This patient is asymptomatic. She recently moved here and her new dentist noted a parulis buccal to #30. She is ~85 years old. Probing depths were 2-3mm with bleeding on probing and a class 1 furcation involvement. The margins on the composite were open. Due to the compromised restorative prognosis and the furcation radiolucency, I recommended extraction. She does not wish to replace this tooth at this time, but an FPD is likely her best option. She is fortunate to have full molar occlusion on her left side.

I hope that our readers learned something from these cases. You will probably realize that I started no new root canal treatment today, and that all our cases were complex diagnostically and involved molars. This is typical for our practice.

If you have any input or questions, please voice them in the comments, but please remain constructive. As always, I invite readers to see more cases posted regularly on our facebook page at

If you have any suggestions or requests for future posts, please leave them in the comments!