Collaborations with Dr. Sheng Zhang
- Dr. Jimmy Chan
- Apr 4
- 4 min read
Updated: Aug 30
While in Auckland, I was fortunate enough to work with my good friend, Dr. Sheng Zhang, from Dental Artistry. We performed many joint surgeries together to manage a plethora of complex endodontic and periodontic problems.
In this blog, we will explain one of these joint cases.
A patient presented with a painful tooth (46) and persisting thermal sensitivity that did not resolve after initiation of root canal treatment. Upon further investigation, there was an undiagnosed grade 2 furcation defect due to an enamel projection towards the furcation and a missed radix canal.
After explaining to the patient that endodontic treatment alone will not resolve his issues and the pain that the he was experiencing was due to the accumulation of debris at furcation site.
The treatment plan offered to him was to complete his endodontic treatment by me and Dr. Zhang to perform guided tissue regeneration at the furcation. He accepted the treatment plan.
The radix canals are often missed and can be challenging to negotiate. The trick is to use the buccal pit as the reference point and use small-sized K files, such as 6, 8, and 10, only. The canals were then prepared to a size of 25 4%. The canals were then disinfected and medicated with calcium hydroxide.
He was reviewed a month later, and he reported that the pain still comes and goes, but his thermal sensitivity has resolved. His tooth was not tender to percussion, and the associated periapical tissues were not tender to palpation. Furthermore, there is no development of a periapical radiolucency on the follow-up radiograph. Thus, I am confident that my root canal treatment was successful despite the persisting pain. (Root canal treatment can only control the contents of the root canal spaces.) His root canal treatment was thus completed, and he was referred to Dr. Zhang for the GTR.
From the basic sciences, it is known that periodontal tissues do not attach to enamel, thus forming a platform for biofilm to grow and eventually cause bone loss around the enamel projection. The bone loss will then allow material to accumulate inside the furcation, causing inflammation and pain (which is the persistent pain problem). The enamel projection was then removed with a diamond-tip ultrasonic scaler and smoothed with hand instruments.
After the enamel projection has been removed, a connective tissue graft was harvested from the palate to be used as a "membrane". The reason is that the seal around the furcation is crucial in GBR procedures, as we do not want the bone graft material placed inside the furcation to be infected after flap closure. The CT graft acts as a living membrane that can protect against the influx of saliva and bacteria.
Upon completion of filling the space with bone graft, the harvested CT graft was then placed over the bone graft-Emdogain mixture, acting as a biological barrier.
Once the graft is attached firmly, a muscle release is performed to reapproximate the flap.
After 1 week, the appearance is concerning. However, if we think about it scientifically, what is actually happening is predictable. The CT graft was harvested from the palate; it will revascularise to the surrounding tissues, and the graft is doing its job to protect the furcation (inflammation).
The flap that was placed above(CT graft) allows the connective tissue to merge with the palatal CT graft. The old keratinised tissue will necrose and shed, and new keratinised gingiva will form. Thus, we expect that after some more time, the keratinised tissue will emerge over and replace the old attached keratinised gingiva.
After one month, the tissue appearance improved, with no secondary infection of the graft. The junctional epithelium begins to form at the furcation. Therefore, it is recommended not to probe the area for at least 6 months. After six months....
His pain and swelling around the area are gone. He is satisfied with the results.
The crown was done by another favourite dentist of mine in Auckland, Dr. Sara Stockham. I cannot emphasise enough that a well-sealing crown is as necessary as the root canal itself. GP is a poor material for placement inside root canal spaces. But this is the standard we all agree is good. Thank you, Sara, for the beautiful crowns and for always protecting my work.
Successful treatment often requires collaboration with other clinicians. I am grateful to have friends like Sheng and Sara who make me a better operator.