In October 2020, I wrote a blog on a patient whose upper front central incisor (tooth #21) had external resorption. The resorption was extensive and rendered the tooth hopeless in prognosis. Different options were presented and discussed – endodontic treatment and extraction with a fixed bridge, a removable denture, or an implant-supported crown as the final prosthesis. Another factor we debated on the challenge in her case besides the time and surgical procedures going to involve – is her oral lichen planus.
Oral lichen planus can present in six types clinically: Reticular (fine white striae cross each other in the lesion), Atrophic (areas of erythematous lesion surrounded by reticular components), papular type, bullous type, plaque-type, erosive or ulcerative type. This disease occurs more frequently in females and is a T-cell mediated autoimmune disease. The ramification is the delayed healing of the gum tissues, leading to a higher chance of infection after surgery.
Despite the higher chance of failure, she elected to have the tooth removed and replaced with an implant-support tooth.
Therefore, the patient had to take a high dosage of antibiotics and rinse her mouth with antiseptic with meticulous oral hygiene before and after the surgery.
The first appointment in October 2020 was to extract tooth #21 and bone graft the socket with mineralized freeze-dried bone allografts (FDBA). The purpose of the bone graft is to create more bone dimensions for the future implant.
X-ray of the upper central incisor before extraction, after extraction with the bone graft, and with the implant.
Bone graft particles
Right after the tooth was extracted, a simple cantilever bridge was fabricated and bonded to the other central incisor to provide a temporary tooth to replace the extracted tooth. The bone was allowed to remodel inside the extraction sockets for over eight months. The healing was non-eventful overall. In August 2021, another course of antibiotic and mouth rinse regimes were initiated for a week before placing a Straumann bone level taper implant (Roxolid SLA) in the grafted site. I attached an immediate temporary crown made of polyether ether ketone (PEEK).
The upper left central incisor before extraction.
A temporary bridge after the extraction
The upper left central incisor replaced with an immediate temporary crown attached to an implant
A temporary PEEK crown attached to the implant lets the surrounding gums remodel to provide a natural appearance. During the remodelling period, the temporary crown was removed a few times during the six-month healing period to recontour the shape of the temporary crown – 1) to allow the gums to form a natural appearance and 2) to achieve an aesthetically balanced tooth shape that the future permanent crown can model on. Meanwhile, the other upper central incisor (tooth #11) was modified to remove the black triangle (the excessive space between the two front teeth at the gums) and to make the tooth less ovoid in shape. The results are far more natural and harmonious.
After both the upper central incisors were modified
At this stage, after the implant has been placed in the bone for over six months, the implant was tested for stability using a resonance device to make sure it has good bone ingrowth into the implant. The result was excellent, with a reading of over 80, which indicates that the implant has pretty good stability.
Knowing that the implant is ready for a definitive “permanent” crown, an impression was obtained using our latest 3-D scanner to make the digital topographic impression. It is a technique to measure the sizes, locations, orientations, depth, morphologies, and angulations of all the teeth and other tissues in the mouth. The scanner can also select the shade and chroma of the teeth that match the standard Vita shade guide. A 3-D printer can print out the digital impression if needed.
A digital impression of upper teeth taken by a Trios scanner
The “permanent” crown for the implant is being fabricated during the writing of this blog. The crown will have three components – the base made with machined titanium, the white zirconia bonded onto the titanium base and a layer of live-like material made with lithium disilicate baked on top of the whiter zirconia.
Once I have the crown attached to the implant, I will continue to blog on the progress of the final stage of this exciting journey.
