IAC seats or not, Dental Education Lecture

IACs were seated for Sergio last week as shown by Fig.1. A few days later, he reported that the crown(s) was/were loose. Did I show you in web how to tell whether an IAC or abutment is completely seated? Where can we find the page?

Why were these two IACs in fact not completely seated indeed? Can you look at the X-ray with critical thinking? Is there anything wrong with the X-ray, even though it was taken by the doctor?

Interestingly, he said that these two crowns were found to be loose in the morning. He has history of snoring and bruxism. The IACs were tapped in more secure manner by Carmen. The new X-ray reveals something unexpected and interesting. What do you expect to see? What should we do further to prevent them becoming loose again? Please respond. What is the trick to find answers?

Hi Dr wei:
1. Did I show you in the web how to tell whether IAC or abutment is completely seated?
-Yes we can go to Bone Graft article to see IAC. Yes we can go to Prevent Infection article and you can see whether abutment is completely seated.
-the abutment/crown unit is tapped into the implant with two visible threads instead of three
-the latter indicates that the abutment is completely seated
2. Why were these two IAC in fact not completely seated indeed?
-he was grinding his teeth at night which means the IAC is not seated (This is a fact, but not reason)
So he needs a night guard for him to protect his teeth
3. Is there anything wrong with the x-ray
-the x ray is not in the center (see below)
4. What do you expect to see?
-I saw that the x-ray has one line of thread inside implant well (Carmen has advantage of seeing it today)
5. What should we do farther to prevent them becoming loose again?
-I don't know yet. give me time to check the answer Carmen

Is there anything wrong with the x-ray? Implant threads (outside) which are not distinct (blurred), suggests that the sensor was not placed parallel to the upper anterior jaw (implants) in Fig.1. The threads seen across the inside of the implant well are also difficult to comprehend. In contrast, the X-ray taken today is much better (Fig.2).

Hi Dr. Wei
1. What should do further to prevent them becoming loose again?
-i knew the answer was nightgaurd yesterday but i was too tired to
email it to you because i had to sleep early
-you can also tap stronger to prevent it from becoming loose. Carmen

Doctor Wei: About the old X-ray, I think it shows the sensor was not paralleled with number 8 tooth, that is why number 8 implant root threads look blurry on the X-ray, so it is not very clear if there are two threads space or three. If it was two, that means the IACs were completely seated.

If there were two threads space between the IAC and implant well, but crown still loosened, then I think patient probably loosened this crowns by grinding teeth at night.

If it is true, on the new X-rays, I would expect to see the wearing on the crowns.
What should we do further to prevent them becoming loose again? Let him wear night guard? Jenny

Jenny: You are a genius. Your analysis of blurry threads of #8 implant and of sensor parallelism is exceptional. Maybe you have to forgive me if my further explanation for one line of thread does not sound scientific. In fact Carmen helps take impression for night guard today. When I trim the model, I find strange wear pattern on #8 IAC (lingual incisal edge) with puzzle. Now you provide the answer. Last, can you help suction down the night guard. Thanks a lot.