Open Dental Forum

I was wondering if anyone has experienced this problem:
I have Windows 8. Mostly, when I take x-rays on patients, they don't come out but when I test the sensor outside the mouth, they come out. I tested it with the sensor in the holder as well.
I use the holders Dexis provides. I have checked to make sure when the patients are not biting on the cord, sensor being placed correctly, and cord not being stretched. I can't think of any other reason for x-rays not to come out. I even changed the sensor and the new one does the same thing. I test with non-digital x-rays and they work so it's not the x-ray machine either.
I'm just confused and don't understand why this happens. Any ideas?
Thanks in advance

It could be that you need to adjust the exposure on your machine. The sensor will need less radiation when used outside the mouth to trigger an image. That needs to be increased a bit when you place it inside the mouth. If the sensor does not receive enough radiation, it will not trigger.

Thank you Jorge. I did try that but it made no difference. Same problem still persists. It's very unpredictable and becomes very frustrating. I am hoping I can find a solution soon.

Hi Alexi, I am just now seeing this. Is your problem fixed yet? I passed it on to one of our long-standing team members. Do you want to contact him directly? Thanks, Team DEXIS

TeamDEXIS wrote:Hi Alexi, I am just now seeing this. Is your problem fixed yet? I passed it on to one of our long-standing team members. Do you want to contact him directly? Thanks, Team DEXIS

No. I'm still having this problem. I also had someone from Henry Schein come out and check my x-ray unit and he said it's working fine and couldn't find any problems.
So far all the professionals that have come to find out what's wrong, can't find anything wrong but I'm still having the problem I started with. I feel like I have hit a dead-end and can't think of what else to do.

Please contact me and I will put you in touch with one of most experienced techs. I've already told him about your issue. jackie.raulerson@dexis.com

From a friend:

Well not so technical but if it doesn’t detect exposure it should be one of Six things:

1. Dose hitting sensor – looks like he has confirmed that is not issue – if he cranked exposure up to 200ms to test and it doesn’t expose then it is probably Not Dose from the source causing the issue.

Is this a handheld low ma x-ray source? That can be more challenging but have not heard many/any issues with Dexis sensors detecting low exposure as they are very sensitive.



2. Coning – if not enough of a sensor is illuminated by radiation then it doesn’t matter if one corner of the sensor was exposed at 300ms, it won’t detect/trigger. Can happen but he should know if he sees some coning on the images he does get if they are having consistent problems with positioning of the sensor.



3. PC incompatibility – This would not be typical and should cause other issues IN ADDITION to not detecting exposure – like Not Arming to start with to even get to waiting for exposure. The only thing that cautions me a bit is “Windows 8”…



4. Cable issue – this is one of the most likely issues – cables get bent with high radius and pressures when in holders and when they ARE ACTUALLY PLACED into the oral cavity. When doc says sensor exposes when not in the mouth but in the holder then make sure to test that thoroughly. For example when it doesn’t work in the mouth what holder is it in and what placement (anterior vertical, bitewing horizontal, etc…) and test THAT exact position externally to the mouth in the holder with the cable bent just like it happens in the mouth. Bend the cable when in the holder and take an image, bend it another way try to take an image, simulate this many times and as close to the exact position as when placed in the mouth.



5. Known Issue – Dexis sensors have some issues with certain sensors that “lose communication” with the USB port while in the armed state – this can be caused by a non-compatible PC, an early highly intermittent cable failure, or environmental issues like magnetic interference from an ultrasonic cleaner. There is a software fix for this symptom that checks for this condition and re-attaches/re-syncs the sensor should this occur. It has been out for a couple years but if this doc has not updated his DEXIS software in the last year or so he may not have that fix.



6. Technically it could be inside the sensor and a problem with the actual response of the sensor (CMOS die) or the A/D convertor not outputting properly/proper data – but again typically you would see that in other areas such as bad / not as good images when it did detect radiation and delivered an image.



I would say it is #4 or #5 and possibly #3 (if it has been an issue since day one and his PC’s are all the same)– Does he have another sensor – if so, it becomes very easy to rule in or out a specific sensor or a specific computer or computers they are being plugged into.

What the Schein rep should have done was brought another Dexis sensor for comparison which would have most likely narrowed it down to root cause.

If it is highly intermittent (works 99% of the time) then can be harder and might need a loaner sensor for a day or two to figure out…

Also, does it happen on all his machines, are they all the same model or does it just happen on one machine, if he has other models does it work on that machine, etc…

Hope that helps.

p.s. The person above who recommend Jackie is good as well – Jackie is a very good clinical trainer, - not technical but because she is a trainer has seen most everything at least once and may have some good input or if there are any “new” gremlins in Dexis software or sensor…

thanks

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Justin - me... would like to add that few people on earth are as "technical" as my friend.

Justin and TeamDEXIS,

Thank you for all the info. I very much appreciate it. I had some other people come out to evaluate the problem and turns out it is actually the x-ray unit. When the x-ray unit head twists, it doesn't function due to wires getting twisted inside (although it doesn't happen all the time).
The tech from Henry Schein was not able to find the problem and had told me if there is something wrong with the wires inside the unit it would have to be replaced as they can't fix it. HS sent me an invoice for $170 for 30 minutes of tech's time although it was of no use and they expect me to pay for it. Anyway, now I have to figure out if my BELMONT model-070 can be repaired or not.
Thanks again.