Dental xray problems

Re: Dental xray problems

Evelyn Barbour-Hill — Wed, 14 Jan 2015 14:38:15 GMT

[quote user="Jillian Hall"]

Looking closer at our machine it is mAs that only goes as low as 0.21 and Rachel was referring to time settings. I think 0.21 mAs coincides with an exposure time of 0.6sec so perhaps my problem is not as simple as changing the film type.

[/quote]

I note that it is always Agfa systems that give this trouble.

Would it not be part of the after-sales service to sort the problem out?

Re: Dental xray problems

Jillian Hall — Wed, 14 Jan 2015 13:36:03 GMT

Re: Dental xray problems

Jillian Hall — Wed, 14 Jan 2015 13:27:38 GMT

We seem to have the exact same problem with our AGFA dental film and digital processing. It is frustrating how inconsistent the faults seem to be.

However the most common problem is that the image looks massively overly exposed. Adjusting the image manually will reveal the image of a tooth somewhere but it usually far to grainy to be diagnostic, as with the image above.

Rachel's point about digital film needing lower exposures seems to fit. Our dental X-ray unit (a FONA XDG) only goes down to 0.21mAS and is fixed at 70kV. Can I infer from this that getting self-developing human films would be a way around this problem? Buying some new film seems like a more attractive proposal than replacing our new Xray head. If so, does anybody know a good place to order self-developing film?

One of our vets gets more consistent pictures putting the film the "wrong" way round in the envelopes i.e. blue side adjacent to the tooth and the Xray beam. This seems to give more reliable images however they are all less contrasty than I feel they should be, they are quite grey all over. Would this make sense on the basis of a lower proportion of the Xrays getting through the backing to reach the black side of the film?

Re: Dental xray problems

Evelyn Barbour-Hill — Wed, 03 Sep 2014 16:53:06 GMT

[quote user="Oli_J"]I also found another old high speed handpiece that didn't foam anywhere near as much (although the water totally misses the drill tip, which is why it was replaced in the first place...), so I think it is a handpiece problem, although it is new.[/quote]

Which reminds me, handpieces can be repaired and often are. Of course if it was a cheap one it might not be worth it.

Re: Dental xray problems

Rachel Perry — Wed, 03 Sep 2014 15:23:47 GMT

older human dental Xray generators were designed to be used with film. The beauty of newer digital systems is that they require much less exposure (safer for patients), and this is achieved by reducing the time of the exposure. If 0.25s is the lowest you can go , this is too much time IMO, and hence being over-exposed. Normally I will use 0.064s with feline digital rads.

Re: Dental xray problems

Anthony Todd — Wed, 27 Aug 2014 09:19:04 GMT

PS. re scalers.

I know the purists will howl in protest but the best scalers we used, so the users said, were "Woodpeckers" from eBay and China. You can buy the replacement solid tips too.

Cavitron and Bobcat had the long push in tips that were expensive [vets etc. dropped them all the time] and seemed to give more trouble than they were worth.

Re: Dental xray problems

Mark Hedberg — Wed, 27 Aug 2014 09:02:19 GMT

[quote user="Anthony Todd"]

[/quote]

Considering how nasty UK tap water tastes, why was this surprising?

Re: Dental xray problems

Anthony Todd — Wed, 27 Aug 2014 08:43:06 GMT

[quote user="Evelyn Barbour-Hill"]block the fine water passages in the handpieces.[/quote]

We used to fit in line filters on the water line; Luer fit, disposable. Kent Express do them I think.

It was surprising to see the crud which was collected.

Re: Dental xray problems

Evelyn Barbour-Hill — Tue, 26 Aug 2014 20:21:07 GMT

Distilled water because tapwater contains all sorts of solutes – and sometimes particles – which may gradually foul up the internal workings of the machine or block the fine water passages in the handpieces. Also because the microbial content of distilled water will be less. Some manufacturers stipulate that the warranty is void if anything other than distilled water (or CLS, in iM3 machines) is used.

The main purpose of CLS in my view is as a flush after use. Occasionally I use it in the scaler, never in anything else, in actual work.

Could there be traces of CLS still in the water line? Did the service man check for any air leaks into the water line? Has your nurse been putting anything in the water bottle? Is the gasket on the handpiece sound?

Does your unit have a gauge to show air pressure to the handpiece in operation (not the same as the tank pressure)? What does it read when the handpiece is operating?

Re: Dental xray problems

Oli_J — Tue, 26 Aug 2014 19:40:38 GMT

I have just asked about the water and no it is not distilled! I never thought to check before. The nurse then asked me why we should only use distilled water and to be honest I couldn't remember... Anyone?

I also found another old high speed handpiece that didn't foam anywhere near as much (although the water totally misses the drill tip, which is why it was replaced in the first place...), so I think it is a handpiece problem, although it is new.

Do most people routinely use CLS in the water? I tried without but still seems just as foamy.

Re: Dental xray problems

Oli_J — Tue, 26 Aug 2014 19:40:28 GMT

Do most people routinely use CLS in the water? I tried without but still seems just as foamy.

Re: Dental xray problems

Evelyn Barbour-Hill — Tue, 26 Aug 2014 18:45:04 GMT

[quote user="Oli_J"]I have actually printed it out to show the boss,[/quote]

Cripes

[quote user="Oli_J"] We have had the compressor adjusted and it has made no difference to the amount of foaming from the high speed handpiece, I tried to reduce it by turning the water down, but it seems to either be off or high, there are 2 water streams that hit the tip from each side then kind of diverge out and soak the cat/dog, hard to explain.[/quote]

Dunno, even if there's too much water I don't understand why it's foaming. Are you sure that's distilled water you've got there?

Re: Dental xray problems

Oli_J — Tue, 26 Aug 2014 09:55:47 GMT

Thanks so much for the detailed reply Evelyn, I have actually printed it out to show the boss, alongside some special deals I managed to negotiate with IM3, fingers crossed!

Surgery ran overtime on Monday so the xray man is coming later in the week. We have had the compressor adjusted and it has made no difference to the amount of foaming from the high speed handpiece, I tried to reduce it by turning the water down, but it seems to either be off or high, there are 2 water streams that hit the tip from each side then kind of diverge out and soak the cat/dog, hard to explain.

The 'universal' scaling tip is sickle shape, but not really thin enough to get subgingivally in cats. The scaler is brand new so tips are not worn down, we are just after some guidance about how to use it which has not been forthcoming from the supplier.

I am currently located in New Zealand (no Bank holiday for us this week) so unfortunately there is nobody close enough to give us a demonstration.

Thanks for all the help I will keep you posted about the outcome.

Oli

Re: Dental xray problems

Edward Jones — Sun, 24 Aug 2014 21:26:58 GMT

Firstly, I assume you're digitally collimating the image manually after it's been acquired, so the computer can apply its algorithm appropriately? On our AGFA system several dental exposures are acquired all at once from the same plate and the automatic cropping can't deal with it.

Secondly, the exposures from a dental unit are quite long, usually a significant fraction of a second. If you don't press and hold the button for long enough the exposure will be aborted half way through resulting in under exposure. If this happens the computer might still generate a black/dark looking image because it's trying to rescue whatever information it can, which can make it non-obvious that there was an under-exposure in the first place.

Thirdly, I'm out of ideas! Perhaps the generator is failing?

Re: Dental xray problems

Evelyn Barbour-Hill — Sun, 24 Aug 2014 20:09:23 GMT

PS what does this "universal" scaling tip look like? A rod? A sickle?

PPS If your scaling tip has worn down, don't increase the power, just throw it away.

PPPS If your scaling tips are wearing down at a detectable rate at all, either you've got bad ones or you are pressing them too hard on the tooth.

PPPPS Don't forget to tell us the solution and final outcome. It may be useful for others with similar systems.

Re: Dental xray problems

Evelyn Barbour-Hill — Sun, 24 Aug 2014 19:58:54 GMT

Gurls oo gosh

Well if the problem's in the computing one would hope that the Agfa techie will find the answer sharpish. (Not on Monday, though, it's a Bank Holiday) With all the resources of Agfa there must surely be a more sophisticated solution than making manual adjustment every time. (But then again, if the facility for dental sensors was just an afterthought by Agfa, with a bodged-up mechanism.....)

The sensors do deteriorate eventually, I'm told, but only over a very long time, unless abused.

The thing about a secondhand ex-human Xray generator is that it may, probably will, soldier on for years and years, but you just never know when something might fail. I imagine it's been serviced properly annually?

There are many different makes of handpiece. I think probably there are no bad ones but there are cheap, middling and expensive ones and you get what you pay for. Many of the purveyors of "package" dental units will attach the cheapest handpieces they can get. The plastic gizmo to aid in changing burs is an iM3 invention, because the pushbuttons on iM3 handpieces (rebadged W&H and very very good indeed) can be a bit stiff for dinky thumbs. I have to say that the usual reason for the bur falling out is that it was not in properly in the first place: sometimes you need a pretty firm push to get it right in. The other reason would be that the collets are damaged, perhaps by someone running the handpiece with no bur in it.

Anyway the air and water pressures are a function of the airdriven unit and the service man should be able to put this right, assuming he knows what he's doing. If you are getting a sort of high-pressure foam, there might be an air leak into the water system somehow.

Scalers: I think possibly, as with the dental unit, this is the hazard of buying dental equipment from firms such as Vet Direct or JAK, who haven't actually got a clue what they are selling; or from firms whose main business is with human medical practice but think they might make an extra bob or two by selling to veterinary surgeons; they are experts on what they are selling but haven't got a clue what veterinary practice demands. I'm not closely acquainted with the scaler you have, but looking it up I get the impression it's a pretty good and advanced one for human practice, and there are a large number of quite sophisticated tips for it for special purposes, which may or may not have veterinary application. I suspect that the suppliers have just chucked in a "universal" tip and a random handful of others. Throw away the ones for which you are sure you have no use.

What you must have is a scaler in which the water is conducted to the tip of the tip: without that, you are limited to supragingival work which is only slightly more than merely cosmetic, so you can't do your job properly at all. You also need to know in what mode the oscillations work: as far as I know the iM3 (or Odontoson) is the only one where the tip moves in tiny circles round its long axis; in all others the movement is an up-and -down one of some sort. This means the iM3 can be used much more freely (but it stil has to be used correctly!) without risking damage to the tooth substance.

The "power" setting of the scaler alters the amplitude of the oscillations. I can only suggest that you start with the lowest and gradually work up until you find the lowest that will do the job. Then you might want to turn it up a bit for stubborn chunks of calculus, or turn it down a bit for deep subgingival work.

[quote user="Oli_J"]I called the supplier to enquire about which power setting and which tips to use on cats vs small vs large dogs and for subgingival scaling and they simply advised that none of the tips should ever come in contact with the tooth and to just hover them above teeth for scaling (?!) and none should be used subgingivally.[/quote]

They obviously don't know anything about veterinary work. In view of what they say about "never use subgingivally" I'd be very careful to check how the machine operates, as I suggested above. The advice about the tip not contacting the tooth is strictly correct but the gap can be of the minutest; if you have an iM3 it is fine to lightly contact the tooth with the side of the tip. And of course, you can certainly contact calculus directly with the tip. (What you must never do is contact the tooth with the point of the tip: you must only use the side, or the flat if it's a flat one).

I have no shares in iM3 but in my opinion the only excuse for not investing in an iM3 42/12 scaler is that you really really cannot afford it. Then you might as well get the sort of thing that's one-fifth the price, but then you may not be able to do a proper job so you never ever will be able to afford the iM3.

Whereabouts are you, Oli? (Is that your name?). I may know someone in your region who might be persuaded to pop in and look your stuff over from a practical point of view.

(I also know this cool guy in North Wales who will come and give tuition on your own equipment, and his charges are very reasonable )

Re: Dental xray problems

Michael Woodhouse — Sun, 24 Aug 2014 18:45:59 GMT

[quote user="Oli_J"]I called the supplier to enquire about which power setting and which tips to use on cats vs small vs large dogs and for subgingival scaling [/quote]

Almost all the ultrasonic scalers used in the vet sphere are human machines and generally cost 1/5 the cost of the IM3 one everyone swoons over. That just means you get a load of tips to throw in the bin as unsuitable for vet use. In terms of setting my advice would be to start with a low setting and work your way up until you are getting the effects you need in practice. I have found that as the tip wears you need a higher setting. You can get replacement tips from companies like Roots dental or Vet Direct, but I've found the ebay ones from China much cheaper and last as well (in my basic experience).

[quote user="Oli_J"]The drill piece has also fallen out on me several times [/quote]

This is most likely user error. You need to make sure the burr is properly seated in the head. If in doubt then keep pushing the button on the back of the hand piece and push against the table. When we got our dental machine we were advised to always leave something in the chuck even when not using the machine. It came with a 'blank' and we use that.

Do you have a manufacturers name on the high speed? What pressure is the gauge reading on the dial? Having accidentally run my machine on the tank pressure alone (when plug pulled out) the handpieces seem quite forgiving of reducing pressure until a point.

Re: Dental xray problems

Oli_J — Sun, 24 Aug 2014 00:01:51 GMT

Thanks again for the helpful replies.

You are right Evelyn, we place the small dental sensors inside an ordinary size cassette for developing. Have got the AGFA tech organised to come round and look at the machine on Monday, fingers crossed it can be sorted soon.

I have recently started my current job and one of the major attractions was the seemingly good dental set-up, upgraded just before I started 2 months ago, however, I've had no end of problems with it. Apart from the xray problems I am not really sure how to use the dental scaler. It is a Bonart ART BS Piezo human scaler and it comes with one tip that looks like the universal tip by IM3 and the rest are weird thick and round tips that don't really fit between teeth or subgingivally. It has a power (frequency?) setting that can be adjusted from 0-45. Nobody else in the practice is interested in dentistry at all so when the machine was installed they didn't ask any questions! The manual is useless as it only relates to human dentistry and mainly talks about machine maintenance not how to use it.

I called the supplier to enquire about which power setting and which tips to use on cats vs small vs large dogs and for subgingival scaling and they simply advised that none of the tips should ever come in contact with the tooth and to just hover them above teeth for scaling (?!) and none should be used subgingivally.

Does anyone have experience with this scaler? I am trying to convince the boss to return it and get the IM3 4212 instead but he doesn't see the problem with it :(

The other issue is the brand new high speed handpiece (not sure which brand, definitely not one I have heard of). It seems that the water pressure is very hard to regulate and so much foam comes out (even when using plain water without CLS) that I can barely see what I am doing. The drill piece has also fallen out on me several times (luckily it got wedged in the tooth and did not fly out and get somebody in the eye!). Again I called the supplier and they said the compressor must be set too high (but shouldn't they have checked this when machine was installed?!) so have somebody coming out to look at the compressor on Monday also. I asked them about the little plastic cap that is used on IM3 machines to get the drill bits in and out but they didn't know what I was talking about... ***sigh***

Sorry about the rant, and thanks for the helpful suggestions.

Oli

P.S. I am a girl ;)

Re: Dental xray problems

Evelyn Barbour-Hill — Thu, 21 Aug 2014 14:36:45 GMT

[quote user="Alan Tevendale"]

The only reason I mentioned the software settings is that I have seen a similar problem in the past. No settings changed at all. It was just the computer trying to interpret what it thought the images should be vs what they were. Have you looked at trying to recollimate the images manually on the computer?

[/quote]

Yes but if his dental radiographs have been all right in the past something must have been changed. If the system is designed to take both standard size and dental size sensors there must be some settings, even if normally automatic and invisible, that tell the computer which it is dealing with.

As far as I can see this Agfa machine works with dental sensors by the sensor being placed inside an ordinary size cassette after exposure. Is that right?

Re: Dental xray problems

Anthony Todd — Thu, 21 Aug 2014 08:50:33 GMT

You can get test strips of calibrated exposed film which, when processed in the usual way will tell you if processing is, in any way, at fault.

Usually the fault lies at the processing end so you can save time and money quickly by eliminating the most likely source of problems.

Velopex did them.

Re: Dental xray problems

Alan Tevendale — Thu, 21 Aug 2014 08:19:03 GMT

Re: Dental xray problems

Oli_J — Thu, 21 Aug 2014 02:32:06 GMT

Thank you for the helpful comments.

The other xrays developed by the AGFA system are coming out fine, it is just a dental xray problem. I assumed it was less likely a computer or developer problem as the variation in xray quality occurs without changing any of the settings, and yes we do select on the computer which arcade is being processed.

Seems like either the tube head or maybe the films, do these get worn quickly? The only difference between the xrays is the film used, all settings on the machine and computer remained the same.

Thanks again,

Oli

Re: Dental xray problems

Bob Russell — Wed, 20 Aug 2014 17:18:36 GMT

I have just looked up the 'processor' and it is a CR system. Ours is a DR so if you haven't already, ignore my comments! I would be more suspicious of an issue with 'collimation' and interpretation by the software.

Have you asked the suppliers?

Re: Dental xray problems

Evelyn Barbour-Hill — Wed, 20 Aug 2014 17:14:38 GMT

[quote user="Alan Tevendale"]This looks to me like your developer is trying to interpret the whole image rather than your collimated area. This would certainly give you the picutre you are getting but there could be other reasons. Can you manually alter your collimation on your computer to reinterpret the image for the image you are after only?[/quote]

I assumed that was how the Agfa machine worked with dental size films. But certainly it would be worth checking the computer settings – it is not unknown for them to get accidentally altered. Especially if this set-up needs different settings for "standard" size sensors. Has somebody in another department been messing with the settings?

Re: Dental xray problems

Alan Tevendale — Wed, 20 Aug 2014 17:06:56 GMT

This looks to me like your developer is trying to interpret the whole image rather than your collimated area. This would certainly give you the picutre you are getting but there could be other reasons. Can you manually alter your collimation on your computer to reinterpret the image for the image you are after only?