Talk:Dental restorative materials

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[edit] structural integrity

I read a few years ago about a dentist who said he had a problem with current practice because the teeth with fillings eventually cracked. They didn't help as much as advertized. In fact he wondered if they were all about money rather than helping the patient. I have had teeth filled and cracked and then capped and wondered what if they had been left alone. Obviously, none of this warrents repeating in an encyclopedia article, but perhaps my message here will encourage someone to help the article with information related to all of this. WAS 4.250 04:30, 6 December 2005 (UTC)

Generally speaking,teeth are filled when they develop caries,that is tooth decay. If untreated caries can result in pain, infection and a tooth that is not restorable,resulting in the need for extraction.

Unfortunately,fillings often do not maintain their integrity for the remainder of the patients lifetime. It is hard to give a time scale, but what one would consider a good filling may last 10 years.It may,and often will last much longer. No filling material is as strong as the tooth tissue it has replaced.Fillings can crack. The teeth containing the fillings can develop more caries or break themselves. This leads to a situation whereby the filling must be replaced or the tooth must be crowned if the filling is too large to replace. If these things are not done,then extraction of the tooth may be required.

Response to Structural Integrity: There is no perfect restoration. Fillings can crack, crowns can leak. Even if you crown a tooth, you still might get decay right at the margins of the crown, and then you're screwed, especially if the decay reaches down into the roots. What would be awesome would be a dental vaccine, but that's not really an option right now. Crowning (aka capping) every tooth that gets decayed, however is an option, but it's not usually the best option since it necessitates the removal of lots of tooth structure. - Sfdavedds

[edit] hydroxylapatite question

Over at the tooth enamel page, it's stated that the enamel is hydroxylapatite. Can anyone add to this article why hydroxylapatite isn't used for fillings? (I also mentioned this on the hydroxylapatite discussion page.) Thanks - Tempshill 06:32, 20 January 2006 (UTC)

Slight correction: Enamel is not made solely of hydroxyapatite. It is only the primary mineral. As stated in the tooth enamel article, 96% of enamel is minerals, the majority of which is hydroxyapatite, and the rest of the 4% is organic material. - Dozenist talk 11:59, 20 January 2006 (UTC)
Response to structural hydroxylapatite: Couple reasons why; enamel gets its strength not only from the material itself, but also from the way it is organized structurally. The hydroxylapatite crystals are secreted by ameloblasts in a very organized fashion, which gives it very good structural stability. If we were to grind up hydroxylapatite and plop it in there, it would be a lot more disorganized and most likely be very brittle. Besides, porcelain itself never decays. The acids from the bacteria are able to dissolve hydroxylapatite over time, so we're really no better off than when we started. You can make the hydroxylapatite more resistant to decay by replacing the calcium ions with fluoride - which is why we've got fluoride toothpastes these days. - Sfdavedds
what he's trying to say is hydroxyapatite is a crystal, crystals need to grow; you can't just chuck hyroxyapitite in a hole and hope that it sticks. what you need is a way to not only make these crystals grow in the tooth, but you also need a way to make them grow in perfectly straight rows.... its not going to happen for some time yet.(Bouncingmolar 14:31, 13 February 2007 (UTC))

[edit] About the redirect from filling

I think that the redirect from filling should be replaced with a disambiguation page. See, for example, casserole. I'd make the word filling in that article a link (even though there isn't yet an article Filling (cooking), to encourage creation), but if I did so, the link would lead to this article. -- X-Man 12:30, 16 March 2006 (UTC)

Currently 4 out of the 6 articles that link to filling are about food. So if anything, filling should redirect to Filling (cooking) and there should be a disambiguation to dental filling! So go for it! Samw 13:31, 16 March 2006 (UTC)
I agree with the first comment. A disambiguation page should be created. - Dozenist talk 23:01, 16 March 2006 (UTC)
Created Filling (disambiguation), made Filling redirect to Filling (cooking). -- X-Man 07:53, 17 March 2006 (UTC)
I'm afraid I'll have to disagree with the redir. "Filling", in my mind, is much more commonly associated with a dental filling than food stuffing. The relative size of the two articles also gives me pause in re a redirect to the cooking one. Finally, although more Wikipedia articles originally linking to "filling" might have been pointing to the cooking article, compare the number of articles now linking to the cooking article with the number now linking to the dental article. I'm redirecting to the disambig page unless a more clear consensus to the contrary is reached (and, if it has to point to one of the two, I would vote the dental article, myself). - Jersykoยทtalk 03:06, 18 March 2006 (UTC)
You said you're redirecting to the disambig page, but instead you changed it to redirect to Dental fillings. I've edited the redirect to point to the disambiguation. I think that the cooking-related meaning of the word filling is what most of the people think of when they hear the word, while the dentistry term is only used by specialists. It's the same as making the word window redirect to Window (computing) just because there are so many articles written about graphical user interfaces. So, I think it should redirect to disambiguation because it's a reasonable consensus. -- X-Man 12:29, 21 March 2006 (UTC)
For the record, I was the one who suggested redirecting to the disambig page, not Jersyko. He was supporting his own argument. Which, by the way, I also believe most people think of "fillings" in reference to teeth. Specialists would be more inclined to say restoration or name the material used, (amalgam, glass ionomer, composite, etc.). - Dozenist talk 12:37, 21 March 2006 (UTC)

[edit] How are fillings done?

There is no mention of how fillings are done on the Dental fillings page ? My questions would be:

- how does the amalgam bond to the teeth

There is no bonding of the amalgam to the tooth. All chemical reactions during the setting of amalgam are limited to the metal and do not interact with the tooth.Donnie 08:28, 4 March 2007 (UTC)

- is it heated to make it maleable, and if not how is it shaped to fit the filling and the profile of your teeth (presumably amalgam is unmaleable at room temp)?

The fillings are not heated for placement in the mouth. Mercury is liquid at room temperature. Upon mixing of the mercury (liquid) and silver alloy (solid in powder form), the alloy begins to transition to a solid phase over approximately 10-15 minutes. During this working time, the alloy is firmly condensed into the preparation to reduce voids and ensure a dense alloy. After setting the alloy is extremely hard, but also very brittle.Donnie 08:28, 4 March 2007 (UTC)

- why is a bigger cavity needed for amalgam compared to white fillings?

Due to the brittle nature of the alloy, there is a minimum thickness necessary to withstand the intra-oral forces, this dimension is approximately 1.5mm3. Additionally, because the alloy needs to be condensed into the preparation site, an extremely small preparation would not allow for proper condensation. In contrast, resin composite is fluid at room temperature and more flexible. This allows it to be placed in much smaller dimension if necessary.

Hope this helps.Donnie

[edit] Accepted beliefs by the scientific community ?

Dear Dozenist;

Your inclusion of "claim that amalgam fillings are safe, even for pregnant women, children, and diabetics, except in rare cases of allergy " is very US centric and not accurately reflecting the situation in the world today. There are many governments who have restricted the use of amalgam in at risks groups such as pregnant women, children, people with kidney problems etc... Sweden has notified a ban on all mercury products including amalgam after having banned it's use in children etc...

Thus your use of beliefs of the scientific community is a point of view since there are scientists who believe that amalgam should not be used, at least in certain population group. Either you present a balanced, neutral, view of the existing situation or you refrain from supporting one point of view in isolation. I chose the latter when I made my edits because I felt that information on amalgam as a filling material should be purely objective and not get into the debate that is well covered in the dental amalgam controversy ( to which the reader is correctly referred to for more information )--Dr. Imbeau 21:30, 11 April 2006 (UTC)

Actually, I am not talking on solely a US centric viewpoint. That is the viewpoint by and large of the dental community all over the world, as is seen, of course, by the ADA, but with international dental groups such as the IADR, FDI WDF, and (I believe but not completely confident) the ICD. Certainly there are some people in the scientific community that disagree, but as recently as the 1970s there were some people in society that believed the world was flat. Still, we do not need to model all articles on the topic "Earth" around the flat earth model. This encyclopedic article in the amalgam section should link to the amalgam controversy article to give viewers a chance to read more indepth on differing theories, but in this article the official stance of the dental community is needed. This applies to all other medical/dental articles as well, in which a few people disagree with the majority opinion in their respective fields. In those articles, an "official" position is given as represented by medical/dental communities at large. Considering that the international associations of at least the IADR and the FDI WDF support amalgam use and believe in its safety, there is a reasonable argument that this represents the majority opinion of experts in the field. - Dozenist talk 01:31, 12 April 2006 (UTC)
  • Dear Dozenist: First there is a difference between the dental and the scientific community. As far as I know the dental community does not encompass the entire scientific community. Th earth is flat is a bad example as most people then, as the majority of the dental community today, believed that the earth was flat until a few, better informed, showed that to be false. When Galileo proved that the earth was orbiting around the sun instead of the reverse , he went through a rough ride as he challenged the beliefs of the majority. The majority is not always right. There is a significant body of scientific opinion that does not adhere to the position that amalgam is inocuous. Furthermore it incorrect to state that some government agencies "claim that amalgam fillings are safe, even for pregnant women, children, and diabetics, except in rare cases of allergy " while ignoring that there are also some government agencies who have restricted the use of amalgam in these population groups. It is not just one or two government agencies either. Based on your point of view it seems like scientists in these countries all think that amalgam is fine to use in pregnant women, children etc.... Clearly that must not be the case since various governments have contra-indicated the use of amalgam in such population groups.

So it does appears that instead of objectively describing the material that is amalgam you have chosen to included a point of view while ignoring the others. And you do this because you say it is the point of view of the majority of the dental profession and assume that, by extension it is also the point of view of the majority of the scientific community. My point is that it is certainly not necessary in an article that is supposed to describe dental materials with a NPOV.--Dr. Imbeau 04:31, 12 April 2006 (UTC)

  • And, by the way, I assume that when amalgam manufacturers such as Denstply/Caulk states: "The use of amalgam is contraindicated. In children 6 and under..." and "...In expectant mothers." And Kerr, Inc. warns: "The health authorities of the various countries, including Canada, Germany, France, the United Kingdom and Austria have recommended against the placement or removal of an amalgam in certain individuals such as pregnant and nursing women and persons with impaired kidney function " that they do not know what they are talking about.... Or is it that a portion of the dental community is not passing on the warnings that is distributed with the product ? Certainly, someone reading the top paragraph in the amalgam section will conclude that amalgam is fine to use with pregnant women and children etc... Are the manufacturers above just another minority which should be ignored according to your point of view on the issue ? --Dr. Imbeau 07:32, 12 April 2006 (UTC)
  • Dear Dozenist: I have yet to receive a reply. Since there is a link to the dental amalgam controversy article were both side of the issue is presented , there is no need for the sentence on " some governments... " . It is POV and is not presented in a balanced, neutral manner. I suggest removing the sentence. Readers will learn what amalgam is from the article and can learn more about safety issues in other article,if they wish.--Dr. Imbeau 00:26, 14 April 2006 (UTC)
    • Sorry that I cannot reply as frequently as you do... I have been too busy to be able to adequately engage conversations in full. And I am still really busy, so I only have time for a quick response. It is interesting that you are not opposed to the sentence that says "Due to the toxicity of Mercury, the principle component of amalgam fillings, there is great debate as to the safety of these fillings" or to other references about possible health effects. But concerning the statement on the support of government agencies (and it should mention most medical/dental organizations) is NOT in any way POV. It demonstrates reality, which is that there is currently a consensus among dental professionals and that consensus is that amalgams are safe. That is all I have time for right now. You will just have to wait for a more thorough response. - Dozenist talk 02:27, 14 April 2006 (UTC)
  • Dear Dozenist: Of course you are a very busy person who may not have full time access to an internet connection.... As for the phrase " Due to the toxicity of Mercury, the principle component of amalgam fillings, there is great debate as to the safety of these fillings" I agree it should also be removed. So I suggest: " Amalgam fillings are an alloy of mercury (from 43% to 54%) along with silver, tin, zinc and copper. Due to the known toxicity of Mercury, the principle component of amalgam fillings, there is an ongoing dental amalgam controversy on the use of this filling material." I have taken a sentence from the last portion of that section which was repetitive and combined, after some modifications, it with the first sentence of the beginning paragraph of the section. Short and to the point. So I have made the change in the article.--Dr. Imbeau 04:18, 14 April 2006 (UTC)
Hello, I have read the dialog regarding this topic and I have changed the sentence back to how you described it should be (links refering to the amalgam controversy). Before I edited it, someone had added some references and quotes from some article regarding information that belonged on the amalgam controversy page.
Regarding "US centric views" i am not from the US, and our dental philosphies are not even based on american ones and using evidence based research, aka using peer reviewed scientific articles following scientific principles, (i.e. not the label that kerr has written to cover their buttocks from the lawyers) it is accepted by the world health organisation and the australian dental association that amalgams are safe for use as filling materials. information pamphlets written on products are hardly the place where scientific conclusions should be drawn from. if that was the case we would only use one cartridge of local anaesthetic per appointment in fear of overdose
I would be interested to see where you got your information regarding the so called 'ban of amalgam' in sweden. As I can not find that information anywhere credible. I did however find this link http://www.dentalwatch.org/hg/myths110.html which agrees with your point about relative. contraindications but it goes on further to say that this was governed by local councils. However, perhaps this discussion should really continue on the amalgam controversy page as it will start to become off topic if continued discussion about it takes place here.(Bouncingmolar 15:09, 13 February 2007 (UTC))

[edit] Gold Direct and Indrect restorations

In the indirect restoration section, under gold, the article states:

There are two categories of gold fillings, cast gold fillings ( gold inlays and onlays ) made with 14 or 18 kt gold, and gold foil made with pure 24 kt gold that is burnished layer by layer.

Are not gold foil restorations DIRECT restorations? Should not the mention of gold foil be taken out of the indirect section, and placed in its own category under the direct section? I realize Gold Foil restorations are very rare these days(probably more to do with time factors and cost than to any clinical factors), but I'm sure there are still a few docs still doing them.