cons sheet # 11 - Lama Assayed

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cons sheet # 11 - Lama Assayed

Post by Shadi Jarrar on 15/5/2011, 2:38 pm

بسم الله الرحمن الرحيم

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http://www.4shared.com/file/L2S314Ie/cones_2.html

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Cons
Abbreviations in this sheet:
u = you
ur = your
Amalgam restoration
Any amalgam restoration you do it should end up in restoring 7 things:
1. Anatomy
Any restoration u make should replicate the anatomical landmarks of the tooth structure.
After doing the cavity u should pay attention to the remaining cuspal plane & grooves because they will guide you during the carving procedure.
If u don’t have remaining tooth structure look at the contra-lateral side’s morphology to get a hint like if you are working on lower right 6 and you don’t have remaining tooth structure look at lower left 6 .
The marginal ridge and the triangular fossa should be curved to approximate the anatomy of the natural tooth. For example if u are doing a class 2 cavity on the mesial surface of a molar and u have intact distal surface u can use the level of the distal fossa as a guide to carve the mesial fossa, if u don’t have any one of them look at adjacent marginal ridges which is the best way to correctly restore the marginal ridges, it’s very important to restore the marginal ridges properly to avoid serious complications like fracture.
Also in restoring the marginal ridges u can use the opposing tooth and the degree of eruption!
Excessive carving of the occlusal anatomy doesn’t serve any functional purpose, it can make ur restoration even weaker, because during this excessive carving u can change the thickness of ur restoration making it less than it should be which will make ur restoration week leading to fracture .
Note: restoring the natural look of the tooth is not considered excessive carving, excessive carving result in very deep grooves and by this u will lose the occlusion with the opposing tooth so if u noticed that u have lost the occlusion then u have done an excessive carving.
2. Contour
It should conform closely the original contour of the proximal surface, and it should be continuous, and it will be influenced by the contour of the matrix band , if u place it properly u will get a good contour, but if u place it in a wrong way then u will get a faulty contour.
3. Contact
In any restoration u make that involve a proximal surface like class 2 or 3 u have to restore the contact area
How to check the contact area?
a. Mostly by using the floss
b. Also if the contact area was open (u hadn’t restore it) u will be able to see it, u will see a space between teeth but this way is not always correct especially with posterior teeth so it’s better to use the floss
When u insert the floss between the teeth u should feel a snap before it goes under the contact area, if it was loose , then u hadn’t properly restore the contact area.
Another way to faulty restore the contact area is to make excessive contact, u can know it by also using the floss it won’t be able to be inserted and if u managed to do so it will tear.
Do u think this is possible ( to make excessive contact area)?
Yea, because teeth are movable in their sockets, they are fixed by the flexible periodontal ligament , so if u over separate the tooth using the wedge then u will over do the contact area
So the contact area shouldn’t be nighters tight nor loose ,it should be adequate .
4. Marginal integrity
Should blend with the adjacent enamel so that the margins are undetectable to the tip of an explorer passed over the surface of the enamel and restoration . when u pass the probe over the margin if it’s tip sinks then u have a compromised margin and u have to repeat it ( this is called open margin) because the purpose of ur filling is to seal the cavity so there shouldn’t be any space between the cavity and the filling! Because inadequate seal will lead to recurrent caries and failure of ur restoration.
also No overhang should be tolerated at the gingival margin, over hang can result from improper use of the matrix band or not using the wedge , overhang area can result in plaque retention and accelerates the growth of microbes which will lead to periodontal disease
5. Occlusion
put an articulating paper between the patient’s teeth and ask him to tap gently then areas of contact will be marked.
Now if ur filling was high u will see marks on the filling, or there might be marks on other teeth but the intensity of the marks on the filling is much more, this means that there is heavier contact on the filling and u have to reduce it .
If u got diffuse marks all over and equally distributed this means that u have a good occlusion & nothing is wrong.
If all the teeth are marked except the filling this means that it’s low and out of occlusion and it should be repeated.
Some people say that the articulating paper itself is not accurate because it’s thick so there might be no contact and even though there is a mark on the tooth, so scientist made something better called shim stock which is a paper made out of a very thin metal, it doesn’t mark the tooth.
This is the way how to use it:
put it between the teeth and ask the patient to close then u try to pull it outward, if it pulls then there is no occlusion!, but if it stuck then there is occlusion.
Shim stock is used more with crown restoration than in fillings because crowns don’t get marked probably by the articulating paper and also crowns are permanent restoration and cannot be easily changed as fillings.
so check the tooth where ur restoration is, then check adjacent teeth, then check the contra-lateral side, if there is any disocclusion anywhere then u have a problem,, disocclusion on the contra-lateral side might means that ur restoration is high.

6. Consistency
The polished surface should be free of grooves, scratches, pits, gross ,irregularities and smooth with a high metallic luster visible in accessible areas.
Nowadays polishing of amalgam is not much preferable and done as in the past, because in the past they used low cupper amalgam which undergoes corrosion and attrition much faster than high cupper amalgam, so polishing used to enhance the physical properties of low cupper amalgam, but now we use high cupper amalgam and it doesn’t need to be polished, polishing is not preferable these days also because it will result in a very shiny restoration which will compromise esthetics.
Now look at the picture in page number 4 in the handout, some dentists when they are trying to curve the filling they make grooves in attempt to restore the natural look of the tooth, but the polished surface should be free of these grooves & pits & any irregularities because they will accumulate food and microbes …. , u shouldn’t do groove what u should do is a smooth depression and then you’ll get the natural anatomy of the tooth
7. Postoperative cleaning (waste management):
The oral cavity should be free of all restorative material particles and other debris.
u should clean around the tooth there shouldn’t be any amalgam in the gingival sulcus or anywhere in the oral cavity after finishing ur restoration.

Composite restoration
1. Anatomical form
The restoration should be continuous with the tooth’s anatomy, same as in amalgam
2. Shade “ color” match
Color should blend with the tooth restored and adjacent teeth, good color match renders the restoration almost invisible.
Shade matching is a whole science, and it’s very important for anterior esthetic areas.


3. Contour
It should conform closely to the original contour of the proximal surface. It will be influenced by the contour of the matrix,,, same as amalgam.
4. Marginal adaptation or integrity
Marginal integrity in composite restoration is not easily gained as in amalgam due to the polymerization shrinkage of composite, improper bonding and beveling can lead to a failure in the margins of ur restoration this failure can range from only staining to a micro-leakage that can proceeds to caries.
5. Surface texture
The surface Should be smooth , dense and free of scratches or porosity ,, same as in amalgam .
What’s important in composite is the sequence of finishing, correct sequence of using finishing burs and discs will guarantee a smooth good restoration, if u skipped one of them u can tell the difference.
6. Contact
It’s harder to make good contact in composite as it in amalgam, and the reason is also polymerization shrinkage, that’s why in composite attempt to over wedge the tooth, to compensate for the shrinkage
Note: the Tofflemire bands we used in the lab are not the best thing there are better ones!
7. Occlusion
During closure, the restoration should not interfere with the occlusion of other teeth.
8. Postoperative cleaning
In composite u should be careful while using the bonding agent, because it’s very flowable and can accumulate in the gingival sulcus and set there easily so u should clean around the tooth also debris from the composite itself can reach adjacent tooth and set there which can interfere with occlusion. (by set I mean chemical setting of the material! )

The last slide in the handout is examples of faulty restorations
The pictures are not clear they are even black so i’ll write what the doctor said about them and try to imagine and if u attended the lecture try to remember.
• There is something wrong with the filling of a central incisor,,, color, texture (not smooth), contour …. All are wrong
• In the lower picture there is fracture and the most common reason for this is not doing proper cavity design and beveling.
• There is a picture where the restoration didn’t restore the anatomical landmarks at all.

Good luck

Done by lama alsayed

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Shadi Jarrar
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عدد المساهمات : 997
النشاط : 12
تاريخ التسجيل : 2009-08-28
العمر : 26
الموقع : Amman-Jordan

http://jude.my-rpg.com

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