cons sheet # 2-Salah Da7bor

Field isolation for restorative dentistry

We have to isolate the field we are working with for three main goals:
1- Moister control.
2- Retraction and access.
3- Harm prevention.

Moisture control:
• We have to obtain a clean and dry field for our operative procedure.
• Moisture can come from saliva, gingival bleeding (trauma, gingivitis) and different kinds of fluids.
• We should also prevent any hand piece spray or restorative debris to be aspirated or swallowed by the patient, and this prevention is also considered with moisture control.
• As we know, when we work with high speed instruments, the hand piece will spray lots of water and with time this water will accumulate in the patient’s mouth, and it’s not convenient to make the patient to keep on spitting it or to let him swallow it, so we should control this kind of moisture.

Retraction and access:
As we all know, inside the oral cavity aren’t only teeth, but also the tongue, cheeks, lips, and also soft tissue (the gingival), and all of these should be retracted to gain accessibility.

Harm prevention:
• We should prevent any harm to the patient from any instrument or restorative debris we use, by preventing the patient from swallowing or aspirating anything from the operative field.
• Swallowing something from the field is not as bad as aspirating it, because aspirating something from the field will go to the lung, and the only way to remove it from there is by surgery, so be careful.
• We should also prevent any soft tissue accidental injury by the burs or anything else, and as the doctor said it does happen a lot, suddenly the field will be flooded with blood, without knowing the source, again be careful.
• Harm prevention will lead to comfort of the patient, and the patient can trust u more, so you’ll be a better dentist in the patient’s eye.


Advantages of having dry and clean field:
• When we retract the soft tissue we will get better accessibility and visibility of the operative field.
• We will also improve the properties of the dental materials by isolation, and by improving the properties we mean optimizing the properties of the dental materials (the reaction of the material will react as it’s supposed to).
• And by isolating the field, we will protect the patient (as I said before), and we also protect the operator him self by maximizing infection control, because by isolation of the field we prevent blood or saliva contact with the operator, thus minimizing infection.
• Also another advantage is operation efficiency, by optimizing material properties as I said before, and minimizing side talk with the patient that sometimes can be annoying.


-All these advantages mainly apply to something we call a rubber dam isolation.
-We will concentrate on the rubber dam isolation because it’s mainly the best isolation method.
-There are also other different methods for isolation that can achieve the same results as the rubber dam isolation.

Disadvantages of isolation:
• Time consuming, but it really doesn’t consume that much time if u know how to organize your time, like after applying the anesthesia it will take several minutes to work, during this time you can apply the rubber dam isolation or any other method of isolation.
• It might be patient objectionable, but recently patients prefer it.


Rubber dam isolation:
• Really old method, since (1864).
• It is used to define the operative field by isolating one tooth or more from the oral environment.
• It is the ideal way for isolating.
Materials used with rubber dam isolation:
1- Plastic sheet.
• Has different colors (purple, green, and blue), dark colors are preferred to improve the contrast, because they are less light reflectors.
• Some are sterile and others are not, the sterile ones come in individual packs, while the non-sterile ones come all in one pack.
• There are also different sizes, 5X5, used for primary teeth, and 6X6, used for permanent teeth.
• They also have different thicknesses, thin, medium, and heavy. The thin ones are easier for gliding in contact areas, but also easily tear, while the thick ones result in more retraction of the gingival tissue, and they do not tear as fast as the thin ones.
• Some are latex free, and others are not, latex is the powder on your hands after wearing gloves.
• For restorative dentistry we mostly use 6X6, dark color, and heavy rubber dams.
2- Rubber holders or frames.
• It is something just to maintain the rubber dam in position.
• It may be metal or plastic, metal frames are positioned over the dam, to minimize contact of the metal with the patient’s face, on the other hand, we place the plastic frames under the dam.
3- Retainers or clamps.
• It looks like a ring around the tooth, and it’s commonly called a clamp, but some textbooks refer to it as a retainer because it retains the rubber dam on the tooth, so it is used to anchor the dam to the most posterior tooth for isolation.
• It is also used to retract the gingival tissue.
• It consists of, 4 prompts, 2 jaws, and a bow.
• It is positioned toward the faciolingual side, not the mesiodestal side of the tooth.
• Each prompt should have one contact point. And mentioned before, we have 4 prompts, 2 on the facial side and 2 on the lingual side. It is important that each prompt should have only one contact point with the tooth to stabilize the clamp in position, otherwise it will be moving, and that will affect the isolation.
• The jaws should also be positioned on the facial and lingual side, but they should not be extending beyond the line angle of the tooth, if it does we will face problems like difficulty in placing a matrix band and a wedge, it may also be harmful to the gingival tissue, and it will affect the isolation.
• There are also 2 holes on the jaws to hold the clamp and open the jaws to place the clamp on the tooth.
• Clamps have different shapes, anterior clamps are different from posterior clamps, some clamps are with wings (winged-clamps) others are wingless.
• The difference between winged-clamps and wingless clamps is that the winged-clamps can carry the rubber dam before applying it on the tooth, while the wingless one can’t, so you have to apply the wingless clamp on the tooth first, then you apply the rubber dam over it.
• For restorative dentistry we usually use wingless clamps, while winged-clamps are mostly used with endodontic treatments.
• Clamps have different numbers, but we usually name them by the name of the tooth we are going to apply it on (e.g. molar clamp, premolar clamp, etc…).
• Clamps for anterior teeth are called anterior tooth clamps, we can also call them by their number (212).
• The difference between molar clamps and premolar clamps is only the size (the molar clamps being bigger), on the other hand anterior clamps have completely different shapes from the molar ones.
• We usually tie the clamp with floss (floss ligature), because sometimes the clamp breaks, so in order to prevent the patient from swallowing it, we just pull the floss it was tied to.
• The ideal method for tying the clamp with the floss is passing the floss through the two holes on the jaws and rapping it around the bow of the clamp.
• The clamp is usually positioned occlusally and distally to the tooth it’s applied on, because if it was on the mesial side the operator won’t be able to see the tooth he is operating on.
• We use a retainer forceps to carry the clamp and place it on the tooth and for removing it from the tooth.
Applying the rubber dam:
• Obviously, to apply the rubber dam on a tooth there should be a hole on the dam for the tooth to go through. We make these holes by something (a tool) called a punch, it consists of a rotating disc on one side with different sizes of holes on that disc, and a sharp plunger on the other side to punch the dam with the needed size on the disc.
• Sometimes we place some kind of napkin under the rubber dam, because some patients complain from the rubbery feeling of the dam, so the napkin can help comfort the patient, it can also help in absorbing the moisture.
• We should also use a water base lubricant on the dam, to help in placing the dam on the tooth, especially in gliding the dam underneath the contact area.
• Never use other kinds of lubricants (water insoluble) other than water base lubricants, because the lubricant we use should be easily washed away, and it should not interact with the bonding of the composite to the tooth structure when using composite restorative materials, and only water base lubricants have these two properties.
• Sometimes, we use modeling compounds (a green stick for example) especially in class five cavities, between the clamp and the tooth, to help stable the clamp on the tooth.
• Dental floss is also used to help in gliding the dam in the contact areas.
• For anterior teeth isolation, we usually isolate the teeth from the canine to the other canine, or from one first pre molar to the other, we also don’t need clamps or retainers because the contact areas are enough to hold the dam in position.
• Punching the rubber dam depends on the number of teeth being isolated, and to know where to punch it, we may use some templates to help locate the position of the hole on the dam. By time, locating the holes position will become easier.
• Punching the dam also depends on the size and the shape of the patients arch, malocclusion should also be taken into consideration.
• There are some guidelines we can use to help in positioning the holes on the dam, for the upper arch (isolation of the upper arch) we puncture the upper middle part of the dam, and for the lower arch we puncture the lower middle part of the dam, so don’t puncture on the sides of the dam. That might cause exposure of the oral cavity.
• For occlusal cavities (class one cavity) it is enough to isolate one tooth just to gain access and visibility.
• For proximal cavities (class two or three) more than one tooth should be isolated, for example, class two for posterior teeth. It is sometimes needed to isolate the whole quadrant plus the central and lateral incisors of the contra lateral side. This way of isolation grants the accessibility and visibility to the operative field. Remember: the clamp should be positioned on the most posterior tooth.
• Note: the holes on the winged-clamps after applying the rubber dam will expose the oral cavity, so we should release the wings to cover the holes, and by that, the oral cavity will no longer be exposed.
• Releasing the wings: as we know winged-clamps can carry the dam before applying it, so the dam will be over the clamp after applying it, so we push the dam through the holes with a blunt instrument under the clamp. And that’s how we release the wings.
• For class five isolation, the holes on the dam should be a little facial to the position where the original holes should be. So that after applying the dam we can reach the gingival border because as we know, class five caries can sometimes reach sub-gingival.
Inverting the rubber dam:
When we first apply the rubber dam, the edges of the dam will be facing the occlusal side of the tooth, and any positive pressure from the saliva or the tongue will force fluids out of the dam to the operative field. To prevent this from happening we invert the edge of the dam to the apical side and by that any positive force will have no effect on the dam, and fluids will remain under the dam.

Removing the rubber dam:
To remove the dam we should stretch it facially and cut all the inter-proximal areas. After that, we take it out of the patient’s mouth and make sure it is completely out, because if any part of the dam was left in the mouth it might cause gingival inflammation.


Errors in application and removal of the rubber dam:
• In some cases using a rubber dam might be difficult or even impossible as in third molar isolation. In partially erupted teeth, applying a rubber dam is also difficult; in this case we should push the clamp more gingivally to expose the gingival part of the tooth.
Also, in patients with super malocclusion it’s probably impossible to apply a rubber dam.
• The rubber dam should always be positioned in the center of the arch; otherwise some part of the oral cavity will be exposed.
• Placing the holes on the rubber dam in their wrong position may also cause a problem, placing them too close might ease the tearing of the dam while stretching it, placing them too far will make it hard to glide the dam in the contact areas.
• Also, retainers may also be the problem, especially if they were too big or small and that will make them unstable.


Other methods of isolation:
1- Cotton rolls and cellulose wafers:
• They are used to absorb the moisture.
• Placing cotton rolls with the anesthesia will help absorb the saliva.
• Anesthesia is not only used to reduce the pain but also to control the secretion of the saliva.
• They should be removed after saturation with fluids.
• For example working on a mandibular left quadrant, we apply one (cotton roll) in the lingual sulcus, and an other one in the buccal sulcus, the one in the lingual sulcus should be applied with rotational movement to insure it’s located under the tongue. We also apply one in the opposing upper sulcus; in order to block the parotid duct.
• There are also some new modified cellulose wafers that are triangular in shape, and are placed on the posterior part of the inner cheek to absorb any moisture.
2- Throat shields:
• They are a 2X2 (inch) gauze placed against the throat of the patient to prevent any small object used by the operator to be swallowed by the patient.
• These shields are really important, so make sure to use them.
3- High volume evacuators and saliva ejectors:
• The high volume evacuators are preferred over the saliva ejectors.
• Saliva ejectors are easily used, but the high volume evacuators can remove saliva (fluids), and solid objects.
• There are some brand names for saliva ejectors like svedopter, which has a blade like tip, and positioned on the lingual side of the teeth. The blade tip also acts as a mirror to reflect the lingual aspect of the teeth. It sucks the saliva and retracts the tongue, and on the other end of it is a metal clamp-like structure to anchor it in position.
• Another brand is hygoformic saliva ejector it’s a normal suction machine that also retracts the tongue.

4- Retraction cords:
• Used to retract the gingival tissue.
• They are placed in-between the gingival tissue and the tooth to reach the sub gingival area.
5- Mouth props:
• Also used to help in retraction, accessibility, and to maintain the moth open.
• They are place between occlusal surfaces of the teeth.
• They are mostly used when the period of treatment is long.
• There are two types of mouth props, block type and ratchet type.
6- Cheek retractors:
• Used to retract the cheeks and lips.
• Mostly used when we are working on anterior teeth fillings.
7- Drugs:
• Last choice of isolation.
• Most common drug is atropine.
8- Isolite system:
• Consists of high volume suction, bite block (placed on the other side we are working on), light, and a plastic thing that goes around the area we are working on to isolate it.







Done by: Salaheddin Said Dahbour