2 Placing Amalgam Restorations
Chapter 2:
2.1 Loading the Amalgam Carrier
2.1 Loading the Amalgam Carrier
Review the instruments and handling techniques for safe effective amalgam delivery.
2.2 Amalgam: Fill the Prep
This video demonstrates filling and condensing a class two typodont prep with amalgam. Here a first molar is used but the same technique works for any class 2 restoration.
2.3 #14 MO Amalgam Carving
This video demonstrates the carving of anatomy for a class two typodont prep on a maxillary first molar. It includes techniques for clearing flash, shaping embrasures, and marginal ridge height. Also, there are additional explanations of common anatomy terms and identifies tools used.
2.4 #19 DO Amalgam Carving
This video demonstrates the carving of anatomy for a class two typodont prep on a mandibular first molar. It includes techniques for clearing flash, shaping embrasures, and marginal ridge height. Also, there are additional explanations of common anatomy terms and identifies tools used.
2.5 Transcripts
Video Transcript: 2.1 Loading the Amalgam Container
Your amalgam carrier will safely carry workable bits of amalgam from your work area to the prep.
Carriers come in different sizes, often with a small and large carrier on one handle.
Depressing the lever ejects a preloaded pellet from the carrier on command so i’t important to stabilize the lever while loading the carrier.
Press the head of the carrier against the amalgam well, taking little bites of fresh amalgam to fill the carrier.
The carrier should be full and flush, not overfilled.
Video Transcript: 2.2 Amalgam: Fill the Prep
Before you begin, examine the prep noting the varying shapes and location of landmarks. Some of this will be hard to see when the band is on.
Now take a look at your amalgam carrier and plugger. They have two ends. One is large and the other smaller. Check to see which end of the plugger and carrier fits inside the prep.
Load the amalgam carrier and place amalgam in the deepest part of the prep. This is called the box.
Do not put more amalgam in the prep than you can properly condense at one time.
Tack the amalgam in with the largest end on the plugger tat will fit using light pressure.
Making sure to completely fill every corner and level the amalgam. Angle the condenser toward the matrix band and all corners of the box ensuring full coverage. This will eliminate open margins in your final restoration.
To condense the amalgam use more pressure and “walk” the plugger using overlapping steeps. Like tamping out a fire with your feet. Wouldn’t want to miss a spot!
When you have the right pressure you will hear a squeaking sound. It sounds like this:
Not using enough pressure when condensing leaves a weak restoration resulting in flaking when carving and marginal ridge fracture when removing the band, a minor tragedy for sure.
If you have a large surface to cover use the larger end of the amalgam carrier use it and move the head of the carrier around. It’s easier and more efficient.
Continue layering and condensing amalgam. Overfill the prep but not so much that you can’t find the margins again.
Most condensing is done parallel to the long axis of the tooth, however the last layer is condensed perpendicular to the enamel surface, aiming the condenser and compressing amalgam against the margins.
After the prep is full and condensed burnish with an acorn.
At this stage the amalgam should be very pliable like the consistency of room temperature butter. Burnishing is a delicate gesture. Use very light pressure, like buttering a piece of toast.
One or two passes is all it takes to remove excess material, exposing the margins, and bring up the shiny mercury rich layer.
Now you have a blank canvas and you’re ready to carve.
Video Transcript: 2.3 #14 MO Amalgam Carving
Before beginning, imagine the finished product. If you can’t remember the defining features, review the anatomy.
Clear excess amalgam and locate the margins of your prep. A Beavertail works well for laying placemarkers for major groves. Lay the bevertail with the face 90degrees or perpendicular to the enamel surface everywhere except the marginal ridge.
Leave carving the transverse and marginal ridge until the end so not to overcarve while the amalgam is soft.
Lay the blade in the major groves and define them. This serves as a quick sketch to guide more detailed work.
Using the cleoid end of the discoid-cleoid begin to define the distal pit with a rotating motion like scooping ice cream.
Rest the cleoid along the edge of the prep, not freehand, and move with long fluid strokes careful not to carve beyond the central grove.
Major landmarks are refined by taking repeated strokes and removing small amounts of amalgam.
Leave the marginal ridge high but begin to shape the occlusal embrasure imagining where the contact will be.
Remember to face the blade of the cleoid perpendicular to the enamel. This will look as if it is facing down when carving down a cusp slope and facing you when carving up .
When the amalgam is more solid, but not set, connect the mesial and distal pits by continuing the central grove over the transverse ridge.
For this, freehand the cleoid with little pressure and slightly off parallel to the long axis of the tooth.
What you do from one side is repeated on the other.
Remove the band before the amalgam sets. Place a finger over the band and rotate it up and out of the contact gently.
A ball burnisher can support the ridge too.
Now it’s time to shape the embrasure. Using a quade or greg remove excess amalgam from the buccal, lingual, and occlusal surfaces toward the contact removing flash and rounding the material.
Using light pressure mark the height of the marginal ridge using the adjacent tooth as a guide and begin to remove amalgam rounding off any sharp edges.
Continue defining grooves, pits and removing flash. Adjusting, checking from multiple angles and re-adjusting are just part of the process.
Note some strokes are long and others use a scoping motion.
Following short strokes with long strokes makes a smooth shiny restoration.
Keep the restoration clean. It’s easier to do a good job when you can see what you’re doing.
Check that the contact is not too tight or loose and adjust as needed.
In the final restoration note the transverse ridge is slightly higher and the central grove runs up and over it. This is a critical detail of the 1st maxillary molar.
After a final check for flash and occlusion with articulating paper your amalgam is done.
Video Transcript: 2.4 #19 DO Amalgam Carving
Before beginning, imagine the finished product and begin with the end in mind.
First expose the margins of the prep using the bevertail.
Leave the marginal ridge while the amalgam is still soft. It’s easy to overcarve.
Mark the location of major grooves by resting the bevertail on the enamel surface and moving it in a scooping motion. These placemarkers are shallow and can be changed later so see if you like their location.
Keep the restoration clean. It’s easier to do a good job when you can see what you’re doing.
Clear the occlusal embrasure with a shallow sweep of the explorer.
Use the cleoid to further define the location of buccal and lingual groves resting on enamel and making the marks shallow. Remember to keep the face of the instrument perpendicular to the enamel surface.
To begin carving in earnest, angle the point of the cleoid slightly more apical as you remove amalgam to shape the top third of the cusp slope. (1m 38s)
Continue to define the groves by slowly angling the pointed end of the cleoid more apical with each stroke. You might notice defining the grooves also shapes the cusp slope which is a slightly curved line, almost like the back of a spoon, from tip to grove.
Begin to make the distal pit and fossa.
Carve only on the buccal or lingual of the central grove.
Carefully remove the tofflemire, wedge, and band using a finger to support the delicate marginal ridge.
Using a quade or greg shape the buccal-lingual curve of the occlusal embrasure and set the height of the marginal ridge even with it’s neighbor.
Then shape the distal curve of the occlusal embrasure. The finished product will curve from the occlusal embrasure into the distal pit resembling a curling wave.
The marginal ridge may also have a slight v shape where the lingual and buccal cusps meet when viewed from distal to mesial.
Check for and clear flash in the gingival embrasure with a quade or montana jack.
Before the amalgam sets, refine details with long strokes to create a smooth shiny surface.
Check for flash, tightness of the contact,
And the occlusion.
Note the slight W shape of the central grove. This is a defining feature of the 1st mandibular molar. …and now your amalgam is done.