Fixed prosthodontics involves many crucial stages, but one stage stands out as the most critical of all – your personal “quality assurance” checkpoint. This stage is none other than the “Try-in” appointment, or the “fitting of the restoration.”
This isn’t just a quick rehearsal before final cementation. It’s your last chance to spot any issue, no matter how minor, before you permanently seal it with permanent cement. Most complaints we hear post-cementation—like “food gets stuck,” “there’s a bad odor,” or “the bite feels off”—actually stem from rushing through the try-in appointment.
In this article, we’re going to meticulously break down this vital appointment piece by piece. We’ll guide you, step-by-step, on how to thoroughly inspect the restoration from the moment it arrives from the lab until you are 100% confident it’s ready for final cementation.
Phase One: Evaluating the Restoration on the Cast (Before the Patient Even Opens Their Mouth)
Before you even consider placing the restoration in the patient’s mouth, you absolutely must first examine it on the accompanying cast. This stage alone can proactively uncover ninety percent of major lab-related issues.
Examine these five critical points, in order:
1. Proximal Contact
What to Look For: The contact point between your restoration and the adjacent teeth should ideally be a single, precise point, not an entire surface. It needs to be firm and properly closed, but without being excessively tight or “jammed.”
How to Check: Take a piece of dental floss and carefully try to pass it between the restoration and the adjacent tooth on the cast.
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The Ideal: The floss should pass through with slight resistance and a gentle “snap.”
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Red Flags: If the floss doesn’t pass at all or shreds, the contact is too tight. If it slides through with no resistance whatsoever, the contact is open.
2. Margins
What to Look For: The Crown or Bridge Margins must completely seal onto the Preparation Margins on the cast. There should be absolutely no gaps or deficiencies.
How to Check: Use excellent illumination, ideally with loupes. Gently trace the tip of your explorer along the junction where the restoration margin meets the cast. You shouldn’t feel any “ledge” or gap.
3. Occlusion
What to Look For: The restoration needs to occlude perfectly with the Opposing Teeth on the cast, without any High Spots.
How to Check: Carefully articulate the casts together in Central Occlusion. Visually inspect from all angles: Is there any space between the restoration and the opposing teeth? Does the restoration prevent other teeth from occluding properly?
4. Contours
What to Look For: The overall shape and contours of the restoration must appear natural and harmonious. It absolutely shouldn’t be “Bulky” or “over-contoured,” as this inevitably traps food and leads to gingival inflammation.
How to Check: Examine the restoration from all perspectives. Does it have a smooth, anatomical flow? Does it allow for natural Embrasure spaces, vital for gingival health and proper patient cleaning?
5. Esthetics
What to Look For: The shade and form must precisely match your laboratory prescription.
How to Check: Compare the shade against your chosen Shade Guide and confirm that the tooth’s morphology is appropriate.
Golden Tip: If you uncover any significant issues in any of these five steps while evaluating the cast, do not proceed. Send the work back to the lab. If the restoration isn’t correct on the cast, it stands no chance of being correct in the patient’s mouth.
Phase Two: The Real Test – The Intraoral Try-in
Sailed through Phase One? Fantastic! Let’s move on to the actual clinical test.
1. Prepare the Tooth
First and foremost, you need to meticulously clean the prepared tooth. Remove the Temporary Crown and thoroughly clean off any remaining Temporary Cement. A brush and Pumice can be used to ensure the tooth surface is absolutely pristine.
2. Crucial Patient Warning: “Do Not Bite Down!”
This is the most important sentence you must convey to your patient before placing the restoration. Calmly explain: “Please, do not bite or close your teeth down onto this crown at all. I will apply pressure with my finger only.”
Why is this warning so critical? If the crown has a high spot and the patient bites down with full force, they could easily fracture the porcelain, or the crown might “seat” too firmly, making it incredibly difficult to remove later.
3. Finger Pressure Only
Use only your fingers to apply pressure and guide the crown into place. Absolutely avoid using any instrument like a Bite Stick. Your fingers will give you the necessary tactile feedback for seating and will prevent any excessive pressure that could fracture the restoration.
4. Don’t Get Disoriented (Use a Marker)
Sometimes, with posterior crowns, it’s easy to lose track of the correct orientation.
The Solution: Before you even try it in, use a Marker to place a small dot on the Buccal surface of the crown. This will always help you maintain its correct orientation.
Phase Three: Intraoral Adjustments and Evaluation
Now, we’ll repeat those same five steps, but this time, directly in the patient’s mouth. This is where we begin making any necessary adjustments.
1. Proximal Contact
Evaluation: Use Dental Floss in the exact same manner. It must pass with a distinct “snap.”
Issues & Solutions: If the contact is too tight, the patient will likely feel “something stuck between their teeth.” Cementing it like this will almost certainly lead to gingival inflammation and discomfort. If the contact is open, that’s a disaster in the making, as food will invariably get trapped.
The Fix: If the contact is open, the restoration absolutely requires a Remake. If it’s merely too tight, you can cautiously adjust it chairside using Polishing Discs, but always ensure a thorough re-polishing afterward.
2. Margins and Stability
Evaluation: Carefully use your Explorer and trace it along all the Margins of the crown. Do you detect any discernible Open Margin?
Issues & Solutions: The rule of thumb: if the tip of your explorer catches in a gap, it signifies an unacceptable Open Margin, and the restoration must be Remade. Such a gap will collect bacteria, dissolve the cement, and inevitably lead to recurrent decay (1). Apply gentle pressure to the crown from various angles. Do you feel any “rocking” or movement? If so, the work definitely needs a Remake.
3. Occlusion
Evaluation: Use Articulating Paper to precisely identify areas of contact.
Issues & Solutions: If there’s an Under-Occlusion—meaning the crown is “low”—it necessitates a Remake. If there’s an Over-Occlusion—meaning the crown is “high”—this can usually be adjusted chairside. Carefully use Finishing Stones to reduce the high spots until the bite feels comfortable and balanced (2).
Dr. LOD Tip: To proactively avoid occlusal issues, it’s crucial to take an Impression of the original pre-preparation anatomy, or perform an accurate Bite Registration. This provides the lab with a clear, reliable guide to work from.
4. Contours and Esthetics
Evaluation: Observe the crown’s relationship with the gingiva. Is it Bulky, causing pressure on the gums? Assess the shade and form under operatory lighting and, if possible, natural light.
Issues & Solutions: Any excessive contours can be reduced with Finishing Stones and then meticulously polished. If the shade is too light, it might be sent back to the lab for additional Stains. If it’s too dark, it will likely require a Remake.
Conclusion
In summary, the Try-in appointment is your ultimate “quality assurance” session. Never, ever rush through it. Diligently follow these five steps in sequence—first on the cast, then meticulously in the patient’s mouth. If you encounter any significant issue, do not hesitate for a second to send the work back to the lab. Because a minor adjustment sent back to the lab is infinitely preferable to a patient returning repeatedly with complaints and persistent problems.
