Impressions - FAQs – ProMonitoring

Why doesn't ProMonitoring accept alginate material for impressions?

Alginate material is prone to drying out, and can shrink or expand based on environmental factors. This variability can cause the final aligners to be too large or too small, affecting their fit.

Why do you need both arch impressions or scans even for a single-arch case?

Both arches are needed for several reasons:

To understand the positioning of the opposing teeth to avoid inter-arch collision or hyper-occlusion during teeth movement.
To accurately adjust overjet, overbite, midlines, and relationships between canines, premolars, and molars, the opposing arch is necessary to set up the correct alignments.
A passive aligner will be created for the opposite arch in single-arch treatment.
- These passive aligners will cover any permanent retainers on the untreated arch.

How does the impression tray size and material affect the fit of the aligners?

Using an incorrectly sized tray can lead to various issues:

A small tray might not capture all teeth, particularly the molars, which could result in a distorted tooth shape and arch form.
A large tray might spread the impression material too thinly, making it difficult to capture full gingival margins.
Errors like using too much light-body material, too little overall material, or omitting light-body material can reduce impression accuracy, leading to voids, thin walls, and other issues affecting aligner fit.

Why can't we send stone models?

Stone models often do not withstand the shipping process, with common issues like chipping, especially along the cusps and incisal edges. Even minor damage can impact the fit of the aligners. Additionally, the quality of stone models can vary, and issues such as air bubbles might compromise the scan, leaving uncertainties about the tooth's actual shape.

Why aren't physical bite registrations required for PVS impressions?

We verify occlusion accuracy using the photos you provide. When using PVS impressions, please ensure you submit high quality photos accurately depicting the bite.

When taking impressions, I have difficulty capturing the distal of the last molars. Do you have any suggestions?

Capturing the distal aspect of the last molars can be challenging. Here are a few tips to improve your impressions:

Ensure the tray size is correct—it should extend past the last tooth in the arch without pressing against the gums.
Before inserting the tray, apply some light body directly to the occlusal and distal surfaces of the last molar to ensure complete coverage with the impression material.

We can only use impressions of the upper and lower arches.

Any other impressions are discarded.