MIND THE GAP (Ortho-Resto) with AC Aligners

Space Measurement at a Root Level

Dental implants require a minimum of 5.5mm of space. This minimum is determined by the smallest dental implant diameter of 2.9mm, a minimum of 1.0mm of space required between the implant and the adjacent tooth to allow stable osseointegration, and the additional factor of 11% root relapse following orthodontics, which increases the total minimum space requirement to 5.5mm.

We're all familiar with the case. A patient presents with a gap and wants it closed, a crown, bridge or implant, but the space just isn't enough. The gap is too narrow for a properly proportioned tooth.

Sometimes, the neighbouring teeth have drifted and tipped. In other cases, the opposing tooth has over-erupted and taken up the occlusal space we need.

You can still make something fit, but “fit” isn't the same as “beautiful”. You end up with a lateral that looks like a central's little brother, a pre-molar crown as thin as a wafer, or an implant squeezed in so tightly there's no room for healthy gum between it and the next tooth.

After more than 40 years at the bench, I can tell you this: the best restorations start with the right space. These days, creating that space is often easier, quicker and less invasive than people think.

“Ortho-resto” simply means using a short course of orthodontics to move the teeth into the best position before restoring them. It isn't full-blown orthodontic treatment, and the aim isn't a Hollywood smile. It's a targeted few millimetres of movement so that the restoration can be the right size, the right shape and in the right place.

With clear aligners, many of these cases now need only 3 to 6 months. The patient barely notices them, while the dentist ends up with a far better foundation to work on.

Making Room for an Implant

An implant needs space, not just at the crown but between the roots.

As a general guide, you want 1–1.5mm of bone between an implant and the natural root next to it, and around 3mm between two implants. When neighbouring teeth have tipped into the gap, their roots can block the way even when the crowns look far enough apart.

Aligners can upright those teeth and open the space. The surgeon then has room to work, and the gum has room to do its job. This brings us to the Tarnow principle.

Every dentist knows the dreaded “black triangle”, that dark gap between two teeth where the gum, or papilla, should be. Once it's there, it's very hard to hide, however good the crown is.

In 1992, Dr Dennis Tarnow and his colleagues demonstrated something every restorative team should keep in mind. If the contact point between two teeth is 5mm or less above the crest of the bone, the papilla fills the space almost every time. At 6mm, it fills only about half the time. At 7mm, barely a quarter.

That is the Tarnow principle, and it tells us two things.

First, the contact point has to be in the right place. We can only achieve that if the space allows a properly shaped tooth. A natural-looking crown has its contact where nature would put it, close enough to the bone for the papilla to fill in.

Second, forcing a tooth into a gap that's too small works against you. When the space is too narrow, we're forced to make the crown long and thin or taper it at the neck to fit. This pushes the contact point upwards, away from the bone, leaving the papilla without the support it needs.

Squeeze an implant into a restricted space, and the bone between the implant and its neighbour can be lost altogether. Lose the bone and you lose the papilla, usually for good.

A cramped space doesn't just result in an unnatural-looking tooth. It can cost the patient their gum as well.

Opening the space with aligners first allows us to design a tooth with natural proportions, position the contact point correctly and maintain healthy bone either side. The papilla then has everything it needs to fill the gap.

Every technician knows the feeling of opening a case and realising that the available space has already influenced the outcome before we've even started. Proportion, emergence profile, embrasures and gum health all depend on it.

A few months of planning at the beginning can save a lifetime of compromise at the end.

The real secret of Ortho-Resto is reverse planning. Decide what the final restoration should look like first, then work out where the teeth need to be to make it happen.

That's where we come in. With a digital diagnostic wax-up, we can show you and your patient the intended finished result before a single tooth moves. We can then plan the aligner movements to create exactly the space that design needs, no more and no less.

Your patient sees where they're heading, you know exactly what you're aiming for, and we know precisely what we'll be making at the end.

Everybody is working from the same blueprint.

AC Aligners brings the orthodontic and restorative sides of a case together under one roof. Your aligner set-up and final restoration are planned together from day one by people who understand both.

You don't have to coordinate two different suppliers, and you're not left hoping that the space created will suit the tooth that's going into it.

Whether it's a single implant site, a pair of lateral veneers or a full smile makeover, we'd be delighted to help you plan it.

Call the lab on 01765 607347 or send us your scans through your usual scanner portal, and let's talk about your next ortho-resto case.

Mark Ambridge CDT RCSed

Founder, Ambridge Ceramics

Leading Ambridge Ceramics with over four decades of bench craftsmanship, pioneering digital workflows, custom dental appliances, and clinician-led clear aligner solutions across the UK.

01765 607347

info@ambridgeceramics.co.uk

Ripon, North Yorkshire, UK