How Do We Rebuild a Damaged Tooth?

The single most important factor is the ferrule: a collar of sound tooth above the gum, ideally about 1 mm thick and 2 mm high, all the way around. The crown hugs this collar like the metal band on a wooden tool handle, and it is what stops the tooth splitting.

When a tooth has broken to the gum line, there is nothing for the crown to grip. Rather than removing it, the root can be gently extruded with a small orthodontic appliance over a few weeks, bringing healthy tooth up into view. This works as long as enough root remains in the bone: at least as much root as crown, and ideally more.

A root is not solid. It is a slightly flexible tube that thins in places. Put a large, rigid post inside it, under a rigid crown, with no ferrule, and every bite wedges the root from the inside. Over years this fatigue can crack it. Once a crack runs below the bone, the tooth cannot be restored, and the dark shadow it leaves in the bone on an x-ray is often how it is found.

The root canal itself takes very little strength from a tooth. The damage comes from what is cut away, and above all from losing the ridges of tooth along the sides that hold the cusps together.

Front teeth behave the same way. In laboratory studies by Magne and Douglas, each step of tooth removal made the crown of an incisor more flexible, even after it was restored.

In the 1970s it was believed that a post “reinforced” a root-treated tooth. Laboratory work by Guzy and Nicholls in 1979 showed it does not, and clinical studies since have agreed. A post's only job is to hold the core that retains the crown. When one is needed, it is because too little tooth remains to do that job.

Richard Simonsen described how teeth are usually lost: not in one event, but through a cycle of ever larger treatments, each reasonable at the time.

Cast gold has served dentistry for over a century. It is kind to the opposing teeth, seals superbly, and does not depend on bonding. Its drawback is colour, which is why many patients no longer ask for it. On back teeth, and particularly second molars that take the heaviest loads, it remains an outstanding choice.

Bonding needs sound, healthy dentin and a dry field. Traditional restorations are the right choice when:

Classical crowns rely on retention and resistance form: the tooth is shaped with a drill so the crown holds on mechanically. They work, and they still have their place. Bonded restorations are glued to the tooth instead, so far less needs to be removed, and sometimes nothing at all.

The key to a lasting bond is sealing the freshly cut dentin immediately, before impressions are taken, rather than weeks later when the final restoration is fitted. It protects the tooth in between and produces a much stronger, more durable bond.

When the old crown was removed from the incisor below, very little tooth remained. Traditionally this tooth would have needed a root canal, a rigid post, a crown and possibly crown lengthening surgery. Using immediate dentin sealing and a bonded porcelain restoration, none of that was needed. It was placed by Dr. Reshad over twenty years ago and is still in place.

With almost nothing left of the molar below, the usual plan would be a post and crown, or extraction and an implant. After immediate dentin sealing, the overlay was bonded with warmed composite, vibrated into place, forming a thick, durable resin seal.

Both are excellent, and both can break. What matters is how they break. In fatigue testing on root-treated molars with a 3 mm overlay and no post, failures stayed within the restoration and the dentin seal held. A broken overlay can be replaced; the tooth underneath survives.

Glass-fibre posts are tooth-coloured, translucent and bonded in place. They flex much like dentin, so stress is shared rather than concentrated in the root, and they transmit light beautifully. Where the destruction is not extreme, they are the preferred choice for front teeth. Cast posts still have their place when very little tooth remains.

Understanding materials and light lets bonded restorations sit alongside implants and natural teeth invisibly, even in the most demanding smiles.

Each study reports survival for its own patients, materials and length of follow-up, so the charts below compare trends rather than single numbers. Traditional gold, metal and crowns sit beside bonded and fibre-post restorations; back teeth are then set head to head.

Because Dr. Reshad practises both approaches every week, he has no reason to favour one. The traditional reconstruction and the bonded restoration are both tools; the right one depends on how much tooth is left, the quality of what remains, where the margins sit, your decay risk and, above all, your bite.

The bite is the most destructive force a restoration will face. Beautiful work that is not protected from it will not stay beautiful. Managing the bite, and fitting a night guard where there is grinding, is what keeps a result looking and working as it did on the day it was placed.