Rebuilding a Front Tooth Without Losing the Gum Line

The Patient's Journey

This patient presented with a failing upper front tooth and two teeth that had never developed. The upper right central incisor was being destroyed by internal resorption, a process in which tissue inside the root canal gradually consumes the dentine around it. The tooth had been hollowing from within for some time, and by the point at which it was assessed there was too little sound structure remaining to retain any restoration under normal function. This made extraction unavoidable rather than one option among several.

The lateral incisors on both sides had never formed at all, which is a developmental variation affecting roughly two percent of people. Over the years her canines had drifted forward into those empty spaces and settled there. The arch therefore held the correct number of visible teeth in the wrong positions, with each tooth shaped for a different function than the one it had ended up performing. The resulting asymmetry registers with most observers even when they cannot identify its cause. A canine is longer, more pointed and more prominent than the narrow lateral incisor it had come to replace. Fluorosis staining across several of the remaining teeth completed the presentation.

Treating the urgent problem first and addressing the rest afterwards would have been the conventional sequence. That sequence produces smiles in which every individual restoration is technically competent while the completed rehabilitation still announces itself as dentistry, because the proportions were never established beforehand. The plan was therefore built backwards, beginning with the intended final smile and working back to the first surgical step.

Understanding the Challenge

A dental implant replaces a root. It does not replace the bone and gum tissue that the original root was supporting, and in the upper front that distinction determines the outcome. The plate of bone on the lip side of a front tooth is frequently thinner than one millimetre. It depends on the periodontal ligament for its blood supply. When the entire root is removed the ligament is removed along with it, the buccal bone resorbs over the following months. The gingival tissue covering that bone recedes in proportion to the bone lost beneath it.

The visible consequence is difficult to correct afterwards. The replacement tooth sits higher than its neighbours, appears longer than them, and shows a grey shadow at the margin where tissue has been lost. Bone grafting can rebuild some of what disappeared, but predicting exactly where a grafted gum line will settle in the most visible part of the mouth is not reliable. The clinical question in this case was therefore not how to place an implant. It was how to remove a tooth without losing the tissue surrounding it.

How Dr. Mehdizadeh Approached the Extraction

The approach chosen was partial extraction therapy, a group of techniques that deliberately retain part of the natural root rather than removing all of it. In the socket shield technique described by Gluckman, Salama and Du Toit in 2016, the crown is removed and the root is divided lengthwise. The palatal half is taken out and the facial half is left undisturbed against the inner surface of the bone plate. The implant is then placed behind that retained fragment.

The retained root section keeps its periodontal ligament intact, the buccal bone that ligament supplies retains its blood supply and has no physiological reason to resorb after the restoration is placed. The ridge holds its contour because the structure maintaining that contour was never removed. The technique is unforgiving of imprecision, and it requires the retained fragment to be entirely free of periapical infection before placement is contemplated.

The published evidence for these techniques remains limited. The 2016 review that named them counted six case reports, three case series and two animal histology studies, and its authors stated that more long-term data are needed before the approach is widely adopted. It was selected here for one tooth in one position, where the alternative was accepting visible tissue collapse in the part of the smile that shows most. The implant was placed at the same site during the same procedure, and the surgical stages were carried out under intravenous and oral sedation.

Returning Each Tooth to Its Correct Position

With the implant site healing, the developmental problem could be addressed. Orthodontics could have moved the canines back and reopened the lateral spaces. That is the appropriate treatment for some patients and would have extended treatment by a year or more. The alternative was to reassign each tooth through porcelain, and that is the route taken here.

The canines were rebuilt with the proportions, length and surface form of lateral incisors. The first premolars, which now occupied the canine positions, were rebuilt with the length and contour of canines. Additional veneers brought colour, shape and spacing into agreement across the arch. This resolved the fluorosis staining within the same restorative phase rather than as separate treatment. Nine upper veneers and the implant crown were fabricated together.

Simultaneous fabrication matters considerably. An implant crown made after the veneers are finished must be matched to completed work, and the match is rarely exact. Designed alongside the veneers, the implant crown is developed as one tooth within a single design. The lower teeth were sound and required no restoration, so they were whitened first and allowed to stabilise before the veneer shade was selected. Porcelain does not respond to whitening, so any natural tooth not brought to its final colour beforehand will remain darker than the restorations permanently.

The Result After Six Months

Most of the six months was healing rather than active treatment. The restorative appointments occupied a small portion of that period. The remainder allowed the bone and gingival architecture to stabilise around both the retained root fragment and the osseointegrating implant before any impression was taken.

The gum line at the implant site sits level with its neighbours rather than above them, which was the objective that governed the extraction decision. The fluorosis discoloration has been eliminated across the restored dentition. The lower teeth now match the shade of the upper restorations. The arrangement is now conventional: lateral incisors occupy the lateral positions, canines occupy the canine positions. The implant restoration is indistinguishable from the natural dentition surrounding it. She has lateral incisors, which she was born without.