Putting in the hard graft

Soft tissue grafting – a guide for the general practitioner by Dr Paul Quinlan

The gingival tissues surrounding a tooth are intrinsic to the health of a tooth and the success of a restoration placed upon that tooth. Examination of pocket depths is important but not the only element for evaluation of the health and adequacy of gingival tissues.

Of importance are the soft tissue morphotype and the volume of tissue surrounding a tooth or covering an edentulous ridge. These elements are often just as important for the health of a tooth or the aesthetics of a final restoration as caries status or pocket depths. Neglecting these tissues in an examination and treatment plan may lead to a suboptimal treatment outcome.

Common problems detected around teeth and edentulous areas include lack of keratinised tissue, thin tissue, recession and inadequate tissue volume.

A variety of procedures exist to correct these mucogingival problems. The purpose of this article is to review the application of two of the most commonly performed mucogingival surgical procedures: the free gingival graft and the connective tissue graft.

The free gingival graft

This is a very predictable procedure, primarily used to augment the keratinised tissue around teeth and implants.

Controversy exists in the dental scientific literature regarding the necessity for a band of keratinised tissue around teeth and implants. It is the author’s opinion that, while a keratinised tissue deficiency can be maintained with exquisite plaque control, long-term stability and maintenance are best served with a band of keratinised tissue.

Figure 1 illustrates a mandibular left central incisor lacking keratinized tissue with a high frenal attachment in a patient with an otherwise reasonable standard of oral hygiene. The patient presented complaining of discomfort, bleeding and recession from this area.

The area was debrided and oral hygiene reinforced. The tooth was monitored over a six-month period. Despite maintaining a generally high standard of oral hygiene the patient was unable to maintain this area and recession progressed on both central incisors.

The free gingival graft procedure involves the placement of tissue harvested from the palate and transplanted to the area of deficient tissue. The graft consists of epithelial and connective tissues

1-1.5mm thick. Harvesting of the graft results in the presence of an open wound on the palate that heals by secondary intention healing. Figure 2 illustrates the outline incisions on the palate for a free gingival graft prior to harvesting and removal.

Free gingival grafts are usually indicated in areas were keratinised tissue is deficient and progressive recession has been noted. In some instances the patient presents complaining of discomfort from the area. Figure 3 demonstrates an area that on initial presentation was deficient in keratinised tissue and the patient reported was uncomfortable. Figure 4 demonstrates the area after graft placement with an increased band of keratinised tissue; the patient reported that the area was no longer uncomfortable.

Other areas where free gingival grafts may be considered are where restorative margins are placed at or below the gingival margin. A free gingival graft placed in an area

prior to crown preparation and placement increases the ease and accuracy of impression making and reduces the risk of gingival recession post crown placement.

Figure 5 illustrates three provisional restorations. Lack of keratinised tissue, especially on the second premolar tooth, may make impression making more challenging and increase the risk of recession after crown placement.

Free gingival grafts can also be placed during implant treatment. The presence of a band of keratinised tissue around the margin of an implant abutment can allow for easier maintenance and result in greater stability of the implant-soft tissue interface. The area in figure 6 was treatment planned for placement of three implants. Keratinised tissue present at the crest of the residual ridge was deemed inadequate and the area treatment planned for a free gingival graft at the time of implant placement. Figure 7 illustrates the final restoration and healed free gingival graft.

The free gingival graft has a number of limitations. The nature of the wound created in the palate, as a result of graft harvesting, can be uncomfortable in the post-operative period. Adequate pain control medication and coverage of the wound are necessary to control this problem.

A colour disharmony can occur due to the difference in colour of the palatal and gingival tissues, with the result that the grafted tissues can be noticeably different from the surrounding recipient tissues. This problem can be reduced with proper surgical technique but patients should be counselled about this colour difference.

The connective tissue graft The connective tissue graft involves harvesting connective tissue from the palate. The overlying tissues are retained and an open wound, as seen with the free gingival graft, is avoided. Figure 8 illustrates the appearance of a donor site after graft harvesting. When the graft is placed at the recipient site it is usually covered by the tissues at this site and results in thicker tissue that is identical in colour to the surrounding tissues.

A primary indication for a connective tissue graft is the exposed root surface. The placement of the connective tissue graft can result in complete root coverage and a return to normal soft tissue anatomy, which can be maintained over long periods. Patients should be monitored to ensure their brushing techniques are atraumatic and plaque control optimal. Figures 9 and 10 illustrate anterior maxillary teeth that had experienced gingival recession and the coverage achieved after connective tissue graft placement.

In areas where crowns are to be placed, the placement of a connective tissue graft prior to crown placement will normally result in a thicker tissue that may be more resistant to recession. This is especially true for crowns that are being replaced due to the visibility of dark roots above the gingival margin. In these areas if thin tissue is present and not treated, it is possible that a short time after the new crowns are placed, the gingival tissues may recede and the dark roots becomes reposed. Figure 11 illustrates a patient who presented requesting new crowns. The treatment plan included placement of connective tissue grafts to thicken the gingival tissues reducing the risk of recession reoccurring and camouflaging the dark root of the lateral incisor tooth.

Connective tissue grafts may also be utilised to enhance the aesthetics of a tooth-supported bridge. The graft is placed at an edentulous ridge to increase the tissue volume and restore the form of the alveolar ridge. Once augmented the soft tissues can be manipulated to facilitate placement of a pontic that more closely mimics the emergence profile of a natural tooth.

The patient in figure 12 has had a connective tissue graft placed at the maxillary central incisor sites. This has been allowed to develop and mature with the aid of a provisional restoration. Figure 13 demonstrates the ovate pontic sites upon removal of the provisional bridge.

Connective tissue grafting has become an integral part of implant placement in areas of aesthetic concern. The placement of a connective tissue graft can replace soft tissue volume lost after tooth extraction. The placement of dense tissue on the facial aspect of a restoration can reduce the risk of dark gingival as a result of show-through of metal components and reduce the risk of recession as the restoration ages.

The patient in figure 14 presented having lost her maxillary central incisor tooth. Treatment included hard and soft tissue augmentation. Figure 15 demonstrates the soft tissues after final implant crown placement.

Conclusions

Examination of the gingival tissues should not be limited to checking for plaque, inflammation and periodontal pocketing. Correction of deficiencies in soft tissue anatomy can reduce the risk of recession, enhance the aesthetics of a final restoration and contribute to the maintenance of a patient’s dentition. Soft tissue grafting with free gingival and connective tissue grafts provides one means of correction of these deficiencies.

Full references are available by visiting http://www.quinlandentalspecialists.com Dr Paul Quinlan qualified from Dublin Dental School in 1991 and gained his Masters Degree from the Eastman Dental Insititute in 1993. In 1995 he became a Fellow of the Royal College of Surgeons of Glasgow ,and in 2002 he gained his Certificates of Prosthodontics and Periodontics as well as a Masters Degree from the University of Texas Health Sciences Centre at San Antonio.

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