The aesthetic prosthodontic management of periodontally involved teeth

Pink composite

The use of a gingival shade composite to match adjacent soft tissues was first described by Zalkind and Hochman in the management of a cervical defect.¹¹ Pink composite can be used to eliminate dentine hypersensitivity and to restore the lost gingival tissues aesthetically by placing pink composite directly onto the exposed root surface.^8,18 The pink composite in this position restores the anatomical size of the crown of the tooth and minimizes/alleviates the long clinical crown height present.

This technique is minimally invasive, can be easily modified and replaced, and is particularly useful around crowned teeth with exposed root surfaces, thus alleviating the need for crown replacement.¹⁹ However, use of composite is technique sensitive and can be challenging due to difficulties in moisture control around the gingival tissues as a result of gingival crevicular fluid; it can also be a challenge to ensure that there are no ledges/overhangs of the restoration, which can act as a plaque retentive factor and lead to further recession.³ To minimize this, gingival retraction techniques (Figure 4) can be used and careful manipulation of the composite is required. In the two cases shown (Figures 5, 6 and 7), GC Composite Primer (GC Corporation, Tokyo, Japan) was used (which helps rebuild the inhibition layer for bonding between composite layers and also can be used to lubricate the instruments and reduce the composite ‘sticking’ to the instruments), along with GC Gradia Brush Flat No 1 (GC Corporation, Tokyo, Japan) (Figure 8) and very thin-bladed composite instruments to manipulate the composite, which is particularly useful at the gingival margin.

There are some aesthetic issues with using pink composite for the treatment of gingival recession; one of the main issues being the lack of shades available.⁸ The lack of shades and the limits of this treatment modality may not provide the desired aesthetics and may be aesthetically undesirable for some patients. Careful case selection and a mock trial in the mouth can help assess these potential aesthetic issues before proceeding with treatment. One way to assess this is to place a small amount of the pink composite onto the root of the tooth and light curing without any preparation of the tooth to assess the shade matching and the rough aesthetics briefly before proceeding (Figure 9).

Pink porcelain

Where extra-coronal restorations are provided for teeth with recession, gingival coloured/pink porcelain can be incorporated into extra-coronal restorations.^16,20 This may, however, lead to excessive tooth tissue removal and also lead to the restorative margins being placed onto the root dentine as the preparation extends down onto the root surface.

The clinical process involved is the same as for any extra-coronal restoration, except that a clinical decision of where the laboratory should place the pink porcelain should be communicated clearly to the laboratory and careful cementation of the extra-coronal restoration is required to ensure that the cement lute doesn't encroach on the gingival margin/sulcus.³ The technical work by the laboratory needs to be carefully carried out like any other extra-coronal restoration to ensure an optimal marginal fit without any ledges, as this can act as a plaque retentive factor and lead to further recession.

The use of extra-coronal restorations can be excessively destructive of tooth tissue and can compromise pulpal health,³ and they are also more difficult to refurbish and replace in comparison to direct restorations. There can also be aesthetic issues associated with the use of pink porcelain which is the same as with direct pink composite, which includes the lack of pink porcelain shades and the potential unpleasing aesthetics that it provides; again, this should be discussed and envisaged with the patient before preparation of the tooth/teeth.

Composite resin restorations

Composite can be used to cover sensitive root dentine or used to modify the shape/contour of the teeth. Using composite on the root surface will inevitably lead to longer clinical crown height which may not be aesthetically acceptable to all patients. It can also be used to modify the contour/shape of the teeth and may be particularly useful where there has been loss of the interdental papilla. By reshaping the contours of the teeth, the contact point can be lengthened and located more apically, which in turn will reduce the embrasure/‘black triangles’ and, in some cases, can allow the coronal displacement of the interdental gingiva.^21,22

However, there are limits to what this technique can achieve and it is often only used in milder cases when few teeth are involved. A more optimal outcome may be achieved with use of gingival veneers or pink composite, where gingival recession is extensive or generalized through the dentition.

Gingival veneer

Gingival veneers, also termed gingival masks,²³ gingival slips, flange prostheses²⁴ and removable gingival prostheses,¹⁵ are a removable prosthesis worn on the labial aspect of the dental arch, which aims to restore the muco-gingival contour and aesthetics in areas where periodontal tissues are deficient.²⁵ They may be used to replace tissue lost as a result of periodontal disease, surgical periodontal procedures, trauma, ridge resorption or traumatic tooth extraction, which can result in aesthetic and functional deficit.²⁶

Gingival veneers are indicated in cases when the aesthetics are compromised, which include disproportionately elongated clinical crowns, visible crown margins and exposed root surfaces.²⁷ They are particularly useful in patients that have lost the interdental papillae, leading to unsightly ‘black triangles’ between the teeth (Figures 1 and 10).²⁸ Functionally, they can be used to improve speech and phonetics by reducing air escape through interdental spaces,²³ and also act as a barrier to stop saliva passing interdentally, which can create foaming of saliva or spitting during speech.²⁹ They are also particularly useful in patients where periodontal surgery to correct these deficits is not amenable, predictable, not wanted by the patient or contra-indicated.

Gingival veneers can also be used to deliver local medicaments, which include desensitizing agents for the management of dentine hypersensitivity of exposed root surfaces,²⁴ steroid medicaments against affected mucosa in patients with desquamative gingivitis,³⁰ placement of fluoride supplements in head and neck cancer patients after radiotherapy who are at high risk of root caries,³¹ and can also be used to deliver periodontal dressings.³²

Gingival veneers, however, are contra-indicated in patients with uncontrolled periodontal disease or incomplete periodontal therapy, an allergy to acrylic or silicone, poor manual dexterity or patients at risk of inhalation.²³ They are also contra-indicated in patients who have a high caries susceptibility and those patients that are unable to maintain meticulous oral hygiene,²³ as the veneer will retain more plaque like any removable prosthesis.

The prosthesis can be fabricated from composite resins, porcelain, acrylic (Figure 11) and silicone (Figure 12) materials. Traditionally, acrylic²⁶ was the most commonly used material (Figure 13), however, silicone is becoming increasingly²⁴ used due to its improved aesthetics and flexibility, which makes the prosthesis more comfortable for the patient to wear (Figures 14 and 15).²⁹

The gingival veneers are retained by mechanical and/or adhesive forces. Mechanically they are retained by engaging the interproximal undercuts²⁴ and around the distal aspect of the terminal abutment teeth²³ (Figure 16). Due to this, there should be a delay of at least three months after successful periodontal treatment to allow stabilization of the gingival tissues and the teeth, otherwise the veneers will become readily loose and non-functional.³² Gingival veneers can be used with the natural dentition or used in conjunction with fixed prosthesis,¹⁵ including implant-retained prostheses,^27,33 and can even be incorporated into the fixed prosthesis using precision attachments to help retain the gingival veneer.^27,34 However, this can be complicated and challenging both clinically and technically, particularly when it requires replacement.

The gingival veneer can be fabricated either directly or indirectly.²⁷ The direct technique involves construction of the gingival veneer chairside by the clinician. This technique is not commonly used to produce the definitive gingival veneer and is more commonly used to construct a temporary veneer or used for diagnostic purposes to assess the aesthetics and function with the patient prior to construction of a definitive indirect veneer.²⁹ Silicone is often used for this technique³² and is placed directly and manipulated into the desired prosthesis. The indirect technique³⁵ involves taking an impression that captures the interproximal spaces and the full depth and width of the sulcus for the span of the planned veneer (Figures 17, 18 and 19). This can be carried out using a modified stock tray or using a specifically designed special tray^24,29,36 (Figure 20).

The gingival veneer is a relatively straightforward and predictable approach to replacing lost tissue architecture, especially when a large volume of tissue needs replacement, and has been shown to have little or no detrimental effect on the gingival tissues in the long term in motivated patients.^15,29,36 However, the prosthesis is removable, which for some patients may not be acceptable, and aesthetics can be compromised in some patients due to a lack of shade availability of some of the materials (Figure 21). Overall, the prosthesis can offer a good long-term solution or be used as an interim solution for patients who may wish to have time to consider their options of more advanced and complex treatment.