Interdisciplinary esthetic approach in clinical dental rehabilitation.

During the esthetic evaluation of smile, the presence of diastemas, tooth color, size and shape, and the amount of gingival exposure are important factors to be considered. A 23-year-old female patient was referred to us with a dissatisfaction with her smile. After clinical examination revealed esthetic alterations as generalized tooth yellowish discoloration, a slight diastema in the upper anterior region, and a shortened appearance of maxillary dental crowns, providing a gingival smile. The proposed treatment consisted of an esthetic rehabilitation for resolution of gummy smile and closure of diastema in anterior teeth by the use of digital planning as a guide for the accomplishment of integrated procedures. The result obtained by the multidisciplinary treatment associating periodontal surgical procedure for esthetic crown lengthening with in-office bleaching and direct restorations with composite resin, by digital planning, provided evident harmonization between tooth color and shape and gingival contour, enabling more harmonious smile esthetics. Copyright:

INTRODUCTION

Gummy smile is a clinical condition characterized by excessive exposure of gingival tissue when smiling. When this exposure is ≥4 mm, it is generally considered unattractive for both professionals and patients.[12] Gingival smile is considered one of several mucogingival changes around teeth and can negatively impact the oral health-related quality of life, including aspects of functional limitation, psychological discomfort, and social difficulties.[3] Its prevalence is estimated around 10% among individuals aged 20–30 years and is more common in women (14%) than men (7%).[4]

Diastemas in the upper anterior region are frequent malocclusions in permanent dentition, affecting 1.2% to 22% of the population.[5] Some clinical approaches are used in its treatment such as orthodontic corrections, restorative procedures, or the combination of both.[6] With the evolution of adhesive dentistry, porcelain or composite resin veneers are commonly used.[78]

The smile esthetics seems to be clearly affected by these two alterations, gummy smile, and diastema, and these abnormalities are even more noticeable in young and female individuals.[9]

The objective of this paper is to describe a multidisciplinary esthetic rehabilitation in a patient with gummy smile and anterior diastemas by the use of digital planning as a guide for the accomplishment of integrated procedures.

CASE REPORT

Female patient, of African descent, aged 23 years, sought dental care due to dissatisfaction with her smile. The initial evaluation revealed esthetic alterations as generalized tooth yellowish discoloration, a slight diastema in the upper anterior region, and a shortened appearance of upper dental crowns, providing a gingival smile [Figure 1a]. Clinical examination by periodontal probing showed that the gingival margin was positioned at 3 mm from the cementoenamel junction (CEJ) in incisal direction [Figure 1b]. A periapical radiograph with a gutta-percha cone adhered to the buccal surface of one central incisor at the level of the gingival margin was achieved to help identify the relationship between gingival margin, bone margin, and the CEJ [Figure 1c and d].[10] The association of clinical and radiographic examinations allowed to determine that the bone margin was located at <1 mm from the CEJ, justifying the presence of short teeth and confirming the presumed diagnosis of gummy smile. The patient had good periodontal health and the radiographic findings did not show any abnormality in the supporting and dental tissues analyzed.

Figure 1

(a) Initial smile of the patient. (b) Periodontal probe. (c and d) Clinical insertion of gutta-percha point and radiographic image for periodontal diagnosis. (e) Initial full-thickness flap. The bone margin is <1 mm from the cementoenamel junction. (f) Immediate aspect after osteotomy. (g) Frontal clinical appearance of smile 30 days after surgery

The treatment plan established after careful analysis and discussion with the patient comprised a multidisciplinary intervention to improve the patient's esthetic conditions. With these findings and after informed consent of the patient about the established treatment plan, surgical planning was performed to esthetic crown lengthening. A virtual planning was suggested by intraoral scanning, smile drawing on a specific software, and achievement of models in a three-dimensional (3D) printer after the surgical procedures for esthetic rehabilitation.

After intraoral antisepsis with 0.12% chlorhexidine solution, anesthesia was performed by bilateral local blockage in the upper premolar region. Using a Bard-Parker style scalpel handle and a 15c blade (Carbon steel, Swann-Morton, Sheffield-England), an internal bevel incision was made from upper canine to upper canine in the gingiva attached at the height of the CEJ. A second incision was made inside the sulcus. With removal of the gingival collar and detachment of the periodontal surgical flap, it was observed that in some places, the bone margin coincided with the CEJ and in others, there was a distance of 1 mm between these structures [Figure 1e]. For adequate positioning of the gingival margin, at the same level as the CEJ, osteotomy was performed using a carbide round bur n.3018 (KG Sorensen, Cotia, SP, Brazil) under thorough irrigation with saline solution and a Rhodes chisel n. 36/37 (Trinity Indústria e Comércio Ltda., São Paulo, SP, Brazil) until a distance of 2–3 mm from the CEJ to the bone crest was obtained [Figure 1f].

After this procedure, the flap was repositioned and suspensory sutures between the premolars and vertical sutures in anterior aspect with the suture ending toward the palate using 4–0 nylon (Ethicon, Johnson and Johnson, Skillman, NJ, USA) were performed in the region of interdental papillae. The patient was instructed not to brush the upper anterior region and to perform chemical control of dental biofilm using mouthwashes with 0.12% chlorhexidine digluconate (Periogard®, Colgate Palmolive company, NJ, USA), for 1 min, twice a day, for 7 days. At 30 days after clinical crown augmentation surgery, it was possible to observe the upper central incisors and canines with similar heights and slightly smaller lateral incisors, achieving a harmonious smile [Figure 1g].

The first in-office tooth bleaching session was performed 6 months after the surgical procedure. Initially, the tooth shade was obtained by the visual method using a Vita scale (Vita Zahnfabrik H. Rauter GmbH and Co., Bad Säckingen, Germany). A lip retractor was placed, and a light-cured protective gingival barrier (Top Dam– FGM, Joinville, SC, Brazil) was adapted at the gingival margin. Then, 35% hydrogen peroxide (Whiteness HP– FGM, Joinville, SC, Brazil) was applied according to the manufacturer's instructions [Figure 2a]. The proportional mixture of thickening agent and hydrogen peroxide was manipulated and applied using a brush on the buccal surface of upper and lower teeth up to the premolar region. A period of 45 min was allowed, and the mixture was homogenized with a brush at every 5 min. A second in-office bleaching session was performed 7 days after the first session. After 7 days, the patient returned to the clinic where a bleaching procedure was evaluated, and an excellent result was observed where a good chromatic harmonization was noticed and without any report by the patient of tooth hypersensitivity.

Figure 2

(a) Initial in-office dental bleaching. (b) Digital wax-up and silicone guide on the printed model. (c) Initial composite resin layer on the palatal surface supported by the silicone guide. (d) Aspect of the developmental lobes. (e) Application of the last layer of composite resin. (f) Final clinical aspect

After 2 weeks of the tooth bleaching procedure, an intraoral scan was performed and a silicone guide was obtained (Scan-Yller Biomaterials SA, Pelotas, RS, Brazil), through 3D printed models which was the base for fabrication of direct composite resin restorations [Figure 2b]. Digital planning was performed after bleaching because more than 6 months had passed since surgery, and there was already a new periodontal anatomical perspective present and suitable for planning the closure of the diastemas and the new morphology of the anterior teeth to be restored.

The virtual planning was performed from an intraoral scan (CS3600– Carestrem– USA) to achieve STL files (Standard Template Library) of the maxilla and mandible, which were inserted in the software (Exocad GmbH– Darmstadt– Germany). The diagnostic wax-up was performed using a virtual teeth library. The goal was to correct the shape and proportion of central and lateral incisors, besides closing the diastema. The initial and wax-up models were exported and printed on a 3D printer (D7 Plus–Wanhao–China) using Dental Model resin (Yller Biomaterials SA– Pelotas, RS, Brazil) [Figure 2b].

In the maxillary central and lateral incisors, esthetic restorations were performed 2 weeks after the end of the bleaching procedure without any type of tooth surface wear. After cotton roll isolation, enamel surface etching was performed with 37% phosphoric acid (Condac– FGM FGM, Brazil) for 30 s on teeth 12, 11, 21, and 22. The acid was removed with an intense water spray and dried with light air jet for application of the adhesive system (Adper Scotch Bond Multi-Purpose, 3M ESPE). The palatal surface was restored with translucent resin shade Trans 20 (IPS Empress Direct–Ivoclar Vivadent, Liechtenstein) supported on the silicone guide [Figure 2c]. The proximal closure of crests was performed using the same resin with a translucent characteristic. The developmental lobes were demarcated using opaque resin shade DA0 (Vittra, FGM, Brazil) [Figure 2d]. For the last layer, E-Bleach enamel resin (Vittra, FGM, Brazil) was used and applied with a spatula (OptraSculpt–Ivoclar Vivadent, Liechtenstein [Figure 2e], and in the proximal surfaces, the resin was adapted using a flexible ultra-thin spatula. The same procedures were performed for teeth 13 and 23.

Finishing and texturing were performed using diamond burs 3195F, 3195FF, 3168F, and 3168FF (Invicta-American Burrs, SC, Brazil) underwater cooling followed by polishing using a sequence of spiral soflex discs (Twist-Gloss-American Burrs, SC– Brazil).

The result obtained by the multidisciplinary treatment associating periodontal surgical procedure for clinical crown augmentation with in-office bleaching and direct restorations with composite resin, by digital planning, provided evident harmonization between tooth color and shape and gingival contour [Figure 2f], enabling a more harmonious smile esthetics and improving the patient's self-esteem.

DISCUSSION

In the present case report, the patient's chief complaint was the presence of small teeth, great gingival exposure when smiling, and evident space between the anterior teeth. To solve these clinical changes, virtual planning was performed by intraoral scanning, smile drawing on a specific software, and achievement of models in a 3D printer. These procedures allowed better assessment of the different treatment options, considering the predictability and limitations of each of these therapeutic possibilities. Furthermore, it allowed better communication with the patient.

During the esthetic evaluation of smile, the presence of diastemas, tooth color, size and shape, and the amount of gingival exposure are important factors to be considered. In the present clinical case, these characteristics were fundamental for the treatment plan. Considering the diagnosis that at least 2 mm of clinical crown of upper anterior teeth were covered by gingival tissue, it was possible to increase the size of these teeth while decreasing the gingival appearance with the same surgical procedure. There was enough keratinized tissue, and thus, the flap was performed with removal of gingival collar. Since the patient had a thick gingiva in the buccolingual dimension and there was a need to recover the biological space to position the gingival margin at the height of the CEJ, a full-thickness flap with osteotomy was performed instead of gingivectomy, which may also be used in these cases.[11]

During clinical examination of the patient, it was possible, by transperiodontal probing and periapical radiographic examination, to clearly determine the CEJ of anterior teeth and the buccal bone margin. This procedure demonstrated that there was a distance of up to 1 mm between these two structures, thus clearly indicating the need for osteotomy to allow positioning of the gingival margin close to the CEJ.[12] The transperiodontal measurement approach is adequate for diagnosing invasions of the periodontal biologic width.[12] For this reason, it was not necessary to use other resources that may also be indicated to establish this diagnosis, such as computed tomography. Notwithstanding, it has been described that periodontal probing is only effective in some cases since only a small groove is felt during subgingival probing, and it is difficult to distinguish the CEJ from the bone crest. Furthermore, even if these two structures are detected, it can be very difficult to determine whether the distance between them is physiological (1–2 mm) or not.[13]

The supracrestal attachment tissues, formerly called biological space, represent the vertical dimension of gingival tissues and are formed by the connective attachment, which has an average of 1.07 mm, and by the junctional epithelium, which has 0.97 mm. This distance determines the amount of osteotomy to be performed during the surgical procedure since this “space” is essential to organize the gingival tissues. To position the gingival margin over the CEJ, its distance to the bone margin is kept between 2 and 3 mm. The initial incision of the flap was performed at a height coincident with the CEJ, thus the flap margin served as reference for osteotomy so that 2–3 mm were achieved between the bone margin and the new free gingival margin, as previously performed by other authors.[14]

To aid the restorative procedures, a digital diagnostic wax-up was performed with a dental computer-aided design software, which allowed the fabrication of a silicone guide that accurately translated the size and shape of the virtually planned restoration. This technique contributed to a better understanding of the case, expanding the diagnostic perspective, visualizing the esthetic limitations, risk factors, and predictability.

Although different materials and techniques have been described for diastema closure, the present case was restored by the direct technique using composite resin, mainly to avoid wear on the tooth surface due to the preparation for the ceramic use. The procedure of direct composite resin was also quickly performed in a single session. In addition, these restorations are easy to repair, and studies with 4-year follow-up or longer have already shown that these materials have excellent quality and excellent esthetic and functional results for diastema closure even in the long term.[15]

The main limitation of rehabilitation performed in this case is related to the main factors responsible for the failure of composite resins over time, such as bruxism, eating habits, and smoking.[1516] Concomitantly, the consumption of foods as coffee/cola/tea directly impacts the incompatibility of shades of composite resin restorations.[16]

Although ceramics are highly esthetic materials and thus another good therapeutic option for these cases, their cost is significantly higher because they involve the laboratory phase, besides requiring tooth wear more often. The interaction between the different techniques performed in this case provided a harmonious gingival contour with adequate proportions between teeth. Digital planning enabled the complete multidisciplinary rehabilitation of gummy smile, resulting in complete patient satisfaction.

CONCLUSION

Digital planning enabled the complete multidisciplinary rehabilitation of gummy smile, resulting in complete patient satisfaction.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.