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A Conservative Esthetic Approach Using Enamel Recontouring and Composite Resin Restorations

Conservative clinical solutions, predictable esthetic, and immediate outcomes are important concepts of restorative dentistry. The aim of this case study was to recognize the selective enamel removal as an interesting conservative alternative to achieve optimal esthetic results and discuss the clinical protocol. This clinical report described an alternative esthetic and conservative treatment to transform the long and sharp aspect of the maxillary canines with a slightly aggressive aspect into features of slightly curved teeth with delicate lines. An accurate diagnostic and esthetic analysis of the smile was initially performed. The selective enamel removal was performed, and direct composite restoration was strategically placed. Clinical assessment showed good esthetic outcomes, enabling a smile harmony with an immediate, simple, and lower-cost technique. Practitioners should be exposed to conservative approaches to create esthetic smiles based on the selective enamel removal technique combined with composite resin.


Introduction
The esthetic demand for a Perfect Smile has been growing fast year-after-year, as an important way to improve the patient acceptance with tooth appearance especially related to color changes and alignment [1][2][3]. Overall, patients are more confident after dental treatment, which positively affect their personal lives and professional relationships [4][5][6]. On the other hand, esthetic treatment is always accompanied by unique expectations with regard to the final outcomes.
Facial esthetics are guided by the harmony of soft tissue, gingival esthetics, microesthetics, and macroesthetics [7][8][9]. To improve the dental esthetic appearance, restorative approach can be combined with interdisciplinary treatment, such as periodontal and orthodontic treatment [3,10]. However, these techniques require time due to the healing process and changes of the alveolar bone.
Although interdisciplinary evaluation and treatment are crucial in achieving optimum smile composition, under-standing the patient's wishes is essential to the success of therapy [3,10]. Therefore, to cater to the patient requirement for improved dental esthetic results in the shortest possible time, selective enamel recontouring and direct restorations seem to be a good alternative [2,[11][12][13][14][15].
Minimally invasive treatment can be performed using selective enamel recontouring since the removal of a slight amount of enamel is only superficial, without dentin exposure and hence no postoperative sensitivity [2,16]. In addition, the main advantage of this treatment is restoring a more natural teeth appearance using a relatively simple, immediate, and low-cost manner [2]. Thus, the aim of this article was to describe a successful conservative technique when changes in the shape of teeth are required for optimal esthetic results.

Clinical Report
A 26-year-old female patient complained about the elongated and protruded aspect of her maxillary canine (Figure 1).  The patient agreed to treatment and signed an informed consent. An interview of her medical history was performed and no concern was revealed. After clinical examination and esthetic analysis, some alterations were noted: midline variation between the maxillary and mandibular dental arches; changes in the axial inclination of maxillary central incisors; disharmony between the height-width ratio of dental crowns on the lateral incisors; more pronounced proclined maxillary canines with a sharp aspect, giving her smile a more aggressive appearance and masculine characteristic ( Figure 2).
Concerning the gingival esthetics, a cervical gingival gap in the region of the lateral incisors was observed in an intraoral photograph; however, it was not revealed in the smile photography. Therefore, since the patient did not complain about this aspect, no periodontal intervention for esthetic purpose was performed. In spite of recognizing the benefits of an orthodontic treatment, the patient reported satisfaction with the other aspects related to her smile and the color of her teeth. In addition, she was looking for immediate esthetic results and a minimally invasive manner. She also pointed out that she sought dental treatment at that time only to solve the esthetics of her smile as described before. It is emphasized out that the patient has dental implants and their respective implant supported dentures in the region of tooth #1.2 and tooth #2.2 (maxillary lateral incisors).
Initially, occlusal contacts were verified with articulating paper. When the canine guidance was observed, the option taken in order to attend the patient's demand was not to perform any wear in the incisal and palatine surface. As a result, the selective enamel recontouring was planned without reduction of the length of the tooth. To control this procedure, the guide was done with graphite on each tooth (#1.3 and #2.3) (Figures 3 and 4). The enamel recontouring was performed with diamond tip (#9138, KG Sorensen, Cotia, SP, Brazil), at high speed under constant water irrigation. Afterwards, decreasing granulation of aluminum oxide discs (Sof-lex Pop-on, 3M ESPE, St. Paul, MN, USA) was used to refine and polish the enamel surface.
The reduction of the buccal inclination of the incisal third as well as the rounding of incisal edge towards the palatine surface was performed. As shown, the flat area of the buccal surface was reduced in the cervical-incisal direction, giving the teeth a less elongated appearance. In addition, the enamel recontouring promoted better alignment between the incisal third of maxillary canines and incisors. Moreover, the enhanced space in the buccal corridor makes the smile more attractive.
To give the canines a more rounded aspect, which characterizes a more feminine smile, composite resin restorations in the cervical to middle third of the buccal surface of the maxillary canines were planned [8]. Moreover, an additional small direct restoration was indicated at the distal incisal angle fractured of the permanent central incisor (#1.1). The composite resin selection was performed positioning small increments of the selected composite over the teeth, followed by its polymerization [17]. Afterwards, a relative isolation was provided using labial retractor, gingival retraction cord, and cotton rolls. Then, etching enamel with phosphoric acid 37% was performed followed by the application of the adhesive systems (Adper Scotchbond Multipurpose Primer/Adhesive, 3M ESPE). The resin composite (Supreme XT Shade A3-E, 3M ESPE) was applied in the cervical to middle third of the canines in order to reproduce the buccal enamel. For fractured incisor, the resin composite shades A2B and A2E (Supreme XT, 3M ESPE) were used to restore the edge and the external enamel, respectively. All materials were used in Case Reports in Dentistry  accordance with the manufacturer's instructions and lightactivated using a light emitted diode unit (Bluephase, Ivoclar-Vivadent, Schaan, Liechtenstein). Afterwards, the restorations were polished with decreasing grits of aluminum oxide discs. In the smile photograph, the obtainment of more harmonious shapes and sizes of maxillary canines can be observed ( Figure 5).

Discussion
The improvement in self-esteem, quality of life, and social acceptance are important factors that induce the patient seeking esthetic dental treatment [4][5][6]. Optimizing smiles guided by preservation of tooth structure, immediate results, and eventual future replacements are a changeling in restorative dentistry field [18]. Although new techniques and restorative materials are constantly being developed, a conservative and reversible approach to improve the smile design can be obtained by implementing a relative simple technique based on selective enamel removal and composite resin restoration.
In this case presentation, we reported a predictable plan treatment to transform the sharp and aggressive aspect of maxillary canines into more rounded and harmonious design according to the patient's face and gender. Regarding the dental esthetic principles, tooth size, shape, and proportion between height and width of crowns are the most easy perceptible factors in the smile [7]. Moreover, dental morphology should be harmonious with the gender characteristics to make a more natural smile [8,19]. The feminine tooth shows characteristics such as slightly curved, smooth, delicate lines and absence of sharp angles. In contrast, masculine teeth are more angular and have straight lines, giving them an aspect of force and greater aggressiveness [8].
Reshaping performed with restorative techniques such as selective enamel recontouring or additional composite resin has shown advantages. For instance, allow greater preservation of healthy tooth structure, few clinical sessions, and reduced cost when compared to indirect restorations [3,11,12,15,20,21]. It is emphasized that, in spite of being a simple technique, it depends on adequate treatment planning including knowledge of tooth morphology and 4 Case Reports in Dentistry dental/dentofacial esthetic common sense principles [22,23].
After treatment, canine crowns showed a more adequate volume and depth. These morphology characteristics improve the smile attractiveness [8]. Other studies have shown that enamel recontouring is a safe and widely used procedure for the realignment of teeth, especially in canine teeth with rounded salience and large quantities of enamel in the buccal surface [2,11,12]. With regard to enamel removal, this aspect is significantly relevant, since wear can lead to tooth sensitivity, which occurs as a result of dentin exposure.
Selective enamel removal procedures have limitations, especially when compared with orthodontic treatment, since their indications are concerned. Orthodontic treatment can achieve the functional and esthetic requirements, minimizing and avoiding the wear of tooth [24]. On the other hand, if the patient is not inclined to receive this type of therapy and minor changes in the shape and position of the tooth are present, one of the alternative solutions to enhance the esthetic appearance of the smile is the enamel removal combined or not with direct restoration.
The patient's choice of treatment options is fundamental for the success of any procedure and it must be respected since it involves their psychological, physical, and financial aspects [25]. The patient in the present clinical case did not agree to have previous orthodontic therapy for tooth realignment. Therefore, tooth recontouring became a more feasible treatment option, taking into consideration the biological and functional concepts of dental structure preservation and esthetic demand. At the end of the procedure, the patient's satisfaction with the harmony obtained in her smile was achieved and undoubtedly functioned as an important instrument in the final evaluation of the result obtained.
In conclusion, the tooth recontouring techniques based on selective enamel removal and composite resin restorations provide a minimally invasive protocol with excellent esthetic result. This is an interesting restorative alternative based on a relatively simple treatment and lower-cost technique compared to traditional all ceramic restorations.