PMC4686634_01
(a) Initial clinical aspect. (b) Initial radiographic aspect.
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fig1
A nine-year-old girl attended the dental clinic of the Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil), exhibiting a fracture in the middle third of the crown of tooth 21 (Figures 1(a), 2(a), and 2(b)).
(a), (b) Initial clinical aspect, close-up. (c) and (d) Malocclusion in laterality.
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fig2
A nine-year-old girl attended the dental clinic of the Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil), exhibiting a fracture in the middle third of the crown of tooth 21 (Figures 1(a), 2(a), and 2(b)). After anamnesis and clinical and radiographic examination, an assessment of the color and the incisal guides (Figures 2(c) and 2(d)), upper and lower arch molding was performed, as well as casting of the mold with a special type of plaster (Durone Tipo IV, Dentsply, Brazil) to enable the cutting of the tooth fragment and the production of the dentine pins in the laboratory.
(a) Selected extracted central incisor. (b), (c) Mesiodistal measurement of the extracted tooth. (d), (e) Mesiodistal measurement of the remaining tooth in the laboratory.
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fig3
An extracted tooth of the same size, shape, and color as tooth 21 (Figure 3) was used to cut the dental fragment and in the subsequent homogenous bonding.
(a) Cut of the dental element to obtain the restorative fragment. (b) Cut of dental fragment. (c) Adaptation of the fragment to the plaster model, vestibular view. (d) Adaptation of the fragment to the plaster model, palatal view.
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fig4
The cutting of the dental fragment and the "biopins" was performed under extreme refrigeration with diamond burs (Figure 4).  Figure 5(a) displays the production process of the "biopins," which was performed by cutting a coronal slice, following the transverse direction of the tooth, in order that the dentinal tubules were perpendicular along the axis of the pin. After the cutting and adaptation of the restorative fragment to the model (Figure 4), a drilling simulation was performed to place the biopins in the plaster die (Figure 6(a)) and in the fragment (Figure 6(d)), using a spherical bur (1 mm diameter and a depth of 2 mm) with a low rotation.
(a) Dental slice cut to obtain the dentinal pins, with outline showing the area from which they were obtained. (b) Dentinal biopins.
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fig5
The cutting of the dental fragment and the "biopins" was performed under extreme refrigeration with diamond burs (Figure 4).  Figure 5(a) displays the production process of the "biopins," which was performed by cutting a coronal slice, following the transverse direction of the tooth, in order that the dentinal tubules were perpendicular along the axis of the pin. These were then separated until a cylindrical shape of approximately 1 mm diameter and 4 mm length was obtained (Figure 5(b)).
(a) Simulated holes in the model for placement of the biopins. (b) Biopins in place, incisal view. (c) Biopins in place, vestibular view. (d) Holes made in the fragment for adaptation of the biopins. (e) Laboratory sample of the fragment to the biopins. (f) Fragment suitably adapted to the plaster model.
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After the cutting and adaptation of the restorative fragment to the model (Figure 4), a drilling simulation was performed to place the biopins in the plaster die (Figure 6(a)) and in the fragment (Figure 6(d)), using a spherical bur (1 mm diameter and a depth of 2 mm) with a low rotation.
(a) Sample of the biopins in the holes made in the remaining tooth. (b) Acid conditioning of remaining tooth. (c) Acid conditioning of dental fragment. (d) Acid conditioning of the biopins. (e) Application of the primer/adhesive on the remaining teeth. (f) Application of the primer/adhesive in the biopins and dental fragment.
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In the second clinical session, perforation of the remainder of the tooth was conducted, through absolute isolation, for the cementation of the "biopins" with a spherical bur of 1 mm diameter (Figure 7(a)). Subsequently, conditioning treatment with phosphoric acid (37%) was performed for 30 seconds in enamel and for 15 seconds in dentin from the fragment, from the remainder of the tooth, and from the "biopins" (Figure 7). This was followed by application of the adhesive system (Adper Single Bond 2, 3M ESPE, Brazil) and photopolymerization for 20 seconds (Figure 7).
Cemented biopins in the remaining tooth. (a) Vestibular view. (b) Incisal view. (c) Clinical sample of the dental fragment. (d) Fragment adapted to the remaining tooth. (e) Vestibular aspect after bonding the vestibular fragment. (f) Palatal aspect after bonding the fragment.
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fig8
After conditioning, the "biopins" were cemented to the dentin with FLOW resin of color A2 (Vigodent, 3M ESPE, Rio de Janeiro, Brazil) and photopolymerized for 40 seconds (Figures 8(a) and 8(b)). Subsequently, the dental fragment was embedded in the dentine pins, cemented with FLOW resin A2 (Figures 8(c) and 8(d)), and photopolymerized for 40 seconds on all sides (Figure 8(f)).
(a) Clinical aspect of the restoration after removal of the absolute isolation. (b) Clinical aspect in protrusion. (c) and (d) Clinical aspects in laterality.
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After the cementation of the dental fragment (Figure 9), occlusal adjustment was carried out.
(a) Initial clinical aspect. (b) Clinical aspect shortly after bonding. (c) Final radiographic aspect.
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The newly restored dental surface was then finished and polished (Figure 10).
Clinical aspect after 12 months.
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