STRATIFICATION TECHNIQUE OF A NANOCOMPOSITE USING THE SILICON GUIDE

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1 Odontology STRATIFICATION TECHNIQUE OF A NANOCOMPOSITE USING THE SILICON GUIDE Diana PĂRĂU 1, Oana-Costina BIZGAN 2, Mariana SABĂU 3, Mona IONAŞ 3 1 DMD, Dental Medicine Dept. Clinical Hospital of Sibiu Country, Sibiu, Romania 2 DMD, Private Office CMI Bizgan Oana-Costina, Sibiu, Romania 3 DMD, Associate Prof., Faculty of Medicine, Lucian Blaga University of Sibiu, Romania Corresponding author: monaionas@yahoo.com Abstract At present, the stratification technique of composite materials, known as offering most predictible, both functional and aesthetic results, uses a silicone reference quide. This allows the dentist to appreciate the size and thickness of the composite resin layer to be applied, as well as selection of the opacity and translucidity degree according to the reconstructed enamel or dentin structure, thus facilitating the stratification of materials. The minimum adjustment, at the level of the palatal wall, represents another great advantage of the silicone key. Keywords: silicon guide, stratification technique, nanocomposite 1. INTRODUCTION Silicone key or the oral individual matrix represents the conformating imprint of the palatal face of the future reconstruction. The absent crown portion of the tooth, which is to be imprinted for the realization of the silicone key, can be reconstructed either - more frequently - through either wax-up or mock-up, or it can be present as an old obturation with appropriate morphology in the palatal region, yet with colour defects. The imprint of the reconstructed tooth is subsequently applied onto the oral surface of the prepared tooth [1,2]. Thus, a mould, on which the absent portion of the respective tooth is going to be reconstructed, is made. For making the silicone key, C-silicons are used. Direct reconstructions using the silicone key can be made in cases of crown fractures, closing of diastema (facilitating the distribution of the space to be closed), inadequate fillings, caries or wear lesions [3]. In cases of IV th and VI th class cavities, which are frequently reconstructed by this technique, the silicon guide allows the dentist to foresee the lenght of the tooth, while offering a good support for the insertion of the resin layer and for minimizing the finishing and polishing stages of the palatal surface. 2. MATERIALS AND METHODS An extracted upper incisor was used to detail the technique of making the silicone key and the stratification stages of the composite materials (Fig. 1). The working technique involves the following steps: Fig. 1. Initial image of the extracted tooth used in the technique of silicone key 1. Cleaning the tooth surface through professional brushing 2. Determining tooth colour Initial determination of colours made use of a color key. 138 volume 19 issue 2 April / June 2015 pp

2 STRATIFICATION TECHNIQUE OF A NANOCOMPOSITE USING THE SILICON GUIDE The composite, applied on the tooth without adhesives, is polymerized and examined in a dry and wet environment, to see if the nuances coincide (Fig. 2) [4]. In the present study, nuance A3 was obtained. Fig. 4. Preparation of the IVth class cavity; preparation of the bevel 6. Hybridization stages Fig. 2. Testing the colour of composites. Examination in dry and wet environment 3. Impression technique of the initial situation Since the tooth is intact, the impression needs no reconstruction step (Fig. 3). Hybridization assumes etching of enamel (30 sec) and of dentin (15 sec) [5], with phosphoric acid in a concentration of 37%, followed by penetration of the primer and impregnation with adhesive resin (Fig. 5). Fig. 5. Application of phosphoric acid; view of the demineralized tooth; application of bonding Fig. 3. Silicone key 4. Isolation of the operating field Since the studied tooth is extracted, isolation with a dental dam is not necessary. 5. Realizing the preparation A IV th class preparation is realized with a circular bevel (Fig. 4). 7. Using the silicon guide The silicone key is positioned on the operating field, without pressure, after which the limit of the palatal wall will be marked with the tip of the probe (Fig. 6). The composite of the selected enamel nuance, with a thickness of 0.5 mm, is applied directly on the key up to the limiting line, then on the tooth, being correspondingly adjusted to the level of the palatal margin (Fig. 7). After polymerization, the palatal wall is sufficiently strong to support the next stratification steps (Fig. 8). International Journal of Medical Dentistry 139

3 Diana PĂRĂU, Oana-Costina BIZGAN, Mariana SABĂU, Mona IONAŞ Fig. 6. Finish line of the tooth marked on the silicone key Fig. 9. Realization of the proximal wall after matrix removal 9. The stratification technique In order to obtain the A3 nuance, according to the color selection guide from Filtek Ultimate, the following composite layers are necessary: A4D (dentin), A3B (body) and A2E (enamel) (Figs.10-11) [7]. Fig. 7. Application of composite A2E into the key up to the line; adjustment of the key with composite to the palatal wall Fig. 10. a Application of dentin layer A4D. Construction of dental mamelons: b.application of body layer A3B. In some places, mamelons reach the incisal margin Fig. 8. Aspect of the palatal wall after photopolymerization and key removal 8. Realization of the proximal wall The mesial wall of the same enamel nuance used for the palatal wall, with the same thickness (approximately 0.5 mm), uses a celluloid matrix (Fig. 9). The palatal and the proximal walls guide the internal stratification. Fig. 11. a Application of the translucent layer at the level of the incisal margin; b. Application of the last enamel layer A2E 140 volume 19 issue 2 April / June 2015 pp

4 STRATIFICATION TECHNIQUE OF A NANOCOMPOSITE USING THE SILICON GUIDE 10. Finishing and polishing Abrasive bands are used for processing the proximal faces, polished with polishing brushes and polishing paste, gums and discs with various granulations (Fig. 12). Fig. 12. Finishing 11. Assessment of restoration In the end, even if restoration seems not integrated, no decision is made until the tooth is not completely hydrated. Fig. 13. Final aspect of restoration 3. DISCUSSION The working technique with the silicone key allows a very good marginal adjustment at the level of the palatal wall, minimizing the finishing stage. It also allows a careful control of the nuances of stratified resin and of the size and thickness of the applied layers [8-10]. Colour analysis is made before isolation, when the tooth is hydrated and translucent. A scheme of color stratification is precisely determined and observed [11-13]. Even if the final restoration seems not integrated, being yellow, with visible margins, no intervention will be made prior to tooth complete hydration. The intermitent presence of water is not sufficient for rehydratation and for preserving a stable color. Saliva has an extremely important role in this case. Complete rehydration can take hours. The marginal circular mm bevel increases the necessary area for etching and masks the outline of the restoration on the vestibular surface, improving the final aesthetic result through gradual transition between restoration and tooth [3]. Considering the very good results obtained and the technique which can be controled, adhesive systems of total etch type were used in 3 steps, in which the engraving phase is followed by primer and bonding resin application. An adhesive system of the 4-th generation, Scotchbond Multi-Purpose, with water based primer (3M ESPE), has been used [7,14,15]. The success of direct restoration, recorded in time, depends not only on the used material but also on the ability and experience of the dentist, working protocol (isolation with dental dam and meticulous finishing) and condition of the pacient (a very good hygiene and absence of bad customs). Cleaning the tooth with fluorine containing toothpastes is recommended, as they form a film on the tooth surface interfering with the demineralization process [16]. The complications of direct restorations with composite materials are minor, e.g., the surface of the obturation becomes rough, or a ditch appears along its margin, which indicates a deficient adjustment or even fracture of restoration. However, reparations and corrections may be easily and rapidly performed [17]. 4. CONCLUSIONS Direct aesthetic restorations of frontal teeth by adhesive techniques with composite materials using the silicon guide represent a rapid, aesthetic and functional option of treatment in the odontal lesions. The results are excellent and immediate, and can be obtained in one single session, while no provisory prosthesis is necessary. They show a remarkable longevity without microinfiltrations International Journal of Medical Dentistry 141

5 Diana PĂRĂU, Oana-Costina BIZGAN, Mariana SABĂU, Mona IONAŞ when the amelodental bonding is correctly and efficiently realized. This type of restoration has a minimum invasive therapy intervention. All these advantages determine a better acceptance of the therapeutic plan through direct restoration from the part of the pacient. References 1. Behle C. Placement of direct composite veneers utilizing a silicone buildup guide and intraoral mock-up. Pract Periodontics Aesthet Dent Apr;12(3): Magne P, Magne M. Use of additive wax-up and direct intraoral mock-up for enamel preservation with porcelain laminate veneers. Eur J Esthet Dent 2006; 1(1): Lăzărescu F. Incursiune în estetica dentară. Bucharest: SSER Publishing House; Noetzel J, Kielbassa A. Reconstrucţia estetică a dinţilor frontali cu ajutorul materialelor compozite. Cosmetic Dentistry. 2008; 1: Iliescu A, Gafar M. Cariologie şi odontoterapie restauratoare. Bucharest: Medical Publishing House; Malhotra N, Mala K. Light-Curing Considerations for Resin-Based Composite Materials: A Review. Compend Contin Educ Dent 2010; 31(7): Ionaş M, Frăţilă A, Boitor C, Ionaş T. Individualization of the application technique for composite materials. Case study. Ro J Stomatol. 2010; 56(4): Ionaş M, Frăţilă A, Sabău M, Ionaş T. A Simple Simultaneous Aesthetic Restoration Technique of Two Fractured Upper Incisors. AMT. 2010; 2(2): Ionaş M, Sabău M, Ionaş T. Direct aesthetic reconstruction by resizing the upper central incisor a case study. IJMD. 2011; 15(1): Devoto W, Saracinelli M, Manauta J. Composite in everyday practice: how to choose the right material and simplify application techniques in the anterior teeth. Eur J Dent. 2010; 5(1): Margeas R. Composite Resin: A Versatile, Multi- Purpose Restorative Material. Compend Contin Educ Dent. 2012; 33(1): Vanini L. Moving beyond classical shade guides to achieve natural restorations. Dental Tribune, U.S. Edition Feb;7(2). 14. Pashley DH, Tay FR, Imazato S. How to Increase the Durability of Resin-Dentin Bonds. Compend Contin Educ Dent. 2011;32(7): Vârlan C, Dumitriu B, Stanciu D, Suciu I, Chirilă L. Situaţia actuală a adeziunii la structurile dure dentare.locul şi rolul sistemelor adezive amelodentinare în restaurările estetice din medicina dentară. Ghid de adeziune amelo-dentinară pentru restaurările estetice dentare. Bucharest: SSER; Luca R. Metode locale de prevenire a cariei în şanţuri şi fosete. Bucharest: Cerma Publishing House; Almaşi A, Borzea D. Evaluarea performanţelor clinice la un an ale unui material compozit cu nanoumplutură. Clujul Medical 2010; LXXXIII(1): volume 19 issue 2 April / June 2015 pp