Dental Tribune Indian Edition

10 Dental Tribune Indian Edition - January 2013 We checked whether the silicone key could be positioned exactly. (If required, interfering areas can be adjusted using a scalpel until a preci- se fit is achieved.) The enamel areas were etched for 30 seconds and the dentine for 15 seconds. Both were then thoroughly rinsed and dried. Subsequently, the adhesive was ap- plied, while the adjacent teeth were protected with a metal matrix. We used the ExciTE F total-etch adhe- sive (Ivoclar Vivadent) for this step. Owing to the non-retentive prepara- tion design and the fact that most of the restoration would be created on enamel, this type of adhesive proved superior to self-etching products. In order to facilitate penetration into the dentine tubules, the adhesive was gently massaged into the cavity walls. (After the adhesive has dried, the ca- vity must exhibit a glossy appearance. If this is not the case, the procedure needs to be repeated.) The adhesive was then light-cured for 10 seconds with a bluephase cu- ring light (Ivoclar Vivadent). Building up the palatal and proximal walls As a first step, the palatal enamel was built up. A thin layer of enamel material (shade A2) of less than 0.5 mm was applied to the palatal key and smoothed out with a brush. Then the key loaded with composite material was placed in the mouth and the fit was checked again. If necessary, the material may be modified before it is polymerised for 10 seconds. The palatal wall created in the pro- cess showed the exact desired shade and did not touch the adjacent teeth (Fig. 5). Applying a thin layer of enamel material (A2) to the proximal walls changed the complex cavity into a simple one. In order to create the thin layer, we fixed a transparent matrix in place with a wooden wedge, which allowed us to create the transition li- nes (the convex area that separates the proximal from the vestibular area)— the restorative outcome is influenced by the successful design of these tran- sitional areas because it is not possi- ble to design them with rotary instru- ments. We then applied composite material from the distal side of tooth #11, while tightening the matrix from the opposite side and polymerising the material in this position (Fig. 6). Thus, sufficient composite material could be added until the desired tran- sition area was achieved. The mesial side was built up in the same manner (Fig. 7). Building up the dentine core Using dentine materials, a restora- tion is created that shows decreasing saturation from the cervical to the incisal and from the palatal to the ve- stibular area. In order to achieve this, a 3D layering technique is applied, using materials with different levels of saturation. In our case, a material with a saturation one degree higher than the desired final tooth shade was applied. Therefore, dentine material in shade A3 was used in the area of the cervical margin. The layer was applied to the pala- tal wall using a flat spatula suitable for composite resins (Fig. 8). Subse- quently, a layer consisting of dentine material with a lower saturation was applied (shade A2). A pointed silico- ne instrument was used to design a slightly wavy margin covering half of the chamfer up to 1 mm below the incisal edge (Fig. 9). (If this techni- que is applied, the translucency of the enamel material becomes visible in the area of the incisal edge and the transition from tooth structure to composite material is masked.) Each layer was polymerised with the bluephase curing light for ten seconds. Designing the enamel portion The opalescence effect was enhan- ced by applying a thin layer of Trans Opal material in the area of the inci- sal edge. Since the visible effect of this material is very intense, only a small amount could be used. An ena- mel layer (shade A2) was applied in several steps to the vestibular area, then contoured with brushes and cu- red for ten seconds. This enamel ma- terial covered the entire restoration (Fig. 10). Finishing and polishing The patient’s teeth exhibited a very pronounced macro- and microtexture (vertical pits and horizontal streaks, respectively). Imitating these features to achieve a lifelike reflection on the restorative surfaces was a challenging task. This step was similarly important to determining the appropriate sha- de. We imitated the surface texture with fine-grain diamond-coated burs, using flame- and lens-shaped instru- ments (first with the red and then with the yellow colour code). The burs were used in the red handpiece wi- thout water irrigation. Another important step was the finishing of the transition lines and the interproximal areas. It is advi- sable to use abrasive strips for this purpose because rotary instruments may produce flat areas that cause inappropriate reflections. OptraPol Next Generation polishers (Ivoclar Vivadent) with water irrigation were used for the polishing process. We always take great care to polish resto- rations perfectly whilst avoiding any damage to the surface texture we de- sign. The polishing was greatly facili- tated as a result of the extraordinary polishability of this composite mate- rial (Figs. 11 & 12). Conclusion Owing to high-performance ma- terials such as IPS Empress Direct, which are consistently improving, and a clearly defined approach, we may use direct restorations for more indications than ever before, thus con- stantly extending the boundaries of feasibility. The advantage of direct restoration procedures is that they are time saving and conservative. Never- theless, it may happen that directly restored teeth show discolouration again in spite of the perfect aesthetic outcome. In this case, another tre- atment is inevitable.DT Figs 11 & 12: The restored tooth #11 exhibits a harmonious appearance, achieved with a minimal loss of tooth structure. Fig 11 Fig 12 Fig 8 Fig 9 Fig 10 Fig. 8: Application of dentine material in shade A3.—Fig. 9: Application of dentine material in shade A2. The previous layer was entirely covered with this material.—Fig. 10: Application of a covering layer of enamel material in shade A2. Dr Gauthier Weisrock is a dental surgeon from Mar- seille in France. He can be contacted atgauthier. weisrock@gmail.com. Contact Info Trends & Applications NOIDA, India, & ROSWELL, Ga, USA: The increase in medical touri- sm in Asia will apparently only be- nefit certain countries in the region. According to a report released by India-US market research provider Renub Research, over two thirds of the market for foreign medical and dental services will be controlled by India, Thailand and Singapore in the near future. Overall, Renub estimates that the number of arrivals for medical and dental tourists will exceed ten mil- lion by 2015, which would be a 50 per cent increase from the present volu- me. Thailand, which currently sees the largest number of foreign medical tourists per year, is predicted to dou- ble its market volume within the next three years. The country currently holds the largest market share with 40 per cent. It will be followed by Singapo- re, with an estimated one million arrivals per year and India with an expected half a million arrivals. To- gether, all three markets will hold a total share of 80 per cent while countries like South Korea, the Phi- lippines, Malaysia and Taiwan will compete for the remaining 20 per cent. Taiwan in particular is expected to be frequented by members of the Chinese middle class who can incre- asingly afford high-cost medical and dental treatment. Other countries were not included in the report. With rates of up to 30 per cent, medical tourism has been one of the fastest growing business sectors in the region owing primarily to the rising affluence of the middle class and a boom in the private health care sector. Recognising the poten- tial, several countries have recently started initiatives to improve medi- cal facilities and the workforce, as well as to attract more patients from abroad.DT Triumvirate to lead medical tourism Europe closer to amalgam ban A new study, conducted on behalf of the European Commis- sion, has recommended phasing out dental amalgam use over the next few years owing to mercury’s ne- gative impact on the environment. The decision to effect a ban would probably be made in 2013, and be- come applicable five years later, the authors suggested.DT