Dental Tribune India Issue

Introduction Metal free restorations are now widely used and accepted due to their highly aesthetic potential and their excellent biocompati- bility properties. In order to improve strength and fracture toughness, several new ceramic systems and techniques have been developed.1 Many ceramics, such as spinel, alumina, and ceramic reinforced with lithium disilicate, have been proposed for the construction of metal- free restorations. These materi- als have precise indications for fixed partial dentures (FPD);2 on the contrary zirconia has bec- ome popular because of its trans- formation toughening.4 Case presentation The patient, a 30-year-old female, wanted to improve her smile as well as address the constant frac- turing of her composite veneer on 11, 12, 13, 21, 22, and 23 (Fig.1). The clinical examination revealed fracture of composite veneer on,11 and attrition of her anterior and wear facets on her posterior teeth. During the treat- ment planning session, the pati- ent was given an option of porce- lain fused to metal or metal-free restoration.Thepatientoptedfor metal-free restoration. Considering the patient occ- lusion force, which was probable the reason for constant fracture of her veneers, zirconia was chosen as the material of choice. The abutments were prepared, finish line margins were placed at the gingival level (Fig. 2, 3, 4, and5).Thefinalfullarchimpres- sion was made with a combina- tion of heavy and light viscosity polyvinyl siloxane. The shade was determined with a shade guide (Vitapan3DMaster,Vita,Germany). The patient was sent home with prefabricated provisional resto- ration bisacryl material (Fig. 6), taking care that the margins were not over-extended as the fi- nal soft tissue aesthetics depend a lot on the form of provisionals. The temporary crowns were ce- mented with non-euge-nol tem- porary cement (Tempbond NE, Kerr, Romulus, Mich). The com- plete 6 unit Y-TZP based frame work was milled from single block of zirconia (ZIRKON). The framework was clinically chec- ked for the fit, labial profile and clearance for the veneer ceramic at the bisque trial. The final res- toration was cemented with self- adhesive cement Relyx U100 (3M ESPE). Discussion Natural look of soft tissue in contact with FPD is influenced by 2 factors: mucosal thickness and the typology of restorative material.Metal-freerestorations allow preserving soft tissue color more similar to the natural one than porcelain fused to metal restorations (Fig. 8a-c).3 Amon- gst the metal-free restorations, zirconia oxide material has the highest flexure strength with a range of 900 to 1200 MPa.1 This is approximately twice as strong as alumina oxide ceramics cur- rently available and 5 times greater than the standard glass ceramics. Even more important is the fracture toughness of the material which is the ability of the material to resist propa- gation of internal fracture— an important indication of a material’s clinical reliability.2 Due to zirconia’s inherent strength, the material can be cemented to the prepared abut- ment with resin modified glass ionomer or self-etching resin cements successfully with the potential to enhance aesthetics. Further, with these cements the clean-up of the excess cement at the margin is easy, and elimi- nationofexcesscementisalways clinically beneficial. In case of short or extremely-tapered pre- parations, bonded resin cement may be best. Conclusion When beginning with aesthetics all ceramic offer a promising alternative for the restoration of anterior teeth, and short-term clinicalevaluationshavedemon- strated high success rates. The choice of material ultimately depends upon the clinical situa- tion. The dentist needs to deter- mine how much retention the preparation provides, the occlu- sion, the aesthetic demands, and the location of the restoration in the mouth. References 1. Beuer F, Naumann M, Gernet W, Sorensen JA . Precision of fit: Zirconia three-unit fixed dental prostheses. Clin Oral Investig. 2009 Sep; 13(3): 343-9. 2. Manicone PF, Iommetti PR, Raffaelli L. An overview of zirconia ceramics: Basic pro- perties and clinical applications. Journal of dentistry. 2007; 35: 819-826. 3. Jung RE, Sailer I, Hammerle CHF,AttinT,SchmidlinP.Invitro color changes of soft tissues caused by restorative materials. International Journal of Perio- dontics & Restorative Dentistry. 2007; 27: 251–7. 4. Raigrodski AJ. Clinical and laboratory considerations for the use of CAD/CAM Y-TZP- based restorations. Pract Proced Aesthet Dent. 2003; 15: 469– 476. DT Clinical Dentaltribune|July-September, 201022 Fig.1:Pre-treatmentintra-oralviewshowingattritionand discolouration. Fig. 2: Tooth preparations with margins placed at equi- gingival level. Fig. 3: Frontal intraoral view of the upper six prepared teeth. Fig. 4 & 5: Right and Left lateral intraoral view of the prepared teeth. Fig. 6: Provisional crowns with upper six anterior. Fig. 7a to c: Final prosthesis from the lab. Fig. 8a to c: Intraoral final restoration of frontal, right and left lateral views. Restoring anterior esthetics with zirconia Dr Ratnadeep Patil & Dr Dimple Bharadwaj-Bhondele, Smile Care clinic, Mumbai, India Dr Ratnadeep Patil has maintained a successful private practice spe- cializing in esthetic and implant dentistry in Mumbai. He is a Diplo- mate, International College of Oral Implantologists and an active mem- ber of the International Association ofDentalResearch.Hehasauthored a clinical textbook ‘Esthetic Den- tistry-An Artist’s Science’ and has been actively involved in conduct- ing continuing dental education programs with a special focus on smile designing, practice manage- ment and implant dentistry. Dr Dimple Bharadwaj-Bhondele She graduated from College of Dentistry, Manipal University, Kar- nataka, India, and, further, com- pleted her masters in oral science from KUL, Leuven, Belgium. She works with Dr Ratnadeep at the Smile Care clinic, and has been involved in clinical activity and continuing dental education pro- grammes and clinical research. About the authors Fig. 9: Post-treatment 2 mm of incisal edge visible in passive smile.