Porcelain Laminate Veneers PDF

1 Assoc. Prof. Dr. Özay ÖNÖRAL COURSE ID Code of Committee: CS-2 Name of Committee: Fixed Prosthetic Restorations Lecturer: Assoc. Prof. Dr. Özay Önöral Topic of the Course: Laminate Veneer Preparation Techniques Duration of the Course: 50 minutes After completion of this course, the stude...

1 Assoc. Prof. Dr. Özay ÖNÖRAL COURSE ID Code of Committee: CS-2 Name of Committee: Fixed Prosthetic Restorations Lecturer: Assoc. Prof. Dr. Özay Önöral Topic of the Course: Laminate Veneer Preparation Techniques Duration of the Course: 50 minutes After completion of this course, the student will be able to: Compare prepared and unprepared laminate veneer restorations Define reduction limits for labial, incisal, proximal, and lingual aspects for different clinical situations Compare different preparation approaches for the incisal aspect, make a case-specific preference and justify the preference. Contemporary Fixed Prosthodontics, 6th Edition. Book by Junhei Fujimoto, Martin F. Land, and Stephen F. Rosenstiel. Published by Elsevier in 2022. Fundamentals of Fixed Prosthodontics, 4th Edition. Book by Herbert T. Shillingburg, David A. Sather, Edwin L. Wilson, Joseph R. Cain, Donald L. Mitchell, Luis J. Blanco, and James C. Kessler. Published by Quintessence in 2012. Gürel G (2004). Porselen Laminat Venerler Bilim ve Sanatı. Quintessence Yayıncılık, İstanbul. Sevük LG, Sevük SÇ (2011). Diş Kesimi ve Kavite Hazırlama Yöntemleri. Quintessence Yayıncılık, İstanbul. Jordan A. Clinical aspects of porcelain laminate veneers: considerations in treatment planning and preparation design. J Calif Dent Assoc. 2015;43(4):199-202. 4. Sadaqah NR. Ceramic laminate veneers: Materials Advances and selection. Open Journal of Stomatology. 2014:4;268-279. Pini NP, Aguiar FHB, Lima DANL, Lovadino JR, Terada RSS, Pascotto RC. Advances in dental veneers: materials, applications, and techniques. Clinical, Cosmetic and Investigational Dentistry 2012:4;9–16. Learning Objectives of the Course: Suggested References to Review: Near East University, Faculty of Dentistry Prosthodontics Department 2 Assoc. Prof. Dr. Özay ÖNÖRAL PREPARATION PRINCIPLES OF PORCELAIN LAMINATE VENEERS Today, advances in adhesive dentistry and material technology allow the construction of minimally invasive restorations. At the same time, increasing accessibility of information provides awareness of patients and highlights patients' expectation of aesthetic restoration with minimum substance loss. Laminate veneers are full ceramic partial restorations applied to the labial surfaces of the teeth with minimal tooth preparation. The first laminate veneers were created in 1938. It was applied by Charles Pincus without making dental preparations and glued with prosthetic adhesive to temporarily meet the aesthetic expectations of Hollywood stars during film and photo shooting. After the introduction of enamel etching by Buonocore (1955), laminate veneers were allowed to be cemented with resin. Laminate veneers have also been widely used thanks to the full ceramic and adhesive materials developed today. Advantage of laminate veneers; it is a minimally invasive procedure in which aesthetically satisfying results are obtained in correcting the color, shape, and position disorders in the teeth. However, the preparation and cementation stages require precision and experience. For the laminate veneers to be successful; the indication and contraindications must be well-known and the case must be selected correctly. In addition, tooth preparation, selection of full ceramic material and cementation stage are also very important in the success and longevity of the laminated veneers. Failure is inevitable as a result of an error in any of these steps. Tooth Preparation In the literature, there are two approaches to tooth preparation for laminate veneers: making minimal preparation and not making any preparation. The fact that no preparation is made in the tooth is advantageous in that it is a conservative technique and a reversible treatment. However, making dental preparation in laminate veneers also has its advantages: ✓ By providing a suitable place for the full ceramic material, an over-contoured restoration is prevented and a healthier restoration can be fabricated periodontally. ✓ When masking the tooth color, making the preparation provides a material thickness that prevents the reflection of the color below. ✓ Presence of preparation limits ensures that the fit of the restoration to the tooth during cementation can be observed and placed correctly. ✓ The enamel surface, which is rich in fluorine, is removed and thus, the connection between resin cement and the tooth is stronger. ✓ The bonding stress between tooth and laminate veneer decreases. ✓ Interproximal limits can be hidden. ✓ Restoration thickness that can resist breakage is provided. Near East University, Faculty of Dentistry Prosthodontics Department 3 Assoc. Prof. Dr. Özay ÖNÖRAL Because of these advantages, tooth preparation is recommended in laminate veneer restorations. The preparation should remain within enamel limits. Because resin cements are harder to bind to dentine. At the same time, elastic modules of enamel and ceramic are closer compared to dentin. 1. Labial aspect preparation: The most important point in labial aspect preparation is determination of the preparation depth. The thickness of the enamel layer and the degree of coloration affect the depth of preparation. Labial (facial) preparation should be done in 3 planes: cervical, middle, and incisal. The use of depth-setting burs makes the preparation more controlled. Generally, 0.3 mm cutting depth in the cervical region and 0.5 mm in the incisal area are recommended (Figure 1a). However, if the tooth color is 2-3 tones more intense than the target color tone, 0.4 mm in the cervical; 0.6 mm tooth preparation should be made incisal. In cases where there is excessive discoloration such as tetracycline discoloration or discoloration seen in devital teeth after endodontic treatment, the depth of preparation can be increased up to 0.5 mm in the cervical and up to 0.7 mm in the incisal region. However, instead of increasing the depth of preparation in these cases, bleaching the tooth color to lighter tones may give more aesthetic results. At the gingival border, 0.3-0.5 mm wide chamfer finish line is recommended. If the discoloration is too much, 0.5-0.7 mm deep subgingival finishing line can be done. 2. Proximal aspect preparation: The correct positioning of the boundaries is important as the proximal aspect preparation affects aesthetics and oral hygiene. The preparation border should lie within the 0.2 mm labial of the interproximal contact area (Figure 2a). However, in cases where tooth coloration is excessive, the preparation may include the interproximal area to mask discoloration and in the closure of diastema (Figure 2b). 3. Incisal edge preparation: There are different approaches in the laminate veneers at the point of whether the incisal edge is included in the preparation in the incisal edge preparation (Figure 2): Near East University, Faculty of Dentistry Prosthodontics Department 4 Assoc. Prof. Dr. Özay ÖNÖRAL ➢ Window preparation: The incisal edge is not included in the preparation; the boundaries of the preparation are within the labial surface. When anterior guidance is desired to be protected, it can be used in cases where resistance is important and in cases where there is no tooth discoloration. It is the most conservative approach. ➢ Feather-edge preparation: Incisal edge is partially included. The preparation is finished at the incisal edge level in the labial aspect. However, in this preparation, fracture may occur in the tooth or restoration in protrusive movements. ➢ Overlap preparation covering the incisal edge: 1-1.5 mm preparation is made on the incisal edge (Figure 3). It can be created in 2 ways: ֍ Butt-joint: Preparation is made as a flat step in the labio-lingual direction. With the surface prepared in the form of a platform, the resistance of the restoration against the forces in the vertical direction is increased. At the same time, space can be formed for sufficient material thickness on the incisal edge to apply color and translucency effects. ֍ Chamfer: In cases where the thickness of the incisal edge in the labio-lingual direction is sufficient, 0.2-0.3 mm chamfer finishing line is prepared on the lingual surface of the incisal edge in addition to the preparation made on the incisal edge. Approach accepted in the current literature is overlap techniques in which the incisal edge is included in the preparation. Thus, the surface area for bonding is increased, a more aesthetic restoration can be fabricated, and the risk of fracture is reduced by providing sufficient material thickness for the ceramic, which is more resistant to forces. The point to be considered in overlap preparations is that the end limit of the preparation extending to the lingual surface does not come to the occlusal contact points with the opposite teeth. Near East University, Faculty of Dentistry Prosthodontics Department