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23Dental Tribune Middle East & Africa Edition | November-December 2014 aesthetics Dr. Nadia Tufenkeji is a second year resident at Dubai College of Dental Medicine (DCDM), Prosthodontic MSc. Program. Located in Dubai Healthcare City (DHCC) Dr. Fatemeh Amir Rad is a lec- turer of Prosthodontics at Dubai College of Dental Medicine (DCDM). Prof. Crawford Bain is the Direc- tor of the Periodontics MSc. programme at Dubai College of Dental Medicine (DCDM). About the Author Figure 1. A significant staining of the veneer margins as a result of smoking and high coffee consumption. Porcelain laminate veneers – avoiding complications By DCDM D ental Veneering is the process of covering the facial surfaces of teeth by using various types of dental materials. Most commonly used are porcelain veneers which are thin shells of porcelain that are shaped like the outer layer of the teeth and are used to cover the teeth, aiming to enhance their appearance. Many celebrities opt for this es- thetic treatment to achieve what may seem like a picture-perfect smile. This may lead people to a false expectation that every- one is a good candidate for ve- neers. However, from a dental clinician’s perspective prepar- ing and planning for veneers is very challenging, and if prop- er analysis of the patient and proper techniques in preparing the teeth are not used, multiple complications can occur. These include gingival inflammation, chipping and breaking or even complete de-bonding of the ve- neers. To decide whether a patient is a good candidate for veneers many factors should first be as- sessed; the condition of the pa- tient’s teeth, habits, periodontal condition and most importantly the patient’s expectations and willingness to maintain their ve- neers after they are placed. We should start by analysis of the teeth. This involves assess- ing their shape and proportion; diastemas, and analysis of the occlusion. Regarding shape and dimension, there should be suf- ficient tooth structure to retain the veneer, otherwise the lon- gevity can be severely affected. In teeth with small surface areas such as lower incisors, or teeth with multiple cavities and fill- ings which decrease the avail- able surface for bonding, there is an increased chance of the early displacement of the veneer. In such cases full crowns may of- fer a better long term option (H.Serdar Cotert et al, 2009). In terms of diastemas, if these are too large veneers can only partly reduce the space, other- wise gingival inflammation and/ or recession can occur due to the bulkiness of the veneer (Weis- gold and Cohen, 1981) Addition- ally, a tooth which is unnaturally wide for its height looks unat- tractive. Orthodontics may be more appropriate to close gaps than veneers. When assessing a diastema the clinician must establish if it is stable or increas- ing since the latter may indicate periodontal bone loss or a harm- ful habit. Finally in tooth analysis the oc- clusion must be considered. For veneers to have a longer sur- vival rate they should not have excessive biting forces on their edges as is common in patients with an edge-to-edge occlusion which can lead to chipping and breaking of the veneers. Care must also be taken in patients with missing posterior teeth, as this increases the loading on the anterior teeth. Patients’ habits must also be considered. Night- time grinding or heavily clench- ing, often related to stress, or even biting or chewing on fin- gernails or objects like pens, create high horizontal forces impacting on survival of the ve- neers at a rate 8 times higher than patients who don’t have such habits. Such forces can readily lead to fracture, chip- ping or total de-bonding of the veneer. We should also consider the patient’s high consumption of dark or acidic foods as well as smoking habits which can lead to dark stains around the mar- gins of the veneers (Fig 1). Since patients with dark stained teeth will often consider veneers as a solution, habits should be identi- fied changed after veneer place- ment to maintain the esthetics of their veneers (Beier et al, 2012). Marginal stains can be mini- mised by brushing or rinsing af- ter smoking and consumption of dark colored foods. The patient’s oral hygiene must also be assessed, which leads us to the last key point of gingival health. Veneers should not be prepared on bleeding inflamed gingiva, which indicates poor oral hygiene. If this is done, complications which arise in- clude placing the veneer mar- gin too deep due to gingival en- largement, and bleeding during preparation and bonding lead- ing to poor marginal seal and marginal staining after veneer placement. Eventually gingival recession or worsening inflam- mation will result. Good oral hy- giene and gingival health should be achieved before veneers are started. All of these factors need to be considered during the ini- tial assessment to avoid compli- cations. Additional complications can arise during the preparation of teeth. There are two common approaches to placing porcelain veneers, one is done without al- tering the natural teeth - bond- ing the porcelain veneers to un- prepared teeth. This might seem a conservative choice avoiding alteration to tooth surfaces, but it inevitably creates a bulky over-contoured appearance and increases the risk of the veneer de-bonding and gingival com- plications. Alternatively teeth are prepared for veneers by changing external contour, re- moving less than a millimetre of the facial surfaces and around 2 mms of the incisal edges, thus porcelain replaces the tooth structure removed, ensuring the porcelain is seated properly onto the tooth with enough bulk of porcelain at the edge to mini- mise chances of chipping and breaking . Studies have shown that the overall success and sur- vival of the first method is much lower than the second method. The commonest complications with veneers are breaking and chipping (H.Serdar Cotert et al, 2009)(Layton and DPhill, 2013) (Akoglu et al, 2011). Astudyanalyzingtheoverallsur- vival rate of porcelain veneers over a 20 year period concluded that the estimated survival rate over a 5 year period is at 95%, at 8 years is 94%; at 10 years is 86% and at 20 years is 83% (Beier et al, 2012). It should be noted that these were veneers placed after adequate tooth preparation. The clinician must consider all these factors before choosing to place veneers if complications are to be minimised and patient satisfaction achieved. References are available from the authors.