Katsarou Thomai, Antoniadou Maria, Papazoglou Efstratios
Int J Esthet Dent. 2017;12(1):42-59.
To assess the esthetic effectiveness of four illusion techniques applied to a composite resin veneer for diastema closure between maxillary central incisors.
An acrylic model with six natural maxillary anterior teeth was fabricated with a 2-mm diastema between the central incisors. Resin veneers were constructed on the left central incisor and the following cases were derived: V0: no veneer; V1: veneer without optical illusion features; V2: veneer with centralized interproximal ridges; V3: veneer with curved incisal edges; V4: veneer with gray pigment mesially/distally; V5: veneer with gray pigment on the developmental lobes. Digital printed photos of the models (13.2 x 17.8 cm, and 6.1 x 8 cm), with low, medium, and high smile lines and without a smile line (processed by Adobe Photoshop CS6) were shown to three groups of people (faculty members, senior undergraduate students, and patients; n = 25/group) for them to assess the overall size and width of the two central incisors. The results were analyzed by Pearson's and chi-square goodness of fit tests.
There was no significant influence in the estimation of the two central incisors as being the same size, according to the technique used (P = 0.869) and group of evaluators (P = 0.209). The estimated probability of assessing the tested incisor as wider was indicatively lower in V2 compared to V1 (adjusted odds ratio = 0.59; P = 0.088). The height of the smile line affected the evaluation of the veneers only in the large-sized photos.
No interference is the best esthetic decision concerning a 2-mm diastema closure when restoring only one central incisor with a laminate veneer. The next best option is to deliver a veneer with centralized interproximal ridges.
评估四种错觉技术应用于复合树脂贴面关闭上颌中切牙间间隙的美学效果。
制作一个带有六颗天然上颌前牙的丙烯酸模型，中切牙间有2毫米的间隙。在左侧中切牙上制作树脂贴面，并得出以下病例：V0：无贴面；V1：无视觉错觉特征的贴面；V2：具有集中邻面嵴的贴面；V3：具有弯曲切缘的贴面；V4：近中/远中带有灰色色素的贴面；V5：发育叶上带有灰色色素的贴面。将模型的数码打印照片（13.2×17.8厘米和6.1×8厘米），包括低、中、高微笑线和无微笑线的照片（由Adobe Photoshop CS6处理）展示给三组人员（教员、高年级本科生和患者；每组n = 25），让他们评估两颗中切牙的整体大小和宽度。结果通过Pearson检验和卡方拟合优度检验进行分析。
根据所使用的技术（P = 0.869）和评估者组（P = 0.209），对两颗中切牙大小相同的估计没有显著影响。与V1相比，V2中评估受试切牙更宽的估计概率明显较低（调整优势比 = 0.59；P = 0.088）。微笑线的高度仅在大尺寸照片中影响贴面的评估。
当仅用层压贴面修复一颗中切牙的2毫米间隙时，不进行干预是最佳的美学决策。次优选择是提供具有集中邻面嵴的贴面。
