Three-dimensional analysis of the relationship between the structure of maxillary central incisor and the preparation of dental all-ceramic

Abstract

The purpose of this study is to investigate the interrelationship between tooth preparation and dental structure of Chinese maxillary central incisors and provide scientific guidance for clinical all-ceramic restoration. Forty-five specimens of maxillary central incisors were fabricated by 3D printer based on data of Micro CT scanning. Subsequently, every three specimens from the same natural tooth were randomly divided into three groups (n = 15): porcelain veneer, all ceramic crown, and the blank control group. All the specimen teeth were prepared according to routine clinical criteria, reconstructed into 3D models and then measured in software. The results showed that the mean quantity of reduction (volume fraction) was (28.35 ± 4.37) % and (56.93 ± 3.47) % for porcelain veneer and all-ceramic crown, respectively. The bonding areas of different all-ceramic restorations were (128.85 ± 11.73) mm2 and (97.15 ± 9.98) mm2 for all-ceramic crown and porcelain veneer respectively. In porcelain veneer group, the area of enamel adhesive was (54.80 ± 12.70) mm2, and the area of dentin was (42.35 ± 9.62) mm2. As the results of the one-sample t test, the mean distances from medullary angle to incisal edge or adjacent surface have significant differences with the test value which was set as 0.5 (P < .05). The reduction of the tooth for porcelain veneer is less than that of ceramic crown and the cementation of porcelain veneer is mostly dependent on the conservation of the enamel during preparation. The region from mesial adjacent surface to mesiopulpal angle is prone to have the problem of medullary perforation.

Shear bond strength of ceramic laminate veneers to finishing surfaces with different percentages of preserved enamel under a digital guided method

“…Tooth preparation guides were designed to transfer the reduction depths of virtual preparations to definitive preparation [ 19 – 21 ]. Enamel substrate was presented by the superimposition of the prepared tooth and its dentin models [ 22 , 23 ], by which the adhesive guides could be designed to locate the enamel and dentin adhesive surface. With the aid of the surface treatment guides, the enamel and dentin surfaces could be presented and treated separately without impacting each other.…”

Biomechanical impact of labiolingual diameter on endodontically treated anterior teeth with crown restoration under occlusal loading

“…All models were prepared for an all-ceramic crown by removing 1 mm of the incisal edge and preparing a 0.8 mm wide rounded shoulder at the gingival margin, following the minimum clinical recommendations. 12 The luting cement layer thickness between the prepared tooth and the all-ceramic crown was 0.1 mm. 18 For S0 models, the pulp was established previously.…”

“…Tooth preparation reduces residual coronal tooth tissue; in these cases, excessive preparation may be conducted to achieve a sufficient ceramic layer thickness for better aesthetics, further reducing the residual tooth tissue. 12 , 13 Additionally, variation in tooth size between ethnicities contributes to differences, with Asians and Europeans having smaller intact maxillary central incisors than Oceanians and Africans. 14 , 15 This results in a reduced labiolingual diameter of ET teeth.…”

Análisis de máxima tensión compresiva en incisivos centrales superiores rehabilitados con postes de fibra de vidrio y tres tipos de coronas. Un estudio con método de elementos finitos.

“…La rehabilitación de dientes con tratamientos endodónticos, particularmente en el sector anterior, representa uno de los retos fundamentales que enfrenta el profesional (1, 2) pues, al haber una serie de opciones científicamente comprobadas, en cierta modo se dificulta la selección de las restauraciones estéticas más apropiadas y naturales 3 . Además, la estructura dentaria remanente, al ser más frágil que un diente sano, presenta un comportamiento biomecánico diferente 4 ; por lo tanto, el éxito del rendimiento biomecánico está relacionado con múltiples factores que van desde la preservación del tejido dentario y el uso adecuado de materiales biocompatibles con el diente 2 , hasta las cargas oclusales que este soporta 5 .…”