A noninvasive treatment of amelogenesis imperfecta

Comparative evaluation of the mechanical properties of CAD/CAM dental blocks

This study compares the mechanical properties of commercially available CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) millable dental blocks including Vita Enamic, Lava Ultimate, and MAZIC Duro. All the discs were cut in dimension of 1.2 mm in thickness and 12 mm in diameter, ground up to #1200 Sic papers and polished. The biaxial flexure strength of the ceramic discs was measured after thermocycling treatment and the broken surfaces were observed using scanning electron microscopy (SEM). The discs were brushed using a toothbrush testing machine under a 150 g load. Surface roughness and morphology were determined after toothbrushing cycles. Finally, the friction and wear behavior of the materials against an opposing tooth were studied using a reciprocating pin-on-plate test configuration. The vertical loss of dental cusp was measured, and the surface image was examined using field emission scanning electron microscopy (FE-SEM). The biaxial flexural strength data were subjected to Weibull analysis. To compare the significance between the groups, all data were analyzed by one-way analysis (ANOVA). The biaxial flexural strength of the Lava Ultimate and MAZIC Duro materials is significantly higher than that of Vita Enamic. In addition, Lava Ultimate and MAZIC Duro exhibited significantly smoother surfaces than that of Vita Enamic after toothbrushing. Lava Ultimate and MAZIC Duro also showed less wear to the opposing tooth than that of Vita Enamic. In addition, Lava Ultimate possesses more suitable mechanical properties than the Vita Enamic and Mazic Duro for use in oral clinical prosthesis.

Clinical performance of a new biomimetic double network material

BACKGROUND

The development of ceramics during the last years was overwhelming. However, the focus was laid on the hardness and the strength of the restorative materials, resulting in high antagonistic tooth wear. This is critical for patients with bruxism.

OBJECTIVES

The purpose of this study was to evaluate the clinical performance of the new double hybrid material for non-invasive treatment approaches.

MATERIAL AND METHODS

The new approach of the material tested, was to modify ceramics to create a biomimetic material that has similar physical properties like dentin and enamel and is still as strong as conventional ceramics.

RESULTS

The produced crowns had a thickness ranging from 0.5 to 1.5 mm. To evaluate the clinical performance and durability of the crowns, the patient was examined half a year later. The crowns were still intact and soft tissues appeared healthy and this was achieved without any loss of tooth structure.

CONCLUSIONS

The material can be milled to thin layers, but is still strong enough to prevent cracks which are stopped by the interpenetrating polymer within the network. Depending on the clinical situation, minimally- up to non-invasive restorations can be milled.

CLINICAL RELEVANCE

Dentistry aims in preservation of tooth structure. Patients suffering from loss of tooth structure (dental erosion, Amelogenesis imperfecta) or even young patients could benefit from minimally-invasive crowns. Due to a Vickers hardness between dentin and enamel, antagonistic tooth wear is very low. This might be interesting for treating patients with bruxism.