Evaluation of flexure strength and vertical marginal gap distance of 3 unit all-ceramic bridges using a modified technique

ABSTRACT

The proposed study was designed to determine the feasibility of jointing procedure for Inceram fixed partial dentures combining the slip casting technique and machinable ceramic. Twenty Inceram bridges were constructed. The bridges were divided into two equal groups as follows Group [1] Anterior group Ten anterior bridges replacing maxillary central incisor were constructed from Inceram alumina. Group [2] Posterior group Ten posterior bridges replacing mandibular second premolar were constructed from Inceram zirconia. The samples from each group were further subdivided into two equal subgroups according to the technique used as follows Subgroup [A] Conventional technique five anterior and five posterior bridges were constructed using the conventional technique. In this technique, the retainers and the pontic were constructed using the slip casting technique. Subgroup [B] Modified technique five anterior and five posterior bridges were constructed using a modified technique. In this technique, the pontic was constructed using the Celay system, then connected to the two retainers by the slip mix. The bridges constructed in this study were evaluated through the following tests [1] vertical marginal gap distance using the traveling microscope. [2] Flexural strength using the universal testing machine. The obtained results were collected, tabulated and statistically analyzed using analysis of variance ANO-VA. There was no significant difference in the vertical marginal gap distance measurements between the conventional and modified technique among the tested groups. There was no significant difference in the flexural strength values between the anterior conventional and modified techniques. The posterior modified technique recorded a great reduction in the flexural strength values than the posterior conventional technique. The technique of jointing the milled Inceram pontic to the slip cast retainers was successful for Inceram alumina [3 units anterior bridges], but was not met with a great success for the posterior bridges from Inceram zirconia considering the flexural strength. Marginal gap distance was not affected