International Journal of Computerized Dentistry, 02/2013

Purpose: This study evaluated the clinical outcome of CAD/CAM zirconia-ceramic resin-bonded fixed dental prostheses (RBFDPs) with a cantilevered single-retainer design. Materials and Methods: Thirty anterior zirconia-ceramic RBFDPs fabricated with the Cerec CAD/CAM system were inserted using either a phosphate monomer containing resin (Panavia 21 TC; N = 16) or an adhesive bonding system with a phosphoric acid acrylate primer (Multilink- Automix with Metal/Zirconia primer; N = 14). Results: During a mean observation time of 64.2 months, one debonding occurred in each group. Both RBFDPs could be rebonded successfully resulting in a five-year survival rate of 100%. Conclusion: Independent of the bonding system, cantilevered zirconia-ceramic RBFDPs showed promising results during the first five years. (ClinicalTrials.gov Identifier: NCT01411592). Clinical Significance: Single-retainer zirconia ceramic RBFDPs present an alternative treatment option offering good esthetics, a minimally invasive preparation, a high biocompatibility and can even be used to treat juvenile patients who do not yet come into consideration for implant placement. No significant influence of the bonding system used has been detected so far. Keywords: resin bond, randomized clinical trial, zirconia ceramic, fixed dental prostheses, single retainer, bonding system

The third part of this literature review on the clinical relevance of surface electromyography (EMG) of the masticatory muscles summarizes the results of clinical studies in patients with temporomandibular disorders (TMD), preferably randomized controlled trials, examining the impact of changes to the dynamic occlusion. Clenching in left and right laterotrusive positions results in decrease in EMG activity of masseter and temporalis muscles on both working and non-working side. Masseter muscle exhibits largely uniform bilateral activity in laterotrusive positions, independent of canine guidance or group function with and without nonworking side contacts. There is a dominance of temporalis muscle activity on the working side and, in case of posterior contacts and balancing contacts, temporalis muscle activity increases and changes from an unilateral to a symmetrical pattern. Keywords: electromyography, review, chewing, masticatory muscles, maximal voluntary contraction, symmetry, resting activity, oral rehabilitation

This article presents two novel options for lithium-disilicate restorations supported by single-tooth implants. By using a Ti-Base connector, hybrid abutments and hybrid abutment crowns can be fabricated for different implant systems. The latter option in particular is an interesting new process that yields economical and esthetic restorations supported by single-tooth implants. Further studies are urgently needed to validate the usefulness of this system. Keywords: implant, abutment, esthetics, lithium disilicate, all-ceramic, fluorescence, soft-tissue management