Influence of the fixed implant-supported provisional phase on the esthetic final outcome of implant-supported crowns: 3-year results of a randomized controlled clinical trial.

OBJECTIVES The aim of this investigation was to evaluate whether the use of a provisional implant-supported crown improves the final esthetic outcome of implant crowns that are placed within esthetic sites. MATERIALS AND METHODS Twenty endosseous implants were inserted in sites 13 to 23 (FDI) in 20 patients. Following the reopening procedure, a randomization process assigned them to either cohort group 1: a provisional phase with soft tissue conditioning using the "dynamic compression technique" or cohort group 2: without a provisional phase. Screw-retained all ceramic crowns were inserted. Clinical follow-up appointments were completed at 36 months evaluating clinical, radiographic outcomes, and implant success and survival. RESULTS After 3 years, all implants survived; one implant-supported crown was excluded from the study due to adjacent tooth failure replaced with a further implant supported crown. Modified pink esthetic score (ModPES) scores were significantly different between groups 1 and 2 (P = .018); white esthetic scores (WES) were not statistically different between both groups (P = .194). Mean values of combined modPES and WES were 15.6 for group 1, with a SD of 3.20. Group 2 had a mean combined modPES and WES of 12.2, with a SD of 3.86. Mean bone loss after 3 year was -0.05 and -0.04 mm for groups 1 and 2 respectively, without being statistically significant. CONCLUSION Fixed implant-supported provisionals improve the final esthetic outcome of the peri-implant mucosa

Esthetic and Clinical Performance of Implant-Supported All-Ceramic Crowns Made with Prefabricated or CAD/CAM Zirconia Abutments

Patients' esthetic expectations are increasing, and the options of the prosthetic pathways are currently evolving. The objective of this randomized multicenter clinical trial was to assess and compare the esthetic outcome and clinical performance of anterior maxillary all-ceramic implant crowns (ICs) based either on prefabricated zirconia abutments veneered with pressed ceramics or on CAD/CAM zirconia abutments veneered with hand buildup technique. The null hypothesis was that there is no statistically significant difference between the 2 groups. Forty implants were inserted in sites 14 to 24 (FDI) in 40 patients in 2 centers, the Universities of Bern and Geneva, Switzerland. After final impression, 20 patients were randomized into group A, restored with a 1-piece screw-retained single crown made of a prefabricated zirconia abutment with pressed ceramic as the veneering material using the cut-back technique, or group B using an individualized CAD/CAM zirconia abutment (CARES abutment; Institut Straumann AG) with a hand buildup technique. At baseline, 6 mo, and 1 y clinical, esthetic and radiographic parameters were assessed. Group A exhibited 1 dropout patient and 1 failure, resulting in a survival rate of 94.7% after 1 y, in comparison to 100% for group B. No other complications occurred. Clinical parameters presented stable and healthy peri-implant soft tissues. Overall, no or only minimal crestal bone changes were observed with a mean DIB (distance from the implant shoulder to the first bone-to-implant contact) of -0.15 mm (group A) and 0.12 mm (group B) at 1 y. There were no significant differences at baseline, 6 mo, and 1 y for DIB values between the 2 groups. Pink esthetic score (PES) and white esthetic score (WES) values at all 3 examinations indicated stability over time for both groups and pleasing esthetic outcomes. Both implant-supported prosthetic pathways represent a valuable treatment option for the restoration of single ICs in the anterior maxilla ( ClinicalTrials.gov NCT02905838)

Provisional restorations

This chapter will emphasise the need to:Provide a provisional restoration following tooth preparation to protect the pulp; secure positional stability, function and aesthetics; and maintain gingival healthConsider using long-term provisional restorations to assess aesthetic, occlusal and periodontal changes before embarking on definitive restorationsDistinguish between preparations for conventional and adhesive restorations when providing provisional restorationsDetermine in advance the type of provisional restorations and materials to be used, ideally, whilst treatment planningBe aware of materials for making provisional restorations and how to control potential hazardsMake provisional restorations to a high standard to ensure a predictable restorative outcom

Comparison of Channel Estimation Protocols for Coherent AF Relaying Networks in the Presence of Additive Noise and LO Phase Noise

Channel estimation protocols for wireless two-hop networks with amplify-and-forward (AF) relays are compared. We consider multiuser relaying networks, where the gain factors are chosen such that the signals from all relays add up coherently at the destinations. While the destinations require channel knowledge in order to decode, our focus lies on the channel estimates that are used to calculate the relay gains. Since knowledge of the compound two-hop channels is generally not sufficient to do this, the protocols considered here measure all single-hop coefficients in the network. We start from the observation that the direction in which the channels are measured determines (1) the number of channel uses required to estimate all coefficient and (2) the need for global carrier phase reference. Four protocols are identified that differ in the direction in which the first-hop and the second-hop channels are measured. We derive a sensible measure for the accuracy of the channel estimates in the presence of additive noise and phase noise and compare the protocols based on this measure. Finally, we provide a quantitative performance comparison for a simple single-user application example. It is important to note that the results can be used to compare the channel estimation protocols for any two-hop network configuration and gain allocation scheme

A New Era in Restorative Dentistry

none5mixedGiovanna Orsini, Vincenzo Tosco, Riccardo Monterubbianesi, Giulia Orilisi, Angelo PutignanoOrsini, Giovanna; Tosco, Vincenzo; Monterubbianesi, Riccardo; Orilisi, Giulia; Putignano, Angel

Aesthetic control

This chapter will emphasise the need to:Identify and define the patient's aesthetic problemConsider the balance between aesthetics and tooth destruction for conventional and adhesive restorationsBe aware of the aesthetic limitations of restorations, including implant crownsEnsure that a patient's expectations are realistic and be alert to patients with unrealistic expectationsIncorporate procedures leading to better aesthetics at each clinical stageBe confident in determining shade, be aware of digital shade analysis as an option and communicate effectively with the laboratory