Rodriguez y Baena, Ruggero

Purpose: To evaluate the effect of ceramic firing cycles on the interface of screw-retained implant-supported metal-ceramic fixed dental prosthesis. Materials and Methods: Twenty-two frameworks were produced in cobalt-chrome alloy using an integrated CAD/CAM system. The frameworks were manufactured with an additive process on the milled implantframework interface. The total distortion of the interface was measured before (T1) and after (T2) the ceramic firing thermal cycles. The interface distortion was measured using a Coordinate Measuring Machine with an uncertainty of 2.5 nm and a resolution of 25 nm and a universal software for dimensional metrology. To test whether there was a significant difference in total 3D distortion, the Kruskal-Wallis test and Dunn’s test were employed; linear distortions between groups were compared using the Kolmogorov-Smirnov test and the Mann-Whitney test. A p-value of ≤ 0.05 was considered statistically significant. Results: The total 3D distortion between the nominal value and T1 was 0.5 ± 1.0 μm, between the nominal value and T2 was 10.5 ± 4.9 μm, and between T1 and T2 was 10.6 ± 4.9 μm. The distortion between T1 and the nominal value was significantly smaller than that between the other two groups. The average deviations around the three axes and diameters were not significantly different among the three groups. Conclusions: CAD/CAM manufacturing of the implantframework interface is an accurate process and does not present appreciable distortions. The ceramic firing cycles induce three-dimensional interface distortion. The observed distortion values were well below clinically relevant levels.

Purpose: To evaluate the clinical performance of implant-prosthetic rehabilitations carried out using ceramic-coated CAD/CAM titanium abutments. Materials and Methods: Thirty implants were placed in 30 patients and rehabilitated with 30 single crowns attached to CAD/CAM titanium abutments. A conventional procedure was applied, implants were placed after postextraction socket healing, and prosthetic restorations were placed after implant healing. Implant lengths ranged from 6 to 15 mm, and widths were 3.6, 4.2, and 4.8 mm. At the time of prosthesis delivery (T0), after 2 years (T1), and after 5 years (T2), the Plaque Index (PI), bleeding on probing (BoP), pocket probing depth (PPD), marginal bone level (MBL), and pink/white esthetic scores (PES/WES) were evaluated for each implant. Results: No patient dropped out of the study during the follow-up period. All 30 implants were clinically successful 5 years after prosthesis delivery (survival rate: 100%) and showed no signs of peri-implant infection. Peri-implant soft tissues were in good health (BoP at T2: 0% in 73% of patients; 25% in 13% of patients; 50% in 10% of patients; and 75% in 3% of patients). The mean PPD was 2.05 ± 0.56 mm at T0, 1.992 ± 0.6 mm at T1, and 1.867 ± 0.439 mm at T2. The mean MBL was 0.413 ± 0.440 mm at T0, 0.306 ± 0.388 mm at T1, and 0.263 ± 0.368 mm at T2. The mean PES, WES, and PES/WES indices (7.43 ± 1.04, 7.57 ± 0.82, and 15.00 ± 1.17, respectively) indicate good integration of soft tissues, satisfactory esthetics, and overall positive outcomes. Conclusions: The success rates, maintenance of MBLs, and periodontal and esthetic indices suggest the validity of implant-prosthetic rehabilitations with CAD/CAM abutments in cases of single crowns. Keywords: Implant-prosthetic rehabilitation; CAD/CAM abutments; Single crowns; Clinical performance; Peri-implant soft tissues

Purpose: To describe a fully digital workflow for an implant-supported fixed hybrid restoration that involves a double CAD/CAM structure and to highlight the benefits of this type of restoration. Materials and methods: Using a fully digital workflow, starting from intraoral scans, the necessary steps for producing the final hybrid prosthesis are described. The prosthesis consists of a titanium primary structure and a zirconia secondary structure that is cemented onto the primary structure in the laboratory. A clinical case is presented to illustrate the steps required for prosthetic rehabilitation. Results: This technique enables the fabrication of clinically valid and passive prostheses using a fully digital workflow. Conclusion: In just three clinical sessions, a fully digital workflow makes it possible to produce robust implant-supported fixed hybrid prostheses, comprising a titanium primary structure and an outer secondary structure made of zirconia. This procedure can be applied to a wide range of cases from simple to extended, including full-arch restorations. Keywords: CAD/CAM, dental prosthesis, digital workflow, titanium, zirconia Drs Parpaiola, Toia and Norton report a relationship with Dentsply Sirona (Charlotte, NC, USA) that includes speaking and lecture fees. The other authors declare no commercial associations or conflicts of interest relating to this study.

Purpose: Evaluations of multicenter clinical trials are needed to determine the effectiveness of care in routine implant therapy in clinical practice. Materials and Methods: Ninety-two clinicians in 75 clinics in 13 countries recruited five subjects per clinic who were in need of a minimum of two dental implants to restore a partially edentulous quadrant and were followed for a minimum of 1 year after loading. A centralized Internet-based case report form was developed to coordinate data recording. Data entry was done by each clinic, with follow-up source verification. Results: The study recruited 549 subjects in 101 clinics with 1,893 implants placed. Three hundred forty subjects completed the 1-year recall (gender distribution of 56% female, 44% male; mean age of 57 years with a range of 18 to 84 years). In all, 1,246 dental implants were followed; a majority of subjects had two to four implants. Twenty-eight percent of subjects received osseous grafting prior to or coincident with implant placement. In the maxilla, 779 (63%) implants were placed, 256 in the anterior and 523 in the posterior; in the mandible, 467 implants were placed, 85 in the anterior and 382 in the posterior arch. The median edentulous period prior to implant placement was 24 months (range, 0 to 480 months); 46% of all patients received implants within 12 months of tooth loss. At 1 year after prosthesis insertion, 15 subjects had lost a total of 17 implants, for a cumulative implant survival rate of 98.6%. Chi-square and Fisher exact tests indicated a higher risk of implant loss at sites with advanced resorption and for wider-diameter implants (5-mm tapered body). There was no statistical relationship with implant loss relative to implant length or anatomic location within the oral cavity. Conclusions: The outcomes support the need for ongoing involvement of clinicians in routine practice assessments of patient-based outcomes of implant therapy. Keywords: clinical trial, effectiveness trial, outcomes, risk factors, trial design