Translucent monolithic zirconia titanium-supported FP1 full-arch prosthesis: A novel proof of concept to address esthetic, functional, and biologic challenges.

OBJECTIVE: Despite the wide clinical use of translucent zirconia for full-arch implant prostheses, reduced flexural strength and fracture toughness compared with high-strength opaque zirconia needs to be addressed. A novel proof of concept for FP1 full-arch prosthesis featured by translucent monolithic zirconia and titanium framework was presented. CLINICAL CONSIDERATIONS: Computer-guided implant planning and surgery were executed and digitally designed FP1 temporary prosthesis prefabricated. Implant and prosthetic placement were achieved with a set of three-dimensional (3D)-printed templates. Implants were immediately loaded. After 4 months intraoral optical scan was taken to record implant coordinates, soft tissue anatomy, and temporary FP1 prosthesis. A novel digital workflow was used to design and mill overlaying translucent zirconia and anatomically shaped titanium framework with a scalloped soft-tissue interface. Final FP1 prosthesis was assembled cementing zirconia jacket on titanium counterpart. CONCLUSIONS: Translucent zirconia supported by titanium framework can address esthetic and mechanical requirements of FP1 full-arch prosthesis, minimizing risk of fracture and providing a rigid and passive joint with supporting implants. The smooth and highly polished titanium surface with an anatomic design, tightly matching scalloped soft tissue interface, can limit food impaction, air and saliva leakage and contribute to overall biologic integration of FP1 full-arch prosthesis. CLINICAL SIGNIFICANCE: Translucent monolithic zirconia featured with anatomically shaped titanium framework with scalloped transmucosal part, combining a pleasant esthetic outcome with increased flexural strength and fracture toughness, may be indicated to increase the clinical performance of FP1 full-arch prosthesis.

Assessment of Various Risk Factors for Biological and Mechanical/Technical Complications in Fixed Implant Prosthetic Therapy: A Retrospective Study.

The goals of this research were to determine the influence of several factors on implants' biological and technical complications in posterior fixed implant prosthetic therapy. MATERIALS AND METHODS: The study group consisted of 67 edentulous patients (mean age: 63.88 ± 11.709 yrs; 20 males, 47 females) with implant prosthetic therapy for posterior edentulism. A total of 76 implant-supported fixed partial dentures (IP-FPDs) and 178 implants were assessed using clinical and paraclinical assessments. Risk factors for biological complications (peri-implantitis) and technical complications were determined by using the Pearson Chi-squared test and multivariate analysis. RESULTS: The implant success (the absence of biological and mechanical/technical complications) was 66.30%. The prevalence of biological complications was 13.5%. The prevalence of technical complications was 28.70%. Variables that were associated with a higher risk of peri-implantitis were poor oral hygiene and bruxism. In univariate analysis, poor oral hygiene increased the risk of peri-implantitis 5.778 times and bruxism 5.875 times. Variables that were associated with a higher risk of mechanical/technical complications were age group > 60 yrs, smoking, history of periodontal disease, and bruxism. In univariate analysis, the risk of technical complications increased 4.14 times for patients in the age group > 60 years (vs. age group 40-60 years) and 20.5 times for patients with bruxism. Bruxism and smoking were significant predictors of mechanical/technical complications in the multivariate model. CONCLUSIONS: In univariate models, patients with poor oral hygiene and bruxism have an increased risk of peri-implantitis. In multivariate models, we did not identify significant predictors of peri-implantitis. Age group > 60 yrs, smoking, history of periodontal disease, bone grafting, and bruxism are risk factors for the increase in the mechanical/technical complication rate. In the multivariate model, smoking and bruxism are significant predictors of the mechanical/technical complications.

Clinical Advances in Implant Transmucosal Contouring for Single Implant Sites: Prosthetic and Biologic Considerations.

Current evidence suggests that proper implant transmucosal contouring can significantly impact supracrestal soft tissue development and crestal bone response both in early and late stages of treatment. The macrodesign and composition of the anatomical healing abutment or temporary prosthesis used during transmucosal contouring are crucial elements for establishing biologic and prosthetic conditions that minimize early bone remodeling, improve esthetic outcomes, and reduce the possibility for future peri-implant inflammation. This article presents clinical directions on the design and fabrication processes of anatomical healing abutments or temporary prostheses for single implant sites under the interpretation of currently available scientific data.

Immediate One-Time Low-Profile Abutment to Enhance Peri-implant Soft and Hard Tissue Stability in the Esthetic Zone.

Reductions in peri-implant bone height have been acknowledged as a normal consequence of implant therapy. Various restorative factors contribute to this phenomenon. One is repeated abutment retightening, which causes a mechanical disruption at the implant-abutment interface, leading to soft tissue recession. Several investigators proposed placement of the definitive abutment after implant placement as a solution to the problem. The definitive use of an intermediate abutment after implant placement seems to positively affect the soft tissue response. This article aims to present a prosthetic sequence for achieving peri-implant tissue stability in the esthetic zone.

Surgical and prosthetic dental rehabilitation through a complete digital workflow - A case report.

Several aspects of digital dentistry have recently been improved, including new materials, navigated implant placement, digital impression in combination with virtual articulation, and the computer-aided processes of designing and manufacturing of prosthetic restorations. In this case report, the prosthodontic treatment of a patient through a complete digital workflow is presented. A 39-year-old male patient presented for restoration of missing teeth in the posterior maxilla and mandible. In a single-tooth narrow gap (region 15), a Straumann NNC implant was placed by computer-assisted planning and navigation. For the rest of the missing teeth, ZrO2 fixed dental prostheses (FDPs) were manufactured by a computer-aided design/computer- aided manufacturing (CAD/CAM) system after optical impression with an intraoral scanner (iTero), and data transferal to a virtual articulator (Ceramill Artex). Rehabilitation through a complete digital workflow is a promising technology in terms of accuracy, reduced workload, greater control over the final product, and minimally invasive procedures. These advantages may have a potential positive effect with regard to patient satisfaction compared with conventional methods.

A Case Series Treatment Outcome Report Following 5 Years of Implant Overdenture Treatment.

PURPOSE: To assess clinical performance of bar-retained implant overdentures (IOs) with distally placed ERA attachments on four implants, and patient satisfaction after a follow-up period of 5 years in a convenience selection of 15 patients. MATERIALS AND METHODS: Bar-retained IOs with distally placed ERA attachments were placed and clinically monitored. Encountered complications during a 5-year follow-up period were recorded; and a modified OHIP-14 questionnaire was used to assess patient satisfaction. RESULTS: Implant and restoration survival rates of 97.5% and 100%, respectively, were recorded. The most common maintenance requirement was the replacement of ERA retentive elements. A high degree of patient satisfaction was reported. CONCLUSIONS: The proposed IO design is a reliable clinical treatment protocol associated with a high degree of patient satisfaction and minor prosthetic complications.

Restoration of divergent implants with a 2-piece screw-retained fixed, complete dental implant prostheses.

Restoring a severely resorbed maxilla is challenging because of poor bone quality and the resorptive pattern that follows tooth loss. When bone augmentation is not possible, implants are placed in suboptimal positions, making the prosthetic rehabilitation more complex. This report presents the steps used to rehabilitate a severely resorbed maxilla with divergent implants, using an implant-supported 2-piece screw-retained prosthesis.

Definitive abutment-driven stage-two surgery as a means to reduce peri-implant soft tissue changes: introduction of a new concept.

This report introduces an innovative approach for optimizing esthetics and minimizing soft tissue changes in clinical scenarios that involve extensive site preparation and submerged implants. The existing soft tissue morphology is registered at the time of implant uncovery, and an optimal peri-implant transmucosal contour is created indirectly in the lab. The customized definitive abutment is inserted during stage-two surgery and subsequently guides the peri-implant soft tissue, replicating an optimal emergence profile. The concept is demonstrated through the presentation of two clinical cases.

Esthetic considerations when replacing missing maxillary incisors with implants: a clinical report.

Restoring missing maxillary incisors with implants is both challenging and demanding for the clinician. Decisions concerning the number, position, and diameter of implants are crucial to achieve an optimal esthetic result, especially in patients with increased vertical and horizontal overlap. This clinical report presents a treatment where 2 narrow implants, placed in the maxillary lateral incisor positions of the maxilla, support the restoration of the 4 missing incisors. Despite meticulous surgical and restorative treatment procedures, the use of gingiva-colored veneering material was required to achieve a satisfactory esthetic outcome.

Treatment of hemi-mandibulectomy defect with implant-supported telescopic removable prosthesis. A clinical report.

Excision of head and neck tumors (benign or malignant) often leads to large segmental resections of the mandible. The following clinical report describes the oral rehabilitation of a 60-year-old Caucasian man after partial mandibulectomy due to primary oral leiomyosarcoma. Treatment consisted of a free fibula flap and an implant-supported telescopic removable prosthesis.

Identification of monoclinic phase in CAD/CAM zirconia FPD frameworks.

OBJECTIVE: The aim of this study was to identify the presence of monoclinic zirconia phase (m-ZrO2) in 5 computeraided design/computer-assisted manufacture zirconia systems composed of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). MATERIALS AND METHODS: Three-unit fixedpartial dentures were prepared from Cercon (CR); Lava (LW); Zenotec Zr Bridge (WD); In-Ceram YZ (YZ); and IPS e-max ZirCAD (ZC), all milled in a pre-sintered stage and then fully sintered according to the manufacturers' instructions. Raman spectroscopy was used to identify and map the distribution of the m-ZrO2 phase at cervical crown margins, pontic and connector regions. Three sets of data were obtained from each material (n = 2) and the percentage volume (%Vm) of the m-ZrO2 phase was calculated per region. Statistical analysis was performed by two-way analysis of variance and Tukey test (a = 0.05). RESULTS: The m-ZrO2 phase was detected in all the specimens, with the highest intensity located at the crown margins. WD showed the lowest %Vm content (0- 3.14%), followed by LW (10.26-12.39%), CR (11.72-13.19%), ZC (11.13-14.10%) and YZ (12.15-14.99%). No statistically significant difference was found among LW, CR, ZC, YZ per region. Within each material group, significant differences were found between margin-pontic/connector (WD, YZ), margin-connector (CR, ZC) and margin-pontic (LW). SIGNIFICANCE: The Y-TZP destabilizing m-ZrO2 phase was identified in all the fully sintered frameworks tested, with the highest %Vm located at the margins. The extent to which the presence of this phase may be implicated with zirconia low temperature degradation or porcelain to zirconia bonding is unknown.

X-ray microtomographic evaluation of the influence of two preparation types on marginal fit of CAD/CAM alumina copings: a pilot study.

This study evaluated the influence of two preparation types on the marginal fit of computer-aided design/computer-assisted manufacture (CAD/CAM) alumina copings. Two subgroups of four alumina copings each were fabricated using alumina master dies with either a chamfer or 90-degree shoulder preparation. Copings were scanned with an x-ray microtomographic scanner, and marginal fit was evaluated. The preparation types presented no statistically significant differences regarding marginal gap (P = .410) and absolute marginal discrepancy (P = .229). No correlation was found between marginal fit of CAD/CAM alumina copings and preparation type. Marginal fit could be considered within the limits of clinical acceptance.

Micro-CT evaluation of the marginal fit of different In-Ceram alumina copings.

The aim of the study was to evaluate the marginal fit of different In-Ceram alumina ceramic cores manufactured by four different techniques. Four groups of four In-Ceram alumina core specimens (Vita), each 0.6 mm in thickness, were fabricated from a master die using four different techniques: Group SL, the slip-cast technique (In-Ceram system); Group CL, the copy-milling technique (Celay system); Group CR, a CAD/CAM system (Cerec inLab system) and Group WO, the electro-deposition dipping technique (Wol-Ceram). After the core specimens were fitted on the master die, they were scanned with the use of a microtomography device (1072 micro-CT, Sky- Scan). Datasets were processed by software (TView v1.1, SkyScan) and 10 vertical sections from each core were generated. On these microtomographic cross-sections the marginal gap (MG) and the absolute marginal discrepancy (MD) were measured in microscale (microm). The slip-cast and the electro-deposition dipping techniques presented the best results of MG with 22 microm and 35 microm, respectively (alpha<5%). The CAD/CAM system presented an MG of 55 microm. In addition, the slip-cast and the electro-deposition dipping techniques presented the best results of MD with 50 microm and 60 microm, respectively (alpha<5%). The slip-cast technique and the Wol-Ceram system presented the best marginal fit, followed by Cerec inLab, which presented clinically acceptable results. Microtomography analysis seemed to be a reliable method of evaluating the marginal fit of dental restorations.

Zirconia in dentistry: part 2. Evidence-based clinical breakthrough.

An ideal all-ceramic restoration that conforms well and demonstrates enhanced biocompatibility, strength, fit, and esthetics has always been desirable in clinical dentistry. However, the inherent brittleness, low flexural strength, and fracture toughness of conventional glass and alumina ceramics have been the main obstacles for extensive use. The recent introduction of zirconia-based ceramics as a restorative dental material has generated considerable interest in the dental community, which has been expressed with extensive industrial, clinical, and research activity. Contemporary zirconia powder technology contributes to the fabrication of new biocompatible all-ceramic restorations with improved physical properties for a wide range of promising clinical applications. Especially with the development of computer-aided design (CAD)/computer-aided manufacturing (CAM) systems, high-strength zirconia frameworks can be viable for the fabrication of full and partial coverage crowns, fixed partial dentures, veneers, posts and/or cores, primary double crowns, implant abutments, and implants. Data from laboratory and clinical studies are promising regarding their performance and survival. However, clinical data are considered insufficient and the identified premature complications should guide future research. In addition, different zirconia-based dental auxiliary components (i.e., cutting burs and surgical drills, extra-coronal attachments and orthodontic brackets) can also be technologically feasible. This review aims to present and discuss zirconia manufacturing methods and their potential for successful clinical application in dentistry.