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Concept: CAD/CAM Dentistry

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SUMMARY Fracture resistance of inlays and onlays may be influenced by the quantity of the dental structure removed and the restorative materials used. The purpose of this in vitro study was to evaluate the effects of two different cavity preparation designs and all-ceramic restorative materials on the fracture resistance of the tooth-restoration complex. Fifty mandibular third molar teeth were randomly divided into the following five groups: group 1: intact teeth (control); group 2: inlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press, Ivoclar Vivadent AG, Schaan, Liechtenstein); group 3: inlay preparations, zirconia ceramic (ICE Zirkon, Zirkonzahn SRL, Gais, Italy); group 4: onlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press); and group 5: onlay preparations, zirconia ceramic (ICE Zirkon). The inlay and onlay restorations were adhesively cemented with dual polymerizing resin cement (Variolink II, Ivoclar Vivadent AG). After thermal cycling (5° to 55°C × 5000 cycles), specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. Statistical analyses were performed using one-way analysis of variance and Tukey HSD tests. The fracture strength values were significantly higher in the inlay group (2646.7 ± 360.4) restored with lithium-disilicate glass-ceramic than those of the onlay group (1673.6 ± 677) restored with lithium-disilicate glass-ceramic. The fracture strength values of teeth restored with inlays using zirconia ceramic (2849 ± 328) and onlays with zirconia ceramic (2796.3 ± 337.3) were similar to those of the intact teeth (2905.3 ± 398.8). In the IPS e.max Press groups, as the preparation amount was increased (from inlay to onlay preparation), the fracture resistance was decreased. In the ICE Zirkon ceramic groups, the preparation type did not affect the fracture resistance results.

Concepts: Analysis of variance, Teeth, FIA, CAD/CAM Dentistry, Touring car racing, Dental restoration, Crown, Inlays and onlays

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Alveolar distraction osteogenesis (ADO), a novel bone augmentation technique, is gaining acceptance in restoring the vertical bone discrepancy between the transplanted graft and the residual alveolar bone after mandibular reconstruction. This case series presents the outcomes of ADO in fibula-reconstructed mandibles rehabilitated with dental implants, with an emphasis on clinical indications, surgical protocol, clinical outcomes, histologic evidence, and complications.

Concepts: CAD/CAM Dentistry, Osseointegration, Dentistry, Implants, Oral and maxillofacial surgery, Dental implant

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Background The authors describe our current practice of computer-aided virtual planned and pre-executed surgeries using microvascular free tissue transfer with immediate placement of implants and dental prosthetics.Methods All patients with ameloblastomas treated at New York University (NYU) Medical Center during a 10-year period from September 2001 to December 2011 were identified. Of the 38 (36 mandible/2 maxilla) patients that were treated in this time period, 20 were identified with advanced disease (giant ameloblastoma) requiring aggressive resection. Reconstruction of the resultant defects utilized microvascular free tissue transfer with an osseocutaneous fibular flap in all 20 of these patients.Results Of the patients reconstructed with free vascularized tissue transfer, 35% (7/20) developed complications. There were two complete flap failures with consequent contralateral fibula flap placement. Sixteen patients to date have undergone placement of endosteal implants for complete dental rehabilitation, nine of which received immediate placement of the implants at the time of the free flap reconstruction. The three most recent patients received immediate placement of dental implants at the time of microvascular free tissue transfer as well as concurrent placement of dental prosthesis.Conclusions To our knowledge, this patient cohort represents the largest series of comprehensive computer aided free-flap reconstruction with dental restoration for giant type ameloblastoma.

Concepts: Dentistry, Implants, Periodization, CAD/CAM Dentistry, Free flap, Dental implant, Computer-aided design, Oral and maxillofacial surgery

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Routine reconstruction of subtotal defects of the mandible and orthopedic rehabilitation supported by dental implants is achieved by means of detailed planning and lasts over a year. This article shows the outcomes of single-stage surgical treatment and immediate orthopedic rehabilitation performed with the help of preoperative virtual computer simulation. 3D investigation of pathological and donor sites, virtual simulation of tumor resection, positioning of the dental implants into fibula, virtual flap bending and transfer, virtual bending of fixing reconstruction plates, and fabrication of navigation templates and bridge prosthesis supported by dental implants were done preoperatively. The surgery included tumor resection, insertion of dental implants into fibula, elevation of fibula osteocutaneous free flap, rigid fixation within recipient site, and immediate loading by bridge orthopedic device. On 10-month follow-up, functional and esthetic results were asses as reasonable. Radiography showed dental implants to be integrated and positioned appropriately. We found that successful rehabilitation of the patients with extensive defects of the jaws could be achieved by ablative tumor resection, dental implants insertion prior to flap elevation guided by navigation templates, further osteotomy, modeling of the flap based on navigation template, flap transfer, and rigid fixation within recipient site by prebended plates, with application of prefabricated prosthesis.

Concepts: Nobel Biocare, CAD/CAM Dentistry, Computer simulation, Prosthetics, Dentistry, Implants, Dental implant, Oral and maxillofacial surgery

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Preclinical dental students must demonstrate aptitude in the preparation of teeth for treatment with several types of fixed dental prostheses. The optimal sequence of instruction and examination of these crown preparations in preclinical fixed prosthodontics is unknown. The aim of this study was to determine if grading scores by faculty and students were affected by changing the sequence of crown type preparations. Practical exams of two successive student cohorts (n=89 in 2014; n=92 in 2015) at one U.S. dental school using three crown preparations (full cast, porcelain fused to metal, and all-ceramic) in different order were analyzed by faculty grades and student self-assessment. All of the models indicated that the sequence in which the crown type preparations were taught did have an effect on the grades. The 2014 cohort had overall higher grades and particularly higher grades for the all-ceramic crown preparations. Evaluation scores were affected by the sequence in which the different crown type preparations were taught and tested. Although the overall results suggested that students may perform better if the all-ceramic crown preparation is taught last, this tendency may differ between years.

Concepts: Inlays and onlays, Fixed prosthodontics, Restorative dentistry, CAD/CAM Dentistry, Crown, Prosthodontology, Bridge, Dental restoration

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A historical area of referral involves the placement of dental implants. Because there is a high demand for dental implant therapy and relatively few general dentists participating in the surgical aspect, it is important to investigate referral characteristics to specialists. The authors conducted a study in which 6,769 general dentists and specialists were emailed an anonymous online survey. Study participants were given a series of eight questions and asked to rank the importance levels of each when dealing with dental implant referrals. General dentists found that office location and insurance were important factors when making a dental implant referral. Specialists did not find any particular attribute to be significantly important. When the two groups were evaluated, communication, quality of work, and, to a lesser extent, accepted insurance were found to be important attributes to both general dentists and specialists. The results of this research suggest there is a positive correlation among general dentists and specialists in regard to communication, quality of work, and, to a lesser extent, accepted insurance.

Concepts: Characteristic, CAD/CAM Dentistry, Attribute, Osseointegration, Implants, Oral and maxillofacial surgery, Dentistry, Dental implant

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This study compared stability, removal torque, bone implant contact (BIC) and area (BA) of implants installed simultaneously with onlay autografts or allografts in rabbits' tibias.

Concepts: Dentistry, Restorative dentistry, Dental restoration, Osseointegration, CAD/CAM Dentistry, Implants, Dental implant

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Maintenance or reconstruction of interproximal papilla for a successful dental implant restoration can be challenging. To date, the results from various surgical and prosthetic techniques to maintain or regenerate papilla adjacent to dental implants have been unpredictable. To maintain the quality of the soft tissue around an implant, the blood supply must be preserved and formation of scar tissue must be minimized during surgery. Therefore, incision design is vital to producing an esthetic and successful dental implant restoration. In this study, specific incision designs and soft tissue management techniques were used to preserve or create interproximal papilla around single or adjacent implants.

Concepts: CAD/CAM Dentistry, Blood, Osseointegration, Prosthetics, Oral and maxillofacial surgery, Dentistry, Implants, Dental implant

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To investigate the longevity and reasons for failure of posterior cast Class II gold inlays and onlays among a group of Norwegian adults. The term inlay was used for both inlays and onlays.

Concepts: CAD/CAM Dentistry, Dental restoration, Crown, Inlays and onlays