Screw Access Mark for Cemented Implant Crowns: A Universal Technique to Simplify Retrievability.

The use of cemented implant prostheses for partially edentulous patients continues to increase in clinical practice. One of the primary complications of the cemented implant crown is difficulty in retrieval, should the need arise. Drilling through most prosthetic materials is of little difficulty for most clinicians, but the complication lies in determining where exactly the access hole needs to be drilled. During fabrication, the location of the screw access channel is marked with a strong contrasting color stain on the surface of the prosthesis. The technique proposed here marks the location of the screw access directly on the prosthesis, thus improving the ease and predictability of future retrieval.

An electromagnetic thermotherapy system with a deep penetration depth for percutaneous thermal ablation.

Thermal ablation has been a promising method to remove the cancerous tissues. Electromagnetic-based thermotherapy has been extensively investigated for a variety of medical applications recently. In this study, a prototype electromagnetic thermotherapy system has been developed with a new coil design and a two-section needle. The coil can generate an alternating electromagnetic field (EMF) with a deep penetration depth to remotely heat the needle which is located up to 15 cm away, enabling percutaneous thermal ablation. Several important parameters, including the heating effects of the needle at different positions, the intensity of the EMF and the induced temperature distribution on the surrounding tissue, are first explored. An in vitro animal experiment has also been performed which shows EMF-induced ablation in a porcine liver by the needle. Furthermore, an in vivo experiment on an animal model (a New Zealand white rabbit) is also conducted in the study. Thus, the two-section needle combined with the coil-generated EMF has been demonstrated to be a promising thermotherapy system for percutaneous thermal ablation.

Screw-access marking: a technique to simplify retrieval of cement-retained implant prostheses.

One of the commonly cited disadvantages of cement-retained implant prostheses is their inability to be retrievable. The screw-access marking technique discussed in this article allows for any clinician, at any time, to simply and predictably retrieve the cemented implant prosthesis. By applying a discrete, but easily recognizable, marking on the occlusal surface of the restoration, the entry point into the screw-access chamber can be precisely and safely created. The screw-access marking technique is efficient, effective, and widely applicable.

Immediate implant-supported provisional restoration with a root-form pontic for the replacement of two adjacent anterior maxillary teeth: A clinical report.

In implant therapy, the replacement of 2 adjacent maxillary anterior teeth presents several unique challenges: mesiodistal space constraints, the need to maintain or create natural gingival esthetics, the need for esthetic provisional restorations, and the management of nonaxial forces. The treatment presented addresses these challenges through the use of an immediately placed single implant at the central incisor position with a central to lateral incisor cantilever prosthesis in both the immediate provisional and definitive restorations. The provisional restoration was designed to minimize pressure on the surgical site, optimize space for the gingival tissues, and control occlusal loading of the implant during the initial stages of osseointegration. The pontic was modified to replicate the subgingival root anatomy and enhance the gingival esthetic outcome.

Abutment emergence modification for immediate implant provisional restorations.

UNLABELLED: In their stock form, some titanium provisional implant abutments are not ideally designed for use in immediate placement/immediate provisional restoration treatment. This is largely due to the apical flare design that applies excessive pressure to the peri-implant soft tissue complex and crestal bone. This appears to have the undesirable effect of increasing peri-implant bone resorption and severely impeding the potential for increases in gingival volume. This type of stock titanium abutment will therefore benefit significantly from recontouring. The subgingival portion of the abutment is recontoured from the flared stock shape to a straight or parallel design. This modification minimizes pressure on the surgical site and provides additional space around the subgingival portion of the provisional restoration, within which the gingiva has the potential to remodel and fill. This allows the potential formation of additional peri-implant gingival volume and a coronal maintenance or migration of the soft tissue complex. In order to minimize the "graying effect" of titanium abutments, the retentive portion is opaqued by the technician or clinician. These modifications will improve the potential outcomes for both the peri-implant gingiva and the provisional restoration. CLINICAL SIGNIFICANCE: Narrowing the emergence profile of implant abutments for use in immediate implant provisional restorations appears to allow for creation of greater peri-implant volume. Thus resulting in increased esthetic potential and predictability of the peri-implant gingiva.

Partial nephrectomy without renal ischemia using an electromagnetic thermal surgery system in a porcine model.

OBJECTIVE: To test the feasibility of partial nephrectomy using needle arrays under alternating current (AC) electromagnetic field without renal artery clamping. METHODS: We performed an experimental study for partial nephrectomy without renal artery clamping in a porcine model, comparing a new thermal surgery system consisting of an AC electromagnetic field generator and stainless steel needle arrays (using 10 pigs) vs an ultrasonic Harmonic Scalpel (on 8 pigs). Two cm of the upper pole of the kidneys were resected, and then the feasibility, operation time, blood loss, biochemical parameters, pathology, and complications were observed for 14 days. RESULTS: There was no difference by weight in the mean percentage of kidney removed between the 2 groups (8.1 ± 3.4% vs 12.7 ± 5.5%). The estimated blood loss for the partial nephrectomy with electromagnetic thermal surgery system was significantly less compared to the ultrasonic Harmonic Scalpel (53.0 ± 73.0 vs 188.8 ± 49.3 mL). Transection time was shorter with the electromagnetic thermal surgery system (10 vs 12 minutes). Bleeding from the cut surface after partial nephrectomy was noted in 2 pigs (electromagnetic surgery group) and 8 pigs (control group); all the bleeding was controlled with additional monopolar electrocoagulation and sutures. No urinoma was identified in either group when a second laparotomy was performed 2 weeks later. CONCLUSION: Our study of a partial nephrectomy in a porcine model demonstrates that the heat generated by the electromagnetic thermal surgery system is sufficient to coagulate renal parenchyma and to seal off the blood vessels without pedicle clamping.

Dual-row needle arrays under an electromagnetic thermotherapy system for bloodless liver resection surgery.

Electromagnetic thermotherapy has been extensively investigated recently and may become a new surgical modality for a variety of medical applications. It applies a high-frequency alternating magnetic field to heat up magnetic materials inserted within the human body to generate tissue coagulation or cell apoptosis. Using a new procedure with dual-row needle arrays under an electromagnetic thermotherapy system with a feedback temperature control system, this study demonstrates bloodless porcine liver resection, which is challenging using existing methods. In vitro experiments showed that hollowed, stainless-steel needles could be heated up to more than 300 °C within 30 s when centered under the induction coils of the electromagnetic thermotherapy system. In order to generate a wide ablation zone and to prevent the dual-row needle arrays from sticking to the tissue after heating, a constant temperature of 120 °C was applied using a specific treatment protocol. The temperature distribution in the porcine livers was also measured to explore the effective coagulation area. Liver resection was then performed in Lan-Yu pigs. Experimental results showed that seven pigs underwent liver resection without bleeding during surgery and no complications afterward. The dual-row needle arrays combined with the electromagnetic thermotherapy system are thus shown to be promising for bloodless tissue resection.

Dentist-technician collaboration in the digital age: enhancing outcomes through photography, teamwork, and technology.

The cornerstone of a strong and successful dentist-technician relationship is communication. High-level collaboration across distances requires modern technology to communicate expectations, potential outcomes, and limitations. Carefully calibrated digital photography is an essential element in this inherently artistic process. This ensures a system of checks and balances to minimize the potential for miscommunication and remakes. Forthcoming technologies will allow dentist-technician teams to reach ever-greater levels of collaboration.

Maximizing esthetic results on zirconia-based restorations.

With a flexural strength of approximately 900-1,100 MPa, zirconium oxide is one of the toughest all-ceramic materials available in dentistry.1 It can be used to fabricate both single-unit and long-span bridge frameworks. A moderate level of translucency makes it suitable for esthetically demanding clinical cases, such as restoring maxillary anterior teeth. A variety of well-designed porcelain veneering systems allow technicians to apply their artistic skills to create natural, lifelike restorations. A good balance of strength, precision, and translucency allows zirconia-based restorations to accommodate a variety of clinical situations.