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This paper aims to use cone-beam computed tomography (CBCT) and computer-aided design/3D printing technology to design and fabricate a drill guide template for access cavity preparation of permanent molars, and conduct a preliminary evaluation of its effectiveness.

CBCT scans were performed on two permanent maxillary first molars extracted due to periodontitis. Based on the scans, guide templates of access cavities were designed. The angle of the guiding cylinders was determined based on the direction of the long axis of the tooth. A 3D resin printer with high resolution was used to print the guide templates. The printed guide templates were used by a dentist with specialized clinical experience to perform access cavity preparation in a dental simulator. Then the prepared access cavities were scanned again by CBCT, and scan data were compared to the design data.

The 3D printed drill guide template had a close fit with the extracted tooth fit. The access cavity prepared using the guide template enabled the removal of the pulp chamber roof, and formed a straight-line access. Points were selected for measurement at regularly spaced intervals of 0.5 mm along the side wall of the access cavity. The mean deviation between the actual access cavities of the two permanent maxillary first molars and the designed cavities was less than 0.1 mm, with a maximum deviation of about 0.5 mm, showing a good conformance between the actual cavity and the designed cavity.

A drill guide template was designed and fabricated by 3D printing technology, which easily guided burs to complete the access cavity preparation work forming an ideal cavity shape with satisfying accuracy, and thus may reduce the complications during pulp chamber entry.

The purpose is to realize precise apicoectomy with less surgical risk and improved quality and efficiency.

First, the procedure of precise apicoectomy based on additive manufacturing (AM) and digital design is proposed. With CT images of the patient's oral, a 3D model of alveolar bone and teeth is reconstructed, and based on this model, the infected tissue and enclosed root tip can be determined. Thus, a surgical plan can be created based on clear anatomical relationships and minimal negative constraints, which will then determine the drill position, direction and depth, as well as the resection length of root tip. With this plan, a surgical guide design is performed via a composite model from reversed plaster models and hard tissue models from CT, and accessory tools including drill with stop plane and handle are also selected. With the surgical guide, the virtual plan in the computer can be realized in the clinic.

With this methodology, the dentist can perform root-end resection with greater accuracy, save more than 30 percent of operatory time, and the discomfort to the patient is reduced to a minimum.

The proposed methodology has been used in ten cases for root-end resections. In fact, this method of designing a computer-based treatment plan with a 3D model of a patient and applying it in the clinic through guiding tools can be used in other surgeries, such as orthognathic surgery or osteotomy.

This case report illustrates that with AM and digital design methods, optimal operational plans can be designed and realized for apicoectomy, and the quality and efficiency of clinical surgery are greatly improved compared with conventional methods.

This paper aims to present a new design for removable partial dentures (RPDs) for partially edentulous patients to improve the efficiency and quality of RPD manufacturing. Additive and subtractive manufacturing technologies and zirconium silicate micro-ceramic bonding in the aesthetic zone are used herein.

A case was presented. First, RPD digital definitive casts were acquired, and then digital frameworks with crown retainers and digital crowns were obtained by computer-aided design (CAD). The titanium alloy frameworks and resin crowns were fabricated by three-dimensional (3D) printing and computer-aided manufacturing (CAM) processes, respectively. The crowns adhered to the crown retainers. Ceramage bonding was used to reform the gingival anatomy in the aesthetic zone during the fabrication of the RPDs. The finished RPDs were assessed by a clinician and delivered to the patient.

The RPDs were conventionally assessed by a clinician, were deemed to be accurate and satisfied both the patient and clinician.

This novel method provides a way to fabricate RPDs with a combination of additive and subtractive manufacturing technologies. The design of the framework was different from that of a conventional framework because it contained the crown retainers, and the traditional base retainer no longer existed. Ceramage bonding was used to replicate the gingival anatomy in the aesthetic zone. The new RPDs provided accuracy and were less time-consuming to produce than those produced with the traditional method. The new method enables the digital manufacturing of nearly the entire RPDs.

The purpose of this paper is to assess the fatigue life of different sizes of HyFlex CM™ endodontic files when submitted to planar or to non-planar curvatures, and to two different rotational speeds, namely 500 rpm or 250 rpm. The influence of superimposing back and forth motion to rotational bending of endodontic files was also assessed.

In all, 64 HyFlex CM™ files of different sizes, namely ref. 0.04/20, 0.06/20, 0.04/35 and 0.06/35, were submitted to rotational bending tests at two different rotational speeds. The planar radius of curvature imposed to the endodontic files was about 4.5 mm, along an angle of 45°, in order to simulate an apical canal that would induce severe loading to the files during clinical treatment. Additionally, 11 Hyflex CM™ files ref. 0.04/20 were submitted to rotational bending tests at 500 rpm inside a mandible first molar manufactured through selective laser melting (SLM), aiming to simulate non-planar curvatures of a real tooth canal.

When considering planar curvature, the endodontic file ref. 0.06/20, tested at 250 rpm, has shown the highest fatigue resistance (4,185 revolutions, 1,004 seconds), while the lowest fatigue resistance was registered for instrument ref. 0.04/35 submitted to 500 rpm (747 revolutions, 89 seconds). Hence, depending on the rotational speed, surface finish and the size of the endodontic files tested (taper and tip’s diameter), significant differences in fatigue resistance were noticed. If non-planar curvatures were considered, the minimum fatigue resistance was equal to 107 seconds, and back and forth motion allowed extending the minimum fatigue lifetime to 140 seconds.

The fatigue resistance of endodontic files is frequently determined through in vitro fatigue tests carried out under single planar curvature or eventually under double planar curvatures. However, non-planar loadings are frequently induced on endodontic instruments when treating root canals with severe multiplanar curvatures. In the research herein presented, a mandible first molar was 3D printed by using the SLM technique in an AISI 316 L stainless steel and more realistic experimental fatigue tests were carried out.

Closure of a Hospital in an area with a high percentage of elderly people created a need for good‐quality, cost‐effective rehabilitation services. The paper describes the setting up of a rehabilitation team and centre, and the benefits that it has provided.

The ecological decline of ancient Near Eastern civilizations and the violent and explosive characteristics of post‐Columbian colonial ecologies might well remain comfortably remote from us in our twentieth century world were it not for the disturbing parallels that such case histories seem to evoke as we consider our contemporary global circumstance. Just as in ancient times and in the age of colonial expansion, it is in the “remote environments,” usually quite distant from the centers of power, that the crucial indicators of environmental catastrophe first become apparent within the system as a whole. These regions are frequently characterized by weak economies and highly vulnerable ecosystems in our time, just as they were in the past. Accordingly, the environmental circumstances in these regions constitute for the modern world a kind of monitoring device that can provide early warnings of ecological instabilities in the global ecosystem.

Hospitality and Tourism.

Senior undergraduate level and graduate level.

This case study charts out the development of a business plan for Ch’ulel Mendoza, a hypothetical all-villa resort nestled against the Andes Mountains, where guests enjoy luxurious wine-infused spa treatments. The business plan has to be comprehensive because it should become the basis of a turnkey project for potential investors. Ch’ulel Mendoza is surrounded by the lush vineyards of some of the most famous wine estates in Argentina. The spa, facilities and services pay homage to the wine-growing heritage of the region, promoting wine to its guests as both pleasurable for consumption and conducive to healthy living. The architectural design speaks directly to the vines themselves: the earth-covered spa is where guests soak up the healing nutrients in the vinotherapy and water treatments, much like the roots are nourished by the elements and water in the soil; the resort area embraces the outdoors with decks, open patios and pools where guests can bask in the sun and enjoy other natural elements, just like the grape plants themselves. Once it becomes operational, Ch’ulel Mendoza will symbolize a blend of wellness, recreation and the charm of the Latin American culture.

Develop a comprehensive business plan for a new business, understand the business environment, prepare a strengths, weaknesses, opportunities and weaknesses analysis, develop functional (marketing, finance, human resources, operations, etc.) plans and understand the opportunities and challenges in the new product development process.

CSS: 12: Tourism and Hospitality.

This paper explores four works of contemporary fiction to illuminate formal and informal regulation of sex. The paper’s co-authors frame analysis with the story of their creation of a transdisciplinary course, entitled “Regulating Sex: Historical and Cultural Encounters,” in which students mined literature for social critique, became immersed in the study of law and its limits, and developed increased sensitivity to power, its uses, and abuses. The paper demonstrates the value theoretically and pedagogically of third-wave feminisms, wild zones, and contact zones as analytic constructs and contends that including sex and sexualities in conversations transforms personal experience, education, society, and culture, including law.