Publications by authors named "Christopher Herpel"

Objectives: To evaluate the effect of accelerated firing on 3D-printed zirconia.

Methods: To check if formulae provided by ISO 6872 can be extended to thin samples, finite element analyses were carried out in advance of fabricating 3-mol% yttria-stabilized tetragonal zirconia polycrystal discs by milling and by 3D-printing. Four groups (n = 38 each) of 3D-printed specimens were produced with two nominal thicknesses (0.

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Virtual reality (VR) has been shown to be effective in pain management. However, to date, little is known about the mechanisms by which immersive experiences influence pain processing. The aim of this study was to investigate the direct effects of an immersive VR environment on the perception of experimental pain in individuals with chronic pain and pain-free controls.

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Article Synopsis
  • A study aimed to assess the effects of two types of dental appliances on oral health after head and neck radiotherapy, comparing thermoplastic dental splints with semi-individualized, 3D-printed tissue retraction devices (TRDs).
  • The pilot trial included 29 patients, measuring saliva quality, taste perception, and oral disability before and three months after starting treatment.
  • Results showed no significant differences in taste perception or oral disability between the two groups, but TRDs suggested a slight advantage in saliva quantity and overall outcomes, although the small sample size warrants caution in interpreting these findings.
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Radiotherapy with protons or light ions can offer accurate and precise treatment delivery. Accurate knowledge of the stopping power ratio (SPR) distribution of the tissues in the patient is crucial for improving dose prediction in patients during planning. However, materials of uncertain stoichiometric composition such as dental implant and restoration materials can substantially impair particle therapy treatment planning due to related SPR prediction uncertainties.

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Objectives: To compare the clinical performance of occlusal splints printed from thermo-flexible resin with milled splints.

Methods: A parallel two-arm pilot trial was initiated. Forty-seven patients (n women=38) were recruited from a tertiary care center and randomized using an online tool (sealed envelope).

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Head and neck pain drawings have been introduced as part of the diagnostic gold standard for temporomandibular disorders (TMD). We aimed to quantify the spatial extent of pain in TMD patients and to analyze its association with further clinical findings. In a cross-sectional study, 90 patients (median age = 38 years; n women = 68) were diagnosed according to the DC/TMD.

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Objectives: To evaluate the fit of zirconia veneers made by either 3D printing or milling.

Methods: A typodont maxillary central incisor was prepared for a 0.5-mm-thick veneer and was reproduced 36 times from resin.

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Objectives: The purpose of this study was to analyze the color infiltration in monolithic zirconia after grinding, which plays an essential role in the color stability of restorations after occlusal adjustment.

Methods: One hundred and eight white zirconia plates (36 Dentsply Sirona-Cercon high translucency [C], 36 Zirkonzahn-Prettau [P], 36 Zirkonzahn-Prettau anterior [Pa]) were stained by infiltration with target colors Vita A2, A3.5, and A4.

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This study aimed to investigate the geometric reproducibility of three-dimensional (3D) implant planning based on magnetic resonance imaging (MRI) and cone-beam computed tomography (CBCT). Four raters used a backward-planning approach based on CBCT imaging and standard software to position 41 implants in 27 patients. Implant planning was repeated, and the first and second plans were analyzed for geometric differences regarding implant tip, entry-level, and axis.

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The treatment of a 57-year-old woman with combined skeletal and pseudo-class III malocclusion who was also suffering from chronic myofascial orofacial pain is described. The challenge was to treat the patient's malocclusion while simultaneously managing the temporomandibular disorder. After a successful 3-month occlusal device therapy, which substantially reduced the patient's discomfort, a nonsurgical therapy by using complete-mouth fixed restorations was planned.

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Objectives: Computer-aided design and manufacturing (CAD/CAM) has been successfully used to replace conventional steps in the fabrication of double crowns, creating hybrid-workflows that might facilitate the wider application of these restorations in the future. However, in-vivo data are still lacking.

Methods: A prospective clinical trial was designed in which 20 patients (median age = 69 years; n women = 10) with 73 abutment teeth who needed a double-crown-retained removable partial denture (RPD) were consecutively recruited.

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Objectives: In recent years, computer-aided design/computer-aided manufacturing (CAD/CAM) has been used to produce removable complete dentures. Most workflows include fabrication of milled or 3D-printed try-in prostheses. 3D-printing accuracy is affected by laboratory-specific and operator-dependent factors.

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Objectives: Evaluating structural changes in oral epithelium can assist with the diagnosis of cancerous lesions. Two-dimensional (2D) non-invasive optical coherence tomography (OCT) is an established technique for this purpose. The objective of this study was to develop and test the diagnostic accuracy of a three-dimensional (3D) evaluation method.

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Statement Of Problem: Monolithic zirconia restorations have become popular because of their excellent mechanical properties and acceptable esthetics. While the biomechanical properties of zirconia have been investigated, research into their esthetic properties is sparse. Zirconia can be colored by infiltration before sintering, although how occlusal adjustment can affect restoration color is unclear.

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Tissue retraction devices (TRDs) are used for head and neck radiotherapy to displace soft tissues and fixate the mandible. They can increase the accuracy of irradiation and reduce its side effects, such as oral mucositis. However, no method has been described for fabrication of TRDs in edentulous patients.

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Background: Despite modern treatment techniques, radiotherapy (RT) in patients with head and neck cancer (HNC) may be associated with high rates of acute and late treatment-related toxicity. The most effective approach to reduce sequelae after RT is to avoid as best as possible healthy tissues and organs at risk from the radiation target volume. Even small geometric changes can lead to a significant dose reduction in normal tissue and better treatment tolerability.

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Background: Radiotherapy for head and neck cancer may cause various oral sequelae, such as radiation-induced mucositis. To protect healthy tissue from irradiation, intraoral devices can be used. Current tissue retraction devices (TRDs) have to be either individually manufactured at considerable cost and time expenditure or they are limited in their variability.

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Objective: To meet esthetic requirements, monolithic zirconia can be stained by color-infiltration. However, adjustments of occlusal surfaces are often necessary, leading to demasking effects if too much of the color-infiltrated layer is removed. The effect of subsequent material removal on color stability of individually stained zirconia is analyzed here.

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