Perceptibility and acceptability thresholds for color differences of light and dark maxillofacial skin replications.

The aim of this study was to assess the perceptibility and acceptability thresholds of maxillofacial silicones for light and dark skin colors and to evaluate the effect of gender and professional experience on these thresholds. Two different sets of specimens (as light and dark) each, consisting of 14 (25 × 25 × 6-mm) silicone skin replications, were produced. Four specimens of each set were produced from the same silicon mixture of the relevant set and polymerized simultaneously to provide standardized fabrication conditions.

Comparison of Screw Loosening and Fracture Resistance in Different Hybrid Abutment Crown Restorations After Thermomechanical Aging.

Purpose: To investigate the screw loosening and fracture resistance of different hybrid abutment crown restorations after thermomechanical aging.

Materials And Methods: Restorations were produced from zirconia, lithium disilicate, and hybrid ceramics with a CAD/CAM system (n = 10). Restorations and titanium bases (Ti-bases) were cemented, and the abutment screws were torqued to 30 Ncm.

Translucency Parameters and Masking Abilities of Monolithic CAD/CAM Ceramics.

Purpose: To compare the translucency parameters and masking abilities of different monolithic CAD/CAM ceramics placed on different-colored substructures.

Materials And Methods: Square-shaped specimens (12 × 12 × 1.5 mm) were prepared from feldspathic (C), leucite (EMP), lithium disilicate (e.

Fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses after artificial aging.

This study compared the fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses (FDPs) generated by computer-aided design/computer-aided manufacturing (CAD/CAM) after aging in a mastication simulator. Four-unit FDPs were designed from six different all-ceramic systems: 1) monolithic lithium disilicate (M-E), 2) monolithic zirconia (M-TZI), 3) veneered zirconia by conventional layering (V-L), 4) veneered zirconia by lithium disilicate pressing (V-P), 5) veneered zirconia by lithium disilicate fusing (CAD-F-E), and 6) veneered zirconia by feldspathic ceramic cementing (CAD-C-CB). The specimens were divided into control and aging groups (n = 10 per group).

Multidisciplinary rehabilitation of eosinophilic granuloma with bone graft surgery and a modified implant-supported hybrid prosthesis: A case report with a 6-year follow-up.

Eosinophilic granuloma is the most common form of Langerhans cell histiocytosis and corresponds with bone lesions characterized by pain, rapid growth, and high tendency of recurrence after inadequate curettage. It is a rare disease that is difficult to diagnose clinically and radiographically because it mimics other odontogenic cysts and tumors. In this report, the reconstruction of an osseous defect with an iliac graft and a modified implant-supported hybrid prosthesis after surgical excision of an eosinophilic granuloma in the mandible of a 27-year-old male patient was described.

Effect of surface treatments on shear bond strength of resin composite bonded to CAD/CAM resin-ceramic hybrid materials.

Purpose: The purpose of this study was to assess the effect of surface treatments on shear bond strength of resin composite bonded to thermocycled and non-thermocycled CAD/CAM resin-ceramic hybrid materials.

Materials And Methods: 120 specimens (10×10×2 mm) from each material were divided into 12 groups according to different surface treatments in combination with thermal aging procedures. Surface treatment methods were airborne-particle abrasion (abraded with 50 micron alumina particles), dry grinding (grinded with 125 µm grain size bur), and hydrofluoric acid (9%) and silane application.

Clinical and radiographic evaluation of new dental implant system: Results of a 3-year prospective study.

Background/purpose: The aim of this study was to evaluate implant survival, crestal bone level changes, and clinical parameters of IDcam dental implants over a mean follow-up period of 3 years.

Materials And Methods: Seventy-two patients, 32 females and 40 males, received 255 implants. Implant-supported metal-ceramic fixed restorations were inserted.

Finite element analysis of stress distribution with splinted and nonsplinted maxillary anterior fixed prostheses supported by zirconia or titanium implants.

Purpose: The aim of the present study was to evaluate the effect of splinting titanium (Ti) or zirconia (Zr) implants supporting maxillary anterior fixed prostheses on the stress levels and patterns in the implants, prostheses, and the surrounding bone; and to compare the effects of Zr and Ti implant materials on the stress distribution in splinted and nonsplinted designs via finite element modeling.

Materials And Methods: Zr and Ti dental implants and the anterior maxilla were modeled. In the nonsplinted design (D1), implants were placed into the maxillary left central incisor and canine regions, and a three-unit zirconia fixed prosthesis was modeled.

Quality of life of patients with implant-retained maxillofacial prostheses: a prospective and retrospective study.

Statement Of Problem: Clinical studies on implant-retained maxillofacial prostheses have focused on biological outcomes. An assessment of the effect of prostheses on patients' quality of life (QOL) by using specific questionnaires developed for this patient population provides important information on treatment outcomes from the patients' perspectives.

Purpose: The purpose of this study was to report patient-based outcomes of implant-retained maxillofacial prostheses and to evaluate the effect of implant-retained maxillofacial prostheses on QOL of participants in a prospective study.

Effect of fatigue on fracture toughness and phase transformation of Y-TZP ceramics by X-ray diffraction and Raman spectroscopy.

The aim of this study was to evaluate the effect of fatigue on fracture toughness and phase transformation of yttria-stabilized zirconia polycrystal materials (Cercon and Lava). The specimens were tested for indentation fracture toughness either with or without being subjected to fatigue (20,000 cycles, 2 Hz, 200 N load). X-ray diffraction (XRD) analysis was used to examine the phase composition of specimens.

Three-dimensional finite element analysis of titanium and yttrium-stabilized zirconium dioxide abutments and implants.

Purpose: The purpose of this study was to compare the von Mises (vM), compressive, and tensile stresses occurring on implants, abutments, and surrounding bone using three-dimensional finite element analysis (FEA) in three simulations in the anterior maxilla: a single titanium implant with a titanium abutment, a single titanium implant with a zirconia abutment, and a single one-piece zirconia implant.

Materials And Methods: Three types of implants (all were 4 x 12 mm) were modeled using FEA: Astra OsseoSpeed implant with titanium abutment (ATt), Astra OsseoSpeed with zirconia abutment (ATz), and White-SKY (WS) one-piece zirconia dental implant. The anterior maxillary bone was also simulated with FEA.

A method for fabricating an implant-retained orbital prosthesis using the existing prosthesis.

This article describes a time-saving technique for fabricating a new implant-retained orbital prosthesis using the patient's existing prosthesis. The location of the ocular component is transferred; the position and openings of the palpebral anatomic structures and the precise anatomic details of the existing orbital prosthesis are duplicated. Making the impression, fabricating the definitive cast, alignment of the ocular component, and completing the wax sculpture of the prosthesis are accomplished in one appointment.

Cytotoxicity of composite resins before and after expiration date. Preliminary report.

The aim of this study was to compare the cytotoxic effects of expired and non-expired resin-based composite materials at two, five and seven days on L929 cells. Disc-shaped test samples of expired and non-expired composite materials were prepared according to manufacturers' instructions. The samples were transferred into a culture medium for 24 hours.

Effect of fatigue on biaxial flexural strength of bilayered porcelain/zirconia (Y-TZP) dental ceramics.

Objectives: The aim of this study was to evaluate the effect of fatigue on biaxial flexural strength of bilayered disks of two Y-TZP cores.

Methods: Twenty bilayered veneer/zirconia disks were fabricated from each material (Lava veneer+core, 3M/ESPE, and Cercon veneer+core, Densply). Ten specimens from each material were tested for biaxial flexural strength either with or without being subjected to fatigue (20,000 cycles, 2 Hz, 200 N load) in a universal testing machine (1mm/min).

Two-year study of alternative conservative treatment modalities for early anterior permanent tooth loss.

Premature tooth loss in children may consist of single or multiple, primary or permanent, and anterior or posterior units of the dentition. This tooth loss may be due to either trauma or caries and, in some cases, to congenital or genetic defects. With anterior tooth loss cases, there are several problems the dental practitioner must consider.

Evaluation of stresses occurring on three different zirconia dental implants: three-dimensional finite element analysis.

Purpose: The aim of this study was to evaluate the von Mises, compressive, and tensile stresses occurring on three different zirconia dental implants and surrounding bone with three-dimensional finite element analysis.

Materials And Methods: Three different zirconia implants (Z-Systems, Ziterion, and White-Sky), 10 mm in length and 4 mm in diameter, and anterior maxillary bone were modeled using three-dimensional finite element analyses. Zirconia implants were placed into the maxillary left central incisor region.

Retrospective study of treatment outcomes with implant-retained extraoral prostheses: survival rates and prosthetic complications.

Statement Of Problem: Implant-retained extraoral prostheses are an acceptable solution for patients with facial defects. However, these prostheses have a limited service life. Little has been reported on survival periods of implant-retained extraoral prostheses and prosthetic complications of this treatment modality.

Radiation-induced leiomyosarcoma of the maxillofacial region: facial reconstruction with implant-retained prosthesis.

Radiation-induced sarcoma represents an exceptional rarity in the head and neck region. The treatment is surgical excision with negative margins and follow-up. After surgery, reconstruction of the defects can be accomplished either surgically or prosthetically.

Initial stability of two dental implant systems: influence of buccolingual width and probe orientation on resonance frequency measurements.

Background: Although many factors seem to have an impact on the resonance frequency (RF) values of implants, there is a lack of evidence about some other parameters, which may have an influence on implant stability.

Purpose: The aims of the study were to determine whether initial stability of a dental implant differs when the buccolingual width of the bone changes, to determine whether different orientations affect the RF measurements in the RF device, and to investigate two dental implants with different morphologies with regard to their initial stability.

Materials And Methods: Two implant systems (Tidal Spiral Dental Implant Systems, Huntsville, AL, USA, and MIS Seven, MIS Implants Technologies Ltd.

Histopathologic study of rat connective tissue responses to maxillofacial silicone elastomers.

The aim of this histopathologic study was to assess and compare the subcutaneous connective tissue reaction to three different maxillofacial silicone elastomers (Cosmesil, Multisil, Episil). The test materials were directly inserted subcutaneously into the dorsal subcutaneous tissue of Wistar albino rats. Histopathological examinations were done at 7, 30, and 90 days after the implantation procedure.

Survival rates and periimplant soft tissue evaluation of extraoral implants over a mean follow-up period of three years.

Statement Of Problem: The use of implants with extraoral prostheses provides excellent support, stability, and retention, thereby offering the potential for improving a patient's appearance and quality of life. However, few studies have examined cumulative survival rates of extraoral implants, nor have these reports documented long-term aspects of treatment, such as soft tissue health around abutments.

Purpose: The purpose of this study was to evaluate the survival rates and the periimplant soft tissue responses of extraoral implants used to retain facial prostheses.

In vitro cytotoxicity of maxillofacial silicone elastomers: effect of accelerated aging.

The purpose of this in vitro study was to evaluate the cytotoxicity of three maxillofacial silicone elastomers at 24, 48, and 72 h on L-929 cells and to determine the effect of accelerated aging on the cytotoxicity of these silicone elastomers. Disc-shaped test samples of maxillofacial silicone elastomers (Cosmesil, Episil, Multisil) were fabricated according to manufacturers' instructions under aseptic conditions. Samples were then divided into three groups: (1) not aged; (2) aged for 150 h with an accelerated weathering tester; and (3) aged for 300 h.

A pilot study to evaluate the adhesion of oral microorganisms to temporary soft lining materials.

The aim of the study was to compare the adhesion of oral microorganisms to different types of soft liner and acrylic resin surfaces. Three different soft lining materials were applied to cavities formed on the fitting surfaces of prostheses in 17 patients. On days 1, 7 and 14, the specimens were taken out and immediately processed for bacteriological evaluation.

Treatment considerations for a patient with hypohidrotic ectodermal dysplasia: a case report.

Aim: This clinical report describes the oral rehabilitation of a 6-year-old male ectodermal dysplasia (ED) patient diagnosed with hypodontia.

Background: ED is a hereditary disease characterized by a congenital dysplasia of one or more ectodermal structures and their accessory appendages. Common manifestations include defective hair follicles and eyebrows, frontal bossing with prominent supraorbital ridges, nasal bridge depression, and protuberant lips.

Reconstruction of total maxillectomy defect with implant-retained obturator prosthesis.

Total maxillectomy is a relatively uncommon surgical procedure. Lack of support, retention and stability are common prosthodontic treatment problems for patients who have had a maxillectomy. This clinical report describes the prosthodontic management of a patient treated for plasmacytoma who required a bilateral maxillectomy after the radiotherapy.