El grafeno en la rehabilitación bucal y su comportamiento biológico: caso clínico / Graphene in oral rehabilitation and its biological behavior: a clinical case

El grafeno y sus derivados son muy utilizados en ciencia y tecnología por los beneficios que otorgan sus propiedades fisicoquímicas. En el área de la salud en particular, se destacan sus propiedades biológicas debido a su elevada biocompatibilidad, interacción celular y su actividad antibacteriana. La incorporación de grafeno en ciertos materiales permite obtener un material combinado con propiedades mejoradas. Un ejemplo de ello es la incorporación industrial de óxido de grafeno en metacrilato de metilo para generar un polímero (PMMA) mejorado, no solo desde el punto de vista mecánico, sino también una notoria ventaja en la respuesta biológica de los tejidos blandos. Este artículo describe el caso clínico de un paciente de 70 años, que concurrió a la consulta buscando alternativas de tratamiento para mejorar la retención y estabilidad de las prótesis para optimizar la función masticatoria, una alternativa que impacte positivamente sobre su calidad de vida. El plan de tratamiento contempló el reemplazo de las prótesis removibles por prótesis híbridas en ambos maxilares, confeccionadas con PMMA modificado industrialmente con óxido de grafeno, previa colocación de cinco implantes en cada arco (AU)

Graphene and its derivatives are widely used in science and technology due to the benefits provided by their physicochemical properties. In the health area, specifically, its biological properties stand out, due to its high biocompatibility, cellular interaction, and its antibacterial activity. The incorporation of graphene in certain materials allows obtaining a combined material with improved properties. An example of this is the industrial incorporation of graphene oxide in methyl methacrylate, to generate an improved polymer (PMMA), not only from a mechanical point of view, but also a notable advantage in the biological response of soft tissues. This article describes the clinical case of a 70-year-old patient, who attended the consultation looking for treatment alternatives to improve the retention and stability of the prostheses to optimize the masticatory function, or an alternative that had a positive impact on their quality of lifetime. The treatment plan contemplated the replacement of removable prostheses with hybrid prostheses in both jaws, made with PMMA industrially modified with graphene oxide, after placing five implants in each arch (AU)

Evaluation of physical-mechanical properties, antibacterial effect, and cytotoxicity of temporary restorative materials

Abstract The objective of this study was to compare selective physical-mechanical properties, antibacterial effects and cytotoxicity of seven temporary restorative materials (TRM): five resin-based materials [Bioplic (B), Fill Magic Tempo (FM), Fermit inlay (F), Luxatemp LC (L) and Revotek LC (R)], and zinc oxide-eugenol cement (IRM) and glass ionomer cement (GIC) as the controls. Material and methods The physical-mechanical properties were evaluated by determining microleakage (ML), ultimate tensile strength (UTS) and Shore D hardness (SDH). In addition, the polymerization rate (Pr-1), depth of cure (DC), water sorption and solubility (WS/SL) were evaluated. The antimicrobial effects of the materials were assessed by biofilm accumulation of Streptococcus mutans (BT) and the direct contact test (DCT) by exposure to Enterococcus faecalis for 1 and 24 h, and cytotoxicity by MTT assay. The data were analyzed by ANOVA or Kruskall-Wallis tests, and a complementary post-hoc method (p<0.05). Results Group B, followed by FM and GIC had significantly lower percentages of microleakage in comparison with the other groups; Groups FM and L showed the highest WS, while Groups R and FM showed the significantly lowest SL values (p<0.05). Group R showed the statistically highest UTS mean and the lowest DC mean among all groups. Group F showed the lowest S. mutans biofilm accumulation (p=0.023). Only the Group L showed continued effect against E. faecalis after 1 h and 24 h in DCT. The L showed statistically lower viability cell when compared to the other groups. Conclusions These findings suggest the antibacterial effect of the temporary materials Fill Magic and Bioplic against S. mutans, while Luxatemp showed in vitro inhibition of S. mutans biofilm accumulation and E. faecalis growth. Regarding the cell viability test, Luxatemp was the most cytotoxic and Fill Magic was shown to be the least cytotoxic.

Tomographic imaging of fragmented cortical bone heteroimplant and methylmethacrylate in segmental bone defect of rabbit tibia

PURPOSE: To evaluate the performance of composites consisting of fragmented cortical bone heteroimplant in association with methylmethacrylate preserved in 98% glycerin, in segmental bone defect of rabbit tibia medial metaphysis. METHODS: In this study were used twelve adult New Zealand rabbits, divided into three groups of four animals each: G30 (30 days), G60 (60 days) and G90 (90 days). The bone defects previously created in the tibia were filled with composites and both were evaluated by cone-beam computed tomography, immediately after surgery and after 30, 60, and 90 days. RESULTS: The composites fulfilled and remained in the sites of bone defects in all cases and were not registered signals of infection, migration or rejection. CONCLUSIONS: The implanted composites promoted the bone defects repair without signals of infection and/or rejection. The composites are one more option for bone defects repair.

Tomographic imaging of fragmented cortical bone heteroimplant and methylmethacrylate in segmental bone defect of rabbit tibia

PURPOSE: To evaluate the performance of composites consisting of fragmented cortical bone heteroimplant in association with methylmethacrylate preserved in 98% glycerin, in segmental bone defect of rabbit tibia medial metaphysis. METHODS: In this study were used twelve adult New Zealand rabbits, divided into three groups of four animals each: G30 (30 days), G60 (60 days) and G90 (90 days). The bone defects previously created in the tibia were filled with composites and both were evaluated by cone-beam computed tomography, immediately after surgery and after 30, 60, and 90 days. RESULTS: The composites fulfilled and remained in the sites of bone defects in all cases and were not registered signals of infection, migration or rejection. CONCLUSIONS: The implanted composites promoted the bone defects repair without signals of infection and/or rejection. The composites are one more option for bone defects repair. .

Optimization and characterization of curcumin-piperine dual drug loaded self-microemulsifying drug delivery system by simplex lattice design / 中国中药杂志

The objective of the study was to prepare and evaluate the quality of curcumin-piperinedual drug loaded self-microemulsifying drug delivery system(Cur-PIP-SMEDDS). Simplex lattice design was constructed using optimal oil phase, surfactant and co-surfactant concentration as independent variables, and the curcumin and piperine were used as model drugs to optimize Cur-PIP-SMEDDS formulation. In the present study, the drug loadings of curcumin and piperine, mean particle size of Cur-PIP-SMEDDS were made as indicators, and the experiment design, model building and response surface analysis were established using Design Expert 8. 06 software to optimize and verify the composition of SMEDDS formulation. The quality of Cur-PIP-SMEDDS was evaluated by observing the appearance status, transmission electron microscope micrographs and determining particle diameter, electric potential, drug entrapment efficiency and drug loading of it. As a result, the optimal formulation of SMEDDS was CapryoL 90-Cremophor RH40-TranscutoL HP (10:60:30). The appearance of Cur-PIP-SMEDDS remained clarified and transparent, and the microemulsion droplets appeared spherical without aggregation with uniform particle size distribution. The mean size of microemulsion droplet formed from Cur-PIP-SMEDDS was 15.33 nm, the drug loading of SMEDDS for Cur and PIP were 40.90 mg · g(-1) and 0.97 mg · g(-1), respectively, the drug entrapment efficiency were 94.98% and 90.96%, respectively. The results show that Cur-PIP-SMEDDS can increase the solubility and stability of curcumin significantly, in the expectation of enhancing the bioavailability of it. Taken together, these findings can provide the reference to a preferable choice of the Cur formulation and contribute to therapeutic application in clinical research.

Bacterial entombment by intratubular mineralization following orthograde mineral trioxide aggregate obturation: a scanning electron microscopy study / 国际口腔科学杂志·英文版

The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n=10) was filled with phosphate buffered saline (PBS); Group 2 (n=10) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n=20) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA-PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.

Effects of surface treatment of provisional crowns on the shear bond strength of brackets

OBJECTIVE: To assess the adhesive resistance of metallic brackets bonded to temporary crowns made of acrylic resin after different surface treatments. METHODS: 180 specimens were made of Duralay and randomly divided into 6 groups (n = 30) according to surface treatment and bonding material: G1 - surface roughening with Soflex and bonding with Duralay; G2 - roughening with aluminum oxide blasting and bonding with Duralay; G3 - application of monomer and bonding with Duralay; G4 - roughening with Soflex and bonding with Transbond XT; G5 - roughening with aluminum oxide blasting and bonding with Transbond XT and G6: application of monomer and bonding with Transbond. The results were statistically assessed by ANOVA/Games-Howell. RESULTS: The means (MPa) were: G1= 18.04, G2= 22.64, G3= 22.4, G4= 9.71, G5= 11.23, G6= 9.67. The Adhesive Remnant Index (ARI) ranged between 2 and 3 on G1, G2 and G3 whereas in G4, G5 and G6 it ranged from 0 to 1, showing that only the material affects the pattern of adhesive flaw. CONCLUSION: The surface treatment and the material influenced adhesive resistance of brackets bonded to temporary crowns. Roughening by aluminum blasting increased bond strength when compared to Soflex, in the group bonded with Duralay. The bond strength of Duralay acrylic resin was superior to that of Transbond XT composite resin.

OBJETIVO: avaliar a resistência adesiva de braquetes metálicos colados a coroas provisórias confeccionadas em resina acrílica após diferentes tratamentos de superfície. MÉTODOS: cento e oitenta corpos de prova foram confeccionados em Duralay e divididos aleatoriamente em seis grupos (n = 30), de acordo com tratamento de superfície e material de colagem: grupo 1, asperização da superfície com Soflex e colagem com Duralay; grupo 2, asperização com jato de óxido de alumínio e colagem com Duralay; grupo 3, aplicação de monômero e colagem com Duralay; grupo 4, asperização com Soflex e colagem com Transbond XT; grupo 5, asperização com jato de óxido de alumínio e colagem com Transbond XT; e grupo 6, aplicação de monômero e colagem com Transbond. Os resultados foram tratados estatisticamente pela ANOVA e pelo teste de Games-Howell. RESULTADOS: as médias (MPa) foram: grupo 1 - 18,04; grupo 2 - 22,64; grupo 3 - 22,4; grupo 4 - 9,71; grupo 5 - 11,23; grupo 6 - 9,67. O índice de remanescente adesivo (ARI) variou entre 2 e 3 nos grupos 1, 2 e 3. Já nos grupos 4, 5 e 6, variou entre 0 e 1, demonstrando que apenas o material influencia o padrão de falha adesiva. CONCLUSÃO: o tratamento de superfície e o material influenciaram a resistência adesiva dos braquetes colados à coroas provisórias. A asperização por jato de óxido de alumínio elevou a resistência de união quando comparada ao Soflex, no grupo colado com Duralay. A resistência adesiva da resina acrílica Duralay foi superior à da resina composta Transbond XT.

Push-out bond strengths of fiber-reinforced composite posts with various resin cements according to the root level

PURPOSE: The aim of this study was to determine whether the push-out bond strengths between the radicular dentin and fiber reinforced-composite (FRC) posts with various resin cements decreased or not, according to the coronal, middle or apical level of the root. MATERIALS AND METHODS: FRC posts were cemented with one of five resin cement groups (RelyX Unicem: Uni, Contax with activator & LuxaCore-Dual: LuA, Contax & LuxaCore-Dual: Lu, Panavia F 2.0: PA, Super-Bond C&B: SB) into extracted human mandibular premolars. The roots were sliced into discs at the coronal, middle and apical levels. Push-out bond strength tests were performed with a universal testing machine at a crosshead speed of 0.5 mm/min, and the failure aspect was analyzed. RESULTS: There were no significant differences (P>.05) in the bond strengths of the different resin cements at the coronal level, but there were significant differences in the bond strengths at the middle and apical levels (P.05); all other groups had a significant decrease in bond strength at the middle or apical level (P<.05). The failure aspect was dominantly cohesive at the coronal level of all resin cements (P<.05), whereas it was dominantly adhesive at the apical level. CONCLUSION: All resin cement groups showed decreases in bond strengths at the middle or apical level except LuA and Uni.

Disseminated Neonatal Herpes Simplex Virus Infection / 대한구급학회지

Disseminated neonatal herpes simplex virus (HSV) infection is one of the most severe neonatal infections, and can have devastating consequences without early proper treatment. However, the administration of acyclovir can often be delayed because the symptoms and signs of HSV infection are non-specific and because HSV polymerase chain reaction (PCR) results may be negative early in the course of HSV infection. We report a case of disseminated neonatal HSV infection that was diagnosed by type 1 HSV PCR on day 8 of admission. Despite delayed administration of acyclovir, the patient was cured and subsequently discharged after 30 days of admission. Fortunately, this patient was treated successfully, but delayed administration of acyclovir has the potential to lead to significant problems. Considering the seriousness of neonatal HSV infection, empirical acyclovir therapy should be considered if HSV infection is suspected.

The effect of surface treatment conditioning on shear bond strength between zirconia and dental resin cements / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the effect of surface treatment on the shear bond strength of zirconia ceramic to 3 resin cements. MATERIALS AND METHODS: A total of 143 disk-shaped Zirconia blocks (HASS Co., Gangneung, Korea) were randomly divided into three treatment groups: (1) only 50 microm Al2O3 sandblasting, (2) 50 microm Al2O3 sandblast and zircona liner, (3) 50 microm Al2O3 sandblasting and Rocatec (3M ESPE, Seefeld, Germany). Bistite II (Tokuyama Dental Co., Japan), Panavia F (Kuraray Medical, Japan), and Superbond C&B (Sun Medical, Japan) were used to cement onto the zirconia. After 24h of storage in distilled water, shear bond strength was evaluated. High value group was re-tested after thermocycling at 5,000 cycles(5-55degreesC). Shear bond strength data were analyzed with one-way ANOVA, two-way ANOVA test and Post Hoc Test (alpha=.05). Shear bond strength data before and after thermocycling were analyzed with Independent sample T test (alpha=.05). RESULTS: Super-bond C&B treated with Rocatec showed the most high shear bond strength. Super-bond C&B groups resulted in significantly higher than other cement groups (P<.05). Rocatec groups resulted in significantly higher than other surface treatment groups (P<.05). Shear bond strength has increased in Panavia F treated with Zirconia liner (P<.05). After thermocycling, shear bond strength was increased in Super-bond C&B treated with Rocatec but decreased in other groups (P<.05). CONCLUSION: Super-bond C&B cement resulted the highest shear bond strength and Rocatec system enhanced the shear bond strength. After thermocycling, shear bond strength has decreased in most resin cements except Super-bond C&B treated with Rocatec.

Telemedicine of Skin Diseases in Ulleung Island / 대한피부과학회지

BACKGROUND: Telemedicine can be useful in dermatology on Ulleung island which is 217 km away from Pohang and without dermatologists. OBJECTIVE: The purpose of this study is to measure the effectiveness of telemedicine in treating skin diseases on Ulleung island. METHODS: 33 patients on Ulleung island were examined by a fullmotion real-time video by one dermatologist in a Dongsan hospital of Keimyung University once a week. From June 2011 to June 2012, there have been 53 treatments of telemedicine in 33 patients. RESULTS: 14 diseases were found in 33 patients. The most common disease group was infectious skin disease and eczema in 9 patients. In addition, there were other skin diseases such as acne vulgaris, allergic contact dermatitis, prurigo nodularis, lichen simplex chronicus, malignant melanoma, seborrheic dermatitis, polymorphous light eruption and so on. CONCLUSION: Dermatology favors telemedicine because we had investigated its value and possibilities by clinical experience of telemedicine between Ulleung island and Dongsan medical center in Daegu.

Upper Gastrointestinal Hemorrhage from Esophageal Ulcer Caused by Coinfection of Herpes Simplex Virus and Cytomegalovirus in Immunocompromised Patient

Coinfection with herpes simplex virus and cytomegalovirus is a very rare cause of esophageal ulcer and upper gastrointestinal hemorrhage. A 26 year-old male kidney transplant recipient was referred with a complaint of melena. Upper gastrointestinal endoscopy showed a huge esophageal ulcer in the anastomosis site of the esophagogastrostomy. The ulcer occupied about two-thirds of the circumference of the esophageal lumen and an exposed vessel in the ulcer base was noted. Pathologic findings with immunohistochemical stain showed co-infection of herpes simplex virus and cytomegalovirus. He was treated successfully with endoscopic hemostasis and antiviral therapy. We report a case of upper gastrointestinal hemorrhage from esophageal ulcer caused by coinfection of herpes simplex virus and cytomegalovirus.

Upper Gastrointestinal Hemorrhage from Esophageal Ulcer Caused by Coinfection of Herpes Simplex Virus and Cytomegalovirus in Immunocompromised Patient

Coinfection with herpes simplex virus and cytomegalovirus is a very rare cause of esophageal ulcer and upper gastrointestinal hemorrhage. A 26 year-old male kidney transplant recipient was referred with a complaint of melena. Upper gastrointestinal endoscopy showed a huge esophageal ulcer in the anastomosis site of the esophagogastrostomy. The ulcer occupied about two-thirds of the circumference of the esophageal lumen and an exposed vessel in the ulcer base was noted. Pathologic findings with immunohistochemical stain showed co-infection of herpes simplex virus and cytomegalovirus. He was treated successfully with endoscopic hemostasis and antiviral therapy. We report a case of upper gastrointestinal hemorrhage from esophageal ulcer caused by coinfection of herpes simplex virus and cytomegalovirus.

A case of familial X-linked thrombocytopenia with a novel WAS gene mutation / 소아과

Wiskott-Aldrich syndrome (WAS) is an inherited X-linked disorder. The WAS gene is located on the X chromosome and undergoes mutations, which affect various domains of the WAS protein, resulting in recurrent infection, eczema, and thrombocytopenia. However, the clinical features and severity of the disease vary according to the type of mutations in the WAS gene. Here, we describe the case of a 4-year-old boy with a history of marked thrombocytopenia since birth, who presented with recurrent herpes simplex infection and late onset of eczema. Examination of his family history revealed that older brother, who died from intracranial hemorrhage, had chronic idiopathic thrombocytopenia. Therefore, we proceeded with genetic analysis and found a new deletion mutation in the WAS gene: c.858delC (p.ser287Leufs*21) as a hemizygous form.

A Case of Epidermolysis Bullosa Simplex (Other Generalized Type) / 대한피부과학회지

The other generalized type of epidermolysis bullosa simplex (EBS) is a genetic blistering skin disease, caused by a mutation of the genes encoding keratin 5 and 14. EBS starts at birth and is characterized by generalized blisters following a minor trauma that heals with hyperpigmentation. A 19-year-old man presented with 19-year history of multiple erythematous vesicles in a herpetiform arrangement on the trunk, axilla, and thigh with post-inflammatory hyper-pigmentations. On light and electron microscopy, the biopsy specimen showed intraepidermal blisters that formed within the basal keratinocyte. The serum from a patient with bullous pemphigoid antibody and laminin 5 antibody showed the linear deposition at the floor of the blister on immunofluorescence mapping study. On the basis of our clinical, microscopic, and immunofluorescence findings, we diagnosed the patient as having a generalized type of EBS. Herein, we report on an interesting case of the other generalized type of EBS.

Herpes Simplex Encephalitis Suffered Rotatory Dizziness as a Primary Symptom / 대한평형의학회지

Herpes simplex encephalitis (HSE) is rare, serious sporadic encephalitis associated with high mortality in untreated cases. Although cognitive impairment with fever could be the clue of diagnosis, various symptoms can make it difficult to be diagnosed. Dizziness is one of the most frequent symptoms ENT doctors can encounter. Authors experienced the HSE patient suffered rotatory sense of dizziness as a primary symptom and treated the patient successfully without major complication. We reported our experience and findings of vestibular function test of patient. It could be helpful to other ENT doctors who encounter similar patients.

A comparison of the accuracy of patterns processed from an inlay casting wax, an auto-polymerized resin and a light-cured resin pattern material.

Background: Traditionally, inlay casting waxes have been used to fabricate patterns for castings. Newer resin pattern materials offer greater rigidity and strength, allowing easier laboratory and intraoral adjustment without the fear of pattern damage. They also claim to possess a greater dimensional stability when compared to inlay wax. Aims: This study attempted to determine and compare the marginal accuracy of patterns fabricated from an inlay casting wax, an autopolymerized pattern resin and a light polymerized pattern resin on storage off the die for varying time intervals. Materials and Methods: Ten patterns each were fabricated from an inlay casting wax (GC Corp., Tokyo, Japan), an autopolymerized resin pattern material (Pattern resin, GC Corp, Tokyo, Japan) and a light-cured resin pattern material (Palavit GLC, Hereaus Kulzer GmbH, Germany). The completed patterns were stored off the die at room temperature. Marginal gaps were evaluated by reseating the patterns on their respective dies and observing it under a stereomicroscope at 1, 12, and 24 h intervals after pattern fabrication. Results: The results revealed that the inlay wax showed a significantly greater marginal discrepancy at the 12 and 24 h intervals. The autopolymerized resin showed an initial (at 1 h) marginal discrepancy slightly greater than inlay wax, but showed a significantly less marginal gap (as compared to inlay wax) at the other two time intervals. The light-cured resin proved to be significantly more dimensionally stable, and showed minimal change during the storage period. Conclusion: The resin pattern materials studied, undergo a significantly less dimensional change than the inlay waxes on prolonged storage. They would possibly be a better alternative to inlay wax in situations requiring high precision or when delayed investment (more than 1 h) of patterns can be expected.

Evaluation of tensile bond strength of heat cure and autopolymerizing silicone-based resilient denture liners before and after thermocycling.

Aim: To assess the effect of simulated mouth conditions reproduced with thermocycling on the tensile bond strength of two silicone based resilient denture liners with acrylic resin bases. Materials and Methods: Two silicone-based soft denture liners (Mollosil - Chairside autopolymerization and Molloplast B - Heat polymerization) were tested. For each liner, 30 specimens with a cross-sectional area of 10 Χ 10 mm and thickness 3 mm were processed between two acrylic blocks (Trevalon). Specimens were divided into a control group that was stored for 24 hours in water at 37°C and a test group that was thermocycled (2500 cycles) between baths of 5° and 55°C. Tensile bond strength (kg/cm 2 ) was determined in a universal testing machine using crosshead speed of 5 mm/min. Statistical Analysis Used: The student t-test was used to determine the significance of the difference in bond strength between the two liners. Results: The mean tensile bond strength for control and thermocycled specimens of the two liners were: Mollosil (6.82 kg/cm 2 and 8.41 kg/cm 2 ) and Molloplast-B (16.30 kg/cm 2 and 13.67 kg/cm 2 ), respectively. Comparison of bond strength of control specimens with thermocycled specimens of the liners indicated a significant difference for both Mollosil (P=0.045) and Molloplast-B (P=0.027). Comparison between control specimens of both liners and thermocycled specimens of both liners indicated a highly significant difference (P<0.001). Conclusions: Heat polymerized resilient denture liner Molloplast-B had higher tensile bond strength than autopolymerizing liner Mollosil regardless of thermocycling. The bond strength of Mollosil increased after thermocycling while that of Molloplast-B decreased after thermocycling. Clinical Implications: Although heat-polymerized denture liners require more processing time than autopolymerizing liners, but they display much better adhesion properties to denture base resin and should thus be preferred when soft liner has to be used for a longer duration of time.

Evaluation of flexural bond strength of porcelain to used nickel-chromium alloy in various percentages.

Aim: The aim of this in vitro study was to evaluate the flexural bond strength of porcelain to combinations of used and new nickel-chromium alloy in various proportions. Materials and Methods: Used and new nickel-chromium bonding alloys were combined in various proportions (groups I to V; 10 samples per group) and their flexural bond strengths with porcelain were compared. A three-point loading system was used for the application of load. Load was applied at a constant speed of 0.5 mm/minute and the load required to fracture the porcelain was recorded for each specimen. Statistical Analysis Used: (a) Analysis of variance (ANOVA) and (b) Duncan's multiple range tests. Results: The best bond strength values were seen when 100% new alloy was used. According to the findings of this study, there was no adverse effects noted with up to 75% recast metal, but serious changes were found in the bond strength values when 100% old metal was used. Conclusions: The following conclusions were drawn from the study Fresh nickel-chromium alloy shows the greatest porcelain adherence. There is no significant change in bond strength of ceramic to alloy with up to 75% of used nickel-chromium alloy. At least 25%- of new alloy should be added when recycled nickel-chromium alloy is being used for metal ceramic restorations.

A Clinicopathologic Study of 43 Cases of Poroid Neoplasms: A Single Center Study / 대한피부과학회지

BACKGROUND: Poroid neoplasms consist of classic poroma, hidroacanthoma simplex, dermal duct tumor, and poroid hidradenoma. Poroid neoplasms are not rare tumors in dermatology. However, studies of the clinicopathologic characteristics of poroid neoplasms in Korea are very limited. OBJECTIVE: To investigate the clinicopathologic characteristics of poroid neoplasms in Korea. METHODS: The clinicopathologic characteristics of forty three cases of poroid neoplasms were retrospectively analyzed. RESULTS: Poroid neoplasms were diagnosed mostly in the sixth decade, without sex predominance. The most common site was the lower extremities, followed by the head & neck, the trunk, the sole, the palm, and the upper extremities. All cases were observed as a solitary lesion. Papule or nodule shape, verrucous surface, and erythmatous color were most common characteristics of poroid neoplasms. The two cases showed sebaceous differentiation. Some cases showed melanin pigmentations in the lesions or perilesional basal layer. CONCLUSION: Our study will be a resourceful data of poroid neoplasms for dermatologists and pathologists.