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1.
J Craniofac Surg ; 31(4): 912-915, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32068727

RESUMEN

INTRODUCTION: The aim of this study was to assess the efficacy of using bone morphogenetic protein-2 with hydroxyapatite granules (BMP-2/hydroxyapatite) during augmentation of maxillary sinus floor, with respect to changes in volume, relative to conventional bone graft materials. METHOD AND MATERIALS: Twenty of 25 patients in the BMP-2/hydroxyapatite group, and 16 of 33 patients in the conventional materials group met the criteria for inclusion in this study. Computed tomography scans were performed preoperatively, immediately postoperatively, and at follow-up, approximately 6 months postoperatively. Changes in volume and height of both grafted materials were measured using 3-dimensional reconstruction software; these changes were compared between groups. RESULTS: The mean (standard deviation) volumetric changes were 0.25 (0.11) cc and -0.07 (0.35) cc, and the mean rates of volumetric changes were 26.44% (7.78%) and -2.92% (30.92%) in BMP-2/hydroxyapatite and conventional materials groups, respectively. The mean height changes were 0.34 (0.73) mm and -0.63 (1.07) mm, and the mean rates of height changes were 3.67% (7.57%) and -5.95% (9.98%) in BMP-2/hydroxyapatite and conventional materials groups, respectively. CONCLUSION: Compared with the conventional materials group, the BMP-2/hydroxyapatite group showed better maxillary sinus floor augmentation results in terms of volumetric changes and grafted material densities, and can provide predictably reliable outcomes.


Asunto(s)
Proteína Morfogenética Ósea 2/farmacología , Durapatita/farmacología , Seno Maxilar , Elevación del Piso del Seno Maxilar , Factor de Crecimiento Transformador beta/farmacología , Adulto , Femenino , Humanos , Masculino , Seno Maxilar/cirugía , Persona de Mediana Edad , Proteínas Recombinantes/farmacología
2.
J Prosthodont ; 28(2): 195-201, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30427097

RESUMEN

PURPOSE: To evaluate the accuracy of three digitization methods for the maxillary dental arch. MATERIALS AND METHODS: A maxillary typodont with various tooth preparation designs was used as the reference model. The scanned data were classified into direct scanning (DS), cast scanning (CS), and impression scanning (IS) groups according to the techniques applied for digitization (n = 10/group). An intraoral scanner was used for the DS group. Impressions obtained with polyether impression material were scanned with a tabletop scanner for the IS group. For the CS group, the definitive casts fabricated from the obtained impressions were scanned with the same tabletop scanner. The accuracy (trueness and precision) of the produced virtual dental casts was evaluated with specialized software. The full-arch and individual abutment deviations were measured with regard to root mean square error (RMSE) values. Data were analyzed with statistical software with an α = 0 . 05 . RESULTS: The RMSE values for both trueness and precision were lowest in the IS group, followed by the CS and DS groups, with statistically significant differences among the groups (p < 0.05). The trueness of individual abutments was significantly higher in the IS group than in the DS group. In addition, the trueness of individual abutments was affected by the location of the abutments in the DS group, whereas it did not differ between individual abutments in the CS and IS groups. CONCLUSIONS: These findings suggest that the IS method is an accurate digitization technique for the creation of a virtual dental cast.


Asunto(s)
Materiales de Impresión Dental/química , Técnica de Impresión Dental/instrumentación , Procesamiento de Imagen Asistido por Computador , Modelos Dentales , Simulación por Computador , Diseño Asistido por Computadora , Arco Dental , Diseño de Prótesis Dental , Precisión de la Medición Dimensional , Imagenología Tridimensional , Técnicas In Vitro , Maxilar
3.
Acta Odontol Scand ; 75(5): 309-318, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28335666

RESUMEN

OBJECTIVE: The aim of this study is to investigate the behaviour of iPSc derived from dental stem cells in terms of initial adhesion, differentiation potential on differently surface-treated titanium disc. MATERIALS AND METHODS: iPSc derived from human gingival fibroblasts (hGFs) were established using 4-reprogramming factors transduction with Sendai virus. The hGF-iPSc established in this study exhibited the morphology and growth properties similar to human embryonic stem (ES) cells and expressed pluripotency makers. Alkaline Phosphatase (AP) staining, Embryoid Body (EB) formation and in vitro differentiation and karyotyping further confirmed pluripotency of hGF-iPSc. Then, hGF-iPSc were cultured on machined- and Sandblasted and acid etched (SLA)-treated titanium discs with osteogenic induction medium and their morphological as well as quantitative changes according to different surface types were investigated using Alizrin Red S staining, Scanning electron microscopy (SEM), Flow cytometry and RT-PCR. RESULTS: Time-dependent and surface-dependent morphological changes as well as quantitative change in osteogenic differentiation of hGF-iPSc were identified and osteogenic gene expression of hGF-iPSc cultured on SLA-treated titanium disc found to be greater than machined titanium disc, suggesting the fate of hGF-iPSc may be determined by the characteristics of surface to which hGF-iPSc first adhere. CONCLUSIONS: iPSc derived from dental stem cell can be one of the most promising and practical cell sources for personalized regenerative dentistry and their morphological change as well as quantitative change in osteogenic differentiation according to different surface types may be further utilized for future clinical application incorporated with dental implant.


Asunto(s)
Fibroblastos/fisiología , Células Madre Pluripotentes Inducidas/metabolismo , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Implantes Dentales , Encía/citología , Humanos , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Osteogénesis , Propiedades de Superficie , Titanio/farmacología
4.
Implant Dent ; 26(5): 664-673, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28719568

RESUMEN

PURPOSE: This study evaluates the synergistic effect of serial application of bone morphogenetic protein 2 (BMP2) and fibroblast growth factor 2 (FGF2) on both new bone formation and periodontal tissue regeneration using 1-wall intrabony defect in mongrel dogs. MATERIALS AND METHODS: One-wall defects were created at the mesial aspect of the mandibular first molars of 6 male mongrel dogs. Each mandibular defect received 1 of the 2 experimental treatments randomly (BMP2 or BMP2 + FGF2), and it was allowed to heal for either 4 or 8 weeks postoperatively. Histologic and histomorphometric analyses were performed for the evaluation of the overall healing patterns of new bone formation and periodontal tissue regeneration. RESULTS: The results showed that after 8 weeks, serial application of BMP2 and FGF2 significantly improved the periodontal tissue regeneration, whereas application of BMP2 only showed greater new bone formation after 4 weeks. CONCLUSIONS: The serial application of BMP2 and FGF2 may have synergistic effects on periodontal tissue regeneration over time.


Asunto(s)
Proteína Morfogenética Ósea 2/uso terapéutico , Factor 2 de Crecimiento de Fibroblastos/uso terapéutico , Regeneración Tisular Guiada Periodontal/métodos , Animales , Proteína Morfogenética Ósea 2/administración & dosificación , Regeneración Ósea/efectos de los fármacos , Perros , Sinergismo Farmacológico , Factor 2 de Crecimiento de Fibroblastos/administración & dosificación , Masculino , Mandíbula/diagnóstico por imagen , Mandíbula/patología , Periodoncio/diagnóstico por imagen , Periodoncio/patología , Microtomografía por Rayos X
5.
Implant Dent ; 26(1): 46-53, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27779611

RESUMEN

OBJECTIVE: To determine the effects of alendronate on bone remodeling around osseointegrated implants in rats. MATERIALS AND METHODS: The maxillary first molars were extracted from 36 male Sprague-Dawley rats, and replaced with customized implants. They were then administered twice-weekly subcutaneous injections of either alendronate (alendronate group) or saline (control group) after allowing a 4-week period for osseointegration. They were killed at 4, 8, or 12 weeks after the commencement of the injection protocol, and the implant sites were evaluated comprehensively by microcomputed tomographic, histologic, and biochemical assessments. RESULTS: It was hard to find statistically significant differences from microcomputed tomographic analyses. In addition, inconsistent variations were derived from histologic data. However, biochemical data showed statistically significant differences; serum osteocalcin level was statistically significantly lower in the alendronate group than in the control group at 8 weeks after the commencement of injections. In addition, serum osteocalcin level in the alendronate group was statistically significantly lower at 8 and 12 weeks after the initial injection point than at preinjection. CONCLUSIONS: The results suggest alendronate might affect bone remodeling activity around osseointegrated implants negatively, and serum osteocalcin could serve as an accessory tool to evaluate this effect.


Asunto(s)
Alendronato/farmacología , Conservadores de la Densidad Ósea/farmacología , Remodelación Ósea/efectos de los fármacos , Implantación Dental Endoósea/métodos , Animales , Masculino , Oseointegración/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Microtomografía por Rayos X
6.
J Prosthet Dent ; 117(1): 109-115, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27460311

RESUMEN

STATEMENT OF PROBLEM: The marginal and internal discrepancies of computer-aided design and computer-aided manufacturing (CAD-CAM) endocrowns are unknown. PURPOSE: The purpose of this in vitro study was to evaluate the marginal and internal discrepancies of endocrowns with different cavity depths by measuring them with microcomputed tomography (µCT). MATERIAL AND METHODS: Endocrowns (n=48) of 2 different cavity depths (2 mm and 4 mm) were fabricated in 2 different chairside CAD-CAM systems (CEREC AC and E4D). A µCT scan was made before and after cementation. For analysis of the marginal and internal discrepancies, reference points were selected in 2-dimensional views of 3 buccolingual cross-sections and 3 mesiodistal cross-sections. To calculate the total discrepancy volume, the µCT sections were reconstructed 3-dimensional views, and changes in volume and surface area were examined. Statistical analysis was performed using 2-way ANOVA with Bonferroni correction (α=.05). RESULTS: An endocrown with a 4-mm cavity showed a larger marginal and internal volume than one with a 2-mm cavity. Cementation did not show significant differences in total discrepancy thickness. Discrepancies on the pulpal floor were largest in other sites. Both chairside CAD-CAM systems showed similar discrepancy in the endocrowns. CONCLUSIONS: Based on the present study, marginal and internal discrepancies increased depending on cavity depth. Cementation did not increase the dimension of the discrepancy between the restoration and the cavity wall. The discrepancy on the pulpal floor appeared to affect these results.


Asunto(s)
Diseño Asistido por Computadora , Coronas , Preparación de la Cavidad Dental/métodos , Diseño de Prótesis Dental/métodos , Cementación , Adaptación Marginal Dental/normas , Humanos , Técnicas In Vitro , Radiografía Dental/métodos , Microtomografía por Rayos X
7.
J Adv Prosthodont ; 16(2): 67-76, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38694192

RESUMEN

PURPOSE: This study aims to assess and predict lifespan of dental prostheses using newly developed Korean Association of Prosthodontics (KAP) criteria through a large-scale, multi-institutional survey. MATERIALS AND METHODS: Survey was conducted including 16 institutions. Cox proportional hazards model and principal component analysis (PCA) were used to find out relevant factors and predict life expectancy. RESULTS: 1,703 fixed and 815 removable prostheses data were collected and evaluated. Statistically significant factors in fixed prosthesis failure were plaque index and material type, with a median survival of 10 to 18 years and 14 to 20 years each. In removable prosthesis, factors were national health insurance coverage, antagonist type, and prosthesis type (complete or partial denture), with median survival of 10 to 13 years, 11 to 14 years, and 10 to 15 years each. For still-usable prostheses, PCA analysis predicted an additional 3 years in fixed and 4.8 years in removable prosthesis. CONCLUSION: Life expectancy of a prosthesis differed significantly by factors mostly controllable either by dentist or a patient. Overall life expectancy was shown to be longer than previous research.

8.
J Adv Prosthodont ; 16(3): 151-162, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38957292

RESUMEN

PURPOSE: This study aimed to analyze factors influencing the success and failure of implant prostheses and to estimate the lifespan of prostheses using standardized evaluation criteria. An online survey platform was utilized to efficiently gather large samples from multiple institutions. MATERIALS AND METHODS: During the one-year period, patients visiting 16 institutions were assessed using standardized evaluation criteria (KAP criteria). Data from these institutions were collected through an online platform, and various statistical analyses were conducted. Risk factors were assessed using both the Cox proportional hazard model and Cox regression analysis. Survival analysis was conducted using Kaplan-Meier analysis and nomogram, and lifespan prediction was performed using principal component analysis. RESULTS: The number of patients involved in this study was 485, with a total of 841 prostheses evaluated. The median survival was estimated to be 16 years with a 95% confidence interval. Factors found to be significantly associated with implant prosthesis failure, characterized by higher hazard ratios, included the 'type of clinic', 'type of antagonist', and 'plaque index'. The lifespan of implant prostheses that did not fail was estimated to exceed the projected lifespan by approximately 1.34 years. CONCLUSION: To ensure the success of implant prostheses, maintaining good oral hygiene is crucial. The estimated lifespan of implant prostheses is often underestimated by approximately 1.34 years. Furthermore, standardized form, online platform, and visualization tool, such as nomogram, can be effectively utilized in future follow-up studies.

9.
Implant Dent ; 22(6): 666-75, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24185466

RESUMEN

OBJECTIVE: Ultraviolet (UV) light treatment of titanium, ie, photofunctionalization, has been extensively reported to enhance the osteoconductivity of titanium in animal and in vitro studies. This is the first study to examine whether photofunctionalization is effective on commercial dental implants in vivo. MATERIALS AND METHODS: Dental implants with a microroughened surface were placed into dog jawbones. Photofunctionalization was performed by treating implants with UV light for 15 minutes using a photo device immediately before placement. Four weeks after placement, bone-implant integration was evaluated using a removable torque test and static and dynamic histology. RESULTS: Implant surfaces were converted from hydrophobic to super-hydrophilic after photofunctionalization. Removable torque for photofunctionalized implants was significantly higher by 50% than that for untreated implants. Bone-implant contact (BIC) was significantly higher for photofunctionalized implants in all zones examined: marginal, cortical, and bone marrow zones. An intensive mineralized layer was exclusively present in marginal bone at photofunctionalized interface. Dynamic histology identified early-onset, long-lasting robust bone deposition at photofunctionalized interface. CONCLUSIONS: Photofunctionalization enhanced the morphology, quality, and behavior of periimplant osteogenesis, including the increased BIC, expedited robust interfacial bone deposition, and improved marginal bone seal and support.


Asunto(s)
Implantación Dental Endoósea/métodos , Oseointegración/efectos de la radiación , Terapia Ultravioleta/métodos , Animales , Implantes Dentales , Retención de Prótesis Dentales , Análisis del Estrés Dental , Perros , Masculino , Mandíbula/cirugía
10.
J Clin Neurol ; 19(2): 186-194, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36854335

RESUMEN

BACKGROUND AND PURPOSE: Peripheral neuropathies (PNs) are a common but poorly understood complication of chronic obstructive pulmonary disease (COPD). To clarify the initial trigger of a PN in COPD, we investigated the excitability of peripheral nerves in patients with COPD. METHODS: The automated nerve excitability test (NET) using the threshold-tracking paradigm was applied to 20 COPD patients. The recording protocol calculated the strength-duration time constant, threshold electrotonus (TE), current-threshold relationship, and recovery cycle (RC). Each NET parameter was compared with two control groups: normal controls group (NC group) and smokers without COPD group (smoker group). RESULTS: In the motor NETs, the change in the threshold in the mid-depolarizing phase of TE (40-60 ms) was smaller in the COPD group (50.7%±1.2%, mean±SEM; n=20) than in the NC group (54.5%±0.7%, n=25; p<0.01), as was the prominence of superexcitability in the RC (-22.6%±1.5% and -26.4%±1.1%, respectively; p=0.04). There were no significant differences in the sensory NETs. Comparisons between the COPD and smoker groups (n=25) also showed no differences in either the motor or sensory NETs. CONCLUSIONS: The pattern of excitability in COPD revealed a membrane depolarization attributable to Na+-K+-ATPase failure in the axolemma of distal motor nerves. This finding suggests that chronic hypoxemia and adaptative process can alter axonal excitability and trigger a resultant neuropathic process that is antecedent to PN in COPD.

11.
Nanomaterials (Basel) ; 13(8)2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-37110962

RESUMEN

Photobiomodulation (PBM) therapy is known to have the potential to improve bone regeneration after implant surgery. However, the combinatory effect of the nanotextured implant and PBM therapy on osseointegration has not yet been proved. This study evaluated the photobiomodulation-based synergistic effects of Pt-coated titania nanotubes (Pt-TiO2 NT) and 850 nm near-infrared (NIR) light on osteogenic performance in vitro and in vivo. The FE-SEM and the diffuse UV-Vis-NIR spectrophotometer were used to perform the surface characterization. The live-dead, MTT, ALP, and AR assays were tested to perform in vitro tests. The removal torque testing, the 3D-micro CT, and the histological analysis were used to conduct in vivo tests. The live-dead and MTT assay resulted in Pt-TiO2 NTs being biocompatible. The ALP activity and AR assays demonstrated that the combination of Pt-TiO2 NT and NIR irradiation significantly enhanced osteogenic functionality (p < 0.05). The results of in vivo test, employing the removal torque testing, the 3D-micro CT, and histological analysis, showed overall improved outcomes; however, no significant difference was observed between the control and experimental groups (p > 0.05). Therefore, we confirmed the possibility of the combination of Pt-TiO2 NT and NIR light as a promising technology for implant surgery in dentistry.

12.
J Funct Biomater ; 14(3)2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36976094

RESUMEN

We examined whether recombinant human bone morphogenetic protein-2 (rhBMP-2) when applied to collagen membranes, would reinforce them during guided bone regeneration. Four critical cranial bone defects were created and treated in 30 New Zealand white rabbits, including a control group, critical defect only; group 1, collagen membrane only; group 2, biphasic calcium phosphate (BCP) only; group 3, collagen membrane + BCP; group 4, collagen membrane with rhBMP-2 (1.0 mg/mL); group 5, collagen membrane with rhBMP-2 (0.5 mg/mL); group 6, collagen membrane with rhBMP-2 (1.0 mg/mL) + BCP; and group 7, collagen membrane with rhBMP-2 (0.5 mg/mL) + BCP. After a 2-, 4-, or 8-week healing period, the animals were sacrificed. The combination of collagen membranes with rhBMP-2 and BCP yielded significantly higher bone formation rates compared to the other groups (control group and groups 1-5 < groups 6 and 7; p < 0.05). A 2-week healing period yielded significantly lower bone formation than that at 4 and 8 weeks (2 < 4 = 8 weeks; p < 0.05). This study proposes a novel GBR concept in which rhBMP-2 is applied to collagen membranes outside instead of inside the grafted area, thereby inducing quantitatively and qualitatively enhanced bone regeneration in critical bone defects.

13.
Tissue Eng Regen Med ; 20(5): 767-778, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37079199

RESUMEN

BACKGROUND: In guided bone regeneration (GBR), there are various problems that occur in the bone defect after the wound healing period. This study aimed to investigate the enhancement of the osteogenic ability of the dual scaffold complex and identify the appropriate concentration of growth factors (GF) for new bone formation based on the novel GBR concept that is applying rapid bone forming GFs to the membrane outside of the bone defect. METHODS: Four bone defects with a diameter of 8 mm were formed in the calvaria of New Zealand white rabbits each to perform GBR. Collagen membrane and biphasic calcium phosphate (BCP) were applied to the bone defects with the four different concetration of BMP-2 or FGF-2. After 2, 4, and 8 weeks of healing, histological, histomorphometric, and immunohistochemical analyses were conducted. RESULTS: In the histological analysis, continuous forms of new bones were observed in the upper part of bone defect in the experimental groups, whereas no continuous forms were observed in the control group. In the histomorphometry, The group to which BMP-2 0.5 mg/ml and FGF-2 1.0 mg/ml was applied showed statistically significantly higher new bone formation. Also, the new bone formation according to the healing period was statistically significantly higher at 8 weeks than at 2, 4 weeks. CONCLUSION: The novel GBR method in which BMP-2, newly proposed in this study, is applied to the membrane is effective for bone regeneration. In addition, the dual scaffold complex is quantitatively and qualitatively advantageous for bone regeneration and bone maintenance over time.


Asunto(s)
Factor 2 de Crecimiento de Fibroblastos , Osteogénesis , Animales , Conejos , Factor 2 de Crecimiento de Fibroblastos/farmacología , Regeneración Ósea , Cráneo/patología , Colágeno
14.
J Korean Med Sci ; 27(7): 756-60, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22787370

RESUMEN

Evidence suggests that diabetes mellitus (DM) is associated with idiopathic pulmonary fibrosis (IPF). According to the new IPF guidelines, high-resolution computed tomography (HRCT) is an essential means of diagnosing IPF. We investigated the relationship between IPF and DM in patients treated between 2003 and 2007. Newly diagnosed IPF patients in large university teaching hospitals in Korea were enrolled from January 2003 to December 2007. We retrospectively analyzed 1,685 patients using the interstitial lung disease (ILD) registry. In total, 299 IPF patients (17.8%) also had DM. The mean age of our subjects was 68.0 ± 9.4 yr. HRCT showed significantly more reticular and honeycomb patterns in IPF patients with DM than in IPF patients without DM (P = 0.014, P = 0.028, respectively). Furthermore, significantly higher incidences of hypertension, cardiovascular diseases, and other malignancies (except lung cancer) were found in IPF patients with DM than in IPF patients without DM. In conclusion, IPF patients with DM are more likely to have the usual interstitial pneumonia (UIP) pattern, including reticular and honeycomb patterns, on HRCT than are those without DM.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Fibrosis Pulmonar Idiopática/diagnóstico , Anciano , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Femenino , Humanos , Hipertensión/epidemiología , Hipertensión/etiología , Fibrosis Pulmonar Idiopática/complicaciones , Fibrosis Pulmonar Idiopática/diagnóstico por imagen , Incidencia , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , Neoplasias/etiología , Sistema de Registros , República de Corea/epidemiología , Estudios Retrospectivos , Tomografía Computarizada por Rayos X
15.
J Prosthet Dent ; 108(2): 96-101, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22867806

RESUMEN

STATEMENT OF PROBLEM: The opaque color of zirconia copings may compromise esthetics, especially in the facial cervical area. A collarless zirconia coping can be an alternative. However, the strength of zirconia crowns with collarless copings is unknown. PURPOSE: The purpose of this study was to compare the fracture load of zirconia crowns according to coping thickness and facial collar design. MATERIAL AND METHODS: Forty-eight zirconia crowns were fabricated and divided into 4 groups: standard coping group (0.5 mm coping thickness, 0.2 mm facial collar height); collarless coping group (0.5 mm coping thickness, no facial collar); modified thicker coping group (0.7 mm coping thickness, 0.2 mm facial collar height); and thicker coping group (0.7 mm coping thickness including collar height). The fracture load for the crowns was measured in a universal testing machine. One-way ANOVA and the Tukey HSD test for post hoc analysis were used for statistical analysis (α=.05). Ten additional zirconia crowns were fabricated to test the effect of cyclic loading on fracture resistance between the standard coping group and the collarless coping group, and data were analyzed with the Mann-Whitney U test. RESULTS: The fracture load in the collarless coping group (2329.1 N±948.3) was not significantly different from that of the other groups. The thicker coping group (3179.3 N±1137.7) resulted in significantly greater fracture load than the standard (2126.9 N±576.9) and modified thicker coping groups (2112.7 N±623.9) (F=4.193; P=.011). The fracture load after cyclic loading did not differ significantly between the standard coping group and the collarless coping group. CONCLUSIONS: Within the limitations of this in vitro study, the thicker coping group had the highest fracture strength, but the collarless coping group using a 0.5 mm thickness coping was not significantly different from the standard coping group.


Asunto(s)
Coronas , Pilares Dentales , Fracaso de la Restauración Dental , Aleaciones de Cerámica y Metal , Análisis de Varianza , Adaptación Marginal Dental , Diseño de Prótesis Dental , Análisis del Estrés Dental , Humanos , Estadísticas no Paramétricas , Circonio
16.
J Orthop Res ; 40(5): 1065-1074, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34314063

RESUMEN

In the induced membrane (IM) technique for bone reconstruction, a poly(methyl methacrylate) (PMMA) spacer is implanted to induce formation of a foreign body membrane around the defect site. Membrane development is essential for later bone grafting success, yet the mechanism by which the IM promotes bone regeneration remains unknown, as are the ways that spacer composition plays a role in the membrane's healing potential. This study investigated the impact of leached methyl methacrylate (MMA)-the major monomeric component of PMMA-on IM development. In vitro cell culture found that MMA elution did not impact endothelial cell or mesenchymal stem cell proliferation. For in vivo analysis, we advanced a streamlined rat femoral model to efficiently study the influence of spacer properties on IM characteristics. Comparison of membrane formation around polycaprolactone (PCL), MMA-eluting PCL (high-dose PCL-MMA and low-dose PCL-MMA), and surgical PMMA revealed robust membranes enveloped all groups after 4 weeks in vivo, with elevated expression of osteogenic bone morphogenetic protein-2 and angiogenic vascular endothelial growth factor compared with the surrounding muscle and bone tissues. Growth factor quantitation in IM tissue found no statistically significant difference between groups. New bone growth, vascularization, and CD163+ macrophage populations surrounding the polymer implants were also quantified; and blood vessel formation around high-dose PCL-MMA was found to be significantly decreased compared with PCL alone. To the best of our knowledge, these findings represent the first time that results have been obtained about the characteristics of membranes formed around PCL in the IM setting.


Asunto(s)
Polimetil Metacrilato , Factor A de Crecimiento Endotelial Vascular , Animales , Regeneración Ósea , Metacrilatos , Metilmetacrilato , Ratas
17.
Materials (Basel) ; 15(15)2022 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-35955331

RESUMEN

This study was aimed at preparing zirconia samples via additive manufacturing (AM) and subtractive manufacturing (SM) and testing the following aspects: (1) the manufacturing accuracy of the zirconia samples and (2) the bond strength of porcelain to zirconia to evaluate the applicability of the zirconia fabricated by AM in dental clinics. We used three milling machines for SM (AR, K5, and UP) and a 3D printer for AM (AO). The manufacturing accuracy of the zirconia specimen in the internal and marginal areas was evaluated by superimposing techniques to calculate the root mean square (RMS) values. The bond strengths of porcelain to zirconia prepared via SM and AM were measured using a universal testing machine. The internal and marginal RMS values of the zirconia prepared by AM (AO) were within the range of those of the zirconia prepared by SM (AR, K5, and UP). Moreover, the bond strength value of the zirconia prepared by AM (35.12 ± 4.09 MPa) was significantly higher than that of the zirconia prepared by SM (30.26 ± 5.20 MPa). Therefore, AM technology has significant potential for applications in dentistry.

18.
J Oral Maxillofac Surg ; 69(4): 1070-8, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21255895

RESUMEN

PURPOSE: Maxillary posterior teeth exhibit a high incidence of periodontal bone and tooth loss. After tooth loss, the edentulous alveolar process of the posterior maxilla is often affected by resorption, which results in loss of vertical bone volume. Moreover, progressive sinus pneumatization leads to a decrease in the alveolar process from the cranial side. The sinus elevation and augmentation surgical technique opened a new way of anchoring endosseous implants despite discernible bone reduction. However, the surgical interventions require in-depth knowledge of maxillary sinus anatomy such as sinus septum and potential variations. The purpose of this study was to investigate the prevalence, location, height, morphology, and orientation of maxillary sinus septa by use of computed tomography (CT) and 3-dimensional imaging. MATERIALS AND METHODS: Two hundred patients undergoing implant treatment at the Yonsei University College of Dentistry, Seoul, South Korea, were randomly selected for analysis of maxillary sinus septa. CT and DentaScan (GE Medical Systems, Milwaukee, WI)-reformatted data from 400 sinuses were analyzed with the Preview program (Infinitt, Seoul, South Korea). Three-dimensional images were rendered for measurement by use of the Accurex program (CyberMed, Seoul, South Korea). RESULTS: We found 111 septa in 400 maxillary sinuses (27.7%). This corresponded to 37% of the patients. Among total septa, 25 sinus septa (22.5%) were located in the anterior, 51 (45.9%) in the middle, and 35 (31.5%) in the posterior regions. The directional orientation analyses showed that 106 septa were buccopalatal, 4 were sagittal, and 1 was transverse type. The mean septal heights were 7.78 ± 2.99 and 7.89 ± 3.09 mm in the right and left sinuses, respectively. CONCLUSION: Three-dimensional CT image analyses may provide useful information that can avoid unnecessary complications during sinus augmentation procedures by facilitating adequate, timely identification of the anatomic structures inherent to the maxillary sinus.


Asunto(s)
Imagenología Tridimensional/métodos , Seno Maxilar/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Anciano , Diente Premolar , Cefalometría/métodos , Implantes Dentales , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Arcada Edéntula/diagnóstico por imagen , Arcada Parcialmente Edéntula/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Diente Molar , Radiografía Dental Digital/métodos , Radiografía Panorámica/métodos
19.
Materials (Basel) ; 14(20)2021 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-34683564

RESUMEN

The visible light reactions of noble metal-based photocatalysts have been increasingly utilized to investigate their antibacterial activities. Furthermore, the photoreactions at various visible light wavelengths for specific combinations of titania nanotubes and noble metal nanoparticles have been found to promote osteogenic functionality. In this investigation, a novel multi-coating combination of noble metals (gold and platinum) on titania nanotubes was assessed using plasmonic photocatalysis and low-level laser therapy at 470 and 600 nm. The results showed that this coating on the nanotubes promoted antibacterial activity and osteogenic functionality. The order in which the gold and platinum coatings were layered onto the titania nanotubes strongly affected the osteogenic performance of the human mesenchymal stem cells. These results have identified a new approach for the development of efficient novel combinations of noble metal nanoparticles and titania nanotubes with visible light responses, sustainable antimicrobial activity, and osteogenic functionality.

20.
Materials (Basel) ; 14(8)2021 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-33924487

RESUMEN

Osseointegration of titanium implant is important for the success of both dental and medical implants. Previous studies have attempted to improve osseointegration by considering the use of plasma jet technology, where information with animal models and parameters related to osseointegration is still lacking. Therefore, this study investigated the effects of non-thermal atmospheric pressure plasma jet (NTAPPJ) treatment on titanium implants in terms of osseointegration in mongrel dogs. A total of 41 implants; 21 NTAPPJ treated and 20 control, were placed in the maxilla and mandible of six mongrel dogs for either 4 or 8 weeks. The bone volume (BV) and bone-to-implant contact (BIC) ratio were determined by region of interest (ROI). Statistical analysis was performed with the Wilcoxon rank-sum test. The NTAPPJ group at 4 weeks showed higher numbers in both BV and BIC (p < 0.05) compared to the control group. However, at 8 weeks there were less significant differences between the control or experimental group as the control group had caught up with the experimental group. Hence, NTAPPJ may be an effective treatment for the initial healing period which is critical to ensure reliable long-term predictability. The BV and BIC have been clinically proven to accelerate in the initial stages with the use of NTAPPJ to aid in the healing and initial stability of implants.

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