OBJECTIVES: This study was designed to evaluate the synergistic antibacterial effect of xylitol and ursolic acid (UA) against oral biofilms in vitro. MATERIALS AND METHODS: S. mutans UA 159 (wild type), S. mutans KCOM 1207, KCOM 1128 and S. sobrinus ATCC 33478 were used. The susceptibility of S. mutans to UA and xylitol was evaluated using a broth microdilution method. Based on the results, combined susceptibility was evaluated using optimal inhibitory combinations (OIC), optimal bactericidal combinations (OBC), and fractional inhibitory concentrations (FIC). The anti-biofilm activity of xylitol and UA on Streptococcus spp. was evaluated by growing cells in 24-well polystyrene microtiter plates for the biofilm assay. Significant mean differences among experimental groups were determined by Fisher's Least Significant Difference (p < 0.05). RESULTS: The synergistic interactions between xylitol and UA were observed against all tested strains, showing the FICs < 1. The combined treatment of xylitol and UA inhibited the biofilm formation significantly and also prevented pH decline to critical value of 5.5 effectively. The biofilm disassembly was substantially influenced by different age of biofilm when exposed to the combined treatment of xylitol and UA. Comparing to the single strain, relatively higher concentration of xylitol and UA was needed for inhibiting and disassembling biofilm formed by a mixed culture of S. mutans 159 and S. sobrinus 33478. CONCLUSIONS: This study demonstrated that xylitol and UA, synergistic inhibitors, can be a potential agent for enhancing the antimicrobial and anti-biofilm efficacy against S. mutans and S. sobrinus in the oral environment.
Biofilms* ; Hydrogen-Ion Concentration ; Polystyrenes ; Streptococcus ; Streptococcus mutans ; Streptococcus sobrinus ; Xylitol*

With the increasing use of CAD-CAM (computer-aided design-computer-aided manufacturing) methods for prosthesis fabrication, utilization of virtual articulators in CAD software has also increased. Among the various methods of positioning the maxilla in a virtual articulator, there are techniques that utilize CBCT (cone-beam computed tomography) or facial scans without the use of a facebow.In this case, a full-mouth rehabilitation was planned for a patient who exhibited multiple crown fractures and occlusal plane disharmony through maxillary complete denture and mandibular fixed prosthetic restoration. Radiopaque markers were added to the duplicated maxillary temporary denture to take closed-mouth impression, which was then scanned and positioned on the CBCT. On CBCT, hinge axis connecting the medial poles of both mandibular condyles along with the Frankfort horizontal plane was designated and utilized to perform virtual articulator mounting. Maxillary complete denture and mandibular fixed prostheses were fabricated, resulting in satisfactory aesthetic and functional outcomes.

With the increasing use of CAD-CAM (computer-aided design-computer-aided manufacturing) methods for prosthesis fabrication, utilization of virtual articulators in CAD software has also increased. Among the various methods of positioning the maxilla in a virtual articulator, there are techniques that utilize CBCT (cone-beam computed tomography) or facial scans without the use of a facebow.In this case, a full-mouth rehabilitation was planned for a patient who exhibited multiple crown fractures and occlusal plane disharmony through maxillary complete denture and mandibular fixed prosthetic restoration. Radiopaque markers were added to the duplicated maxillary temporary denture to take closed-mouth impression, which was then scanned and positioned on the CBCT. On CBCT, hinge axis connecting the medial poles of both mandibular condyles along with the Frankfort horizontal plane was designated and utilized to perform virtual articulator mounting. Maxillary complete denture and mandibular fixed prostheses were fabricated, resulting in satisfactory aesthetic and functional outcomes.

With the increasing use of CAD-CAM (computer-aided design-computer-aided manufacturing) methods for prosthesis fabrication, utilization of virtual articulators in CAD software has also increased. Among the various methods of positioning the maxilla in a virtual articulator, there are techniques that utilize CBCT (cone-beam computed tomography) or facial scans without the use of a facebow.In this case, a full-mouth rehabilitation was planned for a patient who exhibited multiple crown fractures and occlusal plane disharmony through maxillary complete denture and mandibular fixed prosthetic restoration. Radiopaque markers were added to the duplicated maxillary temporary denture to take closed-mouth impression, which was then scanned and positioned on the CBCT. On CBCT, hinge axis connecting the medial poles of both mandibular condyles along with the Frankfort horizontal plane was designated and utilized to perform virtual articulator mounting. Maxillary complete denture and mandibular fixed prostheses were fabricated, resulting in satisfactory aesthetic and functional outcomes.

With the increasing use of CAD-CAM (computer-aided design-computer-aided manufacturing) methods for prosthesis fabrication, utilization of virtual articulators in CAD software has also increased. Among the various methods of positioning the maxilla in a virtual articulator, there are techniques that utilize CBCT (cone-beam computed tomography) or facial scans without the use of a facebow.In this case, a full-mouth rehabilitation was planned for a patient who exhibited multiple crown fractures and occlusal plane disharmony through maxillary complete denture and mandibular fixed prosthetic restoration. Radiopaque markers were added to the duplicated maxillary temporary denture to take closed-mouth impression, which was then scanned and positioned on the CBCT. On CBCT, hinge axis connecting the medial poles of both mandibular condyles along with the Frankfort horizontal plane was designated and utilized to perform virtual articulator mounting. Maxillary complete denture and mandibular fixed prostheses were fabricated, resulting in satisfactory aesthetic and functional outcomes.

With the increasing use of CAD-CAM (computer-aided design-computer-aided manufacturing) methods for prosthesis fabrication, utilization of virtual articulators in CAD software has also increased. Among the various methods of positioning the maxilla in a virtual articulator, there are techniques that utilize CBCT (cone-beam computed tomography) or facial scans without the use of a facebow.In this case, a full-mouth rehabilitation was planned for a patient who exhibited multiple crown fractures and occlusal plane disharmony through maxillary complete denture and mandibular fixed prosthetic restoration. Radiopaque markers were added to the duplicated maxillary temporary denture to take closed-mouth impression, which was then scanned and positioned on the CBCT. On CBCT, hinge axis connecting the medial poles of both mandibular condyles along with the Frankfort horizontal plane was designated and utilized to perform virtual articulator mounting. Maxillary complete denture and mandibular fixed prostheses were fabricated, resulting in satisfactory aesthetic and functional outcomes.

BACKGROUND: Altered cell cycle regulation may underlie the development and/or progression of human malignancies. The purpose of this study is to determine if the oncogenesis of soft tissue sarcomas could be better explained by examining the components involved in G1 phase progression. METHODS: Sixty-seven soft tissue sarcomas were studied for the immunohistochemical expression of cdk4, cyclin D1, retinoblastoma (Rb) and p16 proteins. For Rb and p16, samples showing either negative or heterogeneous (<80% of tumor cells) staining were considered to be altered. RESULTS: The cdk4 protein was observed in 64 cases (95.5%). Cyclin D1 was expressed in 14 cases (20.9%). The Rb expression was altered in 48 (71.6%). Sixty-three (94%) sarcomas demonstrated altered p16 expressions. All of the samples displayed altered expressions of either Rb or p16. A high percentage of the tumors with altered Rb were observed in relapsed patients (p<0.05). CONCLUSIONS: Disturbance in the cell cycle regulatory system involving the Rb/p16/cdk4/cyclin D1 pathway appears to be relatively frequent in soft tissue sarcomas and may play an important role in the tumorigenesis of these tumors. It is noteworthy that the reduced Rb expression correlates with tumor relapse, suggesting its prognostic significance.
Carcinogenesis ; Cell Cycle ; Cyclin D1* ; Cyclin-Dependent Kinase 4 ; Cyclins* ; G1 Phase ; Humans* ; Recurrence ; Retinoblastoma ; Retinoblastoma Protein* ; Sarcoma*

BACKGROUND: ras gene mutations have been described in various human malignancies, suggesting that their activation may play a role in oncogenesis. However, there are few reports concerning ras gene alterations in malignant fibrous histiocytomas. We therefore designed a study to determine the prevalence and type of mutations in the first exons of H-ras and K-ras genes in these tumors. METHODS: Twenty-seven malignant fibrous histiocytomas were investigated by direct sequencing analysis with the automated DNA sequencing of polymerase chain reaction-amplified ras sequences. RESULTS: Twenty-four mutations were found in 18 (67%) of the tumors: GGC to GAC transition mutations at codon 13 of K-ras (coding for aspartic acid instead of glycine) in 18 of the samples and GGC to GTC transversions at codon 12 of H-ras (coding for valine instead of glycine) in six of the lesions. CONCLUSIONS: Our data suggest an involvement of the ras gene mutation in conjunction with other yet unknown events in the tumorigenesis and/or progression of malignant fibrous histiocytomas. The K-ras gene activation predominated in these tumors by a mutation at codon 13. It is noteworthy that H-ras mutations were detected only in association with the lesions containing K-ras mutated genes, the significance of which remains to be determined.
Aspartic Acid ; Carcinogenesis ; Codon ; Exons ; Genes, ras* ; Histiocytoma, Malignant Fibrous* ; Humans ; Prevalence ; Sequence Analysis, DNA ; Valine