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1.
Cranio ; : 1-8, 2020 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-33074797

RESUMEN

OBJECTIVE: To analyze bite force distribution in subjects with different occlusal characteristics. METHODS: This prospective study included 132 candidates (50 males, 82 females) seeking orthodontic treatment, who were divided into four groups based on Angle's classification of malocclusion. T-Scan® III Version 7.0 was used to record their relative distribution of bite forces, which were compared using gender, Angle's occlusal classification, overjet, overbite, space analysis, sagittal, and transverse skeletal relations variables. RESULTS: ANOVA revealed significant differences in posterior/anterior bite force ratios between sagittal dental and skeletal relationships, overjet, and overbite groups (p < 0.05). No significant difference was found between different space analysis and transverse relationship groups (p > 0.05) or between genders (p > 0.05). CONCLUSION: Subjects with Class III, decreased overjet and decreased overbite displayed higher bite force in posterior teeth compared to other groups. This feature must be considered when evaluating patients with dental and periodontal pathologies that might be affected by excessive tooth stress, especially in subjects with oral parafunctions and bruxism.

2.
J Oral Rehabil ; 47(12): 1503-1510, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32966657

RESUMEN

OBJECTIVES: To analyse occlusion time, occlusal balance and lateral occlusal scheme in subjects with various dental and skeletal characteristics. METHODS: A total of 132 subjects (50 males and 82 females) seeking orthodontic treatment were included in this prospective study. Using the T-Scan III version 7.0 (Tekscan Inc, South Boston, MA, USA), the occlusion time, occlusal balance and lateral occlusal schemes were recorded and compared with gender, Angle's occlusal classification, overjet, overbite, space analysis, skeletal and transverse relations. ANOVA, t test and contingency tables analyses were performed. Statistical significance was set at P < .05. RESULTS: Occlusion time was significantly shorter in subjects with balanced occlusion (0.18 seconds, P < .001), Class I normal occlusion (0.35 seconds, P = .028) and Class I skeletal profile (0.37 seconds, P = .002). Occlusion time was significantly longer in subjects with decreased overjet (0.60 seconds, P = .003). There were significant associations between the distribution of occlusal balance and Angles' classes of occlusion, skeletal relationship, overjet, overbite and space analysis (P < .05). Lateral occlusal schemes were only associated with Angle's classes of occlusion and skeletal relationship (P < .05). CONCLUSIONS: Patients with Class I occlusion showed the least occlusion time, the most balanced occlusion and a higher frequency of canine guidance. Nonetheless, potentially balanced occlusion and group function were highly prevalent in all groups; therefore, ideal occlusion must be considered an ideal to inspire and aim for, but cannot be considered an essential requirement of every dental treatment.


Asunto(s)
Maloclusión de Angle Clase II , Maloclusión , Sobremordida , Oclusión Dental , Oclusión Dental Balanceada , Femenino , Humanos , Masculino , Estudios Prospectivos
3.
FASEB J ; 32(7): 4016-4030, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29533736

RESUMEN

Cell fusion-mediated formation of multinuclear osteoclasts (OCs) plays a key role in bone resorption. It is reported that 2 unique OC-specific fusogens [ i.e., OC-stimulatory transmembrane protein (OC-STAMP) and dendritic cell-specific transmembrane protein (DC-STAMP)], and permissive fusogen CD9, are involved in OC fusion. In contrast to DC-STAMP-knockout (KO) mice, which show the osteopetrotic phenotype, OC-STAMP-KO mice show no difference in systemic bone mineral density. Nonetheless, according to the ligature-induced periodontitis model, significantly lower level of bone resorption was found in OC-STAMP-KO mice compared to WT mice. Anti-OC-STAMP-neutralizing mAb down-modulated in vitro: 1) the emergence of large multinuclear tartrate-resistant acid phosphatase-positive cells, 2) pit formation, and 3) mRNA and protein expression of CD9, but not DC-STAMP, in receptor activator of NF-κB ligand (RANKL)-stimulated OC precursor cells (OCps). While anti-DC-STAMP-mAb also down-regulated RANKL-induced osteoclastogenesis in vitro, it had no effect on CD9 expression. In our mouse model, systemic administration of anti-OC-STAMP-mAb suppressed the expression of CD9 mRNA, but not DC-STAMP mRNA, in periodontal tissue, along with diminished alveolar bone loss and reduced emergence of CD9+ OCps and tartrate-resistant acid phosphatase-positive multinuclear OCs. The present study demonstrated that OC-STAMP partners CD9 to promote periodontal bone destruction by up-regulation of fusion during osteoclastogenesis, suggesting that anti-OC-STAMP-mAb may lead to the development of a novel therapeutic regimen for periodontitis.-Ishii, T., Ruiz-Torruella, M., Ikeda, A., Shindo, S., Movila, A., Mawardi, H., Albassam, A., Kayal, R. A., Al-Dharrab, A. A., Egashira, K., Wisitrasameewong, W., Yamamoto, K., Mira, A. I., Sueishi, K., Han, X., Taubman, M. A., Miyamoto, T., Kawai, T. OC-STAMP promotes osteoclast fusion for pathogenic bone resorption in periodontitis via up-regulation of permissive fusogen CD9.


Asunto(s)
Pérdida de Hueso Alveolar/metabolismo , Proteínas de la Membrana/genética , Osteoclastos/metabolismo , Pérdida de Hueso Alveolar/tratamiento farmacológico , Pérdida de Hueso Alveolar/genética , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/uso terapéutico , Células Cultivadas , Masculino , Proteínas de la Membrana/inmunología , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Tetraspanina 29/genética , Tetraspanina 29/metabolismo , Regulación hacia Arriba
4.
J Orthod Sci ; 6(2): 47-53, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28546957

RESUMEN

OBJECTIVE: This study was aimed to evaluate the dental age in Saudi children from panoramic radiographs using the Demirjian method to estimate their chronological age. MATERIALS AND METHODS: This retrospective cross-sectional study consisted of 1902 panoramic radiographs of 955 boys and 947 girls between the ages of 3-17 years. All children were placed in the age group closest to their chronological age. The dental age was scored on all seven left mandibular teeth by calibrated examiners. Bivariate analyses using the t-test and Pearson correlation were performed. RESULTS: There was significant difference in both boys and girls in all the age groups between their chronological age and dental age. Even though there was a slight overestimation in boys in some age groups and slight underestimation in girls in some groups, correlation analysis showed that there was a highly significant correlation between the chronological age and dental age for both boys (r2 = 0.96, P < 0.001) and girls (r2 = 0.98, P < 0.001). Moreover, correlation analyses for each age group showed a significant correlation between the chronological age and the dental age, using the Demirjian method, in most age groups (P < 0.01). When comparing the maturation score between boys and girls, the Student's t-test showed that there were no statistical differences between boys and girls in most age groups. CONCLUSION: Saudi boys and girls living in the western region of Saudi Arabia exhibited similar pattern of dental development when compared to the Demirjian method. Hence, the Demirjian method could be used as reference in children from the western region of Saudi Arabia.

5.
Quintessence Int ; 48(1): 27-32, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27669727

RESUMEN

OBJECTIVE: To evaluate and compare the volume of removed dentin, transportation, and centering ability of TRUShape (TRS; Dentsply Tulsa Dental Specialties) system with ProTaper Next (PTN; Dentsply Maillefer) by using micro-computed tomography (µCT). METHOD AND MATERIALS: Twenty extracted human mandibular first molars with two separate mesial canals with curvatures of 25 to 35 degrees were divided into two experimental groups (n = 20) according to the rotary nickel-titanium file system used in canal instrumentation as follows: group TRS and group PTN. Canals were scanned before and after instrumentation using µCT to evaluate root canal transportation, centering ratio, and volumetric changes. Data of canal transportation and centering ratio values were analyzed using independent t test. Volume changes data were statistically analyzed using Mann-Whitney test. Statistical significance level was set at P < .05. RESULTS: The PTN group had a significantly lower mean volume of removed dentin (2.09 ±â€¯0.41 mm3) than the TRS group (2.77 ±â€¯0.72 mm3) (P < .05). At the coronal level, there was no significant difference in canal transportation (P = .170) and centering ratio (P = .111) between TRS and PTN groups. However, at the apical and middle levels, the PTN group had a significantly lower mean transportation value and higher centering ratio than the TRS group (P < .05). CONCLUSION: Root canal preparation with the PTN system revealed better performance with fewer canal aberrations than the TRS system in curved root canals.


Asunto(s)
Instrumentos Dentales , Cavidad Pulpar/diagnóstico por imagen , Dentina/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Diente Molar/cirugía , Preparación del Conducto Radicular/instrumentación , Microtomografía por Rayos X/métodos , Aleaciones Dentales , Diseño de Equipo , Humanos , Técnicas In Vitro , Ensayo de Materiales , Níquel , Titanio
6.
J Prosthet Dent ; 115(3): 306-12, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26553256

RESUMEN

STATEMENT OF PROBLEM: The effectiveness of adhesives in enhancing several functional aspects of complete denture performance has been well established. The direct influence of adhesives on occlusal contact simultaneity has not yet been investigated. PURPOSE: The purpose of this crossover clinical trial was to evaluate quantitatively the influence of adhesives on occlusal balance by recording timed occlusal contacts; namely occlusion time (OT) and disocclusion time during right (DT-right) and left (DT-left) excursions by using computerized occlusal analysis. MATERIAL AND METHODS: A crossover clinical trial was adopted. Assessments were carried out while participants (n=49) wore their dentures first without then with adhesives. Computerized occlusal analysis using the T-Scan III system was conducted to perform baseline computer-guided occlusal adjustment for conventionally fabricated dentures. Retention and stability assessment using the modified Kapur index and recording of OT and DT-right and DT-left values using the T-Scan III were subsequently carried out for all dentures, first without adhesives and then after application of adhesive. All T-Scan procedures were carried out by the same clinician. Wilcoxon signed-rank test was used to analyze the Kapur index scores and occlusal parameters (α=.05). RESULTS: Stability and retention of conventional dentures ranged initially from good to very good. However, adhesive application resulted in significant improvement (P<.001) in stability and retention and a significant decrease in duration of all occlusal parameters (OT [P=.003], DT-right [P=.003], and DT-left [P=.008]). CONCLUSIONS: Adhesives significantly decreased OT and DT durations in initially well-fitting complete dentures with fairly well balanced occlusion, and further enhanced denture stability and occlusal contact simultaneity.


Asunto(s)
Adhesivos , Oclusión Dental , Retención de Dentadura , Masticación/fisiología , Estudios Cruzados , Oclusión Dental Balanceada , Dentadura Completa , Humanos
7.
Adv Med Educ Pract ; 6: 259-63, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25878519

RESUMEN

OBJECTIVES: This longitudinal study was aimed to investigate the association between didactic grades and practical skills for dental students and whether didactic grades can reliability predict the dental students' practical performance. MATERIALS AND METHODS: Didactic and practical grades for graduates from the Faculty of Dentistry, King Abdulaziz University, between the years 2009 and 2011 were collected. Four courses were selected: Dental Anatomy, Operative Dentistry, Prosthodontics, and Orthodontics. Pearson product-moment correlation analyses between didactic and practical scores were conducted. RESULTS: There was only a significant correlation between didactic and practical scores for the Dental Anatomy course (P<0.001). There was also a significant correlation between all four subjects in the didactic scores (P<0.001). Only the scores of male students showed a significant correlation in the Operative Dentistry course (P<0.001). There were no correlations between Orthodontic grades. Moreover, a poor degree of reliability was found between didactic and practical scores for all subjects. CONCLUSION: Based on the findings of this study, the relationship between didactic grades and practical performance is course specific. Didactic grades do not reliably predict the students' practical skills. Measuring practical performances should be independent from didactic grading.

8.
J Prosthet Dent ; 111(4): 335-41, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24360012

RESUMEN

STATEMENT OF PROBLEM: Surface roughness and internal porosity are 2 potential risk factors that threaten the biocompatibility and long-term mechanical stability of cast partial removable dental prostheses frameworks. PURPOSE: The purpose of this study was to investigate the influence of the material, of conventional wax patterns, and the recently introduced light-polymerized patterns on the initial surface roughness and internal porosity of the cobalt-chromium castings of partial removable dental prostheses. MATERIAL AND METHODS: Twenty-eight identical partial removable dental prosthesis frameworks were fabricated on a cast of a maxillary Kennedy Class III modification 1 partially edentulous patient. Fourteen frameworks were fabricated from each pattern material. The initial surface roughness, Ra (µm), of the resultant castings was measured with a profilometer. Radiographs of the castings were made on dental occlusal films with a dental x-ray unit with the following exposure conditions: tube voltage 70 kV; exposure time 1.0 seconds; tube current 7 mA; and source-film distance 35 cm. The number and size of porosities in the 3 main components (clasp units, major connectors, denture base meshwork) were assessed. Statistical analysis was conducted with the independent sample t test for surface roughness and the Mann Whitney test for internal porosity (α=.05). RESULTS: The statistical analysis of mean surface roughness and internal porosity revealed no significant difference between the 2 groups. CONCLUSIONS: The surface roughness and internal porosity of frameworks fabricated from conventional wax and Liwa patterns were comparable, with no significant differences between the 2 pattern materials.


Asunto(s)
Acrilatos/química , Aleaciones de Cromo/química , Revestimiento para Colado Dental/química , Técnica de Colado Dental , Materiales Dentales/química , Dentadura Parcial Removible , Ceras/química , Materiales Biocompatibles/química , Abrazadera Dental , Bases para Dentadura , Humanos , Ensayo de Materiales , Polimerizacion , Porosidad , Radiografía Dental , Estrés Mecánico , Propiedades de Superficie
9.
Adv Med Educ Pract ; 4: 223-6, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24159266

RESUMEN

OBJECTIVES: The objective of this study is to investigate the correlation between the psychomotor skills and the academic performance of dental students. METHODS: Didactic and preclinical scores were collected for students who graduated from the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia, in 2011. Three courses (Dental Anatomy, Removable Prosthodontic Denture, and Orthodontics) were selected. Correlations comparing didactic and practical scores were done for the total samples, then for the males and females separately. RESULTS: There was no significant correlation between the practical and didactic scores for the three courses for the total sample. There was a significant correlation between all three subjects in the didactic scores. For females, the results showed that there was only a significant correlation between the practical and didactic scores for Dental Anatomy. For males, no correlation was observed between the practical and didactic scores for all subjects. CONCLUSION: In the present sample, didactic performance did not correlate well with the students' psychomotor performance.

10.
ISRN Dent ; 2013: 582051, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23606978

RESUMEN

Objective. This study aimed to evaluate the effect of different storage solutions that simulate acidic, alkaline, and sebum conditiions on the physical properties of pigmented (colorant elastomer) cosmesil M511 maxillofacial prosthetic material. Materials and Methods. Sixty specimens were prepared according to the manufacturer's instructions and were tested before and after immersion of different storage conditions for six months at 37 °C. The following tests were performed: color changes (group I), solution absorption (group II), surface roughness (group III), and scanning electron microscopy (group IV). Results. There were no significant changes observed in the color and solution absorption tests while surface roughness revealed significant difference between control group and other testing storage medium groups, and this result was supported by SEM analysis that revealed limited surface changes. Conclusions. Cosmaseil material is an acceptable cross-linked formulation that withstands storage in different solutions with variable pH. The addition of pigment cannot vary the physical properties of these materials. Surface roughness test as well as SEM microscopic study showed moderate changes indicating a limited effect on the surface of the material.

11.
Saudi Med J ; 33(11): 1205-10, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23147878

RESUMEN

OBJECTIVE: To evaluate hepatitis B virus (HBV) vaccine coverage and the use of infection control among dentists in Saudi Arabia. METHODS: This cross-sectional study was carried out during the Third International Conference at the King Abdulaziz University Faculty of Dentistry, held on March 2012 in Jeddah, Saudi Arabia. Saudi or expatriate dentists working in Saudi Arabia were included in the study. The questionnaires were designed to meet the objective of the study. RESULTS: A total of 402 dentists of whom 176 (44%) were male and 226 (56%) female took part in this study. Their mean age was 37.4 years. In all, 246 (61%) were general dentists and 156 (39%) specialists. Four-fifths (80.5%) of them had been vaccinated. Almost half (48.5%) had experience of needle stick injury, but none reported having been infected with HBV. Among the vaccinated dentists, 186 (57.5%) had not been screened for HBV antibodies. Younger dentists were more particular about vaccination and more careful in using protective wear. There was an association between protective barriers and HBV vaccination, but there was no association between history of needle stick injury and vaccination. CONCLUSION: Dental healthcare workers have a high risk of infection with HBV due to the nature of their work; so there should be a mandatory program to vaccinate dentists against HBV and to ensure application of protective measures during their practice.


Asunto(s)
Odontólogos , Vacunas contra Hepatitis B , Control de Infecciones , Pautas de la Práctica en Odontología/estadística & datos numéricos , Vacunación/estadística & datos numéricos , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Lesiones por Pinchazo de Aguja/epidemiología , Arabia Saudita
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