15 research outputs found
Ultrashort pulsed laser conditioning of human enamel: in vitro study of the influence of geometrical processing parameters on shear bond strength of orthodontic brackets
[Abstract] The surfaces of 63 extracted premolar teeth were processed with intense ultrashort laser pulses (λ = 795 nm; pulse duration, 120 fs; repetition rate, 1 kHz) to produce cross patterns with different pitches (s) in the micrometer range in order to evaluate the influence of such microstructures on the shear bond strengths of orthodontic brackets to enamel. The samples were classified in nine groups corresponding to the control group (raw samples) and eight different laser-processed groups (cross patterns with s increasing from 15 to 180 μm). Brackets were luted with TransbondTM XT adhesive resin to all the samples; after 72 h, they all were submitted to strength test in a universal testing machine. Additionally, a third of the samples underwent morphological analysis of the debonded surface by means of scanning electron microscope microscopy and an analysis of the failure mode based on the adhesive remnant index. The results showed that enamel microstructuring with ultrashort laser pulses remarkably increase the bond strength of brackets. Dense cross patterns (s 90 μm) give rise to smaller improvements of the bond strength. A strong correlation of this behavior with the predominant failure mode in both scenarios was found. So far, the best compromise between suitable adhesive efficiency, processing time minimization, and enamel surface preservation suggests the performance of cross patterns with pitches in the order of 90 μm.Ministerio de Economía y Competitividad; CSD2007-00013Ministerio de Economía y Competitividad; FIS2009-0952Castilla y León. Junta; SA086A12-
Thermocycling effect on microshear bond strength to zirconia ceramic using Er:YAG and tribochemical silica coating as surface conditioning
[Abstract] The purpose of this study is to evaluate the thermocycling effect on the microshear bond strength (μSBS) of different self-adhesive resin cements to zirconia using tribochemical silica coating Rocatec™ (ROC) and Er:YAG as surface conditioners. Two hundred forty square-like zirconia samples were polished and randomly assigned in four groups according surface treatment applied as follows: (1) no treatment (NT), (2) silica coating with ROC, 3) Er:YAG laser irradiation (LAS: 2.940 nm, 200 mJ; 10 Hz), and (4) laser followed by Rocatec™ (LAROC). Each group was divided into two subgroups according the resin tested as follows: (A) BiFix SE (BIF) and (B) Clearfil SA (CLE). After 24 h, half of the specimens from each subgroup were tested. The other half was stored and thermocycled (5–55 °C/5,000 cycles). A μSBS test was performed using a universal testing machine (cross head speed = 0.5 mm/min). Failure modes were recorded and observed by scanning electronic microscopy. Data was analyzed with ANOVA, Student’s t test, and chi-square tests, and linear regression was performed (p < 0.05). Before thermocycling, both cements showed higher μSBS results with ROC and LAROC. After aging, (1) all BIF specimens evidenced severely decreased adhesion with mostly adhesive failures and (2) CLE maintained the initial results in ROC and LAROC groups, performing better with ROC. Thermocycling did not negatively influence the resin–zirconia μSBS results in the self-adhesive resin cement containing 10-MDP when used on zirconia surface coated with silica, independently of previous Er:YAG surface treatment
Effect of adhesive application on the shear bond strength using different cementing agents in molar and premolar attachments
[Abstract] Objectives: The purpose of the study was to evaluate the effect of adhesive application on the shear bond strength (SBS) of orthodontic brackets and tubes to acid-etched human enamel when using different cementing agents. Study Design: One hundred and sixty metal attachments (80 tubes and 80 brackets) were bonded to human third molars and premolars that were randomly divided into identical groups of four: Transbond XT (XT); Wave MV Flow (WF); APC Plus System (APC); and Fuji Ortho LC (LC). For each experimental group, half of the specimens were bonded in combination with Transbond XT adhesive. After 72 h, a SBS test was performed using a universal testing machine. Statistical analysis was performed using ANOVA with Bonferroni post hoc comparisons, χ2 tests, and linear regression modeling. Adhesive remnant index scores were determined for the teeth after failure. Representative tooth surfaces from each subgroup were assessed under SEM. Results: Considering that each cement was observed, each of them showed similar SBS when the adhesive system was applied as when the adhesive was not applied. By comparing all cements together, it was noted that if an adhesive is not applied, all cements have similar values. If an adhesive is applied, cement XT, WF, and APC showed significantly higher SBS values than LC did. The tubes showed higher SBS than the brackets did in cements XT and WF with or without an adhesive, as well as APC Plus with an adhesive. Conclusions: The use of an adhesive system in bonding brackets and tubes does not influence the SBS obtained, independently of the cement
Dimensional structure of the oral health-related quality of life in healthy Spanish workers
Article number: 24 (2010)[EN]Oral health-related quality of life (OHQoL) is conceived as a multidimensional construct. Here our aim was to investigate the dimensional structure of OHQoL as measured by the Spanish versions of the Oral Impacts on Daily Performance (OIDP) and the Oral Health Impact Profile (OHIP-14) questionnaires applied simultaneously.
Methods
We recruited a consecutive sample of 270 healthy Spanish workers visiting the Employment Risk Prevention Centre for a routine medical check-up. OHIP-14 was self-completed by participants but the OIDP was completed in face-to-face interviews. An Exploratory Factor Analysis (EFA) was performed to identify the underlying dimensions of the OHQoL construct assessed by both instruments. This factorial structure was later confirmed by Confirmatory Factor Analysis (CFA) using several estimators of goodness of fit indices.
Results
EFA and the CFA identified and respectively confirmed a set of 3 underlying factors in both questionnaires that could be interpreted as functional limitation, pain-discomfort, and psychosocial impacts. The model achieved was seen to fit properly for both instruments, but the factorial structure was clearer for the OIDP.
Conclusions
The results provide evidence for construct equivalence in the latent factors assessed by both OIDP and OHIP-14, suggesting that OHQoL is a three-dimensional construct. The prevalence of impact on these three factors was coherent between both indicators, pain-discomfort having the highest prevalence, followed by psycho-social impact, and functional limitation
The effects of lasers on bond strength to ceramic materials: A systematic review and meta-analysis
Lasers have recently been introduced as an alternative means of conditioning dental
ceramic surfaces in order to enhance their adhesive strength to cements and other materials.
The present systematic review and meta-analysis aimed to review and quantitatively
analyze the available literature in order to determine which bond protocols and laser types
are the most effective.
A search was conducted in the Pubmed, Embase and Scopus databases for papers published
up to April 2017. PRISMA guidelines for systematic review and meta-analysis were
followed.
Fifty-two papers were eligible for inclusion in the review. Twenty-five studies were synthesized
quantitatively. Lasers were found to increase bond strength of ceramic surfaces to resin
cements and composites when compared with control specimens (p-value < 0.01), whereas
no significant differences were found in comparison with air-particle abraded surfaces.
High variability can be observed in adhesion values between different analyses, pointing
to a need to standardize study protocols and to determine the optimal parameters for each
laser type
Comparative validity of the OIDP and OHIP-14 in describing the impact of oral health on quality of life in a cross-sectional study performed in Spanish adults
[EN]Objectives: We aimed to compare the utility and validity of two popular socio-dental indicators (OIDP and OHIP-14) for describing the impact of oral conditions on quality of life applied simultaneously.
Study design: We recruited a consecutive sample of 270 healthy Spanish workers visiting the Employment Risk Prevention Centre for a routine medical check-up. OHIP-14 was self-completed before the oral examination and the face to face interview of the OIDP was performed. Both instruments were compared by evaluating its reliability and its validity.
Results and conclusions: The standardised Cronbach alphas for OHIP-14 and OIDP were 0.89 and 0.74 respectively. OIDP showed lower face validity but higher content validity than OHIP-14. Both indicators showed high construct and criterion validity, since individuals perceiving need for dental treatment or having any complaint about their mouth obtained significantly higher total OIDP and OHIP scores than their counterparts. The prevalence of impacts was much higher using the OHIP (80.7%) than the OIDP (27.8%)
RICORS2040 : The need for collaborative research in chronic kidney disease
Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true
Novel Digital Measurement Technique to Analyze the Palatine Suture Expansion after Palatine Rapid Maxillary Expansion Technique
The aim of the study was to validate a novel digital measurement method to quantify the volume of the midpalatal suture after rapid maxillary expansion (RME). Material and methods: Eight patients with maxillary skeletal transverse deficiency were submitted to palatine suture expansion using the McNamara orthodontic appliance during a period of nine months. After 30 days of treatment, all patients were exposed postoperatively to a cone-beam computed tomography (CBCT) scan. Afterwards, the scans were uploaded into the three-dimensional orthodontic-planning software to allow the volumetric assessment of the palatine suture expansion through palatine rapid maxillary expansion using a McNamara appliance. The repeatability was analyzed by repeating twice the measures by a single operator and reproducibility was analyzed by repeating three times the measures by two operators, and Gage R&R statistical analysis was performed. Results: The expansion of the midpalatal suture by means of the rapid maxillary expansion technique, in terms of digital volume measurement, showed a repeatability value of 0.09% and between the two operators a reproducibility value of 0.00% was shown. Conclusions: The novel measurement technique demonstrated a high repeatability and reproducibility rate for volume assessment of the palatine suture expansion through palatine rapid maxillary expansion technique.El objetivo del estudio fue validar un nuevo método de medición digital para cuantificar el volumen de la sutura palatina media después de la expansión maxilar rápida (RME). Material y métodos: Ocho pacientes con deficiencia transversa esquelética maxilar fueron sometidos a expansión de sutura palatina utilizando el aparato de ortodoncia McNamara durante un período de nueve meses. Después de 30 días de tratamiento, todos los pacientes fueron expuestos después de la operación a una tomografía computarizada de haz cónico (CBCT). Posteriormente, los escaneos se cargaron en el software de planificación de ortodoncia tridimensional para permitir la evaluación volumétrica de la expansión de la sutura palatina a través de la expansión maxilar palatina rápida utilizando un aparato McNamara. La repetibilidad se analizó repitiendo dos veces las medidas por un solo operador y la reproducibilidad se analizó repitiendo tres veces las medidas por dos operadores, y se realizó el análisis estadístico Gage R&R. Resultados: La expansión de la sutura mediopalatina mediante la técnica de expansión maxilar rápida, en cuanto a la medición digital de volumen, mostró un valor de repetibilidad de 0,09% y entre los dos operadores se mostró un valor de reproducibilidad de 0,00%. Conclusiones: La nueva técnica de medición demostró una alta tasa de repetibilidad y reproducibilidad para la evaluación del volumen de la expansión de la sutura palatina a través de la técnica de expansión maxilar palatina rápida.Sin financiación4.945 JCR (2020) Q1, 15/117 Health Care Sciences & Service1.254 SJR (2020) Q1, 380/2446 Medicine (miscellaneous)No data IDR (2020)UE