Publications by authors named "María E Iglesias"

9 Publications

  • Page 1 of 1

Transmittance of lithium disilicate ceramic of different thicknesses and opacities with different curing units.

Acta Odontol Latinoam 2021 Aug;34(2):143-148

Universidad de Buenos Aires. Facultad de Odontología, Cátedra de Materiales Dentales, Buenos Aires, Argentina.

The aim of this study was to evaluate the amount of radiating energy transmitted through lithium disilicate discs of different thicknesses and opacities with different curing units (CU). Discshaped specimens 8 mm in diameter and 1.5 mm or 0.7 mm thick were designed with Zbrush® and Cura 3D® software, milled from HT and MO IPS e-maxCAD blocks (Ivoclar Vivadent) with Ceramill Mikro 4 (Amann Girrbach, Austria) and processed according to manufacturer instructions. Thickness was checked with a Mitutoyo (México) caliper. Four groups (n=4) were formed: G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm), and the effect of three CUs: Coltolux (Coltene- Whaledent), LED.C, (Woodpecker Medical Instrument Co.Ltd) and Deepcure L(3M-ESPE) was tested Measurements were taken with a halogen and LED radiometer (Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) after applying the guide of each CU directly on the reading window (d) and after interposing each of the specimens. The ratio of transmitted energy was determined in each case and data was analyzed with repeated measures ANOVA and Tukey test for multiple comparisons. LED.C: d:1600 mW/cm2, G1: 0.31(0.00), G2: 0.14(0.00) G3: 0.54(0.01), G4: 0.38(0.01); Deepcure L: d:1500 mW/cm2, G1: 0.34(0.01), G2: 0.20(0,00), G3: 0.56(0.01), G4: 0.41(0.02); Coltolux: d:1275 mW/cm2, G1: 0.44(0.01), G2: 0.24(0,00), G3: 0.65(0.01), G4: 0.47(0,00). Statistically significant differences were found among the curing units (P<0.001) and for the interaction CU-thickness (P<0.001) and CU-opacity (P=0.023). Within the conditions of this study, the ratio of light transmitted through lithium disilicate structures is related to their thickness and opacity, and to the curing unit employed.
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August 2021

Central incisors shape and proportions prevalence in Argentinian university students: by visual assessment and a new standardized method.

Acta Odontol Latinoam 2021 Aug;34(2):113-118

Universidad de Buenos Aires, Facultad de Odontología, Cátedra de Materiales Dentales, Buenos Aires, Argentina.

The aim of this study was to analyze the dimensions of the clinical crown of upper central incisors and the prevalence of tooth shapes by two different protocols. Assessment was performed on each of the 111 dental stone type V maxillae models of students of dentistry from Buenos Aires University [93 females and 18 males, mean age 23.70 (± 2.26) years] The mesial and distal-vestibular angles were defined on each right upper incisor, and the following segments were defined: AB (zenith - incisal edge), CD, EF, GH (apical, middle, and incisal thirds - vestibule - mesial and vestibule-distal angles) and their lengths were determined with a precision caliper. Then, the CD/AB, EF/AB and mean CD-EF/AB ratios were calculated. Shapes were assessed by four independent observers, three of whom evaluated digital images of the models, while the fourth had no access to the images, and determined the shapes using an algorithm developed from the dimensions of the studied segments. Rates and confidence intervals were determined, and Fleiss' Kappa was calculated to assess the agreement among the evaluators who worked with the images and among all of them. Average incisor length was 10 mm, and widths at CD and EF were 7.35 mm (0.65) and 8.27 mm (0.58), respectively. Regarding shapes, 51.58% (47.90-55.20) of the incisors were identified as square, 18.02% (14.50-21.90) as ovoid and 30.41% (30.00-30.90) as triangular. Fleiss' Kappa agreement was 0.71 (0.62-0.80). The application of the proposed algorithm provided a considerable level of agreement among the observers. Regarding tooth size, both the average segment length and the proportions were similar to those reported by various authors.
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August 2021

Transmittance of lithium disilicate ceramic of different thicknesses and opacities with different curing units.

Acta Odontol Latinoam 2021 Aug;34(1):143-148

Universidad de Buenos Aires. Facultad de Odontología, Cátedra de Materiales Dentales, Buenos Aires, Argentina.

The aim of this study was to evaluate the amount of radiating energy transmitted through lithium disilicate discs of different thicknesses and opacities with different curing units (CU). Discshaped specimens 8 mm in diameter and 1.5 mm or 0.7 mm thick were designed with Zbrush® and Cura 3D® software, milled from HT and MO IPS e-maxCAD blocks (Ivoclar Vivadent) with Ceramill Mikro 4 (Amann Girrbach, Austria) and processed according to manufacturer instructions. Thickness was checked with a Mitutoyo (México) caliper. Four groups (n=4) were formed: G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm), and the effect of three CUs: Coltolux (Coltene- Whaledent), LED.C, (Woodpecker Medical Instrument Co.Ltd) and Deepcure L(3M-ESPE) was tested Measurements were taken with a halogen and LED radiometer (Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) after applying the guide of each CU directly on the reading window (d) and after interposing each of the specimens. The ratio of transmitted energy was determined in each case and data was analyzed with repeated measures ANOVA and Tukey test for multiple comparisons. LED.C: d:1600 mW/cm2, G1: 0.31(0.00), G2: 0.14(0.00) G3: 0.54(0.01), G4: 0.38(0.01); Deepcure L: d:1500 mW/cm2, G1: 0.34(0.01), G2: 0.20(0,00), G3: 0.56(0.01), G4: 0.41(0.02); Coltolux: d:1275 mW/cm2, G1: 0.44(0.01), G2: 0.24(0,00), G3: 0.65(0.01), G4: 0.47(0,00). Statistically significant differences were found among the curing units (P<0.001) and for the interaction CU-thickness (P<0.001) and CU-opacity (P=0.023). Within the conditions of this study, the ratio of light transmitted through lithium disilicate structures is related to their thickness and opacity, and to the curing unit employed.
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August 2021

Central incisors shape and proportions prevalence in Argentinian university students: by visual assessment and a new standardized method.

Acta Odontol Latinoam 2021 Aug;34(1):113-118

Universidad de Buenos Aires, Facultad de Odontología, Cátedra de Materiales Dentales, Buenos Aires, Argentina.

The aim of this study was to analyze the dimensions of the clinical crown of upper central incisors and the prevalence of tooth shapes by two different protocols. Assessment was performed on each of the 111 dental stone type V maxillae models of students of dentistry from Buenos Aires University [93 females and 18 males, mean age 23.70 (± 2.26) years] The mesial and distal-vestibular angles were defined on each right upper incisor, and the following segments were defined: AB (zenith - incisal edge), CD, EF, GH (apical, middle, and incisal thirds - vestibule - mesial and vestibule-distal angles) and their lengths were determined with a precision caliper. Then, the CD/AB, EF/AB and mean CD-EF/AB ratios were calculated. Shapes were assessed by four independent observers, three of whom evaluated digital images of the models, while the fourth had no access to the images, and determined the shapes using an algorithm developed from the dimensions of the studied segments. Rates and confidence intervals were determined, and Fleiss' Kappa was calculated to assess the agreement among the evaluators who worked with the images and among all of them. Average incisor length was 10 mm, and widths at CD and EF were 7.35 mm (0.65) and 8.27 mm (0.58), respectively. Regarding shapes, 51.58% (47.90-55.20) of the incisors were identified as square, 18.02% (14.50-21.90) as ovoid and 30.41% (30.00-30.90) as triangular. Fleiss' Kappa agreement was 0.71 (0.62-0.80). The application of the proposed algorithm provided a considerable level of agreement among the observers. Regarding tooth size, both the average segment length and the proportions were similar to those reported by various authors.
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August 2021

Self-reported habits regarding dental bur use and conditioning among academic and non-academic argentinian dentists.

Acta Odontol Latinoam 2020 Dec;33(3):195-199

Universidad de Buenos Aires. Facultad de Odontología, Cátedra de Materiales Dentales, Buenos Aires, Argentina.

The removal of tissues affected by caries lesions is one of the most frequent procedures in daily dental practice. The aim of this study was to collect information about the habits of members of the academic and non-academic dental community in Argentina regarding the use and conditioning of burs employed in the removal of dentin during the treatment of carious lesions. A 14- item questionnaire was prepared, and once validated in small groups, it was sent to three lists of dental subscribers through the computer services area of the School of Dentistry, University of Buenos Aires, Argentina (FOUBA). By the deadline for receiving responses, which was set as four weeks after the sending date, 294 replies were received. Results: percentage (95%CI): 47.93% (42.18-53.68%) of the respondents were faculty members, of whom 37.24% (31.68-42.81%) claimed to belong to FOUBA. Of the respondents, 26.90% (21.79-32.00%) reported being under 35 years old, 37.59% (32.01-43.16%) 36 to 45 years old, 22.07% (17.30-26.84%) 46 to 55 years and 11.38% (7.72-15.03%) over 55 years. Regarding bur type, 68.07% (62.31%-73.44%) claimed to use round burs to remove carious dentin and 27.72% (22.60%-23.31%) round + others. Regarding rotary speed, 22.07% (17.30-26.84%) use medium speed, 32.76% (27.36-38.16%) use high speed, and 32.76% (27.36-38.16%) use medium + super high. Only 17.93% (13.52- 22.35%) indicated that they know how to quantify the number of times they use their burs, while 50.34% (44.59-56.10%) of the respondents said that they use burs "until they no longer cut", 23.79% (18.89-28.69%) use them 1 to 5 times. 98.27% (96.77-99.77%) said they clean their burs once used. When the answers regarding the use of rubber dam were compared with area of specialization (Chi-square), it was found that faculty members mention the use of burs under rubber dam always or almost always 74.82% (67.60-82.04%) while outside the academic field, 51.01% (42.98-59.03%) of dentists say that they never or almost never do so (p <0.001). Conclusion: Most respondents state that they sterilize their rotary instruments in some way after use. About half of them do not keep track of the number of uses and use burs "until they no longer cut".
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December 2020

Effect of post-curing treatment on mechanical properties of composite resins.

Acta Odontol Latinoam 2014 ;27(2):72-6

Dental Materials Department, School of Dentistry, University of Buenos Aires, Argentina.

The aim of this study is to assess the effect of additional curing procedures on the flexural strength and modulus of elasticity of indirect and direct composite materials. Twenty-four rectangular prism-shaped 2 mm x 2 mm x 25 mm samples of Belleglass, Premisa (Kerr), Adoro and Heliomolar (Ivoclar Vivadent) were prepared. Each composite was packed in an ad-hoc stainless steel device with a TeflonR instrument. A mylar strip and a glass slab were placed on top to obtain a flat surface. Polymerization was activated for 20 seconds with a halogen unit (Astralis 10, Ivoclar - Vivadent) with soft start regime and an output with a 350 to 1200 mw/cm2 range at four different points according to the diameter of the end of the guide. The specimens obtained were then randomly divided into two different groups: with and without additional treatment. In the group with additional treatment, the samples adorro were submitted to 25 minutes in Lumamat 100 (Ivoclar Vivadent) and the rest to 20 minutes in BelleGlass HP (Kerr). After the curing procedures, all samples were treated with sandpapers of decreasing grain size under water flow, and stored in distilled water for 24 h. Flexural strength was measured according to the ISO 404920 recommendations and elastic modulus was determined following the procedures of ANSI/ADA standard No. 27. Statistical differences were found among the different materials and curing procedures employed (P<0.01). The elastic modulus was significantly higher after the additional curing treatment for all materials except Premisa. Further work is needed to determine the association between the actual monomers present in the matrix and the effect of additional curing processes on the mechanical properties of both direct and indirect composites, and its clinical relevance.
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http://dx.doi.org/10.1590/S1852-48342014000200005DOI Listing
November 2016

The hypothetical role of congenital hypotonia in the development of early coronoid hyperplasia.

J Craniomaxillofac Surg 2012 Sep 30;40(6):e155-8. Epub 2011 Aug 30.

Department of Oral and Maxillofacial Surgery, Hospital Clínico Universitario of Valencia, 17 Blasco Ibáñez Avenue, 46010 Valencia, Spain.

Background: Coronoid hyperplasia (CH) is an abnormal bony elongation of a histologically normal coronoid process. Its definitive cause remains unknown.

Objectives: To analyze the possible implication of congenital hypotonia in the pathogenesis of early coronoid overgrowth.

Patients And Methods: Two infants with congenital hypotonia were evaluated for limited mouth aperture. Bilateral CH was diagnosed. Transoral coronoidectomy was followed by an early dynamic physiotherapy program.

Results: Significant improvement of maximum interincisal opening was achieved. The review of the scientific literature proved the diagnosis of CH in the infant age group is extremely unusual and the etiology of the condition is still uncertain.

Conclusions: Besides mouth opening restriction, clinical features of coronoid hyperplasia in infants can include suction or deglutition anomalies, failure to thrive and recurrent episodes of choking or aspiration pneumonia. The authors hypothesize reduced fetal mandibular movements and deglutition as a result of congenital hypotonia may lead to relative hyperactivity of the temporalis muscle that is not counterbalanced by the infra and suprahyoid muscles, thereby facilitating coronoid overgrowth.
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http://dx.doi.org/10.1016/j.jcms.2011.08.005DOI Listing
September 2012

[Contact allergy to 3-dimethylaminopropylamine and cocamidopropyl betaine].

Actas Dermosifiliogr 2006 Apr;97(3):189-95

Unidad de Dermatología, Hospital García Orcoyen, Estella. Pamplona, España.

It has been discovered that all individuals who are allergic to cocamidopropyl betaine (CAPB) are sensitized to 3-dimethylaminopropylamine (DMAPA) and to amidoamine, molecules which are intermediaries in CAPB synthesis, and which persist as impurities in the material that is sold; the amounts vary, depending on the quality of the CAPB in the end product. We present three cases of allergic contact dermatitis to DMAPA. In all three cases, the skin tests for DMAPA were positive, while there was no reaction to CAPB. The current relevance of these tests was confirmed by the patients' re-exposure to the suspect products themselves, which contained CAPB. Contact allergy to CAPB is now infrequent, partly because of the increasing use of new non-irritating surfactants that have been introduced on the market in the last decade. However, cases of patients allergic to commercial CAPB who only react to DMAPA -and not to CAPB- when they are patch tested are still being reported. DMAPA itself, and other molecules like amidoamine, would be the true allergens, and some cases of CAPB allergy are therefore being overlooked because DMAPA is not always included in the cosmetics series. CAPB may no longer be necessary in patch tests, as DMAPA seems to be the principal allergenic fraction in this surfactant, and also because manufacturers of skin allergens currently prepare CAPB extracts that are so pure that they are no longer a good screening tool for contact allergy to commercial CAPB.
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http://dx.doi.org/10.1016/s0001-7310(06)73378-6DOI Listing
April 2006
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