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1.
J Dent ; 115: 103851, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34656658

RESUMO

OBJECTIVES: To evaluate whether the cutting-off and rescanning procedures have an impact on the accuracy (trueness and precision) of the intraoral digital scan. METHODS: A right quadrant digital scan (reference scan) of a participant was obtained using an intraoral scanner (IOS) (TRIOS 4; 3Shape A/S, Copenhagen, Denmark). The reference scan was duplicated 135 times and divided into 3 groups based on the number of rescanned mesh areas: 1 (G1 group), 2 (G2 group), and 3 (G3 group) mesh holes. Each group was subdivided into 3 subgroups depending on the mesh hole diameter: 2 mm- (G1-2, G2-2, and G3-2), 4 mm- (G1-4, G2-4, and G3-4), and 6 mm- (G1-6, G2-6, and G3-6) (n = 15). A software program (Geomagic; 3D Systems, Rock Hill, SC, USA) was used to assess the discrepancy between the reference and the experimental scans using the root mean square (RMS). Kruskal-Wallis and post hoc multiple comparison Dunn's tests were used to analyze the data (α=0.05). RESULTS: Trueness ranged from 5 to 20 µm and precision ranged from 2 to 10 µm. For trueness assessment, Kruskal-Wallis test revealed significant differences on the RMS error values among the groups tested (P<.05). The G3-6 group obtained the lowest trueness and lowest precision values, while the G1-2, G1-4, G2-2, G2-4, and G3-2 groups computed the highest trueness and precision values. When comparing groups with the same number of rescanned mesh holes but with different diameter, the higher the diameter of the rescanned mesh hole, the lower the trueness values computed; however, when comparing groups with the same diameter of the rescanned mesh hole but with differing number of rescanned mesh holes, no significant differences were found in the RMS values among the groups. For the precision evaluation, Levene's test showed a lack of equality of the variances, and therefore of the standard deviations. The F-test with Bonferroni correction identified significant differences between the SDs between group G3-6 and all the other groups. When comparing instead the interquartile range (IQRs) due to the non-normality of the data, groups G1 and G2 also showed lower IQR values or higher precision than groups G3. CONCLUSIONS: Cutting-off and rescanning procedures decreased the accuracy of the IOS tested. The higher the number and diameter of the rescanned areas, the lower the accuracy. CLINICAL SIGNIFICANCE: Cutting-off and rescanning procedures should be minimized in order to increase the accuracy of the IOS evaluated. The intended clinical use of the intraoral digital scan is a critical factor that might determine the scanning workflow procedures.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Desenho Assistido por Computador , Humanos , Imageamento Tridimensional , Telas Cirúrgicas
2.
J Dent ; 110: 103690, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33991598

RESUMO

PURPOSE: To measure the impact of different scanning patches on the accuracy (trueness and precision) of an intraoral scanner (IOS). MATERIAL AND METHODS: A typodont was digitized using an industrial optical scanner (GOM Atos Q 3D 12 M) to obtain a reference mesh. The typodont was scanned using an IOS (TRIOS 3). Three groups were generated based on the rescan areas created: no mesh holes (G0 group), 3 mesh holes distributed on the digital scan (G1 group), and 3 mesh holes located on the left quadrant of the digital scan (G2 group). In the G0 group, a digital scan was completed following the manufacturer's scanning protocol. In the G1 group, a digital scan was obtained following the same protocol as G0 group. Three 12-mm diameter holes were created in the occlusal surfaces of the left second first molar, incisal edges of the central incisors, and right first molar of the digital scan using the IOS software. In the G2 group, a digital scan was obtained following the same protocol as G0 group. Three 12-mm diameter holes in the digital scan were created in the occlusal surface of the left first molar and left second and first premolars using the IOS software program. The discrepancy between the control and the experimental digital scans was measured using the root mean square calculation. The Kolmogorov-Smirnov test demonstrated that data were normally distributed. One-way ANOVA followed by post hoc multiple comparison Bonferroni test were used to analyze the data (α = .05). RESULTS: Trueness values ranged from 15 to 26 µm and the precision ranged from 21 to 150 µm. Significant differences in trueness mean values were found among the groups tested (F(2, 42) = 6.622, P = .003); the Bonferroni test indicated significant mean differences between the G0 and G2 groups (mean difference=0.11, SE=0.003, and P = .002). For precision evaluation, significant precision differences were found between the groups tested (F(2, 39)=9.479, P < .001); the Bonferroni test revealed significant precision differences between G0 and G2 groups (mean difference=-0.12, SE=0.030, and P = .001). CONCLUSIONS: Rescanning mesh holes and stitching procedures decreased the trueness and precision of the IOS tested; furthermore, the number and dimensions of mesh holes rescanned represented an important factor that influenced the scanning accuracy of IOS tested. CLINICAL SIGNIFICANCE: It is a fundamental procedure obtaining intraoral digital scans without leaving mesh holes, so the rescanning techniques are minimized and, therefore, the scanning accuracy of the intraoral scanner tested is maximized.


Assuntos
Técnica de Moldagem Odontológica , Modelos Dentários , Desenho Assistido por Computador , Imageamento Tridimensional , Telas Cirúrgicas
3.
Rev. argent. salud publica ; 10(41): 8-13, 29/12/2019.
Artigo em Espanhol | LILACS, BINACIS, ARGMSAL | ID: biblio-1047429

RESUMO

Las rickettsiosis, ehrlichiosis y anaplasmosis son causadas por bacterias gramnegativas intracelulares obligadas y transmitidas por artrópodos. El objetivo de este trabajo fue determinar especies de garrapatas presentes en caninos de la ciudad de Pergamino y detectar presencia de patógenos de los géneros Ehrlichia, Anaplasma y Rickettsia. MÉTODOS: Se estudiaron 21 garrapatas Rhipicephalus sanguineus s.l obtenidas de caninos de diferentes ambientes de la ciudad de Pergamino. Las muestras fueron analizadas mediante PCR, amplificando un fragmento del gen gltA para Rickettsia spp. y del 16SrRNA para los géneros Ehrlichia/Anaplasma. RESULTADOS: Se detectó positividad a Rickettsia spp. en el 4,76%, identificándose por secuenciación a la especie Rickettsia massiliae. Para la familia Anaplasmataceae se detectó positividad para Ehrlichia canis (23,8%) y Anaplasma platys (19,04%). CONCLUSIONES: Se trata del primer reporte de patógenos de interés zoonótico y/o veterinario pertenecientes a los géneros Rickettsia, Ehrlichia y Anaplasma en garrapatas Rh. sanguineus s.l para el norte de la provincia de Buenos Aires


Assuntos
Rickettsia , Carrapatos , Ehrlichia , Anaplasma
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