Comparison between conventional and chemomechanical approaches for the removal of carious dentin: an in vitro study.

The present study aimed to evaluate the efficiency, effectiveness, and biocompatibility of two agents used for the chemomechanical removal of carious dentin. Sixty extracted carious human teeth were treated with a conventional bur (CBG) or chemomechanical agents - Papacarie Duo (PG) and Brix 3000 (BG). Treatment efficiency and effectiveness were assessed by the working time for carious dentin removal and Knoop microhardness values, respectively. Human pulp fibroblasts (FP6) were used to evaluate cytotoxicity by incorporating MTT dye, and genotoxicity was evaluated with the micronuclei test. The carious tissue was removed in a shorter time with CBG (median = 54.0 seconds) than the time required for chemomechanical agents (p = 0.0001). However, the time was shorter for Brix 3000 (BG) than that for Papacarie Duo (PG), showing mean values of 85.0 and 110.5 seconds, respectively. Regarding microhardness testing, all approaches tested were effective (p < 0.05). The final mean microhardness values were 48.54 ± 16.31 KHN, 43.23 ± 13.26 KHN, and 47.63 ± 22.40 KHN for PG, BG, and CBG, respectively. PG decreased cell viability compared to that of BG, but it presented no genotoxicity. Brix 3000 may be a good option for chemomechanical dentin caries removal due to its reduced removal time and lower cytotoxicity compared to the other treatment options.

Effect of low-level laser therapy and zoledronic acid on bone repair process.

This study aimed to evaluate, through histomorphometric analysis, the bone repair process in the tibia of rats treated with zoledronic acid and submitted to 808-nm low-level laser therapy (LLLT) by using arsenide aluminum gallium laser. For this purpose, 20 rats were used and distributed according to treatment: group 1-saline administration; group 2-treated with LLLT; group 3-treated with zoledronic acid; and group 4-treated with zoledronic acid and LLLT. The zoledronic acid was administered at a dose of 0.035 mg/kg every 2 weeks for 8 weeks. Subsequently, bone defects of 2 mm were prepared in the tibias of all groups. The bone defects in groups 2 and 4 were irradiated with LLLT in the immediate post-operative period. After 14 and 28 days of application, the animals were submitted and euthanized for histomorphometric analysis. The results were submitted to statistical analysis (α = 5%), and the intragroup comparison was performed using the t test. On the other hand, for intergroup comparison, the ANOVA test was performed, and to the groups presenting statistically significant difference, the Student-Newman-Keuls test was used. In intergroup comparison, group 1 (mean ± SD= 45.2 ± 18.56%) showed a lower bone formation compared with groups 2 (64.13 ± 3.51%) (p = 0.358) and 4 (15.2 ± 78.22%) (p = 0.049), at the 14-day period. Group 3 (20.99 ± 7.42%) also presented a lower amount of neoformed bone tissue, with statistically significant difference when compared with groups 1 (p = 0.002), 2, and 4 (p ≤ 0,001). After 28 days, group 1 presented a lower amount of neoformed bone tissue compared with the other groups, with p = 0.020. Thus, it was concluded that LLLT associated with zoledronic acid is effective for stimulating bone formation in surgically created defects in rats, at the periods studied.

Influence of professional experience on detection and treatment decision of occlusal caries lesions in primary teeth.

AIM: To evaluate the influence of examiner's clinical experience on detection and treatment decision of caries lesions in primary molars. DESIGN: Three experienced dentists (Group A) and three undergraduate students (Group B) used the International Caries Detection and Assessment System (ICDAS) criteria and bitewing radiographs (BW) to perform examinations twice in 77 primary molars that presented a sound or carious occlusal surface. For the treatment decision (TD), the examiners attributed scores, analyzing the teeth in conjunction with the radiographs. The presence and the depth of lesion were validated histologically, and reproducibility was evaluated. The sensitivity, specificity, accuracy, and area under the ROC curve values were calculated for ICDAS and BW. The associations between ICDAS, BW, and TD were analyzed by means of contingency tables. RESULTS: Interexaminer agreement for ICDAS, BW, and TD were excellent for Group B and moderate for Group A. The two groups presented similar and satisfactory performance for caries lesion detection using ICDAS and BW. In the treatment decision, Group A was shown to have a less invasive approach than Group B. CONCLUSION: The examiner's experience was not determinant for the clinical and radiographic detection of occlusal lesions in primary teeth but influenced the treatment decision of initial lesions.

Comparação da razão carga/deflexão entre fios ortodônticos de Ni-Ti termoativados 0,014"x0, 025" e 0, 016"x0, 022" / Comparison of the load/deflection ratio between the heat-activated Ni-Ti orthodontic wires 0. 014"x0. 025" and 0. 016"x0. 022"

O conhecimento sobre as propriedades mecânicas dos fios de Níquel-Titânio (NiTi) termoativados das marcas mais acessíveis do mercado nacional ainda é limitado. Diante disso, o objetivo deste estudo foi avaliar e comparar por meio de testes de deflexão em 03 braquetes, os fios NiTi termo ativados retangulares de calibre 0,014''x0,025'' e 0,016"x0,022" de diferentes marcas (MORELLI® ORMCO®, ORTHOSOURCE®, ORTHOMETRIC®, EURODONTO® e ADITEK®). Todos os testes foram realizados na máquina de ensaio universal EMIC DL 2000 sob condições idênticas e controladas a uma temperatura de 36°C ± 0,5°C. Cinco medições (N=5) foram realizadas para cada espessura/marca de fio que foi deflexionado até um limite de 4,0mm a uma velocidade de 1,0mm/min. A cada 0,2mm (ida e volta) de deflexão a força correspondente foi aferida para a construção do gráfico de força x deflexão no programa Tesc versão 3.04. Cada gráfico foi avaliado individualmente segundo as seguintes variáveis: início da transformação martensítica (cN e mm), força máxima (cN), inicio e final do platô de desativação (cN e mm) e comprimento do platô (mm). As médias e o desvio padrão foram calculados para todas as variáveis e a análise estatística foi feita pelos testes ANOVA 2 critérios e Turkey ou Kruskal-Wallis e Dunn, a um nível de significância de 5%. Os resultados evidenciaram que nos testes dos fios 0,014''x0,025'' as marcas ORTHOMETRIC® e ORMCO® apresentaram os melhores resultados, assim como os fios das marcas MORELLI® e ORTHOSOURCE® para os fios 0,016''x0,022''. De uma forma geral, os fios de calibre 0,014''x0,025'' apresentaram níveis de força no platô de desativação até 6 x menores que os de calibre 0,016''x0,022''.

The knowledge of the mechanical properties of nickel-titanium (NiTi) termoactives of the more accessible of the domestic market is still limited. Given this, the objective of this study was to evaluate and compare through deflection tests in brackets NiTi wires 03 term rectangular gauge 0.014" enabled x 0.025" and 0.016" x 0.022" of different brands (MORELLI®, ORMCO® ORTHOSOURCE®, ORTHOMETRIC®, EURODONTO® and ADITEK®). All tests were carried out on universal testing machine EMIC DL 2000 under identical conditions and controlled at a temperature of 36°C ± 0.5°C. Five measurements (N=5) were performed for each thickness/wire tag that was deflected up to a limit of 4.0mm at a speed of 1.0mm/min. Each 0.2mm (round trip) of corresponding strength measured deflection for the construction of the graph of force x deflection at Tesc program version 3.04. Each graphic was evaluated according to the following variables: beginning of the Martensitic transformation (cN and mm), maximum strength (cN), the beginning and end of the plateau of deactivation (cN and mm) and length (mm) plateau. The average and standard deviation were calculated for all variables and statistical analysis was made by ANOVA tests 2 criteria and Turkey or Kruskal-Wallis and Dunn, a 5% level of significance. The results showed that the tests of 0.014"x0.025" ORTHOMETRIC® brands and ORMCO® showed the best results, as well as the wires of the MORELLI® and ORTHOSOURCE® to wires 0.016"x0.022". In General, the gauge wires 0.014"x0.025" showed strength levels on the plateau of deactivation to 6 x smaller than 0.016"x0.022" caliber.

Is it possible to use cross-sectional and vertical facial measurements to establish the shape of the mandibular arch?

BACKGROUND: Given the benefits of radiographic cephalometric studies in determining patterns of dental-skeletal-facial normality in orthodontics, the aim of this study was to investigate the association between mandibular dental arch shape and cross-sectional and vertical facial measurements. MATERIALS AND METHODS: It was analyzed plaster casts and teleradiographs in frontal and lateral norm belonging to 50 individuals, aged between 15 and 19 years, with no previous history of orthodontic treatment and falling into four of the six Andrews's occlusion keys. The plaster models were scanned (3D) and the images of the dental arches were classified subjectively as oval, triangular and quadrangular by three calibrated examiners, with moderate inter-examiner agreement (Kappa = 0.50). After evaluation of the method error by paired t test (p > 0.05), it was carried out the analysis of cross-sectional and vertical facial measurements to be compared to the shape of the dental arch. Data were subjected to one-way analysis of variance with a significance level of 5%. RESULTS: When the VERT index was compared with the three arch shapes, no measurement showed statistically significant differences (p > 0.05): triangular (0.54); oval (0.43); and quadrangular (0.73); as well as there were no differences (p > 0.05) in the widths of the face (141.20; 141.26; 143.27); maxilla (77.27; 77.57; 78.59) and mandible (105.13; 103.96; 104.28). CONCLUSION: It can be concluded that there was no correlation between different shapes of the mandibular dental arch and the cross-sectional and vertical facial measurements investigated.