Abstract To assess the in vitro and in situ effect of experimental combined fluoride and calcium nanocomposite solutions on dental caries prevention. Nanocompound mesoporous silica (MS) with calcium (Ca) and sodium fluoride (NaF) - (MSCaNaF); MS with NaF (MSNaF), NaF solution (positive control), and deionized water (negative control - CG) were studied. The specimens (n=130) were submitted in vitro to a multispecies biofilm in the presence of 2% sucrose. After 24 h and 48 h, the culture medium pH, the percent of surface mineral loss (%SML), and lesion depth (ΔZ) were analyzed. In the in situ study, 10 volunteers participated in four phases of 7-days each. The products were applied on the specimens (n=240) before 20% sucrose solution drips. The polysaccharides (SEPS and IEPS), %SML and roughness (Sa) were evaluated. There was an in vitro decrease in pH values in 24h and 48h, compared to baseline. The MSCaNaF and MSNaF groups obtained lower values of %SML and ΔZ (p < 0.05) than CG and NaF after 24h and were similar to NaF after 48h (p<0.05). In situ results showed similar SEPS and IEPS among all groups after 48h. An after 7-days, the nanocomposites had similar values (p>0.05), while NaF was similar to CG (p>0.05). After 48h, the MSCaNaF and MSNaF reduced the %SML (p<0.05). After 7-days, both experimental nanocomposites were similar to NaF (p>0.05). Regarding Sa, MSCaNaF was better than NaF for both periods (p<0.05). The nanocomposites controlled the in vitro and in situ enamel demineralization, mainly in the initial periods. prevention (MS Ca (Ca (NaF (MSCaNaF) MSNaF, , (MSNaF) positive control, control) negative studied n=130 n130 n 130 (n=130 2 4 %SML, SML (%SML) (ΔZ analyzed study 1 7days days 7 each n=240 n240 240 (n=240 20 drips IEPS, IEPS) Sa (Sa evaluated baseline p 0.05 005 0 05 p<0.05. p005 p<0.05 . (p<0.05) 7days, days, p>0.05, p>0.05 (p>0.05) p>0.05. demineralization (MSCaNaF (MSNaF n=13 n13 13 (n=13 (%SML n=24 n24 (n=24 0.0 00 p00 p<0.0 (p<0.05 p>0.0 (p>0.05 n=1 n1 (n=1 n=2 n2 (n=2 0. p0 p<0. (p<0.0 p>0. (p>0.0 n= (n= p<0 (p<0. p>0 (p>0. (n p< (p<0 p> (p>0 (p< (p>

ABSTRACT Objective: To compare the agreement of images in white light (WL), fluorescence (FL), and digital radiographs (DR), on the diagnosis and treatment decisions for occlusal caries lesions against a micro-CT gold standard. Material and Methods: Ten extracted third molars, with enamel and/or dentin caries (ICDAS 2-4), were included. Occlusal surface images were acquired with an intraoral camera (SoproLife®) in WL and FL modes. DR was obtained using an intraoral X-ray and a semi-direct digital system. A total of 780 images were needed, organized in a template, to be later examined by twenty-six dentists invited to compose the study. The Generalized Estimation Equations model was used to compare the proportions of the correct answers between the three methods and the gold standard. When significant, Bonferroni post-hoc test was used to identify differences (α=5%). Results: Most of the examiners were specialists (76.9%) with 14.5 years of experience. All diagnostic methods were similar and showed low agreement (DR 12.7%, WL 16.5%, and FL 16.5%) compared with gold standard caries diagnostic scores. Regarding treatment decisions, mean agreement for all diagnostic methods was higher (43.2%; p<0.001), and among all methods, WL (48.1%) and FL (51.2%) modes performed better than DR (30.4%, p<0.001). Conclusion: SoproLife® images could help clinicians to propose rational, minimally invasive treatments for occlusal caries lesions. Objective WL, , (WL) FL, (FL) DR, (DR) microCT micro CT Methods molars andor or ICDAS 24, 24 2 4 2-4) included SoproLife (SoproLife® Xray X ray semidirect semi direct system 78 needed template twentysix twenty six study significant posthoc post hoc α=5%. α5 α α=5% . 5 (α=5%) Results 76.9% 769 76 9 (76.9% 145 14 14. experience 127 12 7 12.7% 165 16 16.5% scores 43.2% 432 43 (43.2% p<0.001, p0001 p p<0.001 0 001 p<0.001) 48.1% 481 48 1 (48.1% 51.2% 512 51 (51.2% 30.4%, 304 30 (30.4% p<0.001. Conclusion rational (WL (FL 2-4 (SoproLife α=5 (α=5% 76.9 (76.9 12.7 16.5 43.2 (43.2 p000 p<0.00 00 48.1 (48.1 51.2 (51.2 30.4% 3 (30.4 2- α= (α=5 76. (76. 12. 16. 43. (43. p00 p<0.0 48. (48. 51. (51. 30.4 (30. (α= (76 (43 p0 p<0. (48 (51 30. (30 (α (7 (4 p<0 (5 (3 ( p<

ABSTRACT Objective: To associate caregivers' sense of coherence (SOC) and untreated caries with oral health status in children covered by a dental public health system. Material and Methods: A convenience sample of caregivers/children in Angra dos Reis, Brazil, was surveyed. Caregivers' SOC was evaluated using the 13-question version questionnaire. For both caregivers/children, sociodemographic information was acquired and caries experience was evaluated by DMFT/dmft and PUFA/pufa index. Statistical associations between children's untreated carious teeth and interest variables from the caregivers were evaluated by binary logistic regression assessed by generalized linear modeling. Results: A total of 233 pairs of caregivers-children were included. Children's untreated permanent and primary carious teeth represented 34.8% and 62.2% of the caries experience, respectively and at least one PUFA/pufa scored tooth was detected in 22.7% of them. Caregivers' DMFT was 13.5±7.0, while 33.6% scored on PUFA. A total of 62.1% of them presented untreated carious lesions. Results from the univariate model, correlating children's untreated caries and caregivers' attributes showed a statistical significance for SOC values (p<0.015), untreated decayed teeth (p<0.035), self-perception of oral health (p<0.022) and oral impact on daily performance (p<0.010). The multivariate logistic first model kept the statistical significance only for the caregiver's untreated decayed teeth. Conclusion: Caregivers' SOC and untreated carious teeth could be used as indicators of dental treatment needs in their offspring. Objective (SOC system Methods caregiverschildren Reis Brazil surveyed Caregivers 13question question 13 questionnaire DMFTdmft dmft PUFApufa PUFA pufa index childrens s modeling 23 included Childrens Children 348 34 8 34.8 622 62 2 62.2 227 22 7 22.7 13570 5 0 13.5±7.0 336 33 6 33.6 621 1 62.1 lesions p<0.015, p0015 p p<0.015 , 015 (p<0.015) p<0.035, p0035 p<0.035 035 (p<0.035) selfperception self perception p<0.022 p0022 022 (p<0.022 p<0.010. p0010 p<0.010 . 010 (p<0.010) caregiver Conclusion offspring 3 34. 62. 22. 1357 13.5±7. 33. p001 p<0.01 01 (p<0.015 p003 p<0.03 03 (p<0.035 p<0.02 p002 02 (p<0.02 (p<0.010 135 13.5±7 p00 p<0.0 (p<0.01 (p<0.03 (p<0.0 13.5± p0 p<0. (p<0. 13.5 p<0 (p<0 13. p< (p< (p

Abstract Objective: To evaluate the efficacy of silver diamine fluoride (SDF) in arresting dentin caries lesions when applied under different concentrations and times. Material and Methods: Forty-two bovine blocks were selected and fixed in 24-well plates. Each well received a mixed bacterial inoculum added to the culture medium with 5% sucrose. The plates were incubated in microaerophilia (7 days) for caries formation, confirmed by micro-CT (M1). SDF was applied over the carious lesions for different times and concentrations (n=6): SDF 30% - immediate removal, 1 minute and 3 minutes; SDF 38%, - immediate removal, 1 minute and 3 minutes. The group without treatment was the control. Then, the samples were again scanned by micro-CT (M2) and submitted to a second cariogenic challenge for 21 days. Then, a final scan was performed (M3). Results: Mean pH at the culture medium and lesion depth were compared using Kruskal-Wallis and Wilcoxon tests. 38% SDF showed the lowest metabolic activity of the biofilm. All 38% groups and 30% 1 and 3 minutes did not show an increase in mean lesion depth comparing M3 with M1. However, only 30% 3 minutes and 38% 1 and 3 minutes showed a significant reduction of lesion depth. Conclusion: The minimum application time of 30% SDF to arrest dentin caries lesion was 1 minute, while 38% SDF arrested with application and immediate removal.

Abstract Objective: To investigate the association between caries experience and school performance among children and adolescents living in an island community without fluoridated water supply and to compare data according to the type of attended school (full-time or part-time). Material and Methods: A cross-sectional oral health survey in a convenience sample of students (n=147) attending four public schools was performed. Students were examined by one calibrated dentist in the school environment to the obtain prevalence of dental caries (DMFT/dmft) and its consequences using the PUFA/pufa index. Self-reported oral health behavior was also accessed. Data from each student’s school performance and absenteeism were extracted from official sources and the school performance was classified into “good” and “fair”. The final sample consisted of 120 students. Descriptive statistics, Mann-Whitney, Kruskal-Wallis, chi-square tests and binary logistic regression were performed to evaluate collected data. Results: Students´ age ranged between 5 to 19 years (10±4.3). DMFT/dmft mean were 1.3 (±2.3) and 3.05 (±3.4), respectively. Conclusion: Participants from the full-time school presented better oral health status than their peers in the part-time schools (p<0.05). A significant association was found between the prevalence of caries-free participants and good school performance when the factor age range was controlled (OR=2.87). Moreover, attendance to full-time schools appeared to be a protective factor for good oral health conditions.

RESUMO Este estudo teve como objetivo avaliar o efeito in vitro de uma única aplicação de soluções experimentais de nanocompósitos na prevenção de cárie dentária em braquetes ortodônticos. Os espécimes foram expostos a nanocompósitos de sílica mesoporosa (MS) contendo fluoreto por associação com tetrafluoreto de titânio (TiF4) ou fluoreto de sódio (NaF). Os nanocompósitos também podem conter cálcio e os grupos foram descritos como MSCaTiF4, MSTiF4, MSCaNaF, MSNaF e controles (TiF4 e NaF). Os espécimes foram submetidos à formação de um biofilme multiespécie para gerar um desafio cariogênico. Após 24h, o pH e a concentração de flúor solúvel total do meio de cultura foram avaliados. A perda mineral foi avaliada pela porcentagem de perda mineral superficial (% SML), variação do volume mineral (ΔZ) do esmalte interno e microscopia de luz polarizada (PL). A rugosidade superficial linear (Ra) e volumétrica (Sa) e a microscopia eletrônica de varredura (MEV) foram utilizadas para avaliar a topografia do esmalte. As análises estatísticas foram realizadas considerando p <0,05. MSNaF apresentou o maior valor de pH do meio de cultura após o desafio cariogênico, semelhante ao MSTiF4. Todas as soluções de nanocompósitos liberaram menos flúor do que seus controles NaF e TiF4 (p <0,05). Todas as soluções de nanocompósitos apresentaram% SML menor em comparação com seus respectivos grupos de controle (p <0,05). Ra, Sa e ΔZ menores foram observados para os grupos experimentais em comparação ao TiF4 (p <0,05). Os resultados foram confirmados por análises PL e SEM. As soluções experimentais de nanocompósitos contribuíram para a menor desmineralização do esmalte ao redor dos braquetes ortodônticos.

Abstract This study aimed to evaluate the in vitro effect of a single application of experimental nanocomposite solutions on the prevention of dental caries around orthodontic brackets. The specimens were exposed to mesoporous silica (MS) nanocomposites containing fluoride by association with titanium tetrafluoride (TiF4) or sodium fluoride (NaF). Nanocomposites also could contain calcium and groups were described as MSCaTiF4, MSTiF4, MSCaNaF, MSNaF, and controls (TiF4, and NaF). Specimens were subjected to the formation of a multispecies biofilm to generate a cariogenic challenge. After 24h, both pH and total soluble fluoride concentration of the culture medium were assessed. Mineral loss was evaluated by percentage of surface mineral loss (%SML), mineral volume variation (ΔZ) of inner enamel and polarized light microscopy (PL). Linear (Ra) and volumetric (Sa) surface roughness and scanning electronic microscopy (SEM) were used to assess enamel topography. Statistical analyses were conducted considering p<0.05. MSNaF had the highest value of culture medium pH after cariogenic challenge, similarly to MSTiF4. All nanocomposite solutions released less fluoride than their controls NaF and TiF4 (p<0.05). All nanocomposite solutions presented lower %SML compared to their respective control groups (p<0.05). Lower Ra, Sa and ΔZ were observed for experimental groups compared to TiF4 (p<0.05). The results were confirmed by PL and SEM analysis. The experimental nanocomposite solutions contributed for lower enamel demineralization around orthodontic brackets.

Abstract This study aimed to evaluate the endodontic instrumentation outcomes with asymmetrical files compared to reciprocating and hand files (HFs) in 3D-printed prototypes of upper primary incisors using micro-computed tomography (micro-CT). For this purpose, 50 prototypes were randomly divided (n = 10) according to the instrumentation technique as follows: HFs, a reciprocating file (WaveOne® Gold [WOG]), and three asymmetrical movement files: XP-Endo® Shaper (XPS), XP-Endo® Finisher (XPF), and XP Clean (XPC). The specimens were scanned and, after registration of the baseline and instrumented volumes, changes in the root canal volume (RCV), debris accumulation, removed root material volume (RRMV), non-instrumented areas, and the presence of cracks/perforations were quantified. Data were analyzed by analysis of variance and Student’s t-test, while the effect size was calculated for statistically significant outcomes. All groups showed an increase in RCV after instrumentation (p < 0.05), but this was higher with HFs (p < 0.05). Accumulated debris was higher for WOG and XPS (p < 0.05), but WOG exhibited more in the medium and apical third areas. HFs showed the highest RRMV (p < 0.05), especially at the apical third. The non-instrumented areas were lower for HFs and XPC than for the other systems (p < 0.05). Cracks were present in a few WOG (n = 2) and HF specimens (n = 3) and in this group, one of the cracked specimens and two others showed perforations. The asymmetric systems resulted in conservative dentin removal and fewer cracks/perforations as compared to HFs and a reciprocation file in prototyped primary upper incisors. XPC showed the best compromise between RRMV and non-instrumented areas with a low accumulation of debris.

Abstract Objective: To compare the immediate microleakage of carious fissures sealed with a caries infiltrant covered by a flowable composite or solely with a flowable composite. Material and Methods: Extracted carious molars (n=20) were selected and paired among the experimental groups according to caries progression scores. Experimental groups (n=10) were divided according to the following sealing techniques: 1) caries infiltrant (Icon) + flowable composite (Z350 flow); 2) flowable composite (Z350 flow). Specimens were immersed in 3% methylene blue and evaluated in a stereomicroscope. Microleakage scores were attributed independently by two calibrated evaluators and the mode value was considered as the mean for the specimen. Binomial tests were used to test differences between two independent sample proportions at 5% significance level. Results: In the flowable composite group, a higher prevalence of dye penetration along the full depth of the fissure was observed, compared with caries infiltrant + flowable composite (p<0.05). For specimens showing dye penetration up to half of the fissure, in caries infiltrant + flowable composite group, all specimens showed dye penetration into the sealant, but not over the infiltrant. Conclusion: Using caries infiltrant as sealing material under a flowable composite cover is effective to improve the immediate sealing ability in carious fissures compared to sealing with flowable composite.

Abstract Objective: To verify the concordance in the evaluation of the apical limit of obturation (ALO) in filled root canals of primary teeth between digital and visual methods. Material and Methods: Twenty periapical radiographs of endodontically treated primary teeth were digitalized and evaluated by an endodontics specialist (E1), a PhD pediatric dentist (E2), and a MSc general dentist (E3). Calibrated evaluators (Kappa = 1.00) analysed the images in a light-isolated environment two times (D1 and D2) with a one-week interval between evaluations. ALO scores were categorized as overfilled, flush-filled and underfilled. Results: The intra-rater reliability between methods was 0.82 (D1) and 0.75 (D2) for E1, 0.93 (D1 and D2) for E2, and 0.94 (D1 and D2) for E3. Inter-rater reliability ranged from 0.71 (E1 × E3) and 1.00 (E1 × E2) for the visual method to 0.76 (E1 × E3) and 0.88 (E1 × E2) for the digital method. Spearman correlation coefficients showed a similar ranking among the evaluators. There was greater disagreement among the underfilled and ideal scores. For all evaluators, the digital method favoured the identification of the ideal score. Conclusion: Both methods are suitable for the determination of the ALO of filled primary teeth and can be used in clinical practice.

Abstract The aim of this study was to check the in vitro accuracy of ICDAS criteria on digital images compared to visual examination for the diagnosis of occlusal caries against a micro-CT gold standard. ICDAS was scored in 40 extracted permanent molars by means of visual inspection and stereomicroscopic images. Visual examinations were performed in duplicate and at a one-week interval by three different calibrated examiners. The analysis of digital images by ICDAS criteria was also performed in duplicate, 1 month after visual examinations. The detection methods were compared by means of sensitivity, specificity, area under the curve, predictive positive and negative values, and accuracy for two different thresholds (1- sound vs. carious teeth; 2- tooth requiring operative vs. non-operative treatment). Sensitivity and accuracy values for threshold 1 in the visual ICDAS and image-based ICDAS methods were high for sensitivity (0.93 and 0.97) and for accuracy (0.83 and 0.85), but low for specificity (0.55 for both methods). Specificity values for threshold 2 were 0.77 and 0.82, while sensitivity was 0.33 and 0.28 for each method. Spearman’s rank correlation coefficient was 0.53 and 0.43 (p<0.05) for visual and image-based ICDAS compared to the gold standard scores. Both visual and image-based ICDAS scores were similar to each other in terms of diagnostic accuracy when compared to the micro-CT gold standard. Low specificity for the presence of caries and sensitivity for the detection of caries requiring operative treatment were found.

Resumo O objetivo deste estudo foi avaliar a relação de causa-efeito entre o preparo do canal radicular com o sistema ProTaper Universal (PTU) e a formação de defeitos dentinários usando a análise por micro-tomografia computadorizada (micro-CT). Quarenta raízes mesiais de molares inferiores com a configuração tipo II de Vertucci foram escaneadas com resolução isotrópica de 14.16 μm. A amostra foi distribuída em um grupo experimental (n = 30) e um grupo controle (n = 10), e os canais mesiais foram preparados com o sistema PTU até a lima F2. As amostras do grupo experimental foram escaneadas e as imagens de secção transversal das raízes mesiais, antes e após o preparo, foram analisadas para identificar a presença de defeitos dentinários. No grupo controle, os dentes foram seccionados perpendicularmente em relação ao longo eixo da raiz em fatias de 1 mm de espessura (n = 80) e examinados ao microscópio óptico. Uma vez detectado um defeito dentinário, a fatia foi escaneada através da micro-CT. No grupo experimental, defeitos dentinários foram observados em 4.828 secções transversais (24,04%). Em todas as imagens de secção transversal, os defeitos dentinários após os procedimentos experimentais já estavam presentes na secção pré-operatória correspondente. No grupo controle, 13 das 80 fatias (16,25%) apresentaram pelo menos um defeito dentinário visualizado através do microscópio, o qual foi identificado em um escaneamento posterior. A micro-CT mostrou confiabilidade com a microscopia óptica para detecção e visualização dos defeitos dentinários, permitindo acompanhar o tecido dentinário antes e depois do preparo do canal. O preparo do canal radicular com o sistema PTU não induziu a formação de novos defeitos dentinários.

Abstract This study aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Universal (PTU) system and dentinal defects formation using micro-computed tomography (micro-CT) analysis. Forty mesial canals of mandibular molars with a type II Vertucci's canal configuration were scanned at an isotropic resolution of 14.16 µm. The sample was assigned to an experimental (n = 30) and a control (n = 10) groups, and the mesial canals were prepared with PTU system up to F2 instrument. The specimens from the experimental group were scanned and the cross-section images of the mesial roots, before and after preparation, were screened to identify the presence of dentinal defects. In the control group, the specimens were sectioned perpendicularly to the long axis of the root into 1-mm-thick slices (n = 80) and examined under optical microscope. Once a dentinal defect was detected, the slice was scanned through micro-CT. In the experimental group, dentinal micro-cracks were observed in 4,828 slices (24.04%). In all cross-section images, dentinal defects identified in the postoperative images were already present in the corresponding preoperative image. In the control group, 13 out of 80 slices (16.25%) had at least one dentinal defect visualized under stereomicroscopy, which was identified after a further micro-CT scanning. Micro-CT showed reliability as similar as optical microscopy in detecting dentinal defects, adding the possibility of tracking the dentinal tissue, before and after canal preparation, and providing a clear visualization of micro-cracks. Root canal preparation with PTU system did not induce the formation of new dentinal defects.

Abstract The purpose of this study was to assess the ability of an off-centered rectangular design system [ProTaper Next (PTN)] to maintain the original profile of the root canal anatomy. To this end, ProTaper Universal (PTU), Reciproc (R) and WaveOne (WO) systems were used as reference techniques for comparison. Forty clear resin blocks with simulated curved root canals were randomly assigned to 4 groups (n = 10) according to the instrumentation system used: PTN, PTU, R and WO. Color stereomicroscopic images of each block were taken before and after instrumentation. All image processing and data analysis were performed with an open source program (Fiji v.1.47n). Evaluation of canal transportation was obtained for two independent regions: straight and curved portions. Univariate analysis of variance and Tukey’s Honestly Significant Difference test were performed, and a cut-off for significance was set at α = 5%. Instrumentation systems significantly influenced canal transportation (p = 0.000). Overall, R induced significantly lower canal transportation compared with WO, PTN and PTU (p = 0.000). The curved portion displayed superior canal transportation compared to the straight one (p = 0.000). The significance of the difference among instrumentation systems varied according to the canal level evaluated (p = 0.000). In its straight portion, R and WO exhibited significantly lower transportation than PTN; whereas in the curved portion, R produced the lowest deviation. PTU exhibited the highest canal transportation at both levels. It can be concluded that PTN produced less canal transportation than PTU and WO; however, R exhibited better centering ability than PTN.

Resumo O objetivo deste estudo foi comparar a porcentagem de área não-instrumentada de canais radiculares preparados com diferentes ampliações utilizando sistemas reciprocantes de lima única (Reciproc e WaveOne) e um sistema rotatório convencional de múltiplas limas (BioRaCe) usando a análise da micro tomografia computadorizada. Trinta raízes mesiais de molares inferiores com curvatura moderada (10º a 20º) apresentando a configuração classe II de Vertucci e semelhança de volume do canal foram selecionadas e escaneadas em uma resolução isotrópica de 14,16 µm. A amostra foi dividida em 3 grupos (n=10) de acordo com o sistema utilizado para a preparação do canal radicular: grupo Reciproc, grupo WaveOne e grupo BioRaCe. Segundo e terceiro escaneamentos foram realizados após os canais serem preparados com instrumentos tamanhos 25 e 40, respectivamente. As imagens registradas de voxels da área de superfície dos canais, antes e após o preparo, foram examinadas desde o nível da furca até o ápice para quantificar a superfície não instrumentada. Os dados foram comparados estatisticamente através de GLM para medidas repetidas com um nível de significância de 5%. Os sistemas de instrumentação não influenciaram o percentual de superfícies não tocadas dos canais radiculares (p=0,690), enquanto que uma redução significativa no percentual de voxels estáticos foi observada após o alargamento do canal radicular (p=0,010) em todos os grupos (p=0,507). Nenhum dos sistemas foi capaz de preparar toda a área de superfície do canal mesial dos molares inferiores. O aumento do tamanho final apical resultou num efeito positivo significativo sobre a capacidade de modelar dos sistemas testados.

The aim of this study was to compare the percentage of non-instrumented area of root canals prepared with different enlargements using single-file reciprocating systems (Reciproc and WaveOne) and a conventional multi-file rotary (BioRaCe) system by micro-computed tomographic analysis. Thirty mesial roots of mandibular molars with moderate curvature (10° to 20°) presenting a type II Vertucci canal configuration and similar internal volume were chosen and scanned at an isotropic resolution of 14.16 µm. The sample was assigned to 3 groups (n=10) according to the system used for root canal preparation: Reciproc, WaveOne, and BioRaCe groups. Second and third scans were taken after the canals were prepared with instruments sizes 25 and 40, respectively. The recorded images of the surface area voxels of the canals, before and after preparation were examined from the furcation level to the apex to quantify the non-instrumented surface. Statistical data were compared using GLM for repeated-measures with a significance level set at 5%. Instrumentation systems did not influence the percentage of untouched root canal surfaces (p=0.690) whilst a significant reduction in the percentage of static voxels was observed after the enlargement of the root canal (p=0.010) in all groups (p=0.507). None of the systems was able to prepare the entire surface area of the mesial root canal of mandibular molars. The increased final apical size resulted in a significant positive effect on the shaping ability of the tested systems.

Resumo O objetivo do presente estudo foi comparar a porosidade do AH Plus Jet(tm) dotado de misturador automático com o AH Plus convencional manipulado a mão a partir de um método quantitativo de microtomografia computadorizada (micro-CT). Para cada cimento, sete espécimes foram preparados por um único operador, seguindo as instruções do fabricante, e inseridas em anéis de plástico. Após o tempo de presa, os cimentos foram escaneados utilizando o micro-CT e as imagens foram reconstruídas. Os parâmetros avaliados foram (i) contagem total de poros, (ii) volume total de poros e média dos volumes dos poros, (iii) porosidade total (% de volume de poros em relação ao volume total do cimento) e (iv) distância média dos poros em relação ao perímetro externo (0,05 mm da superfície externa). O AH Plus manipulado a mão apresentou maior número de poros, maior volume total de poros e porosidade total (p=0,001) comparado com o AH Plus com misturador. No entanto, a média de tamanho dos poros foi estatisticamente superior no AH Plus com misturador quando comparado com o AH Plus manipulado a mão (p=0,046). O AH Plus manipulado a mão foi associado com uma maior média de poros, volume e porosidade quando comparado com o AH Plus com misturador.

The aim of the present study was to compare the porosity characteristics of AH Plus Jet(tm) syringe-mix and the conventional hand-mixed AH Plus root canal sealers by three-dimensional quantitative high-resolution micro-computed tomography (micro-CT). Seven test specimens were prepared from each tested sealer by a single operator following the manufacturer's instructions and poured into pre-lubricated plastic split-ring moulds. Set sealer test specimens were scanned using a micro-CT device and the shadow images were reconstructed into cross-sectional slices. The evaluated parameters were (i) total pore count, (ii) total pore volume and mean pore volume, (iii) total porosity (% of pore volume in relation to total sealer volume) and (iv) mean pore distance to the sealer lateral external surface. In both groups, most pores were localized within the external sealer perimeter (0.05 mm from the external surface). Hand-mixed AH Plus specimens showed statistically significant higher mean total pore count, total pore volume and total porosity (p=0.001) than the syringe-mixed specimens. However, mean pore sizes in AH Plus syringe-mixed specimens were significantly higher (p=0.046) than the AH Plus hand-mixed counterparts. Hand-mixed AH Plus was associated with higher total mean pore count, volume and total porosity compared to syringe mixed AH Plus.

O objetivo do presente estudo foi avaliar e comparar a dor pós-operatória após a instrumentação foraminal usando NaOCl 5,25% ou gel de CHX 2% em dentes não vitais unirradiculares após instrumentação reciprocante. Sessenta e dois voluntários, apresentando um único canal radicular diagnosticado com necrose assintomática e periodontite apical, foram randomizados em dois grupos experimentais de acordo com o protocolo de irrigação (ou seja, grupos de NaOCl 5,25% e CHX gel 2%). O tratamento endodôntico foi realizado em uma única visita sob instrumentação reciprocante com instrumentação foraminal. Os voluntários foram instruídos a registrar a intensidade da dor. Escores de 1-4 foram atribuídos a cada tipo de dor após 24, 48 e 72 h. Testes de Kolmogorov-Smirnov e t de Student foram utilizados para determinar diferenças significativas em p<0,05. Em média, o percentual de pacientes que teve nenhumaou leve dor após 24, 48 ou 72 h foi de 77.4%, 88.7% e 95.1%, respectivamente. Não foi encontrada diferença de idade estatisticamente significante entre os grupos (p>0,05, teste t de Student). A dor pós-operatória não apresentou diferença estatisticamente significativa em qualquer período de observação ao usar NaOCl 5,25% ou CHX gel 2% (p>0,05). Além disso, não foi observada diferença significativa no número médio de comprimidos analgésicos utilizados entre os grupos (p>0,05). O uso de NaOCl 5,25% ou CHX gel 2% resultou na mesma dor pós-operatória. Portanto, pode-se inferir que a escolha do irrigante não tem relação com um acompanhamento a curto prazo em relação a dor pós-operatória.

The aim of the present study was to evaluate and compare postoperative pain after foraminal instrumentation using 5.25% sodium hypochlorite (NaOCl) or 2% chlorhexidine (CHX) gel irrigation protocol in nonvital single-rooted teeth after reciprocating instrumentation. Sixty-two volunteers presenting a single root canal diagnosed with asymptomatic necrosis and apical periodontitis were randomized into 2 experimental groups regarding the irrigation protocol (ie, 5.25% NaOCl and 2% CHX gel groups). Endodontic treatment was performed in a single session under reciprocating instrumentation with foraminal instrumentation. Volunteers were instructed to record pain intensity. Scores from 1 to 4 were attributed to each kind of pain after 24, 48, and 72 h. Kolmogorov-Smirnov and Student´s t tests were used to determine significant differences at p<0.05. On average, the percentage of patients that had no or mild pain after 24, 48 or 72 h was 77.4%, 88.7% and 95.1%, respectively. No statistically significant age difference was found between the groups (p>0.05, Student´s t test). Postoperative pain showed no statistically significant difference at any observation period when using 5.25% NaOCl or 2% CHX gel (p>0.05). Moreover, no significant difference was observed in the mean number of analgesic tablets used between the groups (p>0.05). In conclusion, the use of 5.25% NaOCl or 2% CHX gel resulted in the same postoperative pain. Therefore, it can be inferred that irrigant choice has no relation with short-term follow up regarding postoperative pain.