Assessing peri-implant bone microarchitecture: conventional vs. osseodensification drilling - ex vivo analysis.

The aim was to evaluate primary implant stability and bone microarchitecture in two drilling situations, by comparing the conventional technique (CT) and osseodensification (OD) (Versah Burs - Jackson - Mississippi - USA). The implant insertion torque (IT), implant stability quotient (ISQ), and the peri-implant trabecular microstructure were assessed on bone fragments obtained from pig's tibia (n=12), divided between CT (n=6) and OD (n=6). After the drilling procedure, the implants were installed (3.5x8.5 mm, Epikut - SIN - São Paulo - Brazil). The IT and ISQ were measured using a digital torque wrench and resonance frequency analysis. Then, the bone fragments containing the implants were removed with a trephine and analyzed by Microtomography (µCT, 8.0 µm). The comparison between groups was performed using the unpaired t-test (α=0.05). The results revealed that OD promotes a higher insertion torque (CT: 7.67±2.44 Ncm; OD: 19.78±5.26 Ncm) (p=0.0005), although ISQ was not different (CT: 61.33±4.66; OD: 63.25±4.58) (p=0.48). There was a significant increase in peri-implant bone volume (CT: 23.17±3.39 mm3; OD: 32.01±5.75 mm3) (p=0.008), and trabecular parameters: separation (CT: 0.4357±0.03 mm; OD: 0.3865±0.04 mm) (p=0.0449), number (CT: 1.626±0.18 1/mm; OD: 1.946±0.13 1/mm) (p=0.007), and thickness (CT: 0.1130±0.009 mm; OD: 0.1328±0.015 mm) (p=0.02). Structure model index (SMI) data demonstrate no significant differences between groups (CT: 1.7±0.2; OD: 1.4±0.4) (p=0.12). In conclusion, OD increases the insertion torque values and promotes beneficial changes regarding bone microarchitecture compared with CT, revealing more peri-implant bone volume with consequent higher primary stability.

Overweight/obesity and dental caries in Brazilian children and adolescents: a systematic review and meta-analysis.

This review aimed to assess the association between overweight/obesity and dental caries in Brazilian children/adolescents. Searches were performed in the Web of Science, Scopus, Cochrane, PubMed, Embase and SciELO, Lilacs and Open Grey literature databases up to June 2022. The Joanna Briggs Institute checklist for analytical cross-sectional studies, the checklist for cohort studies, and the checklist for case-control studies were used. A total of 41 publications were included, and 15 meta-analyses were performed. The authors analyzed the differences in weighted mean difference (MD) and odds ratios (OR), and their corresponding confidence intervals (CI) (95%) for dental caries among eutrophic and obese and/or overweight children/adolescents. Meta-analyses showed that there was no association between overweight and/or obesity and dental caries in Brazilian children/adolescents for most anthropometric reference curves using BMI (Body Mass Index). A greater experience of dental caries was associated with well-nourished adolescents in permanent dentition, compared with obese individuals in the same dentition, as classified by the CDC 2000 curve (OR = 2.53, 95% CI;1.49-4.29; p = 0.0006; I2 = 0%) in dichotomous outcome studies, and (MD = 0.61, 95%CI: 0.08-1.15; p = 0.02; I2 = 0%) in continuous studies. The strength of the evidence of the results was classified as very low, low or moderate. It was concluded that there is no association between overweight and/or obesity and dental caries in Brazilian children/adolescents for most anthropometric reference curves using BMI. A greater experience of dental caries was associated with well-nourished adolescents in permanent dentition, compared with obese individuals in the same dentition, as classified by the CDC 2000 curve.

Assessing peri-implant bone microarchitecture: conventional vs. osseodensification drilling - ex vivo analysis

Abstract: The aim was to evaluate primary implant stability and bone microarchitecture in two drilling situations, by comparing the conventional technique (CT) and osseodensification (OD) (Versah Burs - Jackson - Mississippi - USA). The implant insertion torque (IT), implant stability quotient (ISQ), and the peri-implant trabecular microstructure were assessed on bone fragments obtained from pig's tibia (n=12), divided between CT (n=6) and OD (n=6). After the drilling procedure, the implants were installed (3.5x8.5 mm, Epikut - SIN - São Paulo - Brazil). The IT and ISQ were measured using a digital torque wrench and resonance frequency analysis. Then, the bone fragments containing the implants were removed with a trephine and analyzed by Microtomography (µCT, 8.0 µm). The comparison between groups was performed using the unpaired t-test (α=0.05). The results revealed that OD promotes a higher insertion torque (CT: 7.67±2.44 Ncm; OD: 19.78±5.26 Ncm) (p=0.0005), although ISQ was not different (CT: 61.33±4.66; OD: 63.25±4.58) (p=0.48). There was a significant increase in peri-implant bone volume (CT: 23.17±3.39 mm3; OD: 32.01±5.75 mm3) (p=0.008), and trabecular parameters: separation (CT: 0.4357±0.03 mm; OD: 0.3865±0.04 mm) (p=0.0449), number (CT: 1.626±0.18 1/mm; OD: 1.946±0.13 1/mm) (p=0.007), and thickness (CT: 0.1130±0.009 mm; OD: 0.1328±0.015 mm) (p=0.02). Structure model index (SMI) data demonstrate no significant differences between groups (CT: 1.7±0.2; OD: 1.4±0.4) (p=0.12). In conclusion, OD increases the insertion torque values and promotes beneficial changes regarding bone microarchitecture compared with CT, revealing more peri-implant bone volume with consequent higher primary stability.

Resumo O objetivo deste estudo foi avaliar a estabilidade de implante e a microarquitetura óssea em duas técnicas de fresagem, comparando a técnica convencional (CT) e a osseodensificação (OD) (Versah Burs - Jackson - Mississippi - EUA). O torque de inserção do implante (IT), quociente de estabilidade primária (ISQ) e a estrutura trabecular peri-implantar foram avaliados em fragmentos ósseos obtidos de tíbia de porco (n=12), divididos entre CT (n=6) e OD (n=6). Após o procedimento de fresagem, foram instalados implantes (3,5x8,5 mm, Epikut - SIN - São Paulo - Brasil). O IT e o ISQ foram aferidos por meio de um torquimetro digital e análise de frequência de ressonância. Em seguida, os fragmentos ósseos contendo os implantes foram removidos com trefina e analisados ​​por microtomografia computadorizada (µCT, 8,0 µm). A comparação entre os grupos foi realizada por meio do teste-t não-pareado (α=0.05). Os resultados revelaram que a OD promove maior torque de inserção (CT: 7,67 ± 2,44º Ncm; OD: 19,78 ± 5,26 Ncm) (p=0,0005), embora a estabilidade primária não tenha sido diferente (CT: 61.33 ± 4.66; OD:63.25 ± 4.58) (p=0,48). Houve um aumento significativo no volume ósseo peri-implantar (CT: 23,17±3,39 mm3; OD: 32,01±5,75 mm3) (p=0,0089) e parâmetros trabeculares: separação (CT: 0,4357 ± 0,03 mm; OD: 0,3865 ± 0,04 mm) (p=0,0449), número (CT: 1,626 ± 0,18 1/mm; OD: 1,946 ± 0,13 1/mm) (p=0,007) e espessura (CT: 0,1130 ± 0,009 mm; OD: 0,1328 ± 0,015 mm) (p=0,02) O índice de modelo estrutural (SMI) não demostrou diferença estatisticamente significativa (p=0.1228). Concluindo, OD apresenta maiores valores de torque de inserção e promove mudanças benéficas na microarquitetura óssea em comparação com a TC, revelando maior volume ósseo peri-implantar.

Overweight/obesity and dental caries in Brazilian children and adolescents: a systematic review and meta-analysis

Abstract This review aimed to assess the association between overweight/obesity and dental caries in Brazilian children/adolescents. Searches were performed in the Web of Science, Scopus, Cochrane, PubMed, Embase and SciELO, Lilacs and Open Grey literature databases up to June 2022. The Joanna Briggs Institute checklist for analytical cross-sectional studies, the checklist for cohort studies, and the checklist for case-control studies were used. A total of 41 publications were included, and 15 meta-analyses were performed. The authors analyzed the differences in weighted mean difference (MD) and odds ratios (OR), and their corresponding confidence intervals (CI) (95%) for dental caries among eutrophic and obese and/or overweight children/adolescents. Meta-analyses showed that there was no association between overweight and/or obesity and dental caries in Brazilian children/adolescents for most anthropometric reference curves using BMI (Body Mass Index). A greater experience of dental caries was associated with well-nourished adolescents in permanent dentition, compared with obese individuals in the same dentition, as classified by the CDC 2000 curve (OR = 2.53, 95% CI;1.49-4.29; p = 0.0006; I2 = 0%) in dichotomous outcome studies, and (MD = 0.61, 95%CI: 0.08-1.15; p = 0.02; I2 = 0%) in continuous studies. The strength of the evidence of the results was classified as very low, low or moderate. It was concluded that there is no association between overweight and/or obesity and dental caries in Brazilian children/adolescents for most anthropometric reference curves using BMI. A greater experience of dental caries was associated with well-nourished adolescents in permanent dentition, compared with obese individuals in the same dentition, as classified by the CDC 2000 curve.

Fractal analysis of the mandible cortical bone: correlation among fractal dimension values obtained by two processing methods from periapical radiograph and micro-computed tomography with cone-beam computed tomography.

The objectives of the present study were to assess Fractal Dimension (FD) values in the mandible cortical bone obtained from digital periapical radiographs (DPR), high-resolution microtomography (µCT), and cone-beam computed tomography (CBCT), by two processing methods: binarization (FD.b) and grayscale-based method (FD.f) and, finally, to identify the correlation among these values with other micro-architectural parameters. For this, a prospective study was conducted on 18 healthy individuals (mean age 23 ± 2.4 years old) who underwent third molar extraction. Pre-operative CBCT scans were conducted, bone fragments were removed from the retro-molar region, and DPR and µCT were performed on those bone samples. FD.b and FD.f values were calculated using three parasagittal sections for CBCT, one image for DPR, and three sections for µCT. The 3D bone microarchitecture was analyzed in µCT (voxel size: 19 µm). As a result, FD.b mean values of 1.55 ± 0.02 and 1.80 ± 0.01 were obtained for CBCT and µCT, respectively. Furthermore, FD.f mean values of 1.22 ± 0.12 for DPR, 0.99 ± 0.04 for CBCT, and 1.30 ± 0.07 for µCT were obtained. Both FD.b and FD.f values showed a good agreement. FD.f was negatively correlated with the standard deviation of the mean gray value (p = 0.003) for DPR and intra-cortical bone surface (p = 0.02) for µCT. In conclusion, image processing with or without binarization revealed different values for FD, although showing agreement. The grayscale-based method retrieved FD values correlated with the gray levels and the cortical porous network, which means that FD can be a valuable index for mandibular cortical bone evaluation. FD is associated with mineralization and microarchitecture. Nevertheless, there was no correlation between FD values obtained from low- (DPR) and high-resolution (µCT) X-ray modalities with FD obtained from the in vivo CBCT.

Fractal dimension, lacunarity, and cortical thickness in the mandible: Analyzing differences between healthy men and women with cone-beam computed tomography.

Purpose: The objective of this study was to assess the fractal dimension, lacunarity, trabecular microarchitecture parameters, and cortical linear measurements in the mandibles of male and female individuals to identify differences between them. Materials and Methods: In total, 116 cone-beam computed tomography scans of healthy individuals of different ages (57 men and 59 women, aged between 20 and 60 years) were selected. The following bone parameters were measured: 1) buccal, lingual, and basal cortical bone thickness in 5 standard parasagittal sections (the midline, the left and right sides of the lower lateral incisors, and the left and right sides of the lower canines); 2) the bone volume fraction of 10 sequential axial sections from each patient by creating a volume of interest in the area between the lower canines; and 3) fractal dimension and lacunarity using grayscale images of the same region of the volume of interest in the anterior mandible. Spearman correlation coefficients and the Mann-Whitney test were used. Results: A significant and positive correlation was found between age and cortical thickness, especially in the region of the central incisors. Significant differences between sexes in terms of fractal dimension, lacunarity, and bone volume were found. Women revealed lower fractal dimension values and higher lacunarity and bone volume ratio values than men. Conclusion: Fractal dimension, lacunarity, trabecular bone volume, and cortical thickness were different between men and women of different ages.

MRI changes and clinical characteristics in temporomandibular joints with displacement of the articular disk without reduction - a cross-sectional observational study.

OBJECTIVES: This study examined changes in magnetic resonance imaging (MRI) of temporomandibular joints (TMJ) with anterior displacement disk without reduction (DDwoR) and its correlation to clinical symptoms. METHODS: 190 individuals with DDwoR were evaluated according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and MRI. Pain's chronicity/intensity and limited mouth opening (locking) were correlated with: TMJ degeneration (MRI T1), effusion (T2), disc's shape and position (proton density). RESULTS: In 103 TMJ with DDwoR, hemiconvex shape (41.6%), sclerosis (45.6%) and mild effusion (47.6%) were the most prevalent findings. There was not association (p > .05) between: different DDwoR positions with pain's intensity/chronicity; effusion with locking. Disk deformation was associated with degeneration (p = .034) and pain's intensity (p = .006). Locking was associated with degeneration (p = .05). CONCLUSIONS: Condylar osteodegeneration is often related to DDwoR. Locking by DDwoR is associated with severe levels of chronic pain and articular disk deformation.

Impacts of the COVID-19 pandemic on the routine of Brazilian oral radiologists.

OBJECTIVE: To analyze the challenges and impacts of COVID-19 on the routine of Brazilian oral radiologists regarding changes in biosafety protocols, number of patients and staff, the flow of acquisition, and availability of images. METHODS: Structured digital questionnaires with questions related to the impacts of the COVID-19 pandemic on Oral Radiology were applied and analyzed. Descriptive statistical analysis was used to describe the items included in the survey, and means and standard deviations were calculated to describe continuous variables and frequency percentages to describe categorical data. RESULTS: A high number of Brazilian oral radiologists continued to work in the pandemic period, with little or no change in their working hours. Digital flow and teleradiology are in most of their workplaces and the changes imposed by the pandemic will be incorporated and permanent, according to most of the participants in this study. CONCLUSIONS: The COVID-19 pandemic brought important impacts on radiology clinics, with changes in the flow of patients, in the service and in the type of exam performed. In addition, adaptation to biosafety standards became necessary, with a significant increase in spending on personal protective equipment.

Position of lingual foramina in cone beam computed tomography and its implications for choosing the dimensions of dental implants for mandibular symphysis / Posição das foraminas linguais na tomografia computadorizada de feixe cônico e suas implicações na escolha das dimensões dos implantes dentários para sínfise mandibular

ABSTRACT Objective: To identify the lingual foramina in a Brazilian population of 210 individuals through Cone-Beam Computed Tomography images, in order to guide the installation of dental implants in the region of the mental symphysis. Methods: After identifying the lingual foramina on a parasagittal section, four measurements were taken: distance to the alveolar ridge, distance to the mandibular lower border, distance to the limit of the vestibular cortical, and alveolar ridge inclination angle. The measurements were compared in relation to gender by the Mann-Whitney test. The association between gender and the number of foramina was done by the chi-square test. Pearson's correlation analyzed the linear relationship between age and number of foramina. Results: Lingual foramina are present in 99.6% of the research participants. In the upper-inferior direction, a mean distance to the alveolar ridge of 21.4 mm was noted, while the mean distance to the lower mandibular border was 13.1 mm. In the bucco-lingual direction, a mean distance from the lingual foramina to the vestibular cortical of 15.2 mm is noted. The inclination angle of the alveolar ridge had a mean of 25.4º. Regarding gender, the test was not significant only for the distance to the vestibular cortical. Conclusion: The lingual foramina had a descending way in 100% of cases, being positioned mainly in the middle thirds (66.5%) and lower thirds (32.7%) of the mandibular ridge height. The use of dental implants up to 13 mm in length and up to 4 mm in diameter in the region of the symphysis mentualis is recommended.

RESUMO Objetivos: Identificar as foraminas linguais em uma população brasileira de 210 indivíduos, por meio de imagens de tomografia computadorizada de feixe cônico, a fim de orientar a instalação de implantes dentários em região de sínfise mentual. Métodos: Após identificação das foraminas linguais em corte parasagital, foram realizadas quatro medidas: distância até à crista alveolar, distância até à borda inferior da mandíbula, distância até o limite da cortical vestibular e ângulo de inclinação do rebordo alveolar. As medidas foram comparadas em relação ao sexo pelo teste Mann-Whitney. A comparação entre os sexos e o número de foraminas foi feito pelo teste qui-quadrado. A correlação de Pearson analisou a relação linear entre idade e número de foraminas. Resultados: As foraminas linguais estão presentes em 99,6% dos indivíduos. No sentido súpero-inferior, nota-se uma distância média até à crista alveolar de 21,4 mm, enquanto a distância média até à borda inferior da mandíbula foi de 13,1 mm. No sentido vestíbulo-lingual, nota-se uma distância média da foramina lingual até a cortical vestibular de 15,2 mm. O ângulo de inclinação do rebordo alveolar apresentou uma média de 25,4º. Em relação ao sexo, o teste só não foi significativo para a distância até a cortical vestibular. Conclusão: As foraminas linguais apresentam um trajeto descendente em 100% dos casos, posicionando-se, principalmente, nos terços médios (66,5%) e terços inferiores (32,7%) da altura do rebordo mandibular. Recomenda-se o uso de implantes dentários de até 13 mm de comprimento e de até 4mm de diâmetro em região de sínfise mentual.

Diagnóstico e manejo das exostoses maxilares: relato de caso / Diagnosis and management of maxillary exostoses: case report

As exostoses maxilares são protuberâncias ósseas de caráter benigno, que se originam da cortical óssea e de etiologia controversa. Sua denominação vai depender da localização anatômica em que se encontra. Podem interferir na mastigação, fonação e adaptação de próteses removíveis parciais ou totais, devendo sua remoção ser considerada. O intuito deste trabalho é relatar o manejo de uma paciente com exostoses vestibulares em maxila e realizar uma breve revisão de literatura.

Maxillary exostoses are benign bony protuberances, which originate from the cortical bone and of controversial etiology. Its denomination will depend on its anatomical location. They can interfere with chewing, phonation and adaptation of partial or total removable prostheses, and their removal should be considered. The aim of this work is to report the management of a patient with vestibular exostosis in the maxilla and perform a brief literature review.

Bone and gingival tissue thicknesses of maxillary anterior teeth with and without a metal post: a cone beam computed tomographic study.

The objective of this retrospective study was to evaluate buccal bone and gingival thickness measurements obtained from cone beam computed tomographic (CBCT) images of maxillary anterior teeth with and without metal posts. A convenience sample of 71 CBCT images of healthy maxillary anterior teeth and 61 CBCT images of maxillary anterior teeth with a metal post were selected from a database. Eight tomographic measurements (4 bone thicknesses and 4 gingival thicknesses) were performed in the parasagittal section of each tooth, perpendicular to the tooth axis. The Mann-Whitney U test was used to compare these thicknesses, and the Spearman correlation coefficient was calculated for correlation of age with sex. Statistically significant differences were observed for almost all measurements (P < 0.05); the CBCT images of teeth with metal posts displayed lower bone thickness values and higher gingival thickness values. No statistically significant correlations were observed between the thickness measurements and age. However, significantly higher bone thickness values were observed in men (P < 0.05). Cone beam computed tomographic images of teeth with metal posts showed differences in mean bone and gingival measurements compared to teeth without metal posts, suggesting a possible interference of metal artifacts.

Artifacts caused by titanium implants in CBCT images of the mandible: an experimental study.

This study evaluated the quantity of metal artifacts produced by dental implants placed in different mandibular regions using various cone beam computed tomography (CBCT) protocols. Titanium implants were placed in 4 regions (incisor, canine, premolar, and molar) of an artificial mandible and subjected to CBCT examinations with the mandibular model placed in different positions within the field of view (FOV) and imaged with different FOV and voxel sizes. An axial section of the cervical region of each implant was selected for artifact quantification. The artifacts were measured by normalizing the actual standard deviation (ASD) of the voxel values. Kruskal-Wallis and Student-Newman-Keuls tests were used to compare the tooth regions and the different positions of the mandible. The Wilcoxon test was used to compare changes in FOV and voxel size. The intraobserver agreement was calculated using the intraclass correlation coefficient. The significance level was 5%. The incisor region showed significantly more artifacts than other regions (P = 0.0315). No statistically significant difference was found when the position of the mandible varied within the FOV (P = 0.7418). Smaller FOV and smaller voxels produced more artifacts (P < 0.0001). The quantity of metal artifacts was affected by FOV and voxel size as well as by anatomical region. Variation of the mandible location within the FOV did not affect the artifacts as defined by the normalized ASD of the voxel values.

Assessment of marginal gaps and image quality of crowns made of two different restorative materials: An in vitro study using CBCT images.

Background: The present study assessed the quality of images and the presence of marginal gaps on cone-beam computed tomography (CBCT) images of teeth restored with all-ceramic and metal-ceramic crowns and compared the gap sizes observed on CBCT images with those obtained on micro-CT images. Methods: Thirty teeth restored with metal-ceramic and all-ceramic crowns, properly adapted and with gaps of 0.30 and 0.50 mm, were submitted to micro-CT and CBCT scans. Linear measurements corresponding to the marginal gap (MG) and the absolute marginal discrepancy (AMD) were obtained. The objective assessment of the quality of CBCT images was performed using the contrast-to-noise ratio (CNR), and the subjective assessment was defined by the diagnoses made by five examiners regarding the presence or absence of gaps. Results: The measurements were always higher for CBCT, with a significant difference regarding AMD. No significant difference in image quality was observed using CNR between the crowns tested. Low accuracy and sensitivity values could be observed for both crowns. Conclusion: Marginal mismatch measures were overestimated in CBCT images. No difference in image quality was observed between the crowns. The correct diagnosis of gaps was considered low, irrespective of crown type and gap size.

Evaluation of the dimensions, morphology, and position of the mandibular condyles in individuals with neurofibromatosis 1: a case-control study.

OBJECTIVES: The aim of this study was to evaluate the mandibular condyles of neurofibromatosis 1 (NF1) individuals without facial plexiform neurofibroma using cone beam computed tomography images. MATERIALS AND METHODS: Eighty cone beam computed tomography scans (160 mandibular condyles) were analyzed: 40 from NF1 individuals (study group) and 40 from individuals without NF1 (control group). The anteroposterior and mediolateral dimensions, height, and volume of the mandibular condyles were measured. The mandibular condyles were classified according to their morphology: healthy (absence of morphological changes), with flattening (loss of rounded contour of at least one of the surfaces), with erosion (loss of continuity of the cortical bone), with osteophyte (exophytic formation of the condyle surface), and with sclerosis (any increase in the cortical thickness in the load-bearing areas). Furthermore, the position of the mandibular condyles in relation to the joint fossa in an anteroposterior view was classified as anterior, concentric, or posterior. RESULTS: The study group had a higher anteroposterior dimension of the mandibular condyles compared with the control group (p < 0.05). There were no differences in condylar morphology and position between both groups (p > 0.05). The morphological alterations were not associated with sex or age in any group evaluated (p > 0.05). For both groups, the concentric position was the most common. For the study group, there was a significant difference in the condylar position between the sides (p < 0.05). CONCLUSIONS: NF1 individuals without facial plexiform neurofibroma present a high prevalence of condyles with a large anteroposterior dimension and asymmetric position in the joint fossa. However, no morphological and volumetric changes were observed in the mandibular condyles of them. CLINICAL RELEVANCE: The knowledge of the TMJ alterations in individuals with NF1 is important to establish an evaluation protocol, which would allow early intervention if indicated.

Implant site preparation-related bone microdamage: An alternative ex vivo analysis of drilling speed protocols / Microdanos ósseos gerados na preparação do sítio de instalação de implantes: uma alternativa para análise ex vivo de diferentes protocolos de velocidade de perfuração

ABSTRACT Objective: The aim of this study was to evaluate bone microdamage in sites prepared for implant placement by using an ex vivo model with three drilling rotation speeds. Methods: Bovine bone ribs were used for the creation of 18 osteotomy sites at different rotation speeds: 1200 rpm, 800 rpm, and 400 rpm. Specimens were stained with xylenol orange and prepared for histological analysis by using fluorescence and polarized light microscopies. Bone microdamage was evaluated by number and based on total bone area, as follows: microfracture density (Fr.D = n/mm2), microcrack morphology (diffuse or linear), and density (Cr.D = n/mm2), and presence of bone chips. To complement the analysis, linear microcracks were assessed by using confocal microscopy for three-dimensional visualization. Results: Bone microdamage on the osteotomy sites included microcracks, diffuse damages, microfracture, and bone chip formation. There was an association between bone microdamage and cancellous bone (p 0.0016), as well as a positive correlation between Fr.D and Cr.D (p 0.05, r 0.54). BM occurrence was not different between the three rotation speeds. In 3D, the height of the microcrack depth was 60.81 µm. Conclusion: Bone microdamage occurs during osteotomy, and the ex vivo model used was effective for the assessment of these biomechanical parameters. In addition, microdamage was not influenced by the drilling rotation speed in this experimental condition.

RESUMO Objetivo: O objetivo desse estudo foi avaliar os microdanos ósseos em locais preparados para a instalação de implantes utilizando um modelo ex vivo acessando três velocidades de rotação de perfuração. Métodos: Fragmentos ósseos de costela bovina foram utilizados para a criação de 18 sítios de osteotomia em diferentes velocidades de rotação: 1200 rpm, 800 rpm e 400 rpm. As amostras foram coradas com Alaranjado de Xilenol e preparadas para análise microscópica em fluorescência e luz polarizada. Os microdanos ósseos foram avaliados em número e calibrados com base na área total óssea: densidade de microfraturas (Fr.D = n/mm2), morfologia (difusa ou linear) e densidade de microtrincas (Cr.D = n / mm2) e presença de espículas ósseas. Para complementar a análise, microtrincas lineares foram avaliadas por meio de microscopia confocal para visualização tridimensional. Resultados: Os microdanos ósseos incluíram microtrincas, danos difusos, microfraturas e formação de espículas. Houve uma associação entre MO e localização em osso esponjoso (p=0,0016), bem como uma correlação positiva entre Fr.D e Cr.D (p=0,05, r = 0,54). A ocorrência de microdanos ósseos não foi diferente entre as três velocidades de rotação utilizadas. Em 3D, a profundidade maior da microfissura atingiu 60,81 µm. Conclusão: Microdanos ósseos ocorrem durante a osteotomia e podem ser acessados em um modelo ex vivo na condução de experimentos em biomecânica. Sugere-se que a presença de microdanos não é influenciada pela velocidade de rotação durante a perfuração.

Cirurgia paraendodôntica com retro-obturação utilizando MTA Repair HP®: análise tomográfica longitudinal prospectiva de dois casos clínicos / Periradicular surgery with retrofilling by MTA Repair HP® having concomitant cone beam computed tomography follow-up analysis: case series repor

Objetivo: Avaliar tomograficamente, em dois casos clínicos, o efeito da nova formulação do MTA, o MTA Repair HP, na contribuição para a remissão de lesões periapicais em cirurgias paraendodônticas, bem como a sua manipulação e as suas propriedades físicas. Relatos de caso: Paciente R.C.R., 57, reportou-se à Faculdade de Odontologia da Universidade Federal de Juiz de Fora para avaliação de lesão periapical no elemento 11. Ao exame radiográfico, observou-se tratamento endodôntico e uma área radiolúcida, unilocular, circunscrita envolvendo o ápice dentário. Solicitou-se um exame de TCFC (I-Cat®, Imaging Sciences International, Hatfield, Pensilvânia, EUA), no qual foi confirmada a presença da lesão com rompimento da cortical óssea vestibular. Foram realizadas apicectomia, curetagem, retropreparo pela Técnica Clássica, e retroobturação com o novo material. Realizaram-se tomografias nos momentos pós-operatórios de três e cinco meses. Paciente R.J.G.M., 46, relatava dor, aumento de volume intraoral e drenagem de secreção purulenta na arcada superior esquerda. Aos exames clínico e radiográfico, observou-se presença de fístula e lesão refratária ao tratamento endodôntico no dente 25. Realizou-se TCFC, na qual pode-se observar a presença de uma área hipodensa circunscrita, envolvendo o ápice do 25, com rompimento da cortical óssea vestibular. Foi proposto o mesmo tratamento descrito no caso anterior. Para o acompanhamento foram realizadas novas tomografias nos mesmos tempos pós-operatórios do caso anterior. Discussão: O MTA Repair HP surgiu da necessidade de um material mais biocompatível com as estruturas dentárias no procedimento de obturação retrógrada. Este produto auxilia na regressão de lesões periapicais e na formação dos componentes do periodonto e apresenta como vantagens, o maior tempo de presa, não provocar o escurecimento coronário e maior facilidade na manipulação. Conclusão: Conclui-se que houve formação de tecido calcificado no decorrer dos tempos de três e cinco meses. Em relação à manipulação do material, não foi observada melhora pela adição de agente plastificante. Contudo, observou-se um tempo de presa menor do que o esperado, dificultando a inserção do material

Aim: To evaluate, tomographically, in two clinical cases, the effect of the new MTA formulation of the Angelus, the MTA Repair HP, in the contribution to remission of periapical lesions in paraendodontic surgery, as well its physical properties and manipulation. Case report: Patient R.C.R, 57, attended at the Faculty of Dentistry of the Federal University of Juiz de Fora for evaluation of periapical lesion in the element 11. It was observed, at the clinical and radiographic exams, endodontic treatment and a circumscribed, unilocular and radiolucid area at the apex of the tooth. It was requested a CBCT exam (I-Cat®, Imaging Sciences International, Hatfield, Pennsylvania, USA), which confirmed the presence of the lesion and rupture of the buccal cortical plate. Thus, it was performed curettage, apicectomy, retropreparation and retrofilling with the described cement. It was solicited two additional CBCT exams at the period of three and five months post-operative. Patient R.J.G.M, 46, with mean complain of pain, increased intraoral volume and purulent discharged in the upper left arch. The clinical and radiographic exams revealed fistu-la and refractory lesion, despite the endodontic treatment of the tooth 25. A CBCT exam was done and it was observed a circumscribed hypodense area, around the apex of the 25, with rupture of the buccal cortical plate. It was suggested the same surgical treatment described in the case above. It was performed two more CBCT exam, at three and five months after the procedure. Discussion: The MTA Repair HP was developed from the necessity of a more biocompatible material with the dental structures in the retrograde filling process. This product helps in the remission of periapicals lesions and in the new formation of the periodontum components; also it has the advantages of longer set-ting time, not causing the darkening of the coronary portion and easier manipulation. Conclusion:Regarding the remission of the lesions, it was noticed the generation of calcified tissue across the periods of three and five months. Regarding the manipulation and application, it was not observed any improvement related to the addition of the plasticizer. However, it was noticed a shorter setting time, making it difficult to insert the material.

Clinical and tomography evaluation of periodontal phenotypes of Brazilian dental students.

BACKGROUND: The periodontal phenotype (PP) plays an important role in the function, esthetics, and maintenance of periodontal health and has a great influence in periodontal, restorative, and dental implant therapies. AIM: The aim of this study was to conduct a clinical evaluation of the PP and its morphometric variations through the cone-beam computed tomography (CBCT), from dentistry students with periodontal health. MATERIALS AND METHODS: Sixty students were examined, and the clinical parameters of probing depth and width of keratinized tissue (WKT) in the upper anterior segment were accessed. The gingival thickness was evaluated as thick or thin, through the translucency of the periodontal probe through the marginal gingiva. By convenience sample, 13 students were selected to assess bone thickness and gingival thickness and biological width through the previous CBCT examination. RESULTS: The most prevalent PP, according to the classification by De Rouck et al., was the thick scalloped (55%), and using the classification of Kao and Pasquinelli, the thick PP was most common (73,3%). The thick PP in both the classifications was more prevalent in both genders and the WKT was significantly higher in the thick-flat scalloped PP. The bone thickness was always greater than the gingival thickness in CBCT examinations both in the measures 1 mm and 3 mm above the bone crest. The average of the biological width measurement was 2.02 mm. CONCLUSIONS: The thick PP was most prevalent in the sample studied, and the gingival thickness was always thinner than the bone thickness in the measures evaluated.

Immediate three-dimensional changes in the oropharynx after different mandibular advancements in counterclockwise rotation orthognathic planning.

BACKGROUND: A retrospective cohort study was performed to evaluate the immediate effect on the oropharynx dimensions from different mandibular advancements in patients undergone counterclockwise rotation (CCW) of the maxillomandibular complex. MATERIAL AND METHODS: 138 CBCT images of patients, who had undergone orthognathic surgery, were identified from Dolphin Imaging archive according to pre- (T0) and post-operative (T1) times. Each pre-operative CBCT image was selected considering retrognathic mandible. Superimpositions of CBCT images were performed to measure mandibular advancement at B point in millimeters (mm) and divided into three groups: G1 (< 5 mm), G2 (between 5 and 10 mm) and G3 (> 10 mm). For evaluating oropharynx dimension at T0 and T1 for each group, medial sagittal area (MSA), volume, and minimum cross-sectional axial area (CSA) were measured on Dolphin Imaging. Pearson correlation verified reliability of method. Paired t-test were applied to compare values of measurements between T0 and T1 (p ≤ 0.05). RESULTS: 88 CBCT images were included. Method was reliable (r ≥ 0.93). According to MSA, volume and CSA values from G1, there was no significant difference between T0 and T1. CSA values presented significant difference comparing T0 and T1 in G2 (p ≤ 0.05). In subjects of G3, measurements increased in T1 significantly affecting oropharynx dimension. CONCLUSIONS: MSA, volume and CSA values showed a significant increase affecting upper airway in advancements higher than 10 mm. Mandibular advancement range showed different effects in the airway space and should be considered to achieve favorable post-operative results in the oropharynx dimensions. Key words:Retrognathia, orthognathic surgery, three-dimensional imaging, oropharynx, airway.

Quantitative assessment of artefacts and identification of gaps in prosthetic crowns: a comparative in vitro study between periapical radiography and CBCT images.

OBJECTIVES: To evaluate, in an in vitro study, the quantity of artefacts generated by two different restorative materials, and to determine the diagnostic accuracy of cone beam CT (CBCT) scans and periapical radiographs in identifying gaps in prosthetic crowns. METHODS: A total of 30 teeth restored with metal-ceramic (n = 15) and all-ceramic (n = 15) crowns, properly adapted and with 0.30- and 0.50 mm gaps, underwent CBCT exams (with voxel sizes of 0.25 and 0.30 mm) and periapical radiographs. The artefacts generated by two different crowns were quantified and compared by the Mann-Whitney test. In addition, five examiners evaluated the presence or absence of gaps in periapical radiographs and CBCT images. The accuracy of tests was determined by the area under the receiver operatring characteristic curve and these values were compared by using the Kruskal-Wallis test. RESULTS: There was no significant difference in artefact values between the different restorative materials and the different resolutions of CBCT images. Regarding the accuracy of the tests evaluated, periapical radiography and CBCT with voxel size 0.25 mm showed the best performance for smaller gaps (0.30 mm). For larger gaps (0.50 mm), all exams tested showed the same performance. CONCLUSIONS: Periapical radiography was still the most cost-beneficial method for the diagnosis of maladaptation in dental restorations. CBCT exams did not improve accuracy in detecting gaps in prosthetic crowns.

Association Between Dental Caries Experience and Socioeconomic Determinants on Oral Health-Related Quality of Life among Children and their Families

ABSTRACT Objective: To assess the association between dental caries experience, severe dental caries experience and socioeconomic determinants on oral health-related quality of life among children and their families. Material and Methods: This is a cross-sectional study whose sample was composed of children aged 4-12 years, who sought dental care in a dentistry school clinic, and their parents/caregivers. Dental caries experience and severe dental caries experience were assessed according to the DMF-T/dmf-t indexes. Parents/caregivers answered the Parental-Caregiver Perceptions Questionnaire (P-CPQ), the Family Impact Scale (FIS) and a questionnaire on socioeconomic and demographic conditions. Data analysis included the chi-square test and Poisson regression (PR). Results: The sample was composed of 105 children and their parents/caregivers. Severe dental caries experience in children was determinant for negative perception of children's OHRQoL by parents/caregivers (PR = 1.22; CI = 1.05-1.41). Negative impact on OHRQoL perceived by family members was determined by severe dental caries experience in children (PR = 1.22; CI = 1.05-1.42) and family income <5 minimum wage (PR = 1.32; CI = 1.08-1.61). Conclusion: Severe dental caries experience was associated with a negative impact on OHRQoL perceived by children and their families. Low family income was associated with a negative impact on the OHRQoL perceived by children and their families.