Analysis of inflammation and bone remodeling of atmospheric plasma therapy in experimental periodontitis.

BACKGROUND AND OBJECTIVE: The biological effects of atmospheric plasma (cold plasma) show its applicability for controlling the etiological factors that involve tissue repair. Thus, the study evaluated the effect of atmospheric plasma therapy in the control of tissue inflammation and bone remodeling in experimental periodontitis. METHODS: Fifty-six rats were subjected to ligation in the cervical region of the first maxillary molars (8 weeks). The animals were divided into two groups (n = 28): periodontitis without treatment group (P group), and periodontitis with atmospheric plasma treatment group (P + AP group). Tissue samples were collected at 2 and 4 weeks after treatment to analyze the inflammation and bone remodeling by biochemical, histomorphometric, and immunohistochemical analyses. RESULTS: Inflammatory infiltration in the gingival and periodontal ligament was lower in the P + AP group than in the P group (p < .05). The MPO and NAG levels were higher in the P + AP group compared to P group (p < .05). At 4 weeks, the TNF-α level was lower and the IL-10 level was higher in the P + AP group compared to P group (p < .05). In the P + AP group, the IL-1ß level increased in the second week and decreased in the fourth week (p < .05), the number of blood vessels was high in the gingival and periodontal ligament in the second and fourth week (p < .05); and the number of fibroblasts in the gingival tissue was low in the fourth week, and higher in the periodontal tissue in both period (p < .05). Regarding bone remodeling, the RANK and RANKL levels decreased in the P + AP group (p < .05). The OPG level did not differ between the P and P + AP groups (p > .05), but decreased from the second to the fourth experimental week in P + AP group (p < .05). CONCLUSIONS: The treatment of experimental periodontitis with atmospheric plasma for 4 weeks modulated the inflammatory response to favor the repair process and decreased the bone resorption biomarkers, indicating a better control of bone remodeling in periodontal disease.

Early In Vivo Osteogenic and Inflammatory Response of 3D Printed Polycaprolactone/Carbon Nanotube/Hydroxyapatite/Tricalcium Phosphate Composite Scaffolds.

The development of advanced biomaterials and manufacturing processes to fabricate biologically and mechanically appropriate scaffolds for bone tissue is a significant challenge. Polycaprolactone (PCL) is a biocompatible and degradable polymer used in bone tissue engineering, but it lacks biofunctionalization. Bioceramics, such as hydroxyapatite (HA) and ß tricalcium phosphate (ß-TCP), which are similar chemically to native bone, can facilitate both osteointegration and osteoinduction whilst improving the biomechanics of a scaffold. Carbon nanotubes (CNTs) display exceptional electrical conductivity and mechanical properties. A major limitation is the understanding of how PCL-based scaffolds containing HA, TCP, and CNTs behave in vivo in a bone regeneration model. The objective of this study was to evaluate the use of three-dimensional (3D) printed PCL-based composite scaffolds containing CNTs, HA, and ß-TCP during the initial osteogenic and inflammatory response phase in a critical bone defect rat model. Gene expression related to early osteogenesis, the inflammatory phase, and tissue formation was evaluated using quantitative real-time PCR (RT-qPCR). Tissue formation and mineralization were assessed by histomorphometry. The CNT+HA/TCP group presented higher expression of osteogenic genes after seven days. The CNT+HA and CNT+TCP groups stimulated higher gene expression for tissue formation and mineralization, and pro- and anti-inflammatory genes after 14 and 30 days. Moreover, the CNT+TCP and CNT+HA/TCP groups showed higher gene expressions related to M1 macrophages. The association of CNTs with ceramics at 10wt% (CNT+HA/TCP) showed lower expressions of inflammatory genes and higher osteogenic, presenting a positive impact and balanced cell signaling for early bone formation. The association of CNTs with both ceramics promoted a minor inflammatory response and faster bone tissue formation.

Absence of melatonin during development impairs craniofacial and dental onset in rats.

OBJECTIVE: Herein, we evaluated pinealectomy-induced melatonin absence to determine its effects on craniofacial and dental development in the offspring. DESIGN: Female Wistar rats in three groups, i.e., intact pregnant rats, pinealectomized pregnant rats (PINX), and pinealectomized pregnant rats subjected to oral melatonin replacement therapy, were crossed 30 days after surgery. The heads of 7-day-old pups were harvested for cephalometric and histological analyses, and maxillae and incisors were collected for mRNA expression analysis. RESULTS: The PINX pups exhibited a reduction in neurocranial and facial parameters such as a decrease in alveolar bone area, incisor size and proliferation, and an increase in odontoblasts and the dentin layer. Based on incisor mRNA expression analysis, we found that Dmp1 expression was upregulated, whereas Col1a1 expression was downregulated. Maxillary mRNA expression revealed that Rankl expression was upregulated, whereas that of Opn and Osx was downregulated. CONCLUSION: Our results demonstrated that the absence of maternal melatonin during early life could affect dental and maxillary development in offspring, as well as delay odontogenesis and osteogenesis in maxillary tissues. CLINICAL RELEVANCE: Our findings suggest that disruptions or a lack of melatonin during pregnancy may cause changes in craniofacial and dental development, at least in animal experiments; however, in humans, these feedings are still poorly understood, and thus careful evaluations of melatonin levels in humans need to be investigated in craniofacial alterations.

Porphyrin-associated fluorescence spectroscopy (Photogen®) for the optical diagnosis of dental biofilm in orthodontic treatment: An observational clinical trial.

OBJECTIVE: This study assessed the presence of dental biofilm with fluorescence spectroscopy associated with porphyrin (Photogen®) in users of orthodontic appliances. METHODS: This cross-sectional observational clinical trial included 21 patients with metallic orthodontic fixed appliances. The presence of biofilm was evaluated by fluorescence spectroscopy (Evince-MMÓptics. São Carlos-SP, Brazil) with a porphyrin photo-evidence device (Photogen®). Digital images of the buccal surface of the upper anterior teeth (central and lateral incisors and canines) without and with porphyrin were analyzed using the histogram R (red) function in ImageJ software. The results were analyzed using the maximum and mode values of the red pixels from the histograms. The statistical analysis considered the significance level of 5%. RESULTS: The maximum values and modes of the red pixels were significantly higher in biofilms analyzed by porphyrin-associated optical spectroscopy compared to optical spectroscopy alone. CONCLUSIONS: Porphyrin-associated fluorescence spectroscopy was able to detect dental biofilm in the oral environment of patients with orthodontic treatment. This method better evidenced the presence of biofilm on the buccal surfaces of the upper teeth compared to that observed with fluorescence spectroscopy without porphyrin.

Electrical Stimulation Therapy and HA/TCP Composite Scaffolds Modulate the Wnt Pathways in Bone Regeneration of Critical-Sized Defects.

Critical bone defects are the most difficult challenges in the area of tissue repair. Polycaprolactone (PCL) scaffolds, associated with hydroxyapatite (HA) and tricalcium phosphate (TCP), are reported to have an enhanced bioactivity. Moreover, the use of electrical stimulation (ES) has overcome the lack of bioelectricity at the bone defect site and compensated the endogenous electrical signals. Such treatments could modulate cells and tissue signaling pathways. However, there is no study investigating the effects of ES and bioceramic composite scaffolds on bone tissue formation, particularly in the view of cell signaling pathway. This study aims to investigate the application of HA/TCP composite scaffolds and ES and their effects on the Wingless-related integration site (Wnt) pathway in critical bone repair. Critical bone defects (25 mm2) were performed in rats, which were divided into four groups: PCL, PCL + ES, HA/TCP and HA/TCP + ES. The scaffolds were grafted at the defect site and applied with the ES application twice a week using 10 µA of current for 5 min. Bone samples were collected for histomorphometry, immunohistochemistry and molecular analysis. At the Wnt canonical pathway, HA/TCP and HA/TCP + ES groups showed higher Wnt1 and ß-catenin gene expression levels, especially HA/TCP. Moreover, HA/TCP + ES presented higher Runx2, Osterix and Bmp-2 levels. At the Wnt non-canonical pathway, HA/TCP group showed higher voltage-gated calcium channel (Vgcc), calmodulin-dependent protein kinase II, and Wnt5a genes expression, while HA/TCP + ES presented higher protein expression of VGCC and calmodulin (CaM) at the same period. The decrease in sclerostin and osteopontin genes expressions and the lower bone sialoprotein II in the HA/TCP + ES group may be related to the early bone remodeling. This study shows that the use of ES modulated the Wnt pathways and accelerated the osteogenesis with improved tissue maturation.

Should midline diastema in mixed dentition be an aesthetic concern?

BACKGROUND: Mixed dentition determines an important period of occlusion development in childhood. OBJECTIVE: This study aimed to evaluate the aesthetic impact of the midline diastema cut-off point in mixed dentition. DESIGN: A cross-sectional study was performed with 257 children aged 8-10 years in late mixed dentition, with midline diastema of 1-5 mm and normal maxillary overjet. Orthodontic Aesthetic Subjective Impact Score determined the aesthetic impact of the midline diastema. Four quartiles of diastema measurements and impact scores were considered as cut-off points. Receiver Operating Characteristic curves were constructed, and the distances representing the distances to the ideal point were calculated. The Yuden index determined the efficiency of measuring the diastema to assess the aesthetic impact. The Kruskal-Wallis test compared the groups of participants classified according to the diastema cut-off by the sample quartile regarding the impact score. The analyses were performed with a significance level of 5%. RESULTS: There was no significant difference between the four groups of measurement quartiles of the diastema regarding the aesthetic impact (P > .05). CONCLUSIONS: The perception of dental aesthetics in mixed dentition children was not affected by the midline diastema, regardless of the cut-off point.

Maxillary and dental development in the offspring of protein-restricted female rats.

Nutritional restriction during developmental periods impairs organ physiology. Female rats were subjected to protein restriction during pregnancy and lactation to analyze dental and maxillary development. Four exposure groups were considered: normal-protein diet during pregnancy and lactation (NP, 17% casein), low-protein diet during lactation (LP-L, 6% casein), low-protein diet during pregnancy and lactation (LP), and low-protein diet during pregnancy (LP-G). Maxillae from 15-day-old male pups were collected. All protein-restricted groups presented increased dentin thickness and reduced alveolar bone area. When protein restriction was applied during both gestation and lactation (LP), harmful effects were observed in the form of loss of protective OPG (osteoprotegerin) in tooth epithelium-mesenchyme, due to higher RANKL expression, delay in odontoblast maturation, less dental pulp vascularity, reduction in amount of alveolar bone, and less matrix mineralization. In the LP-L group, effects of protein restriction seemed less harmful, and despite less alveolar bone, the enhancement in BMP-7, VEGF, and RANKL seems a compensatory signal to maintain maxillary osteogenesis. In LP-G animals, Dspp expression was higher, suggesting a delay in odontoblast maturation or expression recuperation. In conclusion, maternal protein restriction affects dental and maxillary development. A low-protein diet only in gestation allows for normal development. A low-protein diet during gestation-lactation results in impaired odontogenesis that may increase susceptibility of dental anomalies.

What do black patients expect from orthodontic treatment? The aesthetic perception of facial profile between orthodontists and black laypersons.

OBJECTIVE: To evaluate the influence of anteroposterior position of the soft tissue on facial attractiveness in black people, and compare the perception of aesthetics and satisfaction between orthodontists and black laypersons. METHODS: The sample was composed of 69 orthodontists and 69 laypersons of black ethnicity (n=138). Facial profile photographs of two black volunteers, a man and a woman, were digitally manipulated to change the position of the lips and chin, by making gradual changes of 4mm in relation to the true vertical line, simulating advance or retrusion of the soft tissues by -2, -6, -10, +2, +6, +10mm, totalling six images per sex. The photographs were classified by the research participants using a visual analogue scale (VAS), from 0 (unpleasant) to 100 (pleasant). The results were analyzed by generalized linear model and by the Fisher's exact test, considering the level of significance of 5%. RESULTS: The orthodontists and black laypersons considered straight profiles the most pleasant. The two groups classified the male profile as being more unpleasant in comparison with the female facial profile, which was concave. When evaluating all the images together, the image most indicated as being the most pleasant, once again, was the one with the straight profile, for both sexes. CONCLUSION: The influence of orthodontists' and laypersons' aesthetic perception on evaluating the facial profile of blacks was similar. The straight profile was classified as the most pleasant and the concave, as the most unpleasant.

Comparison of the friction forces delivered by different elastomeric patterns and metal ligature on conventional metal brackets with a NiTi arch wire versus a self-ligating system: An in vitro study.

OBJECTIVES: The aim of this study was to measure the frictional resistance of different types of ligatures used on conventional and self-ligating brackets. MATERIALS AND METHODS: Monoblock (conventional) and Portia (self-ligating) brackets were used and the archwire used was nickel-titanium. On conventional brackets the ligatures tested were the Elastomeric type and steel 0.30 tie-wire. The groups were divided according to the ligature types (n=8): (1) conventional elastomeric ligature; (2) relaxed conventional elastomeric ligature; (3) elastomeric ligature in shape-8; (4) double vertical elastomeric ligatures; (5) double-crossed elastomeric ligatures; (6) crossed ligature; (7) steel wire ligature; and (8) self-ligating ligature (self-ligating bracket). A segment of five brackets, each ligature types, was mounted. The archwire, between the bracket and the ligature, was connected on Instron® Universal test machine to simulate the frictional resistance. The maximum frictional resistance was obtained, and the mean values were submitted to the analysis of variance (ANOVA) and the Tukey's post-hoc test (α=0.05). RESULTS: The elastomeric ligature in shape-8 showed the highest value compared with other groups (P<0.05). Although the crossed elastomeric ligature presented the lowest mean value and it was not statistically different regarding relaxed conventional elastomeric ligature, steel wire ligature and self-ligating (P≥0.05). CONCLUSIONS: The frictional resistance was influenced by ligature types. Elastomeric Ligature in shape-8 showed the highest frictional force. Crossed Elastomeric Ligature had the lowest frictional force value.

What do black patients expect from orthodontic treatment? The aesthetic perception of facial profile between orthodontists and black laypersons

ABSTRACT Objective: To evaluate the influence of anteroposterior position of the soft tissue on facial attractiveness in black people, and compare the perception of aesthetics and satisfaction between orthodontists and black laypersons. Methods: The sample was composed of 69 orthodontists and 69 laypersons of black ethnicity (n=138). Facial profile photographs of two black volunteers, a man and a woman, were digitally manipulated to change the position of the lips and chin, by making gradual changes of 4mm in relation to the true vertical line, simulating advance or retrusion of the soft tissues by -2, -6, -10, +2, +6, +10mm, totalling six images per sex. The photographs were classified by the research participants using a visual analogue scale (VAS), from 0 (unpleasant) to 100 (pleasant). The results were analyzed by generalized linear model and by the Fisher's exact test, considering the level of significance of 5%. Results: The orthodontists and black laypersons considered straight profiles the most pleasant. The two groups classified the male profile as being more unpleasant in comparison with the female facial profile, which was concave. When evaluating all the images together, the image most indicated as being the most pleasant, once again, was the one with the straight profile, for both sexes. Conclusion: The influence of orthodontists' and laypersons' aesthetic perception on evaluating the facial profile of blacks was similar. The straight profile was classified as the most pleasant and the concave, as the most unpleasant.

RESUMO Objetivo: Avaliar a influência do posicionamento anteroposterior dos tecidos moles na atratividade facial de indivíduos negros, e comparar sua agradabilidade entre ortodontistas e leigos. Métodos: A amostra foi composta por 138 avaliadores, 69 ortodontistas e 69 indivíduos leigos da raça negra. Fotografias de perfil de dois pacientes negros, um homem e uma mulher, foram modificadas quanto ao posicionamento dos lábios e do mento, deslocados digitalmente em incrementos de 4 mm em relação a uma linha vertical verdadeira, simulando avanços e recuos dos tecidos moles de -2, -6, -10, +2, +6, +10 mm, totalizando seis imagens por sexo, classificadas pelos participantes da pesquisa usando uma escala visual analógica (EVA) de 0 (desagradável) a 100 (agradável). Os resultados foram analisados por meio de modelos lineares generalizados, considerando-se que todos os observadores avaliaram todas as imagens. A análise das escolhas das imagens consideradas mais agradáveis ou mais desagradáveis foi realizada pelo teste exato de Fisher, com um nível de significância de 5%. Resultados: Os ortodontistas e leigos consideraram mais agradáveis as alterações que se aproximavam do perfil reto. Nas imagens em que havia birretrusão facial, os dois grupos classificaram como mais desagradável o perfil do homem do que o perfil da mulher. Ao avaliar todas as imagens juntas, a imagem mais indicada como a mais agradável foi, novamente, a com perfil reto, para os dois sexos. Conclusão: A influência da percepção estética dos ortodontistas e leigos na avaliação do perfil facial de negros foi semelhante, sendo o perfil reto classificado como o mais agradável e o côncavo, o mais desagradável.

Orthodontists' preferences regarding the difference of bracket bonding height between the maxillary incisors.

INTRODUCTION: The vertical position of orthodontic brackets in maxillary incisors may influence the incisal step between the anterior teeth and thereby interfere with the smile esthetics. Even so, esthetic standards have been modified over time and consistently required technical adjustments. OBJECTIVE: This study analyzed orthodontists' preferences regarding the difference of bracket bonding height between the maxillary central incisors (MCI) and maxillary lateral incisors (MLI), and further determined whether the orthodontist sex, age and time of specialization have association to their choices. METHODS: This study collected data through an electronic form. Study participants analyzed a clinical case in which they indicated their preference for bracket bonding height. The placement height options ranged from 3.0 mm to 5.5 mm from the incisal edge, with 0.5-mm intervals, or at the clinical crown center (CCC). The difference in the bonding height between the MCI and MLI was analyzed, considering the formation of incisal steps between these teeth. RESULTS: Participants indicated that the difference in bracket bonding height between the MCI and MLI should be as follows: 0 mm (3.9%); 0.5 mm (78.3%); 1 mm (7.6%); 1.5 mm (0.2%); and CCC (9.9%). There was no statistically significant correlation between the choice for bracket bonding height and sex, age and time since specialization. CONCLUSION: Most participating orthodontists choose the 0.5-mm difference in bracket placement height between the MCI and MLI. The variables sex, age and time since specialization did not influence this choice.

Electrical therapies act on the Ca2+ /CaM signaling pathway to enhance bone regeneration with bioactive glass [S53P4] and allogeneic grafts.

This study aimed to investigate the application of low-intensity electrostimulation (ES) and electromagnetic stimulation (EM) associated with bioactive glass (BG) or allogeneic grafts (BB) in bone regeneration. A cell viability test on osteoblasts (UMR-106) was performed in the presence of BB and BG grafts associated with ES (10 µA/5 min) and EM (500 Hz/2 min). Critical defects (25 mm2 ) in calvaria were generated in male Wistar rats, and bone regeneration was evaluated on the 30th, 60th, and 120th days after surgery. Cell proliferation increased with the application of ES in both grafts and after EM with BG. Bone remodeling was more effective using the allogeneic graft in both therapies, with increased angiogenesis, osteoblast proliferation, and OPN expression in the BB + EM group. A higher number of osteoblasts and osteoclasts, and an increase in bone sialoprotein, Runx-2, and Opn gene expression were found in the BB + ES group. The BG graft associated with EM therapy had an increased proliferation of osteoblasts and increased expression of Runx-2 and Opn. Groups that had BG and ES therapy had increased numbers of osteoblasts, osteoclasts, and increased OPN expression. The expression of voltage-gated calcium channels increased in groups with ES, while calmodulin expression increased in therapies without grafting. ES and EM therapies favored the repair of bone defects upon grafting by improving angiogenesis, osteogenic gene expression, and tissue reorganization. Despite activating different pathways, both therapies increased the intracellular concentrations of calmodulin, leading to cell proliferation and bone regeneration.

Pulpal outcomes in orthodontic tooth movement in diabetes mellitus.

Diabetes mellitus impairs angiogenesis and tissue reorganization during orthodontic tooth movement (OTM). Thus, this study evaluated pulpal outcomes in orthodontic tooth movement through metabolic changes in diabetes. Male Wistar rats were used, and the in vivo study design consisted of four groups (n = 10/group): C-non-diabetic animals not subjected to orthodontic tooth movement; D-diabetic animals not subjected to orthodontic tooth movement; OTM-non-diabetic animals subjected to orthodontic tooth movement; and D + OTM-diabetic animals subjected to orthodontic tooth movement. In addition, the pulps of the distovestibular root (DV) and mesiovestibular root (MV) were assessed by histomorphometric analyses and immunoexpression of the RANKL/OPG system. Pulpal analysis of the MV root showed an increase in blood vessels in diabetic animals. Inflammatory infiltrate and fibroblastic cells were elevated in diabetic animals with tooth movement in the DV and MV roots. In the DV and MV roots, diabetic rats with OTM showed a reduction in birefringent collagen fibers. The immunostaining for RANKL was higher in the pulp tissue of OTM in diabetic and non-diabetic animals. It was concluded that the pulp tissue has less adaptive and repair capacity during OTM in diabetes. Orthodontic strength can alter the inflammatory processes in the pulp.

In Vivo Investigation of Polymer-Ceramic PCL/HA and PCL/ß-TCP 3D Composite Scaffolds and Electrical Stimulation for Bone Regeneration.

Critical bone defects are a major clinical challenge in reconstructive bone surgery. Polycaprolactone (PCL) mixed with bioceramics, such as hydroxyapatite (HA) and tricalcium phosphate (TCP), create composite scaffolds with improved biological recognition and bioactivity. Electrical stimulation (ES) aims to compensate the compromised endogenous electrical signals and to stimulate cell proliferation and differentiation. We investigated the effects of composite scaffolds (PCL with HA; and PCL with ß-TCP) and the use of ES on critical bone defects in Wistar rats using eight experimental groups: untreated, ES, PCL, PCL/ES, HA, HA/ES, TCP, and TCP/ES. The investigation was based on histomorphometry, immunohistochemistry, and gene expression analysis. The vascular area was greater in the HA/ES group on days 30 and 60. Tissue mineralization was greater in the HA, HA/ES, and TCP groups at day 30, and TCP/ES at day 60. Bmp-2 gene expression was higher in the HA, TCP, and TCP/ES groups at day 30, and in the TCP/ES and PCL/ES groups at day 60. Runx-2, Osterix, and Osteopontin gene expression were also higher in the TCP/ES group at day 60. These results suggest that scaffolds printed with PCL and TCP, when paired with electrical therapy application, improve bone regeneration.

Comparation of three methods for measuring the Edge Bevel Radius of rectangular orthodontic wires: An in-vitro study.

OBJECTIVE: To establish a simplified method for measuring the edge bevel radius of 0.019×0.025-in steel rectangular orthodontic wires, achievable in the clinical environment, and to compare it with the photographic method. MATERIALS AND METHODS: Aided by the AutoCAD™ 2016 software, the theoretical mathematical relationship was determined between the edge rounding radius and cross-sectional dimensions (height, width, diagonals), through rectangle drawings that represent cross-sections. Two hundred segments (n=20) were obtained from the posterior portions of 100 archwires from 10 brands (Dentaurum™; American-Orthodontics™; GAC™; 3M-Unitek™; Abzil™; Morelli™; Orthometric™; Aditek™; A-Company™; Orthomundi™). The cross-sectional measures of each segment were obtained with a micrometer and a caliper, and the edge bevel radii of these segments were calculated with the use of a mathematical formula. For the "gold standard", the segments were included longitudinally in a phenolic resin cylinder, cross-sectioned, polished, and photographed in scanning electron microscope (SEM). The images were amplified 770× and the radii were measured with an acetate template. The micrometer and caliper measuring methods were subjected to Bland-Altman analysis and compared with the gold standard (SEM), considering ±10µm as the maximum acceptable difference between methods. RESULTS: In the micrometre measurement, 95% of the differences from the standard were within the limits of agreement (-7.21 and 5.56µm). For the caliper method, 95% of the differences were between -5.46 and 19.83µm, which exceeded the fixed limit ±10µm. CONCLUSION: The calculation method with micrometre measurements is equivalent to the photographic method, but there is no such equivalence for the caliper measurements.

Whitening Dentifrices Effect on Enamel with Orthodontic Braces after Simulated Brushing.

OBJECTIVE: This study aimed to evaluate in vitro the effects of whitening dentifrices on enamel color, the shear bond strength of orthodontic brackets and adhesive remnant index (ARI). MATERIALS AND METHODS: Eighty bovine teeth with brackets were randomly divided into four groups (n = 20): control group (GC)-water, test group 1 (GT1)-Colgate Total 12, test group 2 (GT2)-Curaprox Black Is White, and group test 3 (GT3)-Luminous White. All groups were submitted to brushing, simulating 12 months. The specimens were exposed to spectrophotometer color evaluation and to a shear strength test in a universal test machine using a 300 kN load with a crosshead speed of 0.5 mm/min. The ARI was evaluated with a stereoscopic magnifying glass. STATISTICAL ANALYSIS: Nonparametric Kruskal-Wallis and Dunn's tests were used for the color analysis, and Friedman and Nemenyi tests were used to compare the times in the variable. To compare the shear force between the groups, the data were evaluated by one-way analysis of variance and Tukey's test, and ARI was analyzed using Fisher's exact test, always with a significance level of 5%. RESULTS: In the color analysis, GT3 presented the greatest progression in whitening effect. GT1 had greater shear strength than GT3 did (p ≤ 0.05). For ARI, the score 1 was predominant in the GC and GT1. The GT2 and GT3 groups had scores of 3. CONCLUSION: The whitening dentifrices promoted significant color change over the 12-month brushing time and may have interfered in the resistance to shear bond strength and ARI.

Diabetes mellitus and periodontitis: Inflammatory response in orthodontic tooth movement.

OBJECTIVES: This study evaluated, in experimental model, the inflammatory alterations in gingival tissue and alveolar bone during the orthodontic tooth movement (OTM) in diabetes mellitus (D) and periodontitis (P). SETTING AND SAMPLE POPULATION: Forty male Wistar rats, 90 days old and weighing 300 g. MATERIALS AND METHODS: The sample was divided into four groups (n = 10). OTM: orthodontic movement (10 days, 0.4 N force); P + OTM: periodontitis (ligature-induced periodontitis, 3-0 silk suture thread) and orthodontic movement; D + OTM: diabetes (Alloxan-induced diabetes, 150 mg/kg) and orthodontic movement; and D + P + OTM: diabetes, periodontitis and orthodontic movement. Tooth displacement was measured; fibroblast, inflammatory cells, osteoclast and blood vessels were quantified by histomorphometric analysis. Inflammatory markers, interleukin-6 (IL-6) and tumour necrosis factor (TNF-α) were quantified by ELISA (Enzyme-Linked Immunosorbent Assay) in gingival tissue. The fibroblastic growth factor (bFGF), transforming growth factor (TGF-ß1) and the vascular endothelial growth factor (VEGF) were measured via Western blotting in the alveolar bone. The results were analysed by ANOVA and Tukey's test at a 5% significance level. RESULTS: The quantification of inflammatory cells and the expression of IL-6, TNF-α, TGF-ß1 and bFGF were increased in diabetes and periodontitis. However, the number of fibroblasts and blood vessels and the percentage of birefringent collagen fibres were higher in healthy animals. There was greater tooth displacement in the OTM group. CONCLUSION: Diabetes Mellitus modifies the inflammatory response. The increased expression of inflammatory markers IL-6, TNF-α and TGF-ß1 in diabetic animals impairs neovasculogenesis and tissue reorganization during orthodontic tooth movement, which may be aggravated by periodontitis.

Effect of two corticotomy protocols on periodontal tissue and orthodontic movement

Abstract Objective To compare two corticotomy surgical protocols in rats to verify whether they alter conventional orthodontic movement. Methodology Sixty Wistar rats were divided into three groups - orthodontic movement (CG), orthodontic movement and corticotomy (G1) and orthodontic movement with corticotomy and decortication (G2) - and euthanized after 7 and 14 days. Tooth movement (mm), bone volume fraction and bone volume ratio to total volume (BV/TV), and bone mineral density (BMD) were evaluated by micro-CT. The total amount of bone was measured in square millimeters and expressed as the percentage of bone area in the histomorphometry. The number of positive TRAP cells and RANK/RANKL/OPG interaction were also investigated. Results Day 14 showed a statistically significant difference in orthodontic tooth movement in CG compared with G1 (7.52 mm; p=0.009) and G2 (7.36 mm; p=0.016). A micro-CT analysis revealed a difference between CG, G1 and G2 regarding BV/TV, with G1 and G2 presenting a lower BV/TV ratio at 14 days (0.77 and 0.73 respectively); we found no statistically significant differences regarding BMD. There was a difference in the total amount of bone in the CG group between 7 and 14 days. At 14 days, CG presented a significantly higher bone percentage than G1 and G2. Regarding TRAP, G2 had more positive cells at 7 and 14 days compared with CG and G1. Conclusion Corticotomy accelerates orthodontic movement. Decortication does not improve corticotomy efficiency.

Prognóstico entre eixo de erupção dos caninos permanentes superiores e espaço para erupção dos segundos molares inferiores / Prognosis between superior permanent canines teeth eruption axis and second lower molars space for eruption

Resumo O objetivo deste estudo foi verificar a associação entre a má posição do germe dos segundos molares inferiores com o eixo de erupção dos caninos permanentes superiores na dentadura mista. A amostra foi composta por 506 radiografias panorâmicas digitais, no período intertransitório da fase de dentadura mista, na faixa etária de 7 a 12 anos, de ambos os sexos. Os caninos foram avaliados utilizando-se a divisão da porção anterior do hemiarco em cinco setores sendo o setor 1 a melhor posição para eixo de erupção correto e 5 para a pior. Para a localização do germe dos segundos molares inferiores foi utilizada a distância horizontal entre a face distal dos primeiros molares inferiores e a borda anterior do ramo da mandíbula. Os dados foram analisados por tabelas de distribuição de frequências e regressão logística, com estimação dos Odds Ratio brutos e os respectivos intervalos de confiança. Não houve associação significativa entre o sexo e o eixo de erupção de caninos permanentes superiores (p>0,05). Houve associação entre a má posição de segundos molares inferiores e o eixo de erupção de caninos. Participantes com má posição de segundos molares inferiores apresentaram 3,40 (IC 95%, 2,12-5,47) vezes mais chance de ter o eixo de erupção de caninos permanentes superiores mal posicionados. Conclui-se que houve associação entre a má posição de segundos molares inferiores e o eixo de erupção de caninos.(AU)

Abstract This study aimed to associate malposition of lower second molar germ with the upper permanent canine teeth eruption axis in the mixed dentition. The sample included 506 digital panoramic radiographies taken in the mixed dentition inter-transitional period in the age group of 7 to 10 years of both sexes. The canines were assessed by dividing the anterior portion of the hemiarch into five sectors, in which sector 1 was the best position for the correct eruption axis and 5 was the worst. For locating the lower second molar germ, a horizontal distance was used between the distal aspect of the lower first molars and the anterior margin of the mandibular ramus. The data was analyzed with frequency distribution and logistic regression tables, estimating crude Odds Ratio and respective confidence intervals. There was no significant association between sex and upper permanent canines eruption axis (p>0.05). There was association between the lower second molars malposition and canines eruption axis. Participants with malposition of lower second molars presented 3.40 (95% CI, 2.12-5.47) times more likely to present upper permanent canines eruption axis malpositioned. It was concluded that there was association between the malposition of lower second molars and the canine eruption axis. (AU)