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Separating elastics may be cytotoxic to the interdental gingival tissues. Both latex and non-latex separating elastics are widely used and both types should be biocompatible.

Introduction: This trial aimed to longitudinally evaluate the effect of the treatment of transverse maxillary deficiency using rapid palatal expansion (RPE) on self-perceived oral health-related quality of life (OHRQOL) in children.Methods: Eighty participants aged 8-10 years with transverse maxillary deficiency and bilateral posterior crossbite were randomly assigned to 2 groups (n = 40 each): a group treated with RPE using hyrax-type appliances and a nontreated control group. OHRQOL was assessed by using the Child Perceptions Questionnaire for 8-10-year-olds at 4 times: before RPE, during RPE (T1), at the end of RPE (T2), and 1 month after the appliance removal (T3). Generalized mixed models were used for data analysis (α = 0.05).Results: Both groups exhibited similar demographic characteristics and OHRQOL scores at baseline. All participants completed the study. RPE had a time-dependent effect on OHRQOL. At T1 and T2, this therapy is expected to increase the overall OHRQOL scores by 1.17 times (ie, ∼17% increase; T1 95% confidence interval [CI], 1.08-1.26; T2 95% CI, 1.09-1.27; P = 0.001). In contrast, the overall OHRQOL scores at T3 are expected to be 0.28 times the baseline scores (ie, ∼72% reduction; T3 95% CI, 0.26-0.31; P = 0.001). All individual domains of the OHRQOL evidenced a positive impact of treatment at T3 (P = 0.001). Only the oral symptoms and social well-being domains showed a significantly negative impact of the treatment at T1 and T2.Conclusions: Correction of the transverse maxillary deficiency by RPE in children aged 8-10 years improves OHRQOL. There is a temporary worsening of OHRQOL during the treatment of this condition using RPE.Registration: This trial was not registered.Protocol: The protocol was not published before trial commencement.Funding: This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil, Financing Code 001. [ABSTRACT FROM AUTHOR]

Aim: Facial orthopaedic treatments based on the stimulation or restrictions of craniofacial bone growth are more effective when carried out during the pubertal growth spurt. The aim of this cross-sectional study was to evaluate the reproducibility of two cervical vertebrae methods (CVM) with manual tracing and direct visual inspection. Methods: A sample of 60 lateral cephalometric radiographs (10 of each of the 6 CVM stages) was randomly selected from 171 records. 5 orthodontists classified these radiographs according to the skeletal maturation stage in 2002 and 2005, and the application of both methods was conducted by direct visual inspection and evaluation through manual tracing. Results: The average reliability of the two methods determination and the two forms of evaluation was substantial. The direct visual inspection evaluation showed the highest reliability and agreement interexaminer values for both methods, as well as the intraexaminers evaluation. Conclusion: The reproducibility of CVM method was substantial, indicating its clinical use to determine the skeletal maturity and the ideal moment for treatment execution. [ABSTRACT FROM AUTHOR]

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Fluoridated mouthrinse is indicated for individuals with high risk of caries. Chitosan (Chit) exhibits antibacterial properties, but little is known about its effects on enamel when combined with sodium fluoride (NaF) to form NaF/Chit supramolecular complexes. In our study, NaF/Chit supramolecular complexes structured as microparticles were synthetized and characterized, and their effects on human enamel were evaluated after cariogenic challenge simulating the daily mouthrinse use. Initially, NaF/Chit complex formation was investigated based on several titrations by measuring the zeta potential, electrical conductivity (κ), hydrodynamic diameter (D h), viscosity (η) and heat flow (by isothermal titration calorimetry) against the molar ratio [NaF]/[Chit monomer ], which allowed us to identify the interactions between Chit-NaF with a stoichiometry of approximately 0.68. Spontaneous microparticle formation was observed. Samples of enamel blocks were prepared and divided into eight groups (n = 10/group): (i) 0.2% Chit; (ii) 0.2% NaF; (iii) 0.2% NaF/Chit suspension; (iv) 0.2% acetic acid; (v) 0.05% Chit; (vi) 0.05% NaF; (vii) 0.05% NaF/Chit suspension; and (viii) 0.05% acetic acid. Cariogenic challenge was performed in each sample by cycling in demineralization and remineralization solutions for 7 days. Before each demineralization cycle, the corresponding substances were passively applied daily for 90 s, even in groups with 0.02% concentration. After 7 days, samples were examined for Knoop hardness (KHN) measurements. The data were analyzed by repeated-measures ANOVA and Tukey tests (α = 0.05). The 0.2% NaF and 0.2% NaF/Chit groups showed higher KHN post-challenge values than the other groups. The 0.2% NaF/Chit microparticle suspension reduced the enamel hardness loss after cariogenic challenge as effectively as the 0.2% NaF solution and demonstrated potential for use in a formulation with anti-caries effects. [Display omitted] • NaF/Chit complex was able to form particles like the ionic gelation method. • NaF/Chit complex formed microparticles with 1 μm diameter. • The zeta potential found (+30 mV) confirmed the stability of NaF/Chit system. • The 0.2% NaF and 0.2% NaF/Chit reduced the enamel hardness loss after pH-cycling. [ABSTRACT FROM AUTHOR]

The article provides information on study conducted to evaluate impact of malocclusion on relationships among adults. Topics discussed include development of dental esthetics and its impact on retaining oral health, effect of physical attractiveness on social relationships, and manipulation of software programs to hide malocclusion.

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Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a case study of 25-year-old female, who was suffering from Class II, division 1 malocclusion and deep bite and has undergone orthodontic retreatment. Topics discussed include compliant of the patient for gingival pain during mastication; indication of alveolar bones by panoramic radiograph; bonding of mandibular appliance around molars; and construction of a splint with bilateral contacts.

Purpose: To evaluate the effect of storage in S. mutans culture or water on the durability of fluoride and MDPB-containing adhesive system on artificial caries-affected primary dentin. Methods: Dentin flat surfaces of primary molars were submitted to artificial caries development using S. mutans biofilm. CAPD cavities were restored with Adper Scotchbond Multi-Purpose (SBM) or Clearfil Protect Bond (CPB) and they were serially sectioned into sticks (1 mm2 cross-sectional area) and stored in S. mutans biofilm for 3 days, in deionized water for 3 months and afterwards subjected to microtensile bond strength (|_iTBS) test. A control group was submitted to immediate jxTBS testing. Two-way ANOVA and Tukey's tests were used. Failure sites were observed by SEM and classified as cohesive (dentin or resin) and adhesive failures. Results: The control group showed the highest TBS values (MPa) for both SBM (25.2±8.5) and CPB (15.6±6.1) adhesive systems. A significant decrease in pTBS values after S. mutans biofilm and water storage was observed for SBM (18.7±5.7 and 17.4±4.1, respectively) and CPB (13.9±5.2 and 13.7±4.8, respectively), but no difference was found between them. The highest percentage of adhesive failure was observed for all groups. However, cohesive failure in dentin was observed in a higher percentage for SBM than CP. [ABSTRACT FROM AUTHOR]

Objective: To assess the level of knowledge of primary school teachers in the public school network of Northeastern Brazil with respect to management of dental trauma and its relationship with prognosis. Methods: A questionnaire was applied to 195 school teachers of public schools in Northeastern Brazil. The questionnaire comprised 12 objective questions about dental trauma and methods for its prevention and management. Data were submitted to chi-square test and Poisson regression test (P > 0.05). Results: Out of the 141 teachers who responded the questionnaires, the majority were women (70.2%) and most of them had experienced previous dental accidents involving a child (53.2%). The majority (84.4%) had incomplete college education and few were given some training on how to deal with emergency situations during their undergraduate course (13.5%) or after it (38.3%). Their level of knowledge about dental trauma and emergency protocols showed that unsatisfactory knowledge level was associated with the male sex: 46% higher for men in comparison to women (P = 0.025). Conclusions: Approximately half of teachers evaluated had unsatisfactory knowledge about dental trauma and emergency protocols, with female teachers showing more knowledge than men. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. Methods: Specimens were divided into 4 groups (n = 6) according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil): Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+), a glass specimen (C-) and cell control (CC). Specimens were immersed in Minimum Eagle's Medium (MEM) and incubated for 24 h at 37 °C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA) with a 492-nm wavelength λ=492 nm). Results: There were no statistical differences between the experimental groups and the CC and C- groups. Conclusion: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material. [ABSTRACT FROM AUTHOR]

Introduction: Due to the increasing prevalence of dental erosion in the last years, it is relevant to evaluate the potential of different remineralizing agents to prevent this dental alteration. Objective: To perform a systematic literature review to investigate whether products containing casein phosphopeptide – amorphous calcium phosphate (CPP-ACP) remineralizing agents are effective in preventing enamel erosion in order to provide information to health professionals who deal with patients at risk of erosion. Materials and Methods: A search was performed in the PUBMED database for scientific studies in journals published in English from January 01, 2003 to March 30, 2012. A total of 230 articles were found and 32 of these were selected. Results: All fluoride agents (dentifrices, fluoride gels, varnishes and solutions) were effective in preventing erosion and the higher the concentration and lower the Ph of agents, the greater their prevention. Although several fluoride compounds have been investigated, titanium tetrafluoride has shown the greatest protection against erosion, regardless of the agent. With respect to CPP-ACP agents, these were effective in preventing mineral loss after erosive challenge. Conclusions: The majority of studies were conducted in vitro. The composition, fluoride concentration and pH of remineralizing agents have influenced the effectiveness in preventing enamel erosion. It is important to conduct in vivo studies and clinical protocols for the application of products against erosion. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the inflammatory and cure events of acid-based reactions using glass ionomer cement used for cementation of crowns, bridges, onlays and orthodontic bands implanted in subcutaneous tissue, at different time intervals. A total of 48 male Wistar rats were used, distributed into 4 groups (n = 12), as follows: Group C (control, polyethylene), Group ME (Meron), Group KC (Ketac Cem) and Group PR (Precedent). The animals were sacrificed after time intervals of 7, 15 and 30 days, and their tissues were analyzed under an optical microscope for such events as inflammatory infiltrate, edema, necrosis, granulation tissue, multinucleated giant cells, young fibroblasts and collagen. The results was assessed using Kruskal-Wallis and Dunn's tests (p < 0.05). In the initial period, intense inflammatory infiltrate was observed for all the materials with no significant difference among them (p = 0.104). Groups PR and KC showed significant difference in relation to Group C, at 7 days (p = 0.025) and 15 days (p = 0.006). Edema and giant cells were more expressive in Group ME, differing significantly from Groups C (p = 0.023) and KC (p = 0.039), respectively, at 7 days. Group ME showed a statistically significant difference in relation to Groups PR and KC for the presence of young fibroblasts (p = 0.009) and for collagen (p = 0.002), at 7 days. Within the limits of this in vivo study, Precedent and Ketac Cem glass ionomer cements showed better tissue healing with a greater number of fibroblasts and collagen, as compared to Meron. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate the variation in facial soft tissue thickness in young north eastern Brazilian individuals according to gender and skeletal class. Measurements were obtained from digitized teleradiographs of 300 children, aged from 8 to 12 years, using the Sidexis Xg program. Data of mean, standard deviation, maximum and minimum soft tissue thickness values of the faces of Angle's Class I, II and III individuals, were evaluated. The results demonstrated that there was no difference in soft tissue thickness among the skeletal classes for most of anthropological points. For the Class I, statistical differences were found (P < 0.05) between the genders in the rhinion point, subnasal and upper lip. It was concluded that there was no difference in soft tissue thickness among the skeletal classes, except between Class II and III for the points: Stomion, Bottom lip and Pogonion, allowing definition of parameters of this population for the purpose of facial reconstruction. [Copyright &y& Elsevier]

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to assess the effect of different remineralizing agents on enamel microhardness (KHN) and surface topography after an erosive challenge. Forty-eight human enamel specimens (4 × 4 mm) were randomly assigned to 4 groups: control (no treatment), fluoride varnish, calcium nanophosphate paste and casein phosphopeptide-amorphous calcium phosphate paste (CPP-ACP). Both pastes were applied for 5 minutes, and fluoride varnish, for 24 h. Four daily erosive cycles of 5 minutes of immersion in a cola drink and 2 h in artificial saliva were conducted for 5 days. KHN readings were performed at baseline and after 5 days. The percentage of enamel hardness change (%KHN) was obtained after erosion. The surface topography was evaluated by atomic force microscopy (AFM). The data were tested using ANOVA, Tukey's and paired-T tests (p < 0.05). After an erosive challenge, there was no statistically significant difference between the control (96.8 ± 11.4 KHN / 72.4 ± 3.0 %KHN) and the varnish (91.7 ± 14.1 KHN / 73.4 ± 5.5 %KHN) groups. The nanophosphate group showed lower enamel hardness loss (187.2 ± 27.9 / 49.0 ± 7.9 %KHN), compared with the CPP-ACP group (141.8 ± 16.5 / 60.6 ± 4.0 %KHN), and both were statistically different from the varnish and the control groups. AFM images showed a rough surface for the control and the varnish groups, a non-homogeneous layer with globular irregularities for CPP-ACP, and a thick homogeneous layer for the nanophosphate group. None of the agents provided protection against the development of erosion; however, nanophosphate paste was able to reduce enamel surface softening after the erosive challenge. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to test the hypothesis that there is no difference between stainless steel and low-nickel stainless steel wires as regards mechanical behavior. Force, resilience, and elastic modulus produced by Quad-helix appliances made of 0.032-inch and 0.036-inch wires were evaluated. Methods: Sixty Quad-helix appliances were made, thirty for each type of alloy, being fifteen for each wire thickness, 0.032-in and 0.036-in. All the archwires were submitted to mechanical compression test using an EMIC DL-10000 machine simulating activations of 4, 6, 9, and 12 mm. Analysis of variance (ANOVA) with multiple comparisons and Tukey's test were used (p < 0.05) to assess force, resilience, and elastic modulus. Results: Statistically significant difference in the forces generated, resilience and elastic modulus were found between the 0.032 and 0.036 inch thicknesses (p < 0.05). Conclusions: Appliances made of low-nickel stainless steel alloy had force, resilience, and elastic modulus similar to those made of stainless steel alloy. [ABSTRACT FROM AUTHOR]

Objective: To mechanically evaluate different systems used for incisors retraction. Methods: Three different methods for incisors retraction using 0.019 x 0.025-in stainless steel wire were evaluated. The samples were divided into three groups: Group A (retraction arch with 7-mm high vertical hooks); Group G3 (elastic chain attached to the mini-implant and to the 3-mm stainless steel hook soldered to the retraction arch); Group G6 (elastic chain attached to the mini-implant and to the 6-mm stainless steel hook soldered to the retraction arch). A dental mannequin was used for evaluation in order to simulate the desired movements when the device was exposed to a heat source. The analysis of variance (ANOVA) and the Tukey test were used (p < 0.05). Results: The results demonstrated that Groups G3 and G6 exhibited less extrusion and less incisor inclination during the retraction phase (p < 0.05). With regard to incisor extrusion, statistically significant differences were observed between Groups A and G3, and between Groups A and G6 (p < 0.05). Regarding incisor inclination, statistically significant differences were observed between the three systems evaluated (p < 0.05). Conclusions: Arches with 6-mm vertical hooks allow the force to be applied on the center of resistance of the incisors, thus improving mechanical control when compared with the other two systems. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that there is no difference in cytotoxicity between separating elastics of different manufacturers. Methods: The present article compared latex elastics (4.0 mm, 4.4 mm and 4.8 mm) of four different manufacturers. The sample was allocated to seven groups of 9 elastics: Group A (American Orthodontics, green color, modules), Groups M1 and M2 (Morelli, blue color, modules and free in pack respectively), Groups M3 and M4 (Morelli, green color, modules and free in pack respectively), Group U (Uniden, blue color, free in pack) and Group T (Tec-nident, blue color, free in pack) regarding their possible cytotoxic effects on oral tissues. Cytotoxicity assays were performed using cell culture medium containing epithelioid-type cells (Hep-2 line) derived from human laryngeal carcinoma and submitted to the methods for evaluating the cytotoxicity by the "dye-uptake" test, at time intervals 24,48,72 and 168 h. Data were compared by analysis of variance (ANOVA) and Tukey's test (p < 0.05). Results: Results showed statistically significant difference (p < 0.05) between group U and all the other Groups (A, M1, M2, M3, M 4 and T) at 24 and 48 hours. Conclusions: Uniden elastics evoked more cell lysis at 24 and 48 h, although, all brands showed biocompatibility from 72 h onwards. [ABSTRACT FROM AUTHOR]

Objectives: The objective of the authors was to evaluate fluoride release of 3 glass ionomer cements with immediate protection of fluoride varnish (Cavitine, SS White), divided into 3 groups: Group M (Meron, VOCO), Group V (Vidrion C, SS White) and Group KC (Ketac-Cem, 3M ESPE). Methods: Fluoride release was measured during 60 days by means of an ion-selective electrode connected to an ion analyzer. After 4 weeks, the test specimens were exposed to a solution of 0.221% sodium fluoride (1000 ppm of fluoride). Results: Results showed that the cements reached a maximum peak of fluoride release in a period of 24 h. There was a statistically significant difference between the amount of fluoride released after the applications of fluoride among the groups from the 31st to 60th day (p> 0.05). Conclusion: The Vidrion C and Meron cements showed better performance to uptake and release fluoride when compared with Ketac-Cem cement [ABSTRACT FROM AUTHOR]

Objective: To mechanically evaluate different systems used for canine retraction. Methods: Three different methods for partial canine retraction were evaluated: retraction with elastic chain directly attached to bracket; elastic chain connected to bracket hook and with sliding jig activated with the aid of an elastic chain attached to a mini-implant. For this evaluation, a Typodont was adapted to simulate the desired movements when exposed to a heat source. After obtaining the measurements of the movements, statistical analysis was performed. Results: The mini-implant/sliding jig system (Groups M 0.018-in and M 0.019 x 0.026-in) favored less extrusion and distal inclination of the canines in the retraction stage (p < 0.005). Meanwhile, the retraction system with elastic chain directly attached to the orthodontic brackets (Groups C 0.018-in and 0.019 x 0.026-in) favored greater inclination and extrusion than the others, followed by the system of elastic chain attached to the hook (Groups G 0.018-in and 0.019 x 0.026-in). Conclusions: Canine retraction with the mini-implant/sliding jig system showed the best mechanical control. The worst results were observed with a 0.018 archwire when the elastic chain was attached to the bracket. [ABSTRACT FROM AUTHOR]

This article describes the orthodontic treatment of a patient with Lowe syndrome. The objective of the treatment was to improve the patient’s dental relationships and consequently his quality of life. This was achieved by maxillary expansion and extraction of the mandibular central incisors and maxillary deciduous canines. The teeth were aligned and leveled with a fixed orthodontic appliance. Satisfactory results were obtained at the end of treatment, with substantial improvement in dental esthetics, occlusal function, and facial profile. [ABSTRACT FROM AUTHOR]

The aim of this article was to describe the Sturge-Weber syndrome in a patient with orthodontic requirements. Pathologies involved in this syndrome affect facial cranial growth. [ABSTRACT FROM AUTHOR]

Copyright of RGO: Revista Gaúcha de Odontologia is the property of RGO: Revista Gaucha de Odontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: To verify the hypothesis that self-ligating brackets favor greater aggregation of microorganisms when compared with conventional brackets. Methods: Four types of self-ligating metal brackets were evaluated. Initially, 50 brackets were divided into five groups (n=10): Morelli Conventional, GAC (In-Ovation R, Dentsply Caulk), Aditek (Easy Clip), Ormco (Damon System) and 3M Unitek (Smart Clip). An in vivo evaluation was carried out in which the brackets were bonded to the mandibular teeth of five healthy individuals who had not undergone previous orthodontic treatment. The right hemiarch brackets were used for bacterial plaque collection and those on the left side were examined by scanning electron microscopy (SEM). Before bracket bonding, the bacterial plaque material aggregated to the tooth surfaces was collected, with the areas of choice being the cervical-buccal and mesial and distal interproximal regions. After 21 days had elapsed since bonding, the plaque adhered to the winglet, channel and cervical regions of the bracket bases was collected. The materials collected were diluted and seeded on Petri dishes onto Mitis salivarius medium specific for S. mutans and non-specified BHI culture medium. Colony forming unit (CFU) counts were performed visually after 24, 48 and 72 h of incubation. Results: Greater bacterial accumulation was observed on the winglets of 3M brackets, with statistical statistically significant differences from the other types (p<0.05). As regards the channel regions, most microorganisms accumulated in the Ormco Group (p<0.05), and in the cervical region of Aditek brackets. In all evaluated regions, those with least bacterial accumulation were the conventional brackets. Conclusions: The hypothesis was confirmed, as the self-ligating brackets were shown to have greater bacterial accumulation when compared with the conventional brackets. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: The aim was to verify the hypothesis that orthodontic elastics in chain form become more cytotoxic after the sterilization process. Materials and methods: Orthodontic elastic in chain form with six links each was divided into eight groups according to the sterilization method to be performed. The following groups were formed: Control, alcohol 70, autoclave, glutaraldehyde, microwave, ultraviolet, ethylene oxide and gamma rays. Three additional groups were used, cell control, positive control consisting of cellular detergent Tween 80, and negative control consisting of phosphate buffer solution (PBS). After this, the elastics were immersed in culture media for 24h to release possible toxic substances. After this period elapsed, the medium was placed in contact with L929 cells for 24h. Next, the cells were stained and analyzed in a spectrophotometer with regard to their cell viability. The data obtained were analyzed by the analysis of variance (ANOVA) and the Tukey''s test. Results: The groups of elastic sterilized by chemical means (alcohol 70 and glutaraldehyde) and thermal means (autoclave and microwave) led to an increase in cytotoxicity of the studied elastics, presenting statistically significant differences from the groups sterilized with ethylene, ultraviolet and gamma rays (p <0.05). Conclusion: The hypothesis was partly confirmed, since some of the sterilization methods increased the cytotoxicity of the elastics and others did not. [Copyright &y& Elsevier]

Aim: To test the hypothesis that bone quality may affect the stability of anchorage devices implanted in a rat model. Methods: Twenty male Wistar rats were divided into 2 groups: Group 1 (rats treated with FK506) and Group 2(rats treated with saline solution vehicle). The immunosuppressant tacrolimus was used with the intention of causing a condition of osteopenia in Group 1. A total of 20 orthodontic mini-implants were used. One mini-implant was inserted in the right femur of each rat. After sacrificing the animals, blocks of bone tissue containing the mini-implants were removed for mechanical pull-out tests to be performed in a universal test machine at a crosshead speed of 0.5 mm/s. The maximum insertion force values and pull-out test were recorded and submitted the non-parametric analyses including the Kruskal-Wallis test and Mann-Whitney tests (p<0.05). The test for Pearson's correlation was used to verify the correlation between bone mineral density and the pull-out test. The dose of FK506 was 2 mg/kg/day. Densitometric analysis was performed to observe the effect of FK506 on the bone mineral density. Results: The mean insertion force values were similar in both groups, with no statistically significant difference between them (P > 0.05). The mean pull-out force values were higher in Group 2 than in Group 1, with statistically significant difference between the groups (P < 0.05). Conclusions: Bone quality may affect the stability of mini-implants. Orthodontic mini-implants did not present good primary stability in a rat model with osteopenia. [ABSTRACT FROM AUTHOR]

Purpose: To test the hypothesis that the higher the concentration of carbamide peroxide, the greater is its cytotoxicity to fibroblast cells. Methods: Three concentrations of carbamide peroxide (10%, 16%, and 22%) used in home bleaching techniques were evaluated regarding their cytotoxic effect on gingival tissues. The materials were divided into three groups as follows: Group C10 (White Gold Home 10%, Dentsply), Group C16 (White Gold Home 16%, Dentsply, and Group C22 (Nite White 22%, ACP Discus Dental). The cytotoxicity essay was carried out using cell cultures (mouse fibroblast L929 cell line) in which the viable cells were determined by means of the dye-uptake method performed at 2, 4, and 8 hours. Data were analyzed by analysis of variance (ANOVA) with multiple comparisons and Tukey's test (P<0.05). Results: The results showed statistically significant differences between Groups C10, C16, C22, and the cell control at 2, 4, and 8 hours (P<0.05). The amount of cell lysis increased proportionally to the exposure time to the materials studied. Conclusion: The 22% carbamide peroxide group was more toxic than the other two groups (16% and 10% concentration) regardless of the exposure time. [ABSTRACT FROM AUTHOR]

Copyright of Revista Odonto Ciencia is the property of EDIPUCRS - Editora Universitaria da PUCRS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Certain malocclusions require orthodontists to be capable of establishing a diagnosis in order to determine the best approach to treatment. The purpose of this article was to present clinical cases and discuss some diagnostic elements used in drawing up a treatment plan to support tooth extraction. All diagnostic elements have been highlighted: Issues concerning compliance, tooth-arch discrepancy, cephalometric discrepancy and facial profile, skeletal age (growth) and anteroposterior relationships, dental asymmetry, facial pattern and pathologies. We suggest that sound decision-making is dependent on the factors mentioned above. Sometimes, however, one single characteristic can, by itself, determine a treatment plan. [ABSTRACT FROM AUTHOR]

Background: Separating elastics may be cytotoxic to the interdental gingival tissues. Both latex and non-latex separating elastics are widely used and both types should be biocompatible. Objective: To determine if latex and non-latex orthodontic separating elastics ore cytotoxic. Methods: The cytotoxicity of natural latex (Groups A, D and O) and non-latex (Group M) orthodontic separating elastics were determined by incubating 15 elastics of each type in Eagle's essential medium (MEM), removing the supernatant after 24, 48, 72 and 168 hours and adding it to cultures of L-929 mouse fibroblasts in growth medium (MEM plus glutamine, garamicine, fungizone, sodium bicarbonate, buffered saline and foetal calf serum). To verify the cell response in extreme situations, three additional groups were included: Group CC (cell control), consisting of L-929 cells not exposed to supernatants from the maintenance medium with the elastics; Group C+ (positive control), consisting of Tween 80; Group C- (negative control), consisting of phosphate buffered saline solution. The positive and negative controls were incubated in MEM maintenance medium for 24, 48, 72 and 168 hours and the extracted elutes were added to L-929 line cells incubated in the growth medium. The viability of the cells was determined with neutral red (dye-uptake method) at 24, 48, 72 and 1 68 hours. The data were analysed with the analysis of variance (AN0VA) and Tukey's multiple comparison test. The significance level was p ⩽ 0.05. Results: The elastics in Groups A, D and O induced greater cell lysis at 72 hours compared to the other experimental times. There were statistically significant differences between the cytotoxicity of the elastics in Groups A, D and 0 in relation to Group CC for experimental times of 24, 48, 72 and 168 hours (p > 0.05). There was not, however, a statistically significant difference between Groups D and CC at 24 hours. Conclusion: The latex and Non-latex orthodentic separating elastics tested were considered to be biocompatible. [ABSTRACT FROM AUTHOR]

Aim: To test the hypothesis that gold-coated orthodontic accessories used for canine traction are less cytotoxic than those made of stainless steel. Methods: Six different orthodontic accessories were evaluated, three of them made from stainless steel (1 - bracket, 2 - button, 3 - mesh pad) and three made from a gold-coated alloy (4 - small mesh pad, 5 button, 6 - big mesh pad). Three control groups were also analyzed: Positive control (C+), consisting of Tween 80 cell detergent; Negative control (C-), consisting of PBS; and Cell control (CC), consisting of cells not exposed to any material. Dye-uptake technique, in which neutral red dye is incorporated into viable cells, was used to assess the cytotoxicity of the accessories. Viable cell counting was performed using a spectrophotometer. Data were analyzed statistically by ANOVA and Tukey's test. Results: Statistically significant differences (P< 0.05) were found between Groups 1-3 and Groups 4-6. However, no differences were found between Groups 1-3 and Groups C- and CC, and neither between Groups 4-6 and Group C+. Conclusions: The tested hypothesis was not confirmed since gold-coated orthodontic accessories were found to be more cytotoxic than those made of stainless steel. [ABSTRACT FROM AUTHOR]