Scielo RSS <![CDATA[Brazilian Oral Research]]> vol. 26 num. 2 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<b>The dilemma of researchers, the insensibility of policy-makers and the distress of Brazilian dentistry journals</b>]]> <![CDATA[<b>Children's discomfort in assessments using different methods for approximal caries detection</b>]]> Because discomfort caused by different approximal caries detection methods can influence their performance, the assessment of this discomfort is important. Thus, this study aimed to evaluate the discomfort reported by children after the use of different diagnostic methods to detect approximal caries lesions in primary teeth: visual inspection, bitewing radiography, laser fluorescence (DIAGNOdent pen - LFpen) and temporary separation with orthodontic rubbers. Seventy-six children aged 4 to 12 years were examined using these methods. Their discomfort was assessed using the Wong-Baker scale and compared among the methods. Visual inspection caused less discomfort than did other methods. Radiography and the LFpen presented similar levels of discomfort. Older children reported higher discomfort using temporary separation, whereas younger children reported less discomfort with the LFpen. In conclusion, radiographic, temporary separation and LFpen methods provoke higher discomfort than visual inspection. <![CDATA[<b>Calcium binding to <i>S. mutans</i> grown in the presence or absence of sucrose</b>]]> Sucrose is the most cariogenic dietary carbohydrate because it is a substrate for insoluble extracellular polysaccharide (IEPS) production in dental biofilms, which can proportionally decrease bacterial density and, consequently, the number of biofilm calcium (Ca) binding sites. Ca bound to bacterial cell walls can be released into the biofilm fluid during a cariogenic challenge, reducing the driving force for mineral dissolution provoked by the pH drop. Thus, we investigated the effect of an IEPS-rich extracellular matrix on bacterial Ca binding after treatment with Ca solutions. Streptococcus mutans Ingbritt 1600 was cultivated in culture broths supplemented with 1.0% sucrose or 0.5% glucose + 0.5% fructose. The IEPS concentration in bacterial pellets was determined after alkaline extraction. Bacterial pellets were treated with 1 mM or 10 mM Ca++ solutions at 37ºC for 10 to 60 min. Ca binding to bacterial pellets, determined after acid extraction using the Arsenazo III reagent, was fast and concentration dependent. Although the IEPS concentration was approximately ten times higher in bacterial pellets cultivated in sucrose as compared to its monossaccharides, bound Ca concentration after Ca treatment was similar in both conditions. These results suggest that IEPS may not influence the amount of Ca bound to reservoirs of dental biofilms. <![CDATA[<b>Influence of pulp condition on the accuracy of an electronic foramen locator in posterior teeth</b>: <b>an <i>in vivo</i> study</b>]]> The aim of this study was to assess, in vivo, the accuracy of the NovApex® electronic foramen locator in determining working length (WL) in vital and necrotic posterior teeth. The NovApex®was used in 144 canals: 35 teeth with vital pulps (68 canals) and 42 teeth with necrotic pulps (76 canals). WL was measured with the NovApex® locator and confirmed using the radiographic method. Differences between electronic and radiographic measurements ranging between 0.0 and 0.4 millimeters were classified as acceptable; differences equal to or greater than 0.5 millimeter were considered unacceptable. Pearson's chi-square test was used to assess the influence of pulp condition on the accuracy of NovApex®(a = 0.05). Regardless of pulp condition, differences between electronic and radiographic WL measurements were acceptable in 73.61% of the canals. No statistically significant differences in accuracy were observed when comparing vital and necrotic canals (p > 0.05). There were 38 unacceptable measurements. In none of these cases was the file tip located beyond the radiographic apex; in 32, it was located short of the NovApex® measurement. Pulp condition had no significant effect on the accuracy of NovApex®. <![CDATA[<b>Agreement between adolescents' and their mothers' reports of oral health-related quality of life</b>]]> The aim of this study was to determine the level of agreement between reports by adolescents and their mothers regarding the impact of oral health on the adolescents' quality of life. The sample consisted of 960 pairs of adolescents aged 11 to 14 years and their mothers. The Brazilian version of the Parental-Caregiver Perceptions Questionnaire (P-CPQ) and the short form of the Child Perceptions Questionnaire (CPQ11-14) were administered. Agreement on the total scale and the subscales was determined through a comparison of mean values. The means of the directional and absolute differences were also determined. Agreement on each item on the group level and in the individual pairs was analyzed using the Intraclass Correlation Coefficient (ICC). The difference between the means and the directional differences were significant for the total score as well as for the functional limitation and social well-being subscales (p < 0.001). The ICC for the total P-CPQ and CPQ11-14 scores was 0.43. The ICC indicated weak agreement on the subscales, ranging from 0.36 to 0.40. Agreement between reports by adolescents and their mothers regarding oral health-related quality of life (OHRQoL) was moderate, indicating that both perspectives should be considered. <![CDATA[<b>Risk factors associated with facial fractures</b>]]> The aim of the present study was to identify risk factors for facial fractures in patients treated in the emergency department of a hospital. The medical charts of 1121 patients treated in an emergency ward over a three-year period were analyzed. The independent variables were gender, age, place of residence (urban or rural area) and type of accident. The dependent variables were fractured mandible, zygoma, maxilla, nasal bone and more than one fractured facial bone. Statistical analysis was performed using the chi-square test (a < 0.05), univariate and multivariate Poisson distributions and the logistic regression analysis (p < 0.20). Maxillofacial trauma was recorded in 790 charts (70.5%), with 393 (35.1%) charts reporting facial fractures. Motorcycle accidents were found to be the main risk factor for mandibular fractures (PR = 1.576, CI = 1.402-1.772) and simultaneous fractures of more than one facial bone (OR = 4.625, CI = 1.888-11.329) as well as the only risk factor for maxillary bone fractures (OR = 11.032, CI = 5.294-22.989). Fractures of the zygomatic and nasal bones were mainly associated with accidents involving animals (PR = 1.206, CI = 1.104-1.317) and sports (OR = 8.710, CI = 4.006-18.936), respectively. The determinant for the majority of facial fractures was motorcycle accidents, followed by accidents involving animals and sports. <![CDATA[<b>The antimicrobial effect of 0.1 ppm ozonated water on 24-hour plaque microorganisms <i>in situ</i></b>]]> Ozone is a known oxidant present in the atmosphere and is commercially produced by simple ozonizer machines. It is a powerful antimicrobial agent in its gaseous and aqueous forms. Ozone readily dissolves in water and retains its antimicrobial property even in the dissolved state. In this study, the effect of 0.1 ppm ozonated water was analyzed on 24-hour supragingival plaque (SP) samples in situ. SP was collected from the two most posterior teeth in the contra-lateral quadrants before and after a 30-second rinse with either distilled water (control group) or 0.1 ppm ozonated water (test group). The plaque was used to count the number of total bacteria, total anaerobic bacteria, Streptococcus mutans, and Candida albicans on selective agar media. The statistical analysis of the number of colony forming units (CFUs) obtained demonstrated a significant antimicrobial effect of ozonated water on the total bacteria (p = 0.01) and anaerobes (p = 0.02). A reduction in the post-rinse CFU count for Streptococcus mutans was also observed, but the effect was not statistically significant (p = 0.07). The Candida species was only grown from one sample. Ozonated water at the 0.1 ppm concentration was effective in reducing the load of 24-hour plaque bacteria, but it did not eliminate them completely. <![CDATA[<b>Urban-rural differences in oral and maxillofacial trauma</b>]]> The aim of this research was to assess oral and maxillofacial trauma in urban and rural populations of the same region. The data collected included age, gender, year and month of trauma occurrence, origin (rural and urban), cause of injury, and the type of oral and maxillofacial trauma. Records from 1121 patients with 790 instances of oral and maxillofacial trauma were evaluated. Statistical analysis was performed with the Statistical Package for Social Sciences (SPSS) version 17.0 software and involved descriptive statistics and Pearson's chi-squared test. Male patients were more prone to maxillofacial trauma (n = 537; 68%), and the patients were mostly from urban areas (n = 534; 67.6%). The male-to-female ratio was found to be 2.12:1 (urban zone, 1.72:1; rural zone, 3.49:1). The average age was 25.7 years (SD = 14.1). A traffic accident was the most common cause of oral and maxillofacial trauma (27%). The jaw (18%) was the most commonly fractured bone in the facial skeleton, followed by the zygoma (12.9%). Avulsion (8.5%) was the most common dental trauma. A significant statistical relationship was found between place of origin and gender (p < 0.001). Accidents involving animals were more frequent in rural areas (P < 0.001). Zygomatic fractures (p < 0.001), contusion (p = 0.003), and abrasion (p = 0.051) were the most common injuries among individuals from rural areas. Nasal fracture (p = 0.011) was the most frequent type of trauma in individuals from urban areas. According to these data, it seems reasonable to assume that specific preventive public policy for urban and rural areas must respect the differences of each region. <![CDATA[<b>Dental pulp stem cells express proteins involved in the local invasiveness of odontogenic myxoma</b>]]> Little is known about the histogenesis of the odontogenic myxoma (OM). Dental pulp stem cells could be candidate precursors of OM because both OM and the dental pulp share the same embryological origin: the dental papilla. For the purpose of comparing OM and stem cells, this study analyzed the expression of two proteins related to OM invasiveness (MMP-2 and hyaluronic acid) in human immature dental pulp stem cells (hIDPSCs). Three lineages of hIDPSCs from deciduous and permanent teeth were used in this study. Immunofluorescence revealed positive reactions for MMP-2 and hyaluronic acid (HA) in all hIDPSCs. MMP-2 appeared as dots throughout the cytoplasm, whereas HA appeared either as diffuse and irregular dots or as short fibrils throughout the cytoplasm and outside the cell bodies. The gene expression profile of each cell lineage was evaluated using RT-PCR analysis, and HA was expressed more intensively than MMP-2. HA expression was similar among the three hIDPSCs lineages, whereas MMP-2 expression was higher in DL-1 than in the other cell lines. The expression of proteins related to OM invasiveness in hIDPSCs could indicate that OM originates from dental pulp stem cells. <![CDATA[<b>Skeletal maturation of the cervical vertebrae</b>: <b>association with various types of malocclusion</b>]]> The identification of the skeletal maturation stage of the cervical vertebrae has proven an important reference for orthodontic diagnosis. The aim of the present study was to determine the association between the skeletal maturation stage of the cervical vertebrae and types of malocclusion according to the age and gender of participants. A total of 361 individuals (168 males and 193 females) between 8 and 14 years of age were selected from a convenience sample. Malocclusions were diagnosed through study models using the Angle classification. Maturation stages of the cervical vertebrae were determined using the method proposed by Hassel and Farman. Statistical analysis involved the chi-square test (p £ 0.05) and multiple logistic regression (forward stepwise procedure). Significant differences were observed between the stage of skeletal maturation of the cervical vertebrae and gender at ages 11, 12 and 14 years. Males with Class II malocclusion were twice as likely to be in Stage 1 or 2 of cervical vertebra maturation than individuals with Class I malocclusion (OR = 2.1 [CI 95%, 1.33-3.18]). There were no differences between individuals with Class I and Class III malocclusions. The association between skeletal maturation of the cervical vertebrae and type of malocclusion was significant, suggesting a skeletal component in the determination of Class II malocclusions. <![CDATA[<b>Parental beliefs about children's teething in Udaipur, India</b>: <b>a preliminary study</b>]]> Throughout history, teething has been held responsible for a variety of childhood illnesses. The objective of this study was to assess parents' knowledge and beliefs about teething signs and symptoms and to investigate the practices used to alleviate teething troubles. A cross-sectional survey was conducted using a self-administered questionnaire distributed to 550 parents in Udaipur, India. The questionnaire contained three sections eliciting demographic characteristics and assessing parents' knowledge, beliefs, and practices regarding teething. Statistical analysis used descriptive statistics and the chi-squared test (p £ 0.05). Response to teething was incorrectly attributed to fever (70%), diarrhea (87.5%), and sleep disturbances (48.2%). Only 33.2% of parents allowed their children to bite on chilled objects to relieve symptoms associated with teething. A common lack of knowledge about teething among parents should encourage dental healthcare providers to educate them regarding the teething process and its management. <![CDATA[<b>Evaluation of the effect of an organic extract obtained from <i>Ipomoea alba</i> L. on experimental periodontitis in rats</b>]]> The aim of this study was to evaluate the effect of an organic extract obtained from Ipomoea alba L. (Convolvulaceae or OE 1493), on experimental periodontal disease in rats. Periodontitis was induced in thirty six Wistar rats: a first mandibular molar was randomly assigned to receive a ligature, whereas the contralateral molar was left unligated. Animals were randomly assigned to two groups and treated topically, three times a day, for 11 days, as follows: Control Group - vehicle-treated (n = 18), and Test Group - OE 1493-treated (n = 18). The rats were sacrificed on the 12th day. Morphometrical measurements from the cementoenamel junction to the bone crest were performed to determine alveolar bone loss, using standardized photographs. Single- and multi-dose acute toxicity assays were carried out after OE 1493 treatment. Morphometrical analysis demonstrated that topically-administered OE 1493 showed no effect on reducing bone loss when compared with the control group (p > 0.05). In addition, OE 1493 did not present toxicity. Within the limits of this investigation, it may be concluded that OE 1493 did not show any positive influence on the progression of ligature-induced periodontitis in rats, when administered according to the regimen used in the present study. <![CDATA[<b>Influence of different shades and LED irradiance on the degree of conversion of composite resins</b>]]> The aim of this study was to evaluate the degree of conversion (DC) of two composite resins with different shades that were light cured by light-emitting diodes (LEDs) of different irradiances. Specimens (5 mm ' 2 mm) were prepared with a nanofilled (Filtek Supreme - A2E, A2D, and WE) or microhybrid resin (Opallis - A2E, A2D, and EBleach Low) and were randomly divided into 12 groups (n = 5 each) according to the composite resin and light-curing unit (Elipar FreeLight 2, 1250 mW/cm²; Ultralume 5, 850 mW/cm²). After 24 h, the DC was measured on two surfaces (top and bottom) with Fourier Transform infrared spectroscopy (FTIR). Data were statistically analyzed with two-way ANOVA and Tukey test (a = 0.05). Statistical differences among the surfaces were observed in all experimental conditions, with higher values on the top surface. The microhybrid resin presented the highest DCs for shades A2E and A2D on the top surface. The LED with higher irradiance promoted better DCs. Taken together, the data indicate that the shade of a composite resin and the irradiance of the light source affect the monomeric conversion of the restorative material. <![CDATA[<b>Effect of pre-heated dual-cured resin cements on the bond strength of indirect restorations to dentin</b>]]> This study evaluated the effects of resin luting agents (LA) polymerized using increased temperature on the in vitro microtensile bond strength (mTBS) of indirect restorations to dentin. The occlusal dentin surfaces of 40 human third molars were exposed and flattened. The teeth were assigned to 8 groups (n = 5) according to the LA temperature (25°C o r 50°C), curing mode (dual- or self-curing mode), and product (Excite DSC/Variolink II [VII] and XP Bond/Calibra [Cal]). The bonding agents were applied to the dentin surfaces according to manufacturers' instructions. For preheated groups, the LAs were heated to 50°C, subsequently mixed on a heated stirrer surface, and applied to the previously heated pre-polymerized resin discs (2 mm thickness, TPH-Spectrum). The discs were bonded to the dentin surfaces, and the LAs were either exposed to a curing light according to manufacturers' instructions or allowed to self-cure. Specimens were stored in relative humidity at 37°C for 7 days. Specimens were mesio-distally and bucco-lingually sectioned to obtain multiple bonded beams with a 1-mm² cross-sectional area for mTBS testing. Data (MPa) were analyzed by 2-way ANOVA and Tukey's post hoc test (a = 5%) for each product. Specimen failure patterns were analyzed using a scanning electron microscope. VII groups showed higher mTBS at 50°C than at 25°C regardless of curing mode (p = 0.05). Cal groups showed similar mTBS at 25°C and 50°C in all activation modes. The use of some dual-polymerizing LAs at 50°C may improve the mTBS of indirect restorations to dentin. <![CDATA[<b>Effectiveness of immediate bonding of etch-and-rinse adhesives to simplified ethanol-saturated dentin</b>]]> This study examined the immediate bond strength of etch-and-rinse adhesives to demineralized dentin saturated with either water or absolute ethanol. The research hypothesis was that there would be no difference in bond strength to dentin between water or ethanol wet-bonding techniques. The medium dentin of 20 third molars was exposed (n = 5). The dentin surface was then acid-etched, left moist and randomly assigned to be saturated via either water wet-bonding (WBT) or absolute ethanol wet-bonding (EBT). The specimens were then treated with one of the following etch-and-rinse adhesive systems: a 3-step, water-based system (Adper Scotchbond Multipurpose, or SBMP) or a 2-step, ethanol/water-based system (Adper Single Bond 2, or SB). Resin composite build-ups were then incrementally constructed. After water storage for 24 h at 37°C, the tensile strength of the specimens was tested in a universal testing machine (0.5 mm/min). Data were analyzed by two-way ANOVA and Tukey's test (a = 5%). The failure modes were verified using a stereomicroscope (40'). For both adhesives, no significant difference in bond strength was observed between WBT and EBT (p &gt; 0.05). The highest bond strength was observed for SB, regardless of the bonding technique (p < 0.05). No significant interaction between adhesives and bonding techniques was noticed (p = 0.597). There was a predominance of adhesive failures for all tested groups. The EBT and WBT displayed similar immediate bond strength means for both adhesives. The SB adhesive exhibited higher means for all conditions tested. Further investigations are needed to evaluate long-term bonding to dentin mediated by commercial etch-and-rinse adhesives using the EBT approach.