Scielo RSS <![CDATA[Brazilian Oral Research]]> vol. 29 num. 1 lang. en <![CDATA[SciELO Logo]]> <![CDATA[Preference for using posts to restore endodontically treated teeth: findings from a survey with dentists]]> The aim of this study was to evaluate if clinical experience, whether in relation to length of practice time and/or level of specialization influences the dentist’s preference for using posts to restore endodontically treated teeth. A cross sectional study was carried out using a questionnaire with dentists (n = 276) in Pelotas, southern Brazil. Data were collected regarding clinical experience, post-graduate training, and variables related to restorations (posts/cements and use of rubber dam) for endodontically treated teeth. The data were submitted to a descriptive analysis and associations were tested. The response rate was 68%. Cast metal posts (24.53%), glass fiber posts (20.75%) and resin cement (66.67%) were the most commonly selected materials. In relation to rubber dams, 93.05% of the dentists were found not use them to lute posts. There was a significant association between the level of training of post-graduate dentists and the type of post used (p = 0.027), in that dentists without post-graduate training used cast metal posts more frequently, whereas dentists with post-graduate training reported glass fiber posts as their first choice. The results of the study showed that dentists preferred cast metal posts, glass fiber posts and resin cement. Continuing education influenced the decision of the dentists on their choice of dental posts. <![CDATA[Assessment of apically extruded debris and irrigant produced by different nickel-titanium instrument systems]]> The aim of this study was to evaluate the preparation time and the amounts of apically extruded debris and irrigant using different nickel-titanium instrumentation systems. Forty-five extracted single-rooted mandibular premolar teeth were selected and divided into three groups. The root canals were instrumented according to the manufacturers’ instructions, using a reciprocating single-file system, a single-file rotary system and a multiple-file rotary system. Bidistilled water was used as the irrigant solution. The apically extruded debris and irrigant were collected into preweighed Eppendorf tubes. The amounts of extruded debris and irrigant were assessed with a precision micro-balance. The Eppendorf tubes were incubated at 37°C for 15 days. After the incubation period, they were weighed again to assess the debris extrusion. The time required to prepare the canals was also recorded. The results were statistically analyzed using MANOVA and Bonferroni’s adjustment. Considering the apically extruded debris and irrigant, there were no statistically significant differences among the groups (p &gt; 0.05). The Reciproc group produced the highest debris (0.000632 ± 0.000162 gr) and irrigant (0.844587 ± 0.437814 ml) extrusion values. While the least extruded debris was observed with OneShape (0,000431 ± 0,000171 gr), the least extruded irrigant was observed with ProTaper system (0.564147 ± 0.370596 ml). Instrumentation was faster using the Reciproc than the other two instruments (70.27 ± 13.38 s) (p &lt; 0.05). All of the instrumentation systems used in this study produced apical debris and irrigant extrusion. The reciprocating single-file system tended to produce more debris and irrigant extrusion, compared with the rotary systems. Considering the preparation time, the single-file systems appeared to be advantageous due to their working time. <![CDATA[Diode laser irradiation increases microtensile bond strength of dentin]]> Laser irradiation after the immediate application of dentin bonding systems (DBSs) and prior to their polymerization has been proposed to increase bond strength. The objective of this study was to evaluate the effect of diode laser irradiation (λ = 970 nm) on simplified DBSs through microtensile bond strength tests. Forty healthy human molars were randomly distributed among four groups (n = 10) according to DBSs used [Adper™ SingleBond 2 (SB) and Adper™ EasyOne (EO)], and the respective groups were irradiated with a diode laser (SB-L and EO-L). After bonding procedures and composite resin build-ups, teeth were stored in deionized water for 7 days and then sectioned to obtain stick-shaped specimens (1.0 mm2). The microtensile test was performed at 0.5 mm/min, yielding bond strength values in MPa, which were evaluated by two-way ANOVA followed by Tukey’s test (p &lt; 0.05) for individual comparisons. For both adhesive systems, diode laser irradiation promoted significant increases in bond strength values (SB: 33.49 ± 6.77; SB-L: 43.69 ± 8.15; EO: 19.67 ± 5.86; EO-L: 29.87 ± 6.98). These results suggest that diode laser irradiation is a promising technique for achieving better performance of adhesive systems on dentin. <![CDATA[Antimicrobial activity of different filling pastes for deciduous tooth treatment]]> Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC) was employed as the gold standard (G1). The other associations were: Iodoform, Nebacetin® ointment and CPC (G2); Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3); Iodoform, Maxitrol® ointment and CPC (G4). The associations were tested for Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Bacillus subtilis (B. subtilis), using the methods of dilution on solid medium – orifice agar – and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey), insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth. <![CDATA[CT study of the performance of reciprocating and oscillatory motions in flattened root canal areas]]> Root canal preparation is an important step in endodontic treatment. The anatomical complexity of the middle third of the root compromises the effective cleaning of this area. Thus, advances have been made in instrumentation techniques and instruments for this purpose. The aim of this study was to evaluate the effects of three different instrumentation systems on the enlargement of the middle thirds of root canals in mandibular incisors. The preparation methods used were the reciprocating systems Reciproc (Group I) and WaveOne (Group II) and the oscillatory system Tilos (Group III). Comparisons were made by three-dimensional image reconstruction with cone-beam computed tomography before and after instrumentation. Changes in area, perimeter, centering ability, and pattern of preparation were analyzed. The results were subjected to ANOVA complemented by the Tukey’s test. Changes in area, perimeter, and tendency of transportation showed similar results among groups. The transportation index of the Tilos system was significantly lower than that of the other groups. Qualitative analysis of the preparation pattern showed that the Tilos system had a more uniform preparation, although Reciproc and WaveOne preparations appeared more rounded, incompatible with the original canal anatomy. There was similarity in the systems’ performance on flattened areas, although the Tilos system presented a better pattern of root canal preparation and a lower index of transportation. <![CDATA[Effectiveness of rotatory and reciprocating movements in root canal filling material removal]]> The purpose of this study was to compare the efficacy of reciprocating and rotary techniques for removing gutta-percha and sealer from root canals. Forty straight and oval single-rooted premolars were prepared up to size 30, filled with gutta-percha and sealer, and then randomly allocated to two experimental retreatment groups: ProTaper Retreatment System (PTRS) and WaveOne System (WS). Procedural errors, time of retreatment and apically extruded material were recorded for all the roots. The roots were radiographed after retreatment. The percentage of residual material was calculated using image analysis software. The data were analyzed by Kolmogorov-Smirnov and t tests, with a significance level set at 5%. No system completely removed the root filling material from the root canal. No significant differences were observed between the systems, in terms of residual filling material in any tested third (p &gt; 0.05). WS was faster in removing filling material than PTRS (p &lt; 0.05). Extrusion was observed in 4 cases in PTRS and in 5 cases in WS. No procedural errors were observed in either group. It can be concluded that although no differences were observed in the efficacy of PTRS and WS for removing root filling material, WS was faster than PTRS. <![CDATA[Factors associated with bruxism in children with developmental disabilities]]> The aim of the present study was to investigate factors associated with bruxism in children aged from 1 to 13 years with developmental disabilities. A total of 389 dental records were examined. The bruxism analyzed was determined based on parental reports. The following variables were also analyzed: gender, age, International Code of Diseases (ICD), mouth breathing, history of gastroesophageal reflux, use of psychotropic drugs, gingival status, reports of xerostomia, hyperkinesis, pacifier use, thumb sucking and involuntary movements. For the purposes of analysis, the individuals were categorized as being with and without bruxism. Variables with a p-value &lt; 0.25 in the bivariate analysis were incorporated into the logistic regression models. Females had a 0.44-fold (95%CI: 0.25 to 0.78) greater chance of exhibiting bruxism than males. Individuals with gastroesophageal reflux had a 2.28-fold (95%CI: 1.03 to 5.02) greater chance of exhibiting bruxism. Individuals with reported involuntary movements had a 2.24-fold (95%CI: 1.19 to 4.24) greater chance of exhibiting bruxism than those without such movements. Exhibiting involuntary movements, the male gender and gastroesophageal reflux are factors associated with bruxism in children with developmental disabilities. <![CDATA[Surface roughness and wear of resin cements after toothbrush abrasion]]> Increased surface roughness and wear of resin cements may cause failure of indirect restorations. The aim of this study was to evaluate quantitatively the surface roughness change and the vertical wear of four resin cements subjected to mechanical toothbrushing abrasion. Ten rectangular specimens (15 × 5 × 4 mm) were fabricated according to manufacturer instructions for each group (n = 10): Nexus 3, Kerr (NX3); RelyX ARC, 3M ESPE (ARC); RelyX U100, 3M ESPE (U100); and Variolink II, Ivoclar/Vivadent (VL2). Initial roughness (Ra, µm) was obtained through 5 readings with a roughness meter. Specimens were then subjected to toothbrushing abrasion (100,000 cycles), and further evaluation was conducted for final roughness. Vertical wear (µm) was quantified by 3 readings of the real profile between control and brushed surfaces. Data were subjected to analysis of variance, followed by Tukey’s test (p &lt; 0.05). The Pearson correlation test was performed between the surface roughness change and wear (p &lt; 0.05). The mean values of initial/final roughness (Ra, µm)/wear (µm) were as follows: NX3 (0.078/0.127/23.175); ARC (0.086/0.246/20.263); U100 (0.296/0.589/16.952); and VL2 (0.313/0.512/22.876). Toothbrushing abrasion increased surface roughness and wear of all resin cements tested, although no correlation was found between those variables. Vertical wear was similar among groups; however, it was considered high and may lead to gap formation in indirect restorations. <![CDATA[Morphometric evaluation and planning of anticurvature filing in roots of maxillary and mandibular molars]]> This study aimed to guide the planning of anticurvature filing using pre-determined anatomical points on teeth to establish directions for proper implementation of the technique. Two hundred digital periapical radiographs of human molar teeth were selected and divided into two groups (n = 100): MX (maxillary) and MD (mandibular) molars. Mesiobuccal roots were considered for the MX group and mesial roots for the MD group. Pre-determined anatomical points required for planning the anticurvature filing on the root canal path were located, and the distances between these points obtained. The anticurvature filing was simulated in two different protocols for each group, and the region of dentin removal and the remaining dentin thickness were measured in the safety and danger zones of the root canals. Statistical analysis was carried out at a significance level of 5%. The distances between the anatomical points and the thickness of remaining dentin showed significant differences when the two groups were compared (p &lt; 0.001). No significant differences were found between the two experimental groups regarding the area of dentin removal at the root region, but differences were detected in comparison with dentin removal at the crown (p &lt; 0.001). In terms of wear produced after simulation of both anticurvature filing protocols, significant differences were verified for all regions, except for the dentin remaining at the danger zone. The radiographic location of anatomical points allows for planning and implementation of controlled and efficient anticurvature filing and can be performed in the same manner for maxillary and mandibular molars. <![CDATA[Praxis teaching in the ambit of learning assessment of endodontics in a Chilean university]]> The practice of assessing must ensure that the outcome of the process be a reflection of the learning achieved by students. The aim of this study was to describe the essential attributes of the praxis teacher in the area of Endodontics Learning Evaluation, in the School of Dentistry at the Universidad de Concepción, Chile. This study is designed to diagnose the reliability and objectivity of assessing the learning process, as a framework for innovation, and with a focus on evaluating endodontics skills. This hermeneutic study has a qualitative methodology. It was based on in-depth semi-structured interviews applied to 14 students and 5 teachers, and two focus groups consisting of eight students each. When the study was conducted, the research findings indicated that the evaluation process was not objective and lacked established criteria, and especially a guide to determining the skills. The theoretical evaluation was only summative. The formative role was not formally established. The subjects answered mostly psychometric instruments by multiple choice and with short or extended answers. It was concluded that teacher practice held meaning only if it was backed by academic expertise in the area of endodontics, according to no clear criteria or validated instruments. On the other hand, the groundwork was in place for using an epistemological style in endodontics. This provided a basis for the actual improvements, and allowed the tools developed to be dialectically interconnected with teacher experience. A quantitative analysis was not considered, but could be supplemented later to enhance the data analysis in a future study. <![CDATA[Pacifier-sucking habit duration and frequency on occlusal and myofunctional alterations in preschool children]]> The objective of this study was to evaluate the association of pacifier-sucking habit with occlusal and oral myofunctional alterations in preschool children. Eighty-four 2- to 5-year-old children participated in the study. Data on duration and frequency of pacifier use were collected from parents or guardians. Occlusal and oral myofunctional characteristics were examined by a dentist and a speech therapist, respectively. Chi-square tests and Poisson regression were used to analyze the data. The occlusal characteristics that were significantly associated with a pacifier-sucking habit were anterior open bite, altered canine relation, posterior crossbite, increased overjet, and malocclusion. The oral myofunctional characteristics that were significantly associated with a pacifier-sucking habit were resting lip position, resting tongue position, shape of the hard palate, and swallowing pattern. The strongest associations were for anterior open bite (prevalence ratio [PR] = 11.33), malocclusion (PR = 2.33), altered shape of the hard palate (PR = 1.29), and altered swallowing pattern (PR = 1.27). Both duration and frequency of pacifier-sucking habit were associated with occlusal and oral myofunctional alterations. These results emphasize the need for pediatric dentists to advise parents and caregivers about the risks of prolonged pacifier use and refer children to professionals for multidisciplinary assistance to minimize these risks whenever necessary. <![CDATA[Influence of clinical and socioeconomic indicators on dental trauma in preschool children]]> The aim of the present study was to determine the prevalence of traumatic dental injury (TDI) in the primary dentition and investigate associations with clinical and socioeconomic indicators. A population-based, cross-sectional study was carried out with a randomly selected sample of 301 children aged one to five years. Data were collected through clinical oral examinations and interviews with parents/guardians during immunization campaigns. Statistical analysis involved Pearson’s Chi-squared test and Poisson regression with robust variance. The prevalence of TDI was 33.9%. TDI was more prevalent in children with overjet &gt; 3 mm (p &lt; 0.001) and those with inadequate lip coverage (p &lt; 0.001). A statistically significant association was also found between TDI and household income (p = 0.024). According to the adjusted Poisson regression model, greater prevalence rates of TDI were found for children from families with a monthly income ≥ twice the Brazilian minimum monthly wage (PR: 1.52; 95%CI: 1.10-2.12), those with accentuated overjet (PR: 1.53; 95%CI: 1.05-2.22) and those with inadequate lip coverage (PR: 2.00; 95%CI: 1.41-2.84). The prevalence of TDI was high in the present study and was associated with a higher family income, accentuated overjet and inadequate lip coverage. <![CDATA[Penetration of a resin-based filling material into lateral root canals and quality of obturation by different techniques]]> The aim of this study was to evaluate the penetration of a resin/polyester polymer-based material (Resilon Real Seal; SybronEndo Corp., Orange, USA) into simulated lateral canals, and the quality of obturations by different techniques. A total of 30 standardized simulated canals were divided into three groups according to the technique of obturation used: MS (McSpadden), SB (SystemB/Obtura II), and LC (Lateral Condensation). To analyze the penetration of the filling material, the simulated canals were digitalized and the images were analyzed using the Leica QWIN Pro v2.3 software. The data of the middle and apical thirds were separately submitted to analysis of variance (ANOVA), followed by the Tukey’s test for the comparison of the techniques. Results showed a significant difference (p &lt; 0.05) between groups (LC &lt; SB) in the middle third, and a significant difference (p &lt; 0.05) between groups (LC &lt; SB and MS &lt; SB) in the apical third. To analyze the quality of the obturations, the canals were radiographed and evaluated by three examiners. The Kappa test on interexaminer agreement and the nonparametric Kruskal-Wallis test indicated no significant difference between filling techniques. It was concluded that Resilon achieves greater levels of penetration when associated with thermoplastic obturation techniques.