Resumo em Inglês:

Aim: To evaluate the foraminal transportation during foraminal enlargement after manual instrumentation with stainless steel files, preparation with the Mtwo system and Reciproc R25 file. Methods: Thirty roots were selected, divided in three groups and prepared in accordance with the different instrumentation systems: Hand Files (HF); Mtwo system (MS); and Reciproc system (RS). All groups were prepared with the instrumentation level 1 mm beyond the apex. Photomicrographs were performed using scanning electron microscopy, to record the foraminal anatomy before and after instrumentation. Data were analyzed using ANOVA followed by Tukey's test with a significance level of 5%. Results: The group instrumented with hand files showed higher foraminal transportation when compared to the Mtwo and Reciproc groups (p<0.05). Reciproc group showed lower transportation when compared to the Mtwo group (p<0.05). Conclusions: The stainless steel files caused significant foraminal transportation, while Reciproc system showed safe apical preparation, with little transportation.

Resumo em Inglês:

Aim: To compare 2 types of treatment for Class II malocclusion assessing mandibular behavior in subjects submitted to full orthodontic treatment with standard edgewise appliance and cervical headgear (Kloehn appliance) and those who used cervical headgear in the first period and with full orthodontic appliance in the second period. Methods: The sample consisted of 80 children treated with either cervical headgear combined with full fixed appliances (n=40, group 1), or with cervical headgear at first (n=40, group 2). In both groups, lateral cephalometric radiographs were compared with those made at the beginning of treatment, at its end and at 5-year post-retention phase, in order to quantify the cephalometric measures (8 angular and 3 linear), presenting the mandibular behavior in the antero-posterior and vertical directions. All patients were treated with no extraction and no use of Class II intermaxillary elastics during the full orthodontic treatment. Results: In both groups, the effective treatment of skeletal Class II malocclusion did not interfere in the direction and amount of growth of mandibular condyles and remodeling at the lower border, with no influence on the anti-clockwise rotation of the mandible. The mandibular growth also was observed after the orthodontic treatment, suggesting that it is influenced by genetic factors. Conclusions: These observations may lead to the speculation that growing patients with skeletal Class II malocclusion and low mandibular plane are conducive to a good treatment and long-term stability with one or two periods of treatment.

Resumo em Inglês:

Elderly patients generally use several types of medication, some of which may cause oral side effects. Aim: To investigate the oral side effects caused by medication in an elderly sample. Methods: Three hundred patients were interviewed about their use of medication and were divided in two groups: institutionalized (n=150) and community-dwelling (n=150) elderly. Results: The most used drugs were antihypertensives (53%) for community-dwelling elders and antiulceratives (76%) for the institutionalized ones. The more prevalent side effects were taste alterations that occurred in 19%, dry mouth in 17% and teeth staining in 2%. Conclusions: A high prevalence of oral side effects from medications used by the elderly was found in this study. The health professionals should be aware of the possible side effects caused by prescribed medications.

Resumo em Inglês:

Aim: To evaluate the long-term bond strength, degree of conversion and resistance to degradation in ethanol of HEMA-containing and HEMA-free model adhesive resins of a three-step etch-and-rinse adhesive system. Methods: The superficial dentin of 16 bovine incisor teeth was exposed, and the teeth were divided in two groups according to the HEMA concentration in the experimental adhesive (0% and 15%). In each tooth were made 6 cylindrical composite restorations. Half of the tooth restorations were submitted to microshear bond strength test after 24 h and the other half after 6 months. Degree of conversion of experimental resins was determined by Fourier transform infrared spectroscopy. Crosslink density was indirectly determined by the Knoop hardness of five specimens per group before and after immersion in ethanol for 6 h. Results: The group with 0% HEMA showed no difference in bond strength as compared to the group with 15% HEMA after 24 h or 6 months. There was no difference in degree of conversion and crosslink density between groups. Conclusions: HEMA content of the adhesive resin did not influence the bond strength to dentin, degree of conversion or resistance to degradation in ethanol.

Resumo em Inglês:

Aim: To evaluate the force decay of orthodontic elastomeric chains after immersion in disinfecting solutions. Methods: One-hundred and fifty segments of elastomeric chains were divided in 3 groups: Control group - no disinfection; Chlorhexidine group - disinfection in 0.12% chlorhexidine digluconate solution; and Peracetic acid group - disinfection in 0.2% peracetic acid solution. Elastomeric chains of 14 mm were stretched up to 20 mm and the given force (kgf) was evaluated in an Instron universal testing machine at the following intervals: 1 h, 1 day, 7, 14, 21 and 28 days after the immersion in the disinfecting solutions. Data (kgf) were analyzed statistically by Analysis of Variance and Tukey's test at a 5% significance level. Results: Both groups presented similar force decay along 7 days and remained stable up to 28 days. Force degradation was observed in the first hours of activation (~50%). Conclusions: It may be concluded that there were no significant differences among the investigated groups, in most interval times, indicating that both chemical solutions can be used for previous disinfection of orthodontic elastomeric chains.

Resumo em Inglês:

Aim: To evaluate the effect of different enamel conditionings on the shear bond strength (SBS) and bond failure patterns of a resin modified glass ionomer cement (RMGIC) used to bond ceramic brackets. Methods: 105 human premolars extracted for orthodontic reasons were divided into 7 groups according to the enamel surface treatments: conditioners (35% phosphoric acid and 10% polyacrylic acid), type of adhesive (Transbond(r) and Fuji Ortho LC Capsule(r)), washing time and drying of the surface. Results: A significant p<0.05 was observed among the shear bond strength values obtained with seven different types of enamel preparation prior to bonding. The group that had the tooth surface conditioned with polyacrylic acid and enamel surface slightly dried before bracket placement showed no significant difference (p>0.05) to the group that had brackets bonded with composite resin. The two groups that had enamel prepared with polyacrylic acid and brackets bonded with GIC on a wet surface showed significantly lower shear bond strength than the control group (p<0.05). Conclusions: Moisture contamination decreased SBS, but not enough to preclude the use of RMGIC as an alternative to composite resin (CR) for direct bonding of ceramic brackets.

Resumo em Inglês:

Aim: To evaluate the prevalence of intraoperative accidents associated with extraction of third molars and identify possible risk factors. Methods: Prospective study with patients undergoing third molar surgery by residents of the Oral and Maxillofacial Surgery Service at the Federal University of Parana. Epidemiological data were collected from preoperative evaluation forms. During the surgical procedure were evaluated the radiographic position classifications of all third molars removed, using methods such as osteotomy and/or tooth section, time for the procedure and occurrence of any complication. Results: The students extracted a total of 323 teeth. The mean surgical time was 45 min. Conclusions: The prevalence of intraoperative accidents during extraction of third molars was 6.19%. The most prevalent accident was maxillary tuberosity fracture, followed by hemorrhage. Age, positioning of the teeth and use of the techniques of osteotomy and tooth section are possible risk factors.

Resumo em Inglês:

Aim: To investigate the prevalence of temporomandibular disorders (TMD) in undergraduate students and to correlate its prevalence with occlusal factors and parafunctional habits. Methods: 201 undergraduate students were evaluated. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) was filled out at the beginning of the study, followed by occlusal analysis based on morphological and functional alterations. The identification of tooth grinding and clenching was carried out by self-reports. Statistical analysis was based on chi-square and multivariate logistic regression analyses. p-value for all statistical analysis was set at 5%. Results: According to RDC/TMD, 18.4% of subjects experienced myofascial pain (G-MPD), and 12.4% had joint disorder with disc displacement (G-DD). Tooth clenching was statistically associated with TMD (p=0.000). In the occlusal factors, overjet showed statistically significant correlation only with myofascial pain. No association between functional alteration and TMD was found. No statistically significant correlation was found between G-DD and occlusal alterations or parafunctional habits. Conclusions: Overjet and tooth clenching were correlated with G-MPD. Occlusal alterations or parafunctional habits did not show correlation with G-DD.

Resumo em Inglês:

Aim: To evaluate prospectively the upper airway of 16 patients submitted to surgically assisted rapid maxillary expansion. Methods: Volumetric tomography acquisitions were done preoperatively (T1) and after six months postoperatively (T2), the slices were obtained from the hard palate to the third cervical vertebra (C3), the images were imported and reconstructed in the Dolphin software for 2D definition of the upper airway. A cephalometric radiograph was generated by the software, the cephalometric points were traced at T1 and T2 for all patients in a dark environment always by the same operator and the Arnett-Gunson FAB Surgery analysis was applied. Results: A statistically significant reduction in area (p=0.03) at the level of the nasopharynx was observed, while at the oropharynx and hypopharynx it showed no statistical difference between T1 and T2. Conclusions: The area in the nasopharynx level presented a statistically significant decrease, however, despite the area decrease at this point, the patients seem to do better, and thus, this area decrease may not be clinically significant.

Resumo em Inglês:

Aim: To evaluate of the effect of two different occlusal splints on police officers with TMD. Methods: Thirty police officers were selected based on Research Diagnostic Criteria for TMD and on clinical exams. Volunteers (ten per group) were distributed according to occlusal splints: group A - Control, group B - Michigan Occlusal Splint (MOS), and group C - Planas Appliance (PA). Experimental groups were analyzed using a visual analog pain scale (VAPS), subject to a clinical evaluation of temporomandibular joint. Bilateral surface electromyographic activities of anterior and posterior temporal, masseter and suprahyoid muscles were analyzed at rest and during clenching, before and after four weeks using the occlusal splints. Results: The left and right temporal and masseter muscles sensitivity decreased after using both splints. Pain symptoms increased for group A (Control) and decreased for group C. Conclusions: Planas Appliance was more efficient on pain reduction than the Michigan Occlusal Splint.

Resumo em Inglês:

Aim: To evaluate the reliability of linear measurements in virtual models by comparing measurements performed on virtual models obtained from alginate impression scans, plaster model and measurements performed on conventional plaster model. Methods: The sample comprised 26 randomly selected patients to have impressions of their upper and lower jaws taken using alginate and their bite registration using a wax bite. The virtual models were obtained by scanning the alginate impression and the plaster model in a laser surface scanner (R700; 3Shape, Copenhagen, Denmark), and the measurements were performed using the Ortho Analyser (3Shape) proprietary software. The linear measurements of the size of the teeth mesial to distal, arch perimeter, intercanine distance and intermolar distance in the upper and lower arches were performed on plaster models, digital impressions and digital models, by three observers and repeated after 15 days on 8 models for intra-observer evaluations. Data were tabulated and analyzed statistically. Intra-class correlation to check the agreement of intra and inter-observers and ANOVA test were used to analyze the differences between measurements of digital models from impression and digital models from plaster. Results: The results showed a statistically significant difference (pd"0.05) for the posterior teeth, anterior teeth, upper arch perimeter and lower inter-canine distance, comparing the digital models with plaster models, but these differences are considered clinically non-significant. Conclusions: Digital models were proven be reliable and clinically acceptable for measuring tooth width, perimeter arches, intercanine and intermolar distances.

Resumo em Inglês:

Aim: To evaluate the position, presence, appearance and extent of various anatomical landmarks in the mandibular interforaminal region of Brazilian patients using cone-beam computed tomography (CBCT). Methods: A total of 142 CBCT examinations were analyzed to determine the most common location of the mental foramen (MF), the presence and extent of the anterior loop (AL) of the inferior alveolar nerve, and the appearance and length of the incisive canal (IC). The presence of sexual dimorphism and differences with relation to the left and right sides were also evaluated. Results: Most of the MF (45.5%) was located below the second premolar. The AL and the IC were observed in 18.9 and 96.5% of the images respectively. The average length of AL and IC was 3.14±1.25 mm and 13.68±5.94 mm respectively. No significant differences (p>0.05) between genders or left and right sides were observed for all evaluated parameters. Conclusions: The most common location of the MF, the high rate of visualization of the IC and the occasional presence of AL in the studied Brazilian population demonstrate the importance of using three-dimensional images of the mandibular anterior region, allowing proper surgical planning and preventing injury to the neurovascular bundle.

Resumo em Inglês:

Aim: To evaluate, by confocal laser scanning microscopy (CLSM), the influence of 17% EDTA final irrigation on the penetration of an endodontic resin-based sealer into dentinal tubules after use of 2% chlorhexidine gel. Methods: Forty extracted bovine incisors were instrumented according to the groups: G1 - root canal preparation with 2% chlorhexidine gel (n=10); G2 - root canal preparation with 2% chlorhexidine gel and final irrigation with 17% EDTA (n=10); G3 - root canal preparation with saline and final irrigation with 17% EDTA (n=10); G4 - root canal preparation with saline (n=10). The samples were filled with gutta-percha using AH Plus sealer with rhodamine B fluorescent dye. After seven days, the teeth were sectioned at the coronal, middle, and apical thirds and viewed under confocal microscope. The most representative area of penetration depth was measured in each group. Statistical significance for the sealer penetration area was determined among groups using one-way ANOVA followed by Tuckey test. For thirds comparison, in each group, data were statistically analyzed using Friedman test (p<0.05). Results: The maximum penetration was provided by G2 - 2% chlorhexidine + EDTA (p=0.000). According to this criterion, no differences were found among the other groups and among thirds within the same group. Conclusions: Based on these results, the use of 17% EDTA should be indicated after root canal preparation with 2% chlorhexidine gel for smear layer removal, enhancing the AH Plus sealer penetration.

Resumo em Inglês:

Aim: To evaluate the cephalometric characteristics of Class III malocclusion in Caucasian Brazilian subjects. Methods: The sample comprised 71 lateral cephalograms of individuals not previously submitted to any orthodontic treatment. The Class III group (experimental group) comprised 37 patients with bilateral Class III molar relationship and ANB lower than 1 degree, with a mean age of 21.76+3.89 years (13 males and 24 females). The Class I group (control group) consisted of 34 patients with bilateral Class I molar relationship, ANB angle higher than or equal to 1° and lower than 3°, with a mean age of 21.88+3.5 years (12 males and 22 females). Dental, skeletal and soft tissue measurements were compared using the t test for independent samples. Results: The results demonstrated that the Class III individuals showed significant differences in the cephalometric characteristics, except in vertical skeletal variables. The angular variables (SNA, SNB, ANB, SND, 1.1, 1.NA, 1.NB, IMPA, NA.Pog, H.NB) and the linear variables (Pog-Nperp, Co-Gn, 1-orbit, 1-NA, 1-NB, 1-NPog, 1-ANperp, FN-Pog, H-nose, Pog-NB, E menton) demonstrated statistically significant differences between groups. Conclusions: In Class III group, subjects presented maxilla with normal size, yet retruded in relation to the anterior cranial base; protruded mandible with increased size; and concave skeletal and soft tissue profiles. The maxillary incisors were protruded and buccally tipped, and the mandibular incisors were retruded and lingually tipped. Higher prevalence of mandibular prognathism (67.6%) was observed in the Class III group.

Resumo em Inglês:

Aim: To evaluate the dental development of Brazilian children and adolescents with cleft lip and palate. Methods: The sample consisted of 107 panoramic radiographs of children and adolescents with cleft lip and/or palate (cleft group) and 107 panoramic radiographs of children and adolescents without cleft lip and/or palate (control group), with chronological ages ranging from 6 to 15 years, matched in gender and chronological age within 60 days. Radiographs were digitized and masked and dental age was assessed using the method described by Demirjian et al. (1973). Three trained examiners conducted the assessments. Each examiner evaluated the radiographs three times. Data were statistically analyzed using non-parametric tests and univariate linear regression (p<0.05). Results: The dental age was overestimated in relation to the chronological age in both groups (p<0.0001). Compared to the control group, there was a delay in the dental age in the cleft group of 0.17 years (2.1 months). However, no statistically significant difference in the dental age between the cleft and the control group was found even when considering the different cleft types (p=0.152). Conclusions: There was no statistically significant difference in the dental age between the cleft and the control groups. The evaluation of dental development in individuals with cleft lip and palate should be approached in the same way as in individuals without clefts, with a focus on the individualization of diagnosis and treatment planning.