Scielo RSS <![CDATA[Brazilian Journal of Oral Sciences]]> vol. 14 num. 4 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[Dentists' actions about oral health of individuals with Down Syndrome]]> Abstract Aim: To investigate the knowledge and actions of dentists for treatment of individuals with Down syndrome. Methods: A questionnaire was applied to all the dentists (n=90) working at the FHS (Family Health Strategy) modules in the urban limits of Parnaíba, PI, Brazil. Four of the questions in the questionnaire were written according to the Theory of Planned Behavior Table and Likert scale (questions 6,7,9 and 15), in order to analyze the professionals' intentions. Sixteen objective questions were elaborated with the purpose of collecting information about the degree of the dentists' knowledge as regards the intention of attending courses in the patients with special needs area including DS, and interaction with other professionals and families. The option was to use a questionnaire applied to the dentists of the region, from August to November 2014. Results: It was found that most professionals were women and they considered themselves able to identify these patients. Among the professionals, 70% showed they had no difficulty in identifying the patient with DS, and 5.2% had no opinion about the subject. Only 6.6% of the professionals showed to be certain about their aptitude to attend to these patients; 70% were partially apt, that is, they were not absolutely sure about their aptness. There was a statistical relationship between the variables understanding and difficulty in the treatment. There was no statistical relationship between the variable capacity to identify, understanding of the needs and fitness variable in attendance. Conclusions: Patients with Down syndrome need more attention and care of dentists, they must also be involved in a multidisciplinary approach. Most of the professionals do not follow the procedures laid down by the Ministry of Health, but showed interest in attending a course in this area and there is a low number of SD patients being cared in Parnaíba, PI. <![CDATA[Effect of bleaching agents containing fluoride or calcium on enamel microhardness, roughness and permeability]]> Abstract Aim: To evaluate the effect of different in-office bleaching agents on the permeability, roughness and surface microhardness of human enamel. Methods: For evaluation of roughness and microhardness, 40 hemi-faces of 20 premolars were subjected to initial roughness (Ra parameter) and microhardness (VHN) measurements. Thirty-two premolar's crowns were used for permeability test. Then, all specimens were randomly divided into four groups: C - without bleaching (control), HP35 - bleaching with 35% hydrogen peroxide (HP), HPF38 - 38% HP+fluoride, HPC35 - 35% HP+calcium. Final roughness (FR) and microhardness (FM) measurements were evaluated. For permeability, the 32 crowns were immersed in 1% sodium hypochlorite (20 min) and silver nitrate solutions (2 h) and subjected to developing solution under fluorescent light (16 h). Three sections from the crowns were analyzed in light microscope (100x) to evaluate the scores of permeability: Score 0 - no tracer agent penetration; Score 1 - less than half the thickness of enamel penetration; Score 2 - tracer agent reaching half the enamel thickness; Score 3 - entire enamel depth penetration, without reaching dentin and Score 4 - tracer agent reaching dentin. For roughness and microhardness evaluation were used one-way ANOVA and Dunnet post-test for independent samples, and t test for paired samples. For permeability, the data were analyzed by Kruskal Wallis and Dunn tests. Results: A significantly higher permeability and surface roughness were observed in groups HP35, HPF38 and HPC35 compared to the C group, as well as decreased microhardness (p&lt;0.05). Conclusions: All bleaching agents increased permeability and surface roughness, and decreased microhardness of human enamel; thus, the addition of fluoride or calcium was not beneficial. <![CDATA[Color stability and surface roughness of artificial teeth brushed with an experimental Ricinus communis toothpaste]]> Abstract Aim: To evaluate, in vitro, the effect of brushing with a Ricinus communis-based experimental toothpaste on color stability and surface roughness of artificial teeth. Methods: Ninety artificial teeth (maxillary central incisors) in different shades, light and dark (NatusDent Triple Pressing, Dentbras) were used. Initial color (Spectrophotometer Easyshade, VITA) and surface roughness (Rugosimeter Surfcorder SE 1700, Kosakalab) readouts were performed. After baseline measurements, samples were assigned to 10 groups (n=9) according to the artificial tooth shade and type of toothpaste used during the mechanical brushing test (Pepsodent, MAVTEC): Sorriso Dentes Brancos - SDB, Colgate Luminous White - CLW (Colgate-Palmolive), Close up White Now - CWN (Unilever), Trihydral - THL (Perland Pharmacos) and Ricinus communis - RCE (Experimental). After 29,200 cycles of brushing, corresponding to 2 years of brushing by a healthy individual, new color and roughness readouts of the specimens were performed. Data (before and after the tests) were statistically analyzed (2-way repeated measures ANOVA, Tukey, p&lt;0.05). Results: RCE toothpaste produced the greatest color stability for dark tooth shade and the second best color stability for light tooth shade. For surface roughness alteration, there was no difference (p&gt;0.05) for any tested toothpaste regardless of tooth shade. Conclusions: The experimental Ricinus communis toothpaste did not cause color and surface roughness alteration in the artificial teeth, and it may be considered a suitable option for denture cleaning. <![CDATA[Influence of shade, curing mode, and aging on the color stability of resin cements]]> Abstract The color stability of resin cements is essential for aesthetic restorations. Aim: To evaluate the influence of shade and aging time on the color stability of two light-cured and two dual-cured resin cements. Methods: The CIE-Lab color parameters (n=6) were measured immediately after sample preparation and at 7, 30 and 90 days of aging in distilled water. The color difference (ΔE) was calculated and then analyzed by three-way ANOVA for repeated measures and Tukey's HSD test (α=0.05). Results: ΔE was higher for transparent resin colors, followed by dark and light colors. The mean values of ΔE were lower for both light-cured resin cements compared to the dual-cured cements. As the aging time increased, ΔE values increased. Conclusions: The light-cured resin cements showed greater color stability. The lighter shades of luting were more likely to display a greater color change. <![CDATA[In vitro effects of erosive challenge on the surface properties of sealants]]> Abstract Aim: To assess in vitro the surface roughness (Ra), Vickers hardness (VHN) and surface morphology of resin and glass ionomer materials used for sealants after dynamic erosive challenge. Methods: Twenty specimens of each material were prepared and divided into experimental (erosive challenge) and control groups (n=10): Protect Riva (SDI), Opallis Flow (3M ESPE), Fluroshield (Dentsply), Filtek Z350 XT Flow (3M ESPE). The erosive challenge was performed 4 times per day (90 s) in cola drink and for 2 h in artificial saliva for 7 days. The control specimens were maintained in artificial saliva. Ra and VHN readings were performed before and after erosion. The percentage of hardness loss (%VHN) was obtained after erosion. The surface morphology was evaluated by scanning electron microscopy (SEM). The data were analyzed by ANOVA, Tukey and paired t tests (α=0.05). Results: After erosion and saliva immersion, there was an increase in Ra values for all groups and Riva group showed the highest Ra values. After erosive challenge, Riva and Filtek groups showed significant decrease in VHN values, but Filtek group showed the greatest %VHN. For all groups there was inorganic particle protrusion and matrix degradation after erosion visualized by SEM images. Conclusions: Erosive challenge affected the surface properties of all materials used as sealants, particularly in the Riva and Filtek groups. <![CDATA[Perception of HIV among pregnant women in the public health system in two municipalities of the state of São Paulo]]> Abstract Aim: To verify the knowledge of pregnant women on mother-to-child transmission (MTCT) of HIV, the availability of HIV tests in the public health system and counseling on the disease in two cities, Birigui and Piacatu, São Paulo State, Brazil. Methods: This is a descriptive and exploratory research using as samples, the files of 141 pregnant women attending the Basic Health Unit. Data were collected by survey, followed by a semi-structured questionnaire with open and closed-end questions. Data were analyzed on Epi Info(tm) 7.1.4, by the Chi-square and Exact Fisher tests. Results: From all the 141 pregnant women, 119 were interviewed and 92.4% reported to have been informed about the need of taking the HIV test during prenatal exams. However, only 5.9% were counseled and 20.2% reported to be aware of how to prevent MTCT of HIV, usually mentioning lactation suppression and prescribed medication. The association between the knowledge about how to prevent MTCT of HIV and some social, demographic and economic variables like ethnics, educational level, home location, occupation, age and parenting was not verified. Conclusions: It is necessary to advise pregnant women on the importance of taking the HIV test regardless of the examination outcome, which was not observed in the cities where the research was conducted. <![CDATA[Clinical evaluation of two materials in the restoration of abfraction lesions]]> Abstract Aim: To evaluate the clinical performance of a composite resin (CR) and a resin-modified glass-ionomer cement (RMGIC) for the treatment of abfraction lesions. Methods: Thirty patients with abfraction lesions in at least two premolar teeth were selected and invited to participate in this study. All restorations were made within the same clinical time frame. One tooth was restored with CR Z100TM (3M, St. Paul, MN, USA), and the other was restored with RMGIC VitremerTM (3M). The restorations were assessed immediately and 1, 6 and 12 months after the restoration, using modified US Public Health Service (USPHS) criteria: marginal integrity, marginal discoloration, wear, retention, secondary caries and hypersensitivity. The statistical analysis was based on Friedman ANOVA test and Mann-Whitney test, considering p&lt;0.05 for statistical significance. Results: Both materials demonstrated satisfactory clinical performance after one year. In the individual analysis of each material, there was a significant difference (p&lt;0.05) in the criteria marginal integrity and wear, for both CR and RMGIC. RMGIC exhibited more damage one year after the restoration. Comparing both materials, it was found a significant difference only for marginal discoloration, while the RMGIC restorations showed the worst prognosis after a year of evaluation. There was no significant difference in the number of retentions, caries or hypersensitivity between CR and RMGIC. Conclusions: It was concluded that CR exhibited the best clinical performance according to the cost-effectiveness and evaluation criteria used in this study. <![CDATA[Incidence and classification of bifid mandibular canals using cone beam computed tomography]]> Abstract Aim: To determine the prevalence and classification of bifid mandibular canals using cone beam computed tomography (CBCT). Methods: The sample comprised 300 CBCT scans obtained from the Radiology and Imaging Department database at São Leopoldo Mandic Dental School, Campinas, SP, Brazil. All images were performed on Classic I-Cat(r) CBCT scanner, with standardized voxel at 0.25 mm and 13 cm FOV (field of view). From an axial slice (0.25 mm) a guiding plane was drawn along the alveolar ridge in order to obtain a cross-section. Results: Among 300 patients, 188 (62.7%) were female and 112 (37.3%) were male, aged between 13 to 87 years. Changes in the mandibular canal were observed in 90 patients, 30.0% of the sample, 51 women (56.7%) and 39 men (43.3%). Regarding affected sides, 32.2% were on the right and 24.5% on the left, with 43.3% bilateral cases. Conclusions: According to the results obtained in this study, a prevalence of 30% of bifid mandibular canals was found, with the most prevalent types classified as B (mesial direction) and bilateral. <![CDATA[Impact of hypomineralized teeth and sociobehavioral aspects on caries development: a prospective cohort study]]> Abstract Aim: This prospective cohort study was to evaluate the independent and mutual effects of socioeconomic, oral health behaviors and individual clinical factors, including enamel hypomineralization, as possible risk factors for increase in caries experience in second primary molar (SPM) over a period of 2-years. Methods: Children (n=216) aged 4-6 years were examined for hypomineralized second primary molar (HSPM) and dental caries in school settings and were recalled every 6 months. The caregivers filled out a semi-structured questionnaire about their socio-demographic and oral health-related behaviors. Data analysis was performed using a hierarchical model with three levels. Multiple analyses were performed at each level and variables with p&lt;0.20 were tested by stepwise multiple Generalized Estimating Equation. Results: At final examination, 33.3% of the children had developed new caries lesions in SPM. The model showed that the number of years of mother's schooling and the caregiver´s perception about their children's caries experience played a protective role in the incidence of dental caries. Children who had white spot lesions were more likely to develop new carious lesions in SPM. Children with HSPM showed no higher incidence of caries in their SPM than those without HSPM. Conclusions: Clinical, socioeconomic and behavioral factors impacted on caries development in primary second molars. However, further studies are required to better understand the role of HSPM in caries development in other age groups. <![CDATA[Evaluation of biomaterials with and without platelet-rich plasma: a histometric study using beagle dogs]]> Abstract Aim: To compare the alveolar bone repair process using biomaterial in dogs with and without the incorporation of platelet-rich plasma. Methods: Six beagles were used. Bilateral extractions of the three mandibular premolars were performed. Bio-Gen(r) was applied in the first alveolus, the clot was maintained in the second alveolus and Genox(r) was applied to the third alveolus. PRP was added to all alveoli on the left side only. The dogs were submitted to euthanasia after 30, 60 and 90 days and submitted to histological analysis for the determination of mean area of new bone formation. Tukey's post test was used in the statistical analysis. Results: Significant increase in bone formation occurred in Bio-Gen(r) + PRP when compared with the other groups at 30 and 90 days. In the evaluation at 60 days, no statistically significant differences among the groups were found. Conclusions: The Bio-Gen(r) biomaterial led to the best bone repair and the combination of platelet-rich plasma accelerated the repair process. <![CDATA[Oral health quality of the workers of a telemarketing company and their satisfaction with the treatments provided by the corporative dental insurance plan]]> Abstract Aim: To evaluate the oral health quality of the workers of a telemarketing company and their satisfaction with the dental treatments provided by the corporative dental insurance plan. Methods: Data collection was by an online intranet questionnaire on dental service providers from Uberlândia/MG and Campinas/SP. It was addressed to 6000 associates, with objective and subjective questions, comprising the level of the telemarketing operators' oral health, dental needs, satisfaction with dental care providers and the importance of having the laboral dental services provided by the company. Results: After analysis of the results, we observed that: 57.52% of the workers required improvement in their oral health and 56.03% mentioned prevention as the largest need, 66.70% use the dental providers' services, but only 31.34% were satisfied with them. Conclusions: The results underscore that the workers have an intermediate level of dental needs, with prevention as top importance. Additionally, establishment of a basic attention program inside the company would increase the satisfaction and adhesion indexes of providers and the workers' oral health. <![CDATA[Distinguishing predisposing factors for enamel hypoplasia and molar-incisor hypomineralization in children in Ile-Ife, Nigeria]]> Abstract Aim: To determine if the prevalence of enamel hypoplasia, molar-incisor hypomineralisation (MIH) and deciduous molar hypomineralisation (DMH) is associated with the socioeconomic status of the child and to determine the prevalence of enamel hypoplasia and MIH/DMH co-morbidity in the study population. Methods: Information was collected on the sex and socioeconomic status of the 1,169 study participants' resident in Ile-Ife, Nigeria, recruited through a household survey. The children were clinically examined to assess for the presence of enamel hypoplasia, MIH and DMH. Associations between sex, socioeconomic status and the prevalence of enamel hypoplasia, MIH and DMH were determined. The proportion of children with enamel hypoplasia and MIH/DMH co-morbidity was also determined. Results: Among the 1,169 study participants, 47(4.0%) had MIH, 15 (1.3%) had DMH and 161 (13.8%) had enamel hypoplasia. One (0.09%) study participant had MIH/DMH co-morbidity, 12 (1.0%) had DMH/enamel hypoplasia co-morbidity, and 9 (0.8%) had MIH/hypoplasia co-morbidity. There was no significant association between the socioeconomic status and presence of enamel hypoplasia (p=0.22), MIH (p=0.78) or DMH (p=1.00). Conclusions: The socioeconomic status cannot be used as a distinguishing factor for enamel hypoplasia, MIH and DMH. The possibility of co-existence of enamel hypoplasia and MIH/DMH makes it imperative to find ways to distinguish between the lesions. <![CDATA[Influence of implant-abutment angulations and crown material on stress distribution on central incisor: a 3D FEA]]> Abstract Aim: To investigate the effect of implant-abutment angulation and crown material on stress distribution of central incisors. Finite element method was used to simulate the clinical situation of a maxillary right central incisor restored by two different implant-abutment angulations, 15° and 25°, using two different crown materials (IPS E-Max CAD and zirconia). Methods: Two 3D finite element models were specially prepared for this research simulating the abutment angulations. Commercial engineering CAD/CAM package was used to model crown, implant abutment complex and bone (cortical and spongy) in 3D. Linear static analysis was performed by applying a 178 N oblique load. The obtained results were compared with former experimental results. Results: Implant Von Mises stress level was negligibly changed with increasing abutment angulation. The abutment with higher angulation is mechanically weaker and expected to fail at lower loading in comparison with the steeper one. Similarly, screw used with abutment angulation of 25° will fail at lower (about one-third) load value the failure load of similar screw used with abutment angulated by 15°. Conclusions: Bone (cortical and spongy) is insensitive to crown material. Increasing abutment angulation from 15° to 25°, increases stress on cortical bone by about 20% and reduces it by about 12% on spongy bone. Crown fracture resistance is dramatically reduced by increasing abutment angulation. Zirconia crown showed better performance than E-Max one. <![CDATA[Evaluation of hemosponge in promoting dental socket healing after 3<sup>rd</sup> mandibular premolar extraction in a feline model]]> Abstract Aim: To investigate the healing process following use of collagen sponges in the dental socket after extraction. Wound complications during the study were also evaluated. Methods: 32 cats were included in this study. IV administration of the combination of diazepam (0.22 mg/kg) and ketamine (10 mg/kg) was used to induce general anesthesia. Surgical extraction of both 3rd mandibular premolars was performed. The open dental sockets were divided in two groups. In Group A, the open dental socket on the left side was closed using 4-0 Monocryl in simple interrupted pattern. In Group B, the right dental socket was filled with lyophilized hydrolyzed collagen and the buccal and lingual flaps were sutured using 4-0 Monocryl and simple interrupted pattern. Meloxicam (0.2 mg/kg) was used to manage the post-extraction pain in all cats. Ampicilline 20 mg/kg was used as prophylaxis. The wounds were observed during the study to evaluate any signs of inflammation or dehiscence. Radiographs were taken to compare healing of the socket 3 weeks after the procedure. A 1 mm biopsy punch sample was taken from sockets in all cats for comparison of the healing in both groups. Results: Hemorrhage occurred only in the sockets of Group A. Remission of radiolucent area occurred in both groups. Mean score of inflammation was lower and mean scores of fibrotic reaction and fibroplasia were higher in Group B (p&lt;0.05). Conclusions: Use of hemosponge in alveolar socket may accelerate fibroplasia and formation of the connective tissue and reduce inflammation after tooth extraction. Therefore, post-extraction use of the hemostatic agent in the dental socket is recommended. <![CDATA[Sodium hypochlorite effects on dentin bond strength and acid-base resistant zone formation by adhesive systems]]> Abstract Aim: To evaluate the effects of 10% NaOCl gel application on the dentin bond strengths and morphology of resin-dentin interfaces formed by three adhesives. Methods: Two etch-and-rinse adhesives (One-Step Plus, Bisco Inc. and Clearfil Photo Bond, Kuraray Noritake Dental) and one self-etch adhesive (Clearfil SE Bond, Kuraray Noritake Dental) were applied on dentin according to the manufacturers' instructions or after the treatment with 10% NaOCl (ED-Gel, Kuraray Noritake Dental) for 60 s. For interfacial analysis, specimens were subjected to acid-base challenge and observed by SEM to identify the formation of the acid-base resistant zone (ABRZ). For microtensile bond strength, the same groups were investigated and the restored teeth were thermocycled (5,000 cycles) or not before testing. Bond strength data were subjected to two-way ANOVA and Tukey's test (p&lt;0.05). Results: NaOCl application affected the bond strengths for One-Step Plus and Clearfil Photo Bond. Thermocycling reduced the bond strengths for Clearfil Photo Bond and Clearfil SE Bond when used after NaOCl application and One-Step Plus when used as recommended by manufacturer. ABRZ was observed adjacent to the hybrid layer for self-etch primer. The etch-and-rinse systems showed external lesions after acid-base challenge and no ABRZ formation when applied according to manufacturer's instructions. Conclusions: 10% NaOCl changed the morphology of the bonding interfaces and its use with etch-&amp;-rinse adhesives reduced the dentin bond strength. Formation of ABRZ was material-dependent and the interface morphologies were different among the tested materials.