Acta odontologica latinoamericana : AOL最新文献

The color and the surface roughness of aesthetic restorations are related to the clinical sucess and longevity of these treatments. Aim: This study evaluated the influence of finishing and polishing systems, and storage media on the surface roughness and color stability of aesthetic restorative composites. Materials and Method: Cylindrical specimens (n=10) were prepared and treated according to: 1. Type of composite resin (nanofilled- Filtek Z350XT, suprananofilled- Estelite Omega, nanohybrid- Empress Direct); 2. Type of finishing and polishing systems (no polishing, aluminum oxide discs or abrasive rubber polishers); and 3. Type of immersion medium (water or coffee, 3 h/day/30 days). Surface roughness (Ra - μm) and color stability (L, ΔEab, and ΔE00) were evaluated at baseline (after polishing) and final time (after immersion). Data were subjected to Kruskal-Wallis, Mann-Whitney, Wilcoxon, and Student-Newman-Keuls tests (α=0.05). Results: Nanohybrid (p<0.001) and suprananofilled composite resins (p=0.004) showed an increase in Ra after polishing, regardless the finishing and polishing system. After immersion in coffee, the nanofilled composite had the highest roughness values (p=0.032). L values increased for all resins after polishing (p<0.05). Suprananofilled composites had the greatest color stability with the lowest values of ΔEab and ΔE00. Conclusions: Finishing and polishing systems had an impact on the surface roughness and color stability of all aesthetic resins, and their effectiveness depended on the type of composite resin.

Maintaining pulp vitality and function is a priority of the medicaments employed in pulp therapy to preserve tooth integrity. Aim: This study evaluated inflammatory response and reparative dentin bridge formation after direct pulp capping with two different bioceramics. Materials and Method: This was an in vivo controlled experimental study on 12 male Wistar rats. Pulpotomies were performed and the exposed pulps were capped with Biodentine or Neo MTA. After 15, 45 and 90 days, maxillary segments were obtained and prepared for histologic analysis and Micro-CT. Hounsfield Units (HU) were quantified. Results: Micro-CT analysis showed greater mineralization at 90 days with Neo MTA than with Biodentine. HU did not differ significantly (p >0.05) between molars treated with Biodentine and Neo MTA at 15 and 45 days, but at 90 days, there was statistically significant difference (p <0.05) between them. Reparative dentin was observed near the pulp exposure and canal orifice with both bioceramics. At 45 and 90 days, molars treated with Neo MTA showed mineralized tissue filling the canal orifice. Molars treated with Biodentine showed mineralized tissue and dentin bridge at the site of exposure at 45 days, and total pulp exposure coverage and mineralized entin matrix at 90 days. Conclusions: Biodentine and Neo MTA induce the formation of reparative dentin bridge after 45 days with inflammatory cell infiltrate.

Local anesthetics (LA) can cause undesired effects such as sustained contraction of skeletal muscles as a result of structural and functional changes. Proper skeletal muscle function is controlled by intracellular Ca2+ concentration and efficient energy (ATP) production, which is closely related to cell ultrastructure. Aim: The aim of this study was to identify the structural and functional changes caused by LAs. Materials and Method: Male Wistar rats weighing 200 to 250g were used (n:49). They were divided into seven groups. One group was not anesthetized or treated (Control). The other six groups underwent intramuscular (IM) anesthesia with xylazine 2% (0.05 ml) and ketamine 50 mg/ml (0.1 ml/100g rat weight), and one of the following was applied to the masseter muscle (MM): no further treatment (Anesthetic Control group, CA); 0.1ml physiological saline solution (group SF); Carrageenin (group Carr) 1% as positive control group; prilocaine (group Pri), mepivacaine (group Mepi); or articaine (group Arti) 0.3M, IM. The animals were euthanized by cervical dislocation one hour after treatment. The effects of the different anesthetics on the MM were evaluated histologically and by electronic microscopy (EM). Ca-ATPase and membrane lipid peroxidation (LPX) were evaluated in muscle homogenates under the same conditions as those used to prepare the histological sections. Results: In general, structural damage and increased muscle contraction were observed in tissues treated with anesthetics. The most extreme values of Ca-ATPase activity and LPX were observed in the positive control group (carrageenin). Results were analyzed by one-way ANOVA for multiple comparisons and Tukey's test (p < 0.05). Conclusions: The results suggest that in the short term, local anesthetics affect the muscle function and are associated to structural changes.

Melatonin (MLT) is a hormone that can stimulate bone formation and inhibit bone resorption, among other functions. Aim: To evaluate the effect on new bone formation of MLT applied locally to critical defects created in the calvaria of rats, compared to the effect of Bio-Oss® xenogeneic bone substitute (BO), by analyzing histomorphometry, microtomography and gene expression. Materials and Method: Two critical defects (5.0 mm in diameter) were created in the calvaria of 36 adults male Wistar rats. The rats were divided randomly into two groups: a test group, in which one of the defects was filled with MLT, and the other with MLT with Bio-Oss® (MLTBO), and a control group, in which one of the defects was filled only with the clot (C), and the other with BO. The rats were euthanized 30 days after surgery. Samples of the calvaria containing the critical defects were collected for analysis by histomorphometry, microtomography, and the expression of the genes for type I collagen (COL-I), osteopontin (OPN) and bone morphogenetic protein 2 (BMP-2). Results: A qualitative improvement was observed in bone healing when MLT was used, though there was no statistical difference in the quantification of newly formed bone (p>0.05). Micro-CT showed that bone volume was significantly smaller in absence of BO (p=0.006). Bone trabeculae thickness (p=0.590) and number (p=0.150) were not significantly affected by MLT. Regarding the expression of the genes COL-I, OPN and BMP-2, no significant differences were observed between the MLT, BO and MLTBO groups. Conclusion: Topical application of MLT resulted in a qualitative improvement in bone healing, although it did not affect bone formation quantitatively. In the absence of BO, less bone volume and less bone trabecular thickness were observed.

Dengue is a global public health problem, especially in countries with tropical and subtropical climates. Aim: To describe the oral manifestations, present during dengue infection. Materials and method: A qualitative systematic review was conducted in OSF Registries. The search was conducted in PubMed, Scielo and Scopus, from June 15 to July 18, 2023, using MeSH term equations with Boolean operators. A total 299 articles were analyzed in three stages, leaving 8 studies for review. RAYYAN was used for selection and tables for study analysis. Studies were assessed under two criteria: metadata, and intraoral and extraoral manifestations of dengue. Results: The review included 8 studies, published in 2012, 2013, 2014, 2019, 2020 and 2021. The studies reported hemorrhagic dengue and type 1 dengue as diagnoses. They recorded presence of hemorrhagic and edematous gums, maculopapular lesions in the mucosa of the lower lip with pain and dysphagia, Pseudomembranous candidiasis, and edematous and erythematous taste buds. Conclusions: Reports of oral manifestations of dengue are deficient, and further research is required to enable correct diagnosis and differentiation from other pathologies.

The concept of quality of life (QoL) developed from early studies on subjective wellbeing and satisfaction with life, interpreted as resulting from living conditions, and recognized by means of objective indicators. Indicators have been developed and validated to measure the relationship between quality of life and health Aim: To determine, during an Educational Social Practice, the association between presence of dental caries lesions and its impact on quality of life of adolescents living in rural and urban areas in Argentina. Materials and Method: This was an observational cross-sectional study in (a) a rural area (Tres Isletas; Chaco Province/Schools No. 601 and 477) and (b) an urban area (Villa Soldati; Buenos Aires City/Nuestra Sra. Fátima School). The sample included 40 students from the urban area (UG) and 30 from the rural area (RG). A calibrated researcher (Kappa 0.80) collected the survey data and performed the clinical examinations. The following were recorded: (a) sociodemographic distribution in terms of age and gender; (b) presence of dental biofilm according to Silness and Löe; caries lesions according to ICDAS II /INTCy criteria, and (d) DMFT, total and per component. Quality of life was assessed using the CPQ 11-14r. Statistical processing included calculation of frequency distribution of the variables (X± DS), and chi-square and Mann-Whitney tests to calculate association and comparisons between groups. Results: The sample included 47 girls (67.1%) and 23 boys (32.9%). Distribution according to sex and age did not differ significantly between sites (UG:12.9 years ± 0.5 and RG:11.8 years ±1.1). No significant difference was found between sites for a) plaque biofilm (p=0.759); b) DMFT, total value and per component, or c) individual and grouped ICDAS scores. Percentage analysis of the CPQr 1-14 scores showed significant differences between groups for questionnaire total scores (26.9% ± 2.2 in UG and 4.1% ± 0.8 in RG) and for the different domains. Conclusion: Perceived impact on quality of life caused by dental caries lesions was significantly higher in urban than the rural group, although neither the dental caries process nor the amount of biofilm differed significantly between groups.

Giomers are bioactive hybrid restorative materials consisting of composite resin and glass ionomer filler pre-reacted on the surface, which maintain acceptable clinical qualities over time. One of the main factors that explains this is the surface hardness that is achieved by inhibiting the oxygen layer.

Aim: To compare the effect of blue and conventional Mylar strips used as oxygen inhibiting agents on the surface microhardness of giomer restorative materials.

Materials and method: A total 96 giomer specimens were prepared in disc-shaped molds 2 mm tall x 5 mm in diameter (ISO 4049: 2019-05). The specimens were grouped according to type of giomer: Beautifil II (BII) or Beautifil II LS (BIILS), and according to the type of Mylar strip: conventional, blue, or control group without strip. They were subsequently subjected to the Knoop (KHN) microhardness test. The database was analyzed with Stata SE v18 statistical software, and two-way ANOVA was performed.

Results: Interaction was found between the type of giomer and Mylar strip (p=0.039). Significant differences were found between surface microhardness values according to the type of giomer (0.001) and the type of Mylar strip (0.001). Beautifil II LS presented significant differences between conventional Mylar strip vs. without Mylar strip (43.58 ± 1.65 vs. 40.44 ± 2.12) and between blue Mylar strip and without Mylar strip (44.69 ± 1.75 vs. 40.44 ± 2.12). In the Bonferroni Post hoc test, a significant difference was found between Conventional Mylar Strip and without Mylar Strip (p=0.001) and Blue Mylar Strip and without Mylar Strip (p=0.001).

Conclusion: The use of blue and conventional Mylar strips inhibits the oxygen layer on the Beautifil II and Beautifil II LS giomers, endowing them with high values of surface microhardness.

Bilingual schools have more hours and high levels of academic demands. Aims: To compare the degree of dental wear and frequency of severe wear facets between children from public rural schools (RG) and children from private bilingual schools in Buenos Aires City (PG). To compare the presence of facets to parents' reports on bruxism and their opinion on the importance to health of bruxism and snoring. Materials and Method: The sample (n=90) consisted of 5- and 10-year-old children. Their parents/guardians were asked to complete a structured questionnaire on bruxism and snoring. Children's degrees of dental wear on primary incisors, canines and molars were identified and recorded. The data were analyzed statistically. Results: The relative risk of wear between PG and RG was 1.82. Bruxism and snoring were reported by 22.9% of the parents/guardians of 5-year-olds and 8.8% of the parents/guardians of 10-year-olds. In 10-year-olds, significant differences were found between RG and PG for canine wear degree 3 (p=0.01). Conclusions: Children from highly demanding schools presented more dental wear. Higher frequency of severe dental wear was observed in primary canines and molars late in the tooth replacement period regardless of whether sleep bruxism was reported. Parents/guardians from different social conditions considered that bruxism and snoring are important to health to similar degrees.

This study analyzed a recently developed bone substitute biomaterial made of chitosan-xanthanhydroxyapatite-graphene oxide (CXHAG). The CXHAG particles underwent in vitro structural and morphological characterization, and in vivo testing with or without osteogenic conditioned medium from mesenchymal stem cells. Aim: The aim of this study was to determine whether the CXHAG novel biomaterial, supplemented with conditioned medium from mesenchymal stem cells, could be useful for bone regeneration. Materials and Method: For the in vitro study, cells were incubated with 20mg of CXHAG granules for 24 hours and a MTT assay was performed to tests for cytotoxicity. For the in vivo study, critical size calvarial bone defects were created in twenty-five rats. One animal had the defect unfilled (Control Group-CG) and was euthanized after 42 days. Twelve rats received the CXHAG particles (Group 1-G1) and the other twelve received the CXHAG particles supplemented with the conditioned medium (Group 2-G2). All G1/G2 grafts were covered with a CXHAG membrane. G1/G2 animals were euthanized after 14 days (T1) or 42 days (T2). The specimens were processed and histologically evaluated. Results: SEM analysis of the CXHAG particles showed granules of 300-400μm, with a rough irregular surface. They were not cytotoxic to dental pulp stem cells in vitro. The CG specimen showed loose immature connective tissue and no bone formation at the center of the defect. G1 and G2 presented remnant biomaterial particles at both time points, but only G2 had bone formation at the enter of the defect. Conclusions: The conditioned medium had a positive effect on bone regeneration in rat calvarial critical size defects when associated with the novel bone substitute biomaterial.

The negative oral health outcomes of disadvantaged racial groups have been well-documented, as racial disparity in oral health persists over time and in different locations1. However, it is important to note that skin colour has no biological meaning, and the observed differences can be physiological expressions of social injustice such as racism. Aim: The aim of this study was to analyse the association between levels of modern racism (camouflaged prejudice and affirmation of differences) and sociodemographic characteristics of Brazilian dental students. Material and Method: An epidemiological cross-sectional online survey was conducted on 441 Brazilian undergraduate dental students using Google Forms. Participants were recruited via emails and social media, using the snowball technique. The Checklist for Reporting of Survey Studies (CROSS) was followed. The survey used sociodemographic variables, and the Brazilian version of the Modern Racism Scale (B-MRS), which measures the cognitive component of subtle racial attitudes. The scale assesses the central notion of disguised prejudice and has two domains: 'denial of prejudice' and 'affirmation of differences'. Participants' self-declared skin colour was categorized as "white" and "non-white" (black, brown, indigenous, yellow). Univariate analysis and Poisson regression with robust variance were applied. Results: Participants' mean age was 24.1 years (±5.4). Most participants were self-declared as white (54%) and 46% as non-white skin colour. Higher B-MRS overall-scores were observed in male (p=0.008) and non-white (p=0.002) students. B-MRS scores for the domain 'affirmation of differences' (representation of those who believe that whites and non-whites are truly different) were higher among male dental students (PR=1.138; CI 95%: 1.019-1.271) and those from low-income families (PR=1.306; CI 95%: 1.089-1.565). Scores for the domain 'denial of prejudice' (the idea that non-whites use their race to receive legal benefits) were higher among male dental students (PR=1.328; CI 95%: 1.129-1.562). Conclusions: In general, male non-white students had higher modern racism indicators. Male students from low-income families believed that whites and non-whites are truly different, accounting for the affirmation of difference in this sample.