DNA content and clinicopathological features aid in distinguishing ameloblastic carcinoma from ameloblastoma.

BACKGROUND: Ameloblastoma and ameloblastic carcinoma are epithelial odontogenic tumors that can be morphologically similar. In the present study, we evaluated the DNA content and Ki-67 index in the two tumors. METHODS: The paraffin blocks of the tumors were selected to obtain sections for the immunohistochemical reactions and preparation of the cell suspension for acquisition in a flow cytometer. The Random Forest package of the R software was used to verify the contribution of each variable to classify lesions into ameloblastoma or ameloblastic carcinoma. RESULTS: Thirty-two ameloblastoma and five ameloblastic carcinoma were included in the study. In our sample, we did not find statistically significant differences in Ki-67 labeling rates. A higher fraction of cells in 2c (G1) was correlated with the diagnosis of ameloblastoma, whereas higher rates of 5c-exceeding rate (5cER) were correlated with ameloblastic carcinoma. The Random Forest model highlighted histopathological findings and parameters of DNA ploidy study as important features for distinguishing ameloblastoma from ameloblastic carcinoma. CONCLUSION: Our findings suggest that the parameters of the DNA ploidy study can be ancillary tools in the classification of ameloblastoma and ameloblastic carcinoma.

Validation of an educational comic book to guide conducts in situations of dental trauma.

BACKGROUND/AIM: Childhood dental trauma poses a prevalent concern, and the limited knowledge of lay caregivers toward the needed immediate actions can adversely affect a child's well-being. This study aimed to create and validate an educational comic book for lay individuals, designed to guide immediate actions in dental trauma cases, and assess its effects toward enhancing reader knowledge. METHODOLOGY: The four-stage study involved: (1) Literature review and script development; (2) Version 1 of the comic book creation (including illustrations, layout, and design) and Flesch Readability Index (FI) calculation; (3) Version 1 validation by expert judges, assessed by the Content Validity Index (CVI); (4) Version 1 refinement based on the judges' feedback, recalculation of FI, and a pilot test (CVI) involving lay individuals who validated the final material (Version 2). The validation process involved 67 participants, including 13 specialist judges and 54 elementary school teachers. RESULTS: The CVI for Version 1 was calculated at 0.89 (89%), indicating a favorable level of agreement on the evaluated criteria. The FI was determined as 91.1%, indicating a high level of readability. The FI for Version 2 was 92.1% (indicating a very easy level of comprehension). The CVI calculated for the target audience after the pilot test was 0.99 (99%), denoting a substantial agreement among the participants. In assessing the level of knowledge, a significant increase was observed in the rate of correct answers after the comic book was read by lay individuals (p < 0.05), inasmuch as the percentage rose from 50.5% before to 81.2% after reading it. CONCLUSION: The educational comic book proved valid in terms of readability, appearance, and content. Furthermore, it had a positive impact on gaining the knowledge needed to take the appropriate actions, thus making it a valuable tool for guiding the lay population in cases of dental trauma.

Pre-clinical evaluation of new dibucaine formulations for preventive analgesia.

We have previously developed ammonium sulphate gradient loaded liposomes to encapsulate dibucaine. Thus, the purpose of this study was to evaluate the pre-clinical safety and effectiveness of this novel ionic liposomal formulation of dibucaine (DBC), as described in previous work. Effectiveness was evaluated in vivo on Wistar rats (n = 8) that received plain DBC or liposomal DBC (DBCLUV). Control empty liposomes (without DBC) or saline were also used as control. Sciatic nerve block was performed using the formulations or controls (0.4 mL). A hindpaw incision-based postoperative pain model was used to evaluate mechanical hypersensitivity with von Frey filaments. To verify antiinflamatory activity protein levels of TNF-α, IL-1ß, substance P and CGRP were measured by ELISA in the hindpaw tissue after 1 and 6 hours of the incision. To corroborate drug safety, sciatic nerve Schwann cell cultures were treated with the aforementioned formulations and assessed for cell viability (MTT assay) and death (flow cytometry assay). Histopathology of the tissues surrounding the sciatic nerve region was also assessed 2 and 7 days after treatment. All animals presented post incisional hypersensitivity and DBCLUV showed longer analgesic effect (p < 0.001). DBCLUV reduced TNF-α and CGRP levels (p < 0.05). Histopathological evaluation showed greater inflammatory reaction after the administration of control liposomes when compared to DBC (p < 0.05). There was no difference in Schwann cell viability and death between plain and encapsulated DBC. DBCLUV was safe and enhanced anaesthesia duration due to slow release of dibucaine from ammonium sulphate gradient loaded liposomes.

Photodynamic Therapy and Photobiomodulation on Oral Lesion in Patient with Coronavirus Disease 2019: A Case Report.

Objective: This article reports the case of a patient with oral manifestation of coronavirus disease 2019 (COVID-19) treated with photobiomodulation (PBM) and photodynamic therapy (PDT). Background: Some dermatological and oral mucosal lesions have recently been linked to severe acute respiratory syndrome coronavirus 2 infection. Methods: A 65-year-old female patient with a confirmed real-time reverse transcriptase-polymerase chain reaction diagnosis of COVID-19 presented with dry edematous lips, edema with mucosal desquamation, ulceration and blood crust on the inner aspect of the lips, gingival petechiae and erythematous and pseudomembranous lesions on the dorsum of the tongue. The treatment protocol was three sessions of antimicrobial PDT (aPDT) (660 nm diode laser + methylene blue) to the lips and tongue, every 24 h to control contamination, followed by PBM (low-power laser, 100 mW, 2 J/point) to the lips, tongue, and oral mucosa for additional four sessions every 24 h. Results: Therapy association promoted pain control and healing of oral mucosal lesions in 7 days of treatment. Conclusions: PBM and aPDT could be an interesting approach to manage COVID-19 patients.

A novel dental biosafety device to control the spread of potentially contaminated dispersion particles from dental ultrasonic tips.

Strategies to return to dental practice in pandemic times is a new challenge due to the generation and spread of potentially contaminated dispersion particles (PCDP) that may contain the SARS-CoV-2, the etiological factor of the COVID-19 disease. Due to the significant dispersion of PCDP in the dental environment, the use of equipment such as ultrasonic tips have been inadvisable during the pandemic. Several clinical procedures, however, benefit from the use of such equipment. Thus, using a microbial dispersion model of PCDP, the aim of this study was to compare the dispersion caused by the dental drill (DD) an ultrasonic tip (UT) alone and the UT coupled with a Spray control (SC) device. The DD, UT (with or without the SC) were activated for one minute having had the water from the reservoir replaced with a suspension of Lactobacillus casei Shirota (1.5 x 108 CFU/mL). Petri dishes containing MRS agar were positioned at 50cm, 100cm and 150cm from the headrest of the dental chair at different angles (0 degree and 90 degrees). At 50 cm, the mean CFU (standard deviation) of L. casei Shirota was 13554.60 (4071.03) for the DD, 286.67 (73.99) for the US (97.89% reduction), and 4.5 (0.58) CFU for the UT-SC (p < 0.0001), establishing a further 98.43% reduction between UT and UT with SC. The UT with SC model proved effective in reducing dispersion from the UT, endorsing its use as an additional strategy to reduce PCDP in the dental environment in times of pandemic.

Influence of Dental Pulp Harvesting Method on the Viability and Differentiation Capacity of Adult Dental Pulp-Derived Mesenchymal Stem Cells.

OBJECTIVE: To compare two pulp harvesting methods for stem cell expansion, namely, conservative pulpotomy and pulpectomy from exodontia. METHOD: Ten freshly extracted sound third molars from five patients were selected. Five were used in the control group, where pulp harvesting was performed by exodontia and the remaining teeth were used in the test group, where the pulp was harvested by conservative pulpotomy (preserving the tooth). This was a split-mouth design study, where a third molar from one side was randomly allocated into the test group and the contralateral tooth in the control group. After pulp harvesting, the following evaluations were performed: cell morphology, sterility test, immunophenotyping, differentiation assays, first pass live cell counts, time to cryopreservation, and total number of expanded cells at the end of the fourth pass. RESULTS: Regarding morphology, the cells from both groups presented a fibroblastic phenotype. All samples were sterile. Immunophenotyping demonstrated a positive expression for CD105, CD90, and CD73 and negative expression for CD45 in both groups. Differentiation assays were positive for osteogenic and chondrogenic differentiation in both groups. Regarding live cell counts in the first passage, the control group had 95.8% live cells in the total count and the test group 91.2% (p < 0.05). The time required for cryopreservation was equivalent in both groups 51.6 days and 52.6 days, respectively (p > 0.05). The total number of cells at the end of the fourth passage was 5,286,782 and 5,736,862, respectively (p > 0.05). CONCLUSION: These results suggest that adult stem cell harvesting from conservative pulpotomy is as effective as the traditional exodontia-based method.

Lipoid Proteinosis: A Rare Disease In Pediatric Dentistry.

This report describes the diagnostic process of a rare disorder in a Brazilian female child. The patient presented initially as a 7-year-old with multiple whitish submucosal nodules of a fibrous consistency in the lower lip, but with an inconclusive pathology report. When she turned 9 years of age, she presented with exacerbation of the original clinical findings, which then involved the upper lip, buccal mucosa, tongue and lingual frenulum. In addition, dermatological lesions were noted on the child's limbs and face, as well as a hoarse voice. Histopathological examination of the buccal mucosa revealed dense connective tissue with hyaline foci, which were positive with periodic acid-Schiff (PAS) staining and resistant to diastase digestion. Clinical and histopathological findings led to the diagnosis of a rare genetic disease with fewer than 300 reported cases - lipoid proteinosis. Magnetic resonance imaging revealed calcium deposits in her amygdaloid region of the brain, and nasopharyngolaryngoscopy revealed lesions in her vocal cords. The patient currently is stable and under multidisciplinary follow-up, but no treatment has been recommended to date.

H2S in periodontal immuneinflammatory response and bone loss: a study in rats.

Halitosis is highly prevalent in periodontitis and attributed mainly to the presence of volatile sulfur compounds (VSC), where hydrogen sulfide (H2S) is the chief culprit in the characteristic malodor of periodontitis and thus may play an active role in its pathogenesis. The aim of this study was to evaluate the effect of H2S in the acute, intermediate and chronic immuneinflammatory host response and alveolar bone loss in vivo by using an animal model of induced periodontal disease. Thirtysix rats were divided into 2 groups: test group (n = 18), rats exposed to H2S (NaHS H2S donor molecule) and control group (n = 18), rats treated with saline only (Ctrl). All animals had one of their lower second molars ligated to induce periodontal disease (PD). The sound contralateral molar was used as control (H). Each group was subdivided into 3 (n = 6), according to followup time (3h, 5 days and 14 days). The gingival tissue was used for mRNA expression analysis (IL1, IL6, RANKL, OPG and SOFAT) by realtime PCR and the mandibles were analyzed morphometrically. Data analysis showed that the ligature promoted alveolar bone loss, observed mainly at 14 days, both in the group exposed to H2S and in the Ctrl group. H2S administration did not result in additional bone loss. Gene expression showed a significant increase in IL1, IL6, RANKL and SOFAT only in the CtrlPD group (p<0.05). A significant downregulation in OPG expression was observed over time in the CtrlPD group (p<0.05). In conclusion, H2S had no effect on alveolar bone loss in the absence of a ligature. In the presence of a ligature, however, exposure to H2S had an immunoregulatory effect on the expression of proinflammatory and proresorptive cytokines.

A halitose é altamente prevalente na periodontite e é atribuída principalmente à presença de compostos sulforosos voláteis (CSV), sendo o sulfeto de hidrogênio (H2S) o principal gás relacionado ao mau odor e que pode estar envolvido na patogênese da doença periodontal. O objetivo deste estudo foi avaliar o efeito agudo, intermediário e crônico do H2S na resposta imunoinflamatória e na perda óssea alveolar em ratos, com e sem doença periodontal induzida. Trinta e seis ratos foram divididos em 2 grupos: teste (n = 18), ratos expostos ao H2S (NaHS molécula doadora de H2S) e grupo controle (n = 18), ratos tratados apenas com solução salina (Ctrl). Todos os animais tiveram um dos seus segundos molares inferiores submetidos à colocação de uma ligadura para o desenvolvimento da doença periodontal (DP), em comparação com o dente contralateral saudável (H). Cada grupo foi subdividido em 3 (n = 6), de acordo com o tempo de eutanásia (3h, 5 dias e 14 dias). Os tecidos gengivais foram utilizados para a análise da expressão gênica (IL1, IL6, RANKL, OPG e SOFAT) por PCR em tempo real e as mandíbulas foram analisadas morfometricamente. Análise dos dados demonstrou que a ligadura promoveu perda óssea alveolar, observada principalmente aos 14 dias, tanto no grupo exposto ao H2S quanto no grupo Ctrl. A administração de H2S não resultou em perda óssea adicional. A expressão gênica demonstrou aumento significativo de IL1, IL6, RANKL e SOFAT apenas no grupo CtrlPD (p <0,05). Uma significativa regulação negativa na expressão de OPG foi observada ao longo do tempo no grupo CtrlPD (p <0,05). Podese concluir que o H2S não teve efeito adicional na perda óssea alveolar, na ausência de ligadura. Entretanto, na presença de ligadura, a exposição ao H2S teve um efeito imunorregulatório na expressão de citocinas próinflamatórias e próreabsortivas.

Association Between Implant-Abutment Microgap and Implant Circularity to Bacterial Leakage: An In Vitro Study Using Tapered Connection Implants.

PURPOSE: The aim of this study was to evaluate the microgap between the abutment and implant as well as the circularity of implant platforms and associating conformational errors with bacterial microleakage in tapered connection implant systems. MATERIALS AND METHODS: Four brands of implants with a tapered abutment connection were tested. Bacterial leakage was assessed using 0.3 µL of Escherichia coli suspension inoculated into the abutment screw chamber of the implants, which were then torqued and incubated at 37°C for 14 days. All specimens used for the microbiologic experiment were then cut lengthwise, and the microgap was measured at three points on each side of the sample using scanning electron microscopy (up to 5,000× magnification). Microtomography was used to assess implant platform circularity to validate the microscopic findings qualitatively. RESULTS: Two samples from the Nobel Biocare system, four from the Ankylos (Dentsply) system, four from the Neodent (Straumann) system, and five from the Conexão system were positive for bacterial leakage, with no significant difference between groups. The Neodent system had the highest mean microgap values (5.84 ± 9.83 µm), followed by the Nobel Biocare systems (5.17 ± 4.10 µm), Ankylos (3.47 ± 3.28 µm), and Conexão (2.72 ± 3.19 µm), with no significant difference between systems. All systems showed conformational errors of circularity on microtomography images. CONCLUSION: The tapered connection systems evaluated herein were not able to halt bacterial leakage, nor were they free from conformational errors.

Evaluation of a Titanium Surface Treated with Hydroxyapatite Nanocrystals on Osteoblastic Cell Behavior: An In Vitro Study.

PURPOSE: In the context of macrostructural and microstructural modifications to the design of dental implants, surface topography changes with different treatments have the purpose of accelerating bone formation. The aim of this study was to evaluate in vitro the influence of aggregated hydroxyapatite nanocrystals to surfaces treated with double acid etching (Nano) on osteoblastic cell behavior compared with a conventional double acid-etched surface (DE). MATERIALS AND METHODS: Commercially pure Grade 4 titanium discs (6 × 2 mm) were selected, and both cell proliferation and viability were assessed at 24, 48, and 72 hours using Trypan blue vital dye and MTT, respectively. The expression of type I collagen and osteopontin on such surfaces was evaluated using ELISA. Immunostaining for fibronectin was also performed. Quantitative data were analyzed statistically using two-way analysis of variance (ANOVA) followed by Bonferroni post-test with a 5% significance level. RESULTS: The results showed that in all evaluated time periods, cells expressed fibronectin on both surfaces. The cells presented greater morphologic spreading on the Nano surface when compared with the conventional DE surface in all assessed times. Increased cell proliferation and viability were detected in the Nano surface (P < .05) when compared with the conventional DE surface, especially after 72 hours. Osteopontin expression was higher after 24 hours in the Nano surface when compared with the conventional DE surface (P < .05). For type I collagen, a higher expression was observed with the Nano surface than with the DE surface, again after 72 hours (P < .05). CONCLUSION: This in vitro study showed that the treated Nano surface tested promoted increased cell proliferation and viability when compared with the control surface. Additionally, increased cell spreading as well as type I collagen and osteopontin secretion were observed, favoring the early events of osseointegration.

Gingival Cyst of the Adult: Report of an Inconspicuous Lesion Associated with Multiple Agenesis.

Gingival cyst of the adult is a rare slow growing and asymptomatic lesion that arises from the rests of the dental lamina. The present report describes the case of a miniscule adult gingival cyst in the lower anterior gingiva in a 51-year-old male with agenesis of lower premolars and lateral incisors. This paper contrasts the literature concerning the differentiation between the gingival cyst of the adult and the lateral periodontal cysts as well as the possible misguided concept that the former may be such rare an occurrence.

Can bone marrow aspirate concentrate change the mineralization pattern of the anterior maxilla treated with xenografts? A preliminary study.

OBJECTIVE: To evaluate bony reconstruction of the atrophic anterior maxilla using particulate grafts with or without autologous bone marrow aspirate concentrate (BMAC). MATERIALS AND METHODS: Eight patients with atrophy of the anterior maxilla due to teeth loss were selected and split into groups according to the type of material used: Control Group (CG) (n = 4) - particulate xenograft only and Test Group (TG) (n = 4) - a combination of particulate xenograft and BMAC. Both groups received a collagen membrane to cover the xenograft. After 4 months, during implant placement, a sample of bone was removed from the graft area using a 2 mm diameter trephine bur. The specimens were fixed and preserved for histomorphometric evaluation, which included the following parameters: Mineralized tissue (MT) and non-MT (NMT). Cone beam computed tomography was performed at 3 time intervals to measure bone thickness: (1) Before grafting, (2) 4 months and (3) 8 months postgrafting, using localized bone gain (mm) as the outcome variable. RESULTS: Tomographic analysis revealed bone gain in CG of 3.78 ± 1.35 mm and 4.34 ± 1.58 mm at 4 and 8 months, respectively. TG showed an increase of 3.79 ± 0.52 mm and 4.09 ± 1.33 mm after 4 and 8 months, respectively. Histomorphometric analysis revealed that, for CG, MT- and NMT-related values were 52.3% ± 16.78% and 47.70% ± 5.55%, respectively, whereas for TG, they were 65.04% ± 20.98% and 34.96 ± 10.38, respectively. CONCLUSION: Although radiographic bone gain appeared similar between the groups, the use of BMAC obtained via the BMAC(®) method revealed an increased mineralization trend in the anterior maxilla. It must be highlighted, however, that this is a preliminary study with a relatively small sample population and further studies with larger sample sizes are needed to verify these results.

Peripheral giant cell granuloma associated with a dental implant: a case report and review of the literature.

The peripheral giant cell granuloma (PGCG) is a nonneoplastic lesion commonly caused by local irritation. This report describes a 46-year-old Caucasian male who presented with a PGCG associated with a dental implant. The dental implant was originally placed in August 2012. Ten months later, the patient presented with a well-circumscribed lesion associated with and covering the implant, at which time the lesion was excised. Four months later, due to recurrence of the lesion, a deeper and wider excisional biopsy with curettage of the adjacent bone was performed. No evidence of recurrence has been reported after 12 months of follow-up. Immunohistochemistry, using the antibody CD68, was performed to investigate the origin of the multinucleated giant cells, with their immunophenotype being similar to those of other giant cell lesions, including central giant cell granuloma, foreign-body reactions, and granulomatous reactions to infectious agents.

Lipoid proteinosis: a rare disease in pediatric dentistry

Abstract This report describes the diagnostic process of a rare disorder in a Brazilian female child. The patient presented initially as a 7-year-old with multiple whitish submucosal nodules of a fibrous consistency in the lower lip, but with an inconclusive pathology report. When she turned 9 years of age, she presented with exacerbation of the original clinical findings, which then involved the upper lip, buccal mucosa, tongue and lingual frenulum. In addition, dermatological lesions were noted on the child's limbs and face, as well as a hoarse voice. Histopathological examination of the buccal mucosa revealed dense connective tissue with hyaline foci, which were positive with periodic acid-Schiff (PAS) staining and resistant to diastase digestion. Clinical and histopathological findings led to the diagnosis of a rare genetic disease with fewer than 300 reported cases - lipoid proteinosis. Magnetic resonance imaging revealed calcium deposits in her amygdaloid region of the brain, and nasopharyngolaryngoscopy revealed lesions in her vocal cords. The patient currently is stable and under multidisciplinary follow-up, but no treatment has been recommended to date.

Resumo Este relato descreve o processo diagnóstico de uma doença rara em uma criança brasileira do sexo feminino. A paciente, inicialmente com 7 anos de idade, apresentava múltiplos nódulos submucosos esbranquiçados, de consistência fibrosa, no lábio inferior, mas com um laudo patológico inconclusivo. Quando completou 9 anos de idade, ela apresentou exacerbação dos achados clínicos originais, que envolveram o lábio superior, mucosa bucal, língua e frênulo lingual. Além disso, lesões dermatológicas foram observadas nos membros e no rosto da criança, assim como rouquidão. O exame histopatológico da mucosa bucal revelou tecido conjuntivo denso com focos hialinos, que foram positivos com coloração periódica com ácido-Schiff (PAS) e resistente à digestão da diástase. Os achados clínicos e histopatológicos levaram ao diagnóstico de uma doença genética rara com menos de 300 casos relatados - proteinose lipoide. A ressonância magnética revelou depósitos de cálcio em amígdala cerebral e a nasofaringolaringoscopia revelou lesões em cordas vocais. Atualmente, a paciente está estável e em acompanhamento multidisciplinar, mas nenhum tratamento foi recomendado até o momento.

Image-based study of marginal bone loss in teeth restored with cast endodontic posts / Perda óssea marginal em dentes restaurados com pinos endodônicos: estudo baseado em imagem

ABSTRACT The aim of this study was to assess marginal bone loss in teeth restored with endodontic posts on all four aspects of the teeth using cone beam tomography. Bone loss was assessed via scores (0-5) in relation to root length and bone height. The results showed that the scores for the contralateral and restored sides, respectively, ranged from 0 to 3 and 0 to 5 buccally, 0 to 4 and 0 to 4 palatally, 0 to 3 and 0 and 4 mesially and 0 to 3 and 0 to 4 distally. A significant difference in bone loss was observed between the post-restored teeth and their contralaterals for the buccal, lingual/palatal and mesial aspects (p<0.05), with teeth bearing endodontic posts scoring highest. In conclusion, marginal bone loss was higher in teeth restored with intra-canal posts when compared to their sound contralaterals.

RESUMO O objetivo deste estudo foi avaliar a perda óssea marginal nas quatro faces de dentes restaurados com pinos endodônticos, usando tomografia por feixe cônico. A perda óssea foi avaliada através de escores (0-5) em relação ao comprimento da raiz e altura do osso. Os resultados mostraram que os escores dos lados contralateral e restaurado, respectivamente, variaram de 0 a 3 e 0 a 5 bucalmente, 0 a 4 e 0 a 4 palatalmente, 0 a 3 e 0 e 4 mesialmente e 0 a 3 e 0 a 4 distalmente. Uma diferença significativa na perda óssea foi observada entre os dentes pós-restaurados e seus contralaterais para os aspectos vestibular, lingual / palatal e mesial (p <0,05), com os dentes com pinos endodônticos pontuando mais alto. Em conclusão, a perda óssea marginal foi maior em dentes restaurados com pinos intra-canal quando comparados aos seus contralaterais sonoros.

Effectiveness of a single-tuft toothbrush for control of newly formed dental biofilm

Aim: To compare the effectiveness of a single-tuft toothbrush (STB) with conventional toothbrushes (CT) to control dental biofilm neoformation in the dentogingival area. Methods: For this cross-sectional prospective blind study, 20 periodontally healthy subjects were selected and randomly divided into 4 groups: STB; CT; CHX - chlorhexidine mouthwash (positive control) and PS - placebo mouthwash (negative control). The subjects were instructed to use only the assigned care method for 72 h with a 7-day washout period between experiments. The evaluated parameters were visible and disclosed plaque indices (PI and DPI), gingival bleeding index (GBI) at baseline (T-0) and at the end of each experimental period (T-72). Results: Data analysis demonstrated that at T-0 no difference was observed for any of the parameters (p>0.05); after 72 h, CT, STB and CHX showed equivalente effectiveness at controlling biofilm. When the PI data were analyzed, between T-0 and T-72, STB was similar to CT and CHX (p<0.05), whereas for DPI, STB was significantly superior to the other methods. Except for PS, all methods yielded similar results for GBI (p<0.05). Conclusions: The tested STB was effective at controlling short-term dental biofilm neoformation on the dentogingival area (au)

Effect of gamma radiation on dentin bond strength and morphology / Efeito da radiação gama na força de adesão e morfologia dentinária

A radiação gama é um método de esterilização geralmente utilizado em banco de ossos e de dentes humanos extraídos. A força de adesão de resina composta à dentina de dentes humanos submetidos aos raios gama não tem sido investigada na literatura. O objetivo deste trabalho foi avaliar o efeito da radiação gama na força de adesão de resina composta à dentina e na sua morfologia. Pré-molares íntegros extraídos, após remoção de suas raízes, foram divididos em dois grupos: grupo controle e coroas dentárias submetidas à esterilização pela radiação gama. As coroas dentárias foram incluídas em resina epóxica e o esmalte da face vestibular removido expondo a dentina subjacente. O sistema adesivo SBMPPlus foi aplicado sobre uma área de 3 mm de diâmetro após 15 segundos de condicionamento com ácido fosfórico 37 por cento. Um cilindro de resina composta foi obtido sendo os espécimes armazenados em água destilada a 37°C por 24 horas até o teste de cisalhamento. Fragmentos dentários de ambos os grupos foram preparados para análise em microscopia eletrônica de varredura. Os resultados do teste de cisalhamento demonstraram que não houve diferença estatisticamente significativa entre os dois grupos de acordo com o teste de Tukey (p>0,05). Nenhuma alteração marcante foi detectada na morfologia dentinária avaliada ao microscópio eletrônico de varredura. Os resultados indicaram que a radiação gama não afetou a força de adesão do SBMPPlus à dentina e também não alterou a morfologia dentinária

Biomarkers to predict oral squamous cell carcinoma in precancerous stages

There have been many attempts to establish biomarkers in order to determine the susceptibility of some normal human tissues to undergo malignant change. However, definitive markers for oral squamous cell carcinoma have not been yet achieved. Amongst some of the most promising molecular biomarkers, there is a respectful amount of literature produced on p53, both in human tissue fluids and in biopsies of potentially malignant lesions, 3p gene deletions, and, most recently, image-based ploidy analysis of tissue specimens.. In spite of the experimental character and speculative results of all those novel techniques, the image-based ploidy analysis appears to be the most sensitive and reliable method to predict malignant transformation in potentially malignant lesions of the oral mucosa

Preferências por açúcar e prevalência de cárie dentária em populaçöes desfaveladas de Bauru-SP-Brasil / Taste preference for sweetness in poor school children in Bauru-Brazil: influence on dental caries

Este estudo trasversal foi delineado para estimar a preferência por açúcares em escolares e diferenças apresentadas por grupos de diferentes inserçöes sociais e econômicas. Adicionalmente, com objetivo de avaliar se a preferência gustativa por açúcar mostrava-se associada à prevalência de cárie, foram examinados 527 escolares do grupo etário 10 a 15 anos, procedentes de dois grupos sociais. O primeiro grupo era oriundo de uma escola da área periférica do município (nD8) e o segundo provinha de uma populaçäo com extremas privaçöes sociais, em processo de desfavelamento (ny). A preferência por açúcar foi avaliada por meio de uma versäo modificada do Sweet Preference Inventory. Cada criança provou 5 soluçöes de um suco de fruta, cuja concentraçäo de açúcar variou de 0 a 1,17 Molar (0 a 400g/mol.). A prevalência de cárie foi avaliada por meio do CPOS. No grupo de maiores privaçöes sociais (Desfavelamento), 28,9 por cento preferiram o suco mais adoçado, enquanto no outro grupo 29,3 por cento preferiram esta soluçäo. Os testes de Mann-Whitney e coeficiente de correlaçäo de Spearman foram aplicados para análise estatística (p<0,05). Os resultados mostraram que o nível socioeconômico näo apresentou influência sobre a preferência por açúcar, mas foi significantemente associado à prevalência de cárie