Immersion and haptic feedback impacts on dental anesthesia technical skills virtual reality training.

OBJECTIVES: Administering anesthesia to the inferior alveolar nerve is 1 of the most stressful processes in dental training. Most studies using virtual reality (VR) for dental training have used non-immersive technologies. The purpose of this work is to assess the impact of immersive technologies on skills training. METHODS: On May 2019, an experimental study was conducted with 163 clinical dental students, divided into 4 groups across 2 phases (preceptorship and training) with haptic feedback either On or Off. The participants trained on the inferior alveolar dental anesthesia procedure in a haptic VR simulator. Their technical skills were evaluated in terms of needle insertion features which were computed from a haptic device providing kinematic data. Also, the participants reported their subjective experience with syringe handling and simulator sickness. A machine learning method was implemented to automatically evaluate the needle insertion point performance of the student. RESULTS: Groups receiving immersive preceptorship and/or immersive training showed more accuracy and confidence in administering the anesthesia. Participants perceived a high sense of realism with the haptic feedback when handling the syringe. The machine learning method was validated, with an accuracy of 84%, as a good classifier to assess a student's needle insertion point performance. CONCLUSIONS: The immersive VR simulator allows the practice of the inferior alveolar nerve block under near real conditions and with immediate feedback to the dental student with respect to the needle insertion point. This machine learning based automatic evaluation provides a method to improve technical skills, contributing to dental training.

Green Teeth Related to Bilirubin Levels.

OBJECTIVE: To describe a form of tooth pigmentation caused by serum bilirubin deposition during dental calcification in a premature child. The bilirubin levels during the three months after birth are presented. In this period the crowns of the primary teeth are still forming. Such anomaly does not have symptoms, but has a displeasing effect and great anxiety within the family. CASE REPORT: The case reported here highlights the relevance of past medical history, especially the diagnoses of prolonged conjugated hyperbilirubinemia, in this case, to confirm them and to comfort the family. In this case, no esthetic treatment had been undertaken because the child was still too young and not yet concerned. The dental treatment plan included regular checkups every 3 months for maintaining oral health to prevent caries. CONCLUSION: As this is a rare condition that affects the teeth, parents will most likely look for a dentist for treatment. Therefore, dentists must be aware or such abnormalities and take a multidisciplinary approach, thus making it possible to establish a final diagnosis.

Low intensity lasers differently induce primary human osteoblast proliferation and differentiation.

Among various compounds used in research and clinic for degenerative bone diseases, low level laser therapy (LLLT), comprising low level lasers (LLL) and light emitting diodes (LEDs), has been investigated regarding its effects on bone metabolism. They have specific wavelengths but in general act as a cellular biomodulator, and as a therapeutic agent, rebalancing and normalizing their activity. However, they are not standardized yet, since their parameters of use are relevant for the effects and mechanisms of action. Therefore, the aim of this study was to compare the influence of two spectrums of LLL and LED phototherapy, at the same energy densities (10 and 50J/cm(2)), on human osteoblasts proliferation and differentiation. The involvement of ERK signaling on proliferation was also investigated by evaluating its activation during proliferation under different phototherapies by western blotting and CFSE-based osteoblast proliferation was measured in a presence or absence of the ERK-specific inhibitor. Osteogenic differentiation was evaluated through in vitro mineralization and gene expression of type I collagen (COL1A1) and osteonectin (SPARC) by Real Time- PCR. Increases in viable cells and proliferation were obtained after irradiation, regardless of LLLT type. However, only red at 10J/cm(2) and infrared at both doses, but not LED, induced ERK1/2 activation. In the presence of ERK inhibitor, the LLL-induced proliferation was prevented. In addition, while COL1A1 gene expression was upregulated by red laser, SPARC does so by infrared stimulation. However, LED, at both doses, increased both COL1A1 and SPARC expression. All LLLT increased mineralization, dependent on the dose and time. Thus, LLL and LED differently modulated the metabolism of human osteoblasts, increasing proliferation by mechanism dependent or not of ERK signaling activation and osteogenic differentiation markers.

In Vitro Identification of Histatin 5 Salivary Complexes.

With recent progress in the analysis of the salivary proteome, the number of salivary proteins identified has increased dramatically. However, the physiological functions of many of the newly discovered proteins remain unclear. Closely related to the study of a protein's function is the identification of its interaction partners. Although in saliva some proteins may act primarily as single monomeric units, a significant percentage of all salivary proteins, if not the majority, appear to act in complexes with partners to execute their diverse functions. Coimmunoprecipitation (Co-IP) and pull-down assays were used to identify the heterotypic complexes between histatin 5, a potent natural antifungal protein, and other salivary proteins in saliva. Classical protein-protein interaction methods in combination with high-throughput mass spectrometric techniques were carried out. Co-IP using protein G magnetic Sepharose TM beads suspension was able to capture salivary complexes formed between histatin 5 and its salivary protein partners. Pull-down assay was used to confirm histatin 5 protein partners. A total of 52 different proteins were identified to interact with histatin 5. The present study used proteomic approaches in conjunction with classical biochemical methods to investigate protein-protein interaction in human saliva. Our study demonstrated that when histatin 5 is complexed with salivary amylase, one of the 52 proteins identified as a histatin 5 partner, the antifungal activity of histatin 5 is reduced. We expected that our proteomic approach could serve as a basis for future studies on the mechanism and structural-characterization of those salivary protein interactions to understand their clinical significance.

Histatin 5 inhibits adhesion of C. albicans to Reconstructed Human Oral Epithelium.

Candida albicans is the most pathogenic fungal species, commonly colonizing on human mucosal surfaces. As a polymorphic species, C. albicans is capable of switching between yeast and hyphal forms, causing an array of mucosal and disseminated infections with high mortality. While the yeast form is most commonly associated with systemic disease, the hyphae are more adept at adhering to and penetrating host tissue and are therefore frequently observed in mucosal fungal infections, most commonly oral candidiasis. The formation of a saliva-derived protein pellicle on the mucosa surface can provide protection against C. albicans on oral epithelial cells, and narrow information is available on the mucosal pellicle composition. Histatins are one of the most abundant salivary proteins and presents antifungal and antibacterial activities against many species of the oral microbiota, however, its presence has never been studied in oral mucosa pellicle. The objective of this study was to evaluate the potential of histatin 5 to protect the Human Oral Epithelium against C. albicans adhesion. Human Oral Epithelial Tissues (HOET) were incubated with PBS containing histatin 5 for 2 h, followed by incubation with C. albicans for 1 h at 37°C. The tissues were then washed several times in PBS, transferred to fresh RPMI and incubated for 16 h at 37°C at 5% CO2. HOET were then prepared for histopathological analysis using light microscopy. In addition, the TUNEL assay was employed to evaluate the apoptosis of epithelial cells using fluorescent microscopy. HOET pre-incubated with histatin 5 showed a lower rate of C. albicans growth and cell apoptosis when compared to the control groups (HOET alone and HOET incubated with C. albicans). The data suggest that the coating with histatin 5 is able to reduce C. albicans colonization on epithelial cell surfaces and also protect the basal cell layers from undergoing apoptosis.

Biocompatibility of Portland cement combined with different radiopacifying agents.

The aim of this study was to evaluate the response of rat subcutaneous tissue to Portland cement combined with two different radiopacifying agents, iodoform (CHI3) and zirconium oxide (ZrO2). These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were then stained with hematoxylin and eosin, and inflammatory reaction parameters were evaluated by light microscopy. The intensity of the inflammatory response to the sealants was analyzed by two blind calibrated observers throughout the experimental period. Histological analysis showed that all the materials caused a moderated inflammatory reaction at 7 days, which then diminished with time. At 15 days, the inflammatory reaction was almost absent, and fibroblasts and collagen fibers were observed indicating normal tissue healing. The degrees of the inflammatory reaction on different days throughout the experimental period were compared using the non-parametric Kruskal-Wallis test. Statistical analysis demonstrated no significant differences amongst the groups, and Portland cement associated with radiopacifying agents gave satisfactory results. Therefore, Portland cement used in combination with radiopacifying agents can be considered a biocompatible material. Although our results are very encouraging, further studies are needed in order to establish safe clinical indications for Portland cement combined with radiopacifying agents.

Viability of fibroblasts cultured under nutritional stress irradiated with red laser, infrared laser, and red light-emitting diode.

Phototherapy is noninvasive, painless and has no known side effect. However, for its incorporation into clinical practice, more well-designed studies are necessary to define optimal parameters for its application. The viability of fibroblasts cultured under nutritional stress irradiated with either a red laser, an infrared laser, or a red light-emitting diode (LED) was analyzed. Irradiation parameters were: red laser (660 nm, 40 mW, 1 W/cm(2)), infrared laser (780 nm, 40 mW, 1 W/cm(2)), and red LED (637 ± 15 nm, 40 mW, 1 W/cm(2)). All applications were punctual and performed with a spot with 0.4 mm(2) of diameter for 4 or 8 s. The Kruskal-Wallis test and analysis of variance of the general linear model (p ≤ 0.05) were used for statistical analysis. After 72 h, phototherapy with low-intensity laser and LED showed no toxicity at the cellular level. It even stimulated methylthiazol tetrazolium assay (MTT) conversion and neutral red uptake of fibroblasts cultured under nutritional stress, especially in the group irradiated with infrared laser (p = 0.004 for MTT conversion and p < 0.001 for neutral red uptake). Considering the parameters and protocol of phototherapy used, it can be concluded that phototherapy stimulated the viability of fibroblasts cultured under nutritional deficit resembling those found in traumatized tissue in which cell viability is reduced.

Uso de restaurações indiretas na correção da infra-oclusão: relato de caso / Use of indirect restorative technique for the correction of retained primary molar: case report

A infraoclusão de molares decíduos é uma situação clínica que pode causar prejuízos ao desenvolvimento da oclusão do paciente, mas com o desenvolvimento das técnicas e materiais odontológicos nos últimos anos, esse quadro clínico pode ser solucionado através de uma terapia mais conservadora. Este trabalho tem como objetivo apresentar a reabilitação de um dente em infraoclusão através da utilização de uma restauração indireta em resina composta. Esta técnica permite restabelecer as dimensões anatômicas, o equilíbrio oclusal e a estética da criança. Ao final pôde-se concluir que as restaurações indiretas em resina são uma boa opção de tratamento conservador para os casos de infraoclusão na dentição decídua.

Infraoccluded primary molars is a common clinical situation that can cause several damages for the development of occlusion, but with today?s development of the techniques and dental materials these clinical situation has several ways to be resolved, returning the oclusal balance for the patient. This article had as aim present a clinical report of a rehabilitation of an infraoccluded primary molar with the use of an indirect restoration in composite resin, designed to restore the anatomical size, the occlusion and esthetics of the child. At the end we can conclude that this technique presents several advantages, especially in Pediatric Dentistry.

Avaliação da toxicidade de materiais endodônticos em células-tronco da polpa dentária / Toxicity evaluation of endodontic materials in dental pulp stem cells

O objetivo deste trabalho foi avaliar ao efeito citotóxico doHidróxido de Cálcio, Paramonoclorofenol Canforado, Otosporin eFormocresol diluído em células-tronco da polpa de dente permanentehumano (DPSC). As DPSC foram semeadas em placa decultura na concentração de 1,5X104 células/poço. Foram feitasdiluições das drogas em 1:9, 1:27 e 1:81 e deixadas em contatocom as células por 2 horas, sendo que o grupo controle foi mantidoem DMEM completo. As células foram lavadas com soluçãosalina duas vezes. Foram realizadas avaliações do metabolismo(MTT). Concluiu-se que o Hidróxido de Cálcio e o Otosporinforam as drogas menos tóxicas para as DPSC, enquanto que oParamonofenol Canforado e o Formocresol foram letais em todas asconcentrações.

The aim of this paper was analyze the cytotoxicity effect ofCalcium Hydroxide, Paramonoclorofenol Canforado, Otosporinand Formocresol deluded in dental pulp stem cells (DPSC).Material and Methods: DPSC were grown in 96 wells cultureplate in the concentration of 1.5 X104 cells per well. Dilutionsof drugs were as followed: 1:9, 1:27 and 1:81, and control withDPSC in DMEM. The cells were cultured for an additional 2hours. The cells were washed with bufferin saline solution for2 times and MTT test was performed. Results: The Ca(OH)2and Otosporin were the drugs less toxic to the DPSC, while theParamonophenol Canforated and formocresol were lethal in allconcentrations. Conclusions: all drugs tested were toxic to theDPSC.

Comparative study between homeopathy and nimesulide on the prevention of bone resorption in experimental periodontitis in rats / Estudo Comparativo entre Homeopatia e Nimesulida na Prevenção da Reabsorção Óssea em Periodontite Experimental em Ratos

Periodontitis is a chronic disease characterized by bone loss and inflammatory changes. We studied the effect of a homeopathic agent (Mercúrios Corrosivos 6 CH) and a non-steroidal anti-inflammatory drug (nimesulide) on the alveolar bone loss progression in experimentally induced periodontitis in rats. Sixty (60) Wistar rats were separated into group 1 (homeopathy), group 2 (nimesulide) and group 3 (saline solution). Silk ligatures were placed at the gingival margin level of the lower right first molar of all rats. Alveolar bone loss was evaluated by light microscopic analysis and analyzed using software Image J. The results were submitted to the analysis of variance (ANOVA) and Tukey’s posttest (p<0.05). The analysis revealed that there was a higher bone loss in diseased sites as compared with healthy sites. A significant reduction in the alveolar bone resorption was observed in group 2 (nimesulide) as compared with group 1 (homeopathy) 7 days after the induction of periodontitis. Our data provided evidence that homeopathy does not decrease alveolar bone loss as opposed to nimesulide in experimentally induced periodontitis.