Infrared spectroscopy for fast screening of diabetes and periodontitis.

SIGNIFICANCE: FT-IR is an important and emerging tool, providing information related to the biochemical composition of biofluids. It is important to demonstrate that there is an efficacy in separating healthy and diseased groups, helping to establish FT-IR uses as fast screening tool. AIM: Via saliva diagnosis evaluate the accuracy of FT-IR associate with machine learning model for classification among healthy (control group), diabetic (D) and periodontitis (P) patients and the association of both diseases (DP). APPROACH: Eighty patients diagnosed with diabetes and periodontitis through conventional methods were recruited and allocated in one of the four groups. Saliva samples were collected from participants of each group (n = 20) and were processed using Bruker Alpha II spectrometer in a FT-IR spectral fingerprint region between 600 and-1800 cm-1, followed by data preprocessing and analysis using machine learning tools. RESULTS: Various FTI-R peaks were detectable and attributed to specific vibrational modes, which were classified based on confusion matrices showed in paired groups. The highest true positive rates (TPR) appeared between groups C vs D (93.5 % ± 2.7 %), groups C vs. DP (89.2 % ± 4.1 %), and groups D and P (90.4 % ± 3.2 %). However, P vs DP presented higher TPR for DP (84.1 % ±3.1 %) while D vs. DP the highest rate for DP was 81.7 % ± 4.3 %. Analyzing all groups together, the TPR decreased. CONCLUSION: The system used is portable and robust and can be widely used in clinical environments and hospitals as a new diagnostic technique. Studies in our groups are being conducted to solidify and expand data analysis methods with friendly language for healthcare professionals. It was possible to classify healthy patients in a range of 78-93 % of accuracy. Range over 80 % of accuracy between periodontitis and diabetes were observed. A general classification model with lower TPR instead of a pairwise classification would only have advantages in scenarios where no prior patient information is available regarding diabetes and periodontitis status.

Surface-Enhanced Raman Analysis of Uric Acid and Hypoxanthine Analysis in Fractionated Bodily Fluids.

In recent years, the disease burden of hyperuricemia has been increasing, especially in high-income countries and the economically developing world with a Western lifestyle. Abnormal levels of uric acid and hypoxanthine are associated with many diseases, and therefore, to demonstrate improved methods of uric acid and hypoxanthine detection, three different bodily fluids were analysed using surface-enhanced Raman spectroscopy (SERS) and high-performance liquid chromatography (HPLC). Gold nanostar suspensions were mixed with series dilutions of uric acid and hypoxanthine, 3 kDa centrifugally filtered human blood serum, urine and saliva. The results show that gold nanostars enable the quantitative detection of the concentration of uric acid and hypoxanthine in the range 5-50 µg/mL and 50-250 ng/mL, respectively. The peak areas of HPLC and maximum peak intensity of SERS have strongly correlated, notably with the peaks of uric acid and hypoxanthine at 1000 and 640 cm-1, respectively. The r2 is 0.975 and 0.959 for uric acid and hypoxanthine, respectively. Each of the three body fluids has a number of spectral features in common with uric acid and hypoxanthine. The large overlap of the spectral bands of the SERS of uric acid against three body fluids at spectra peaks were at 442, 712, 802, 1000, 1086, 1206, 1343, 1436 and 1560 cm-1. The features at 560, 640, 803, 1206, 1290 and 1620 cm-1 from hypoxanthine were common to serum, saliva and urine. There is no statistical difference between HPLC and SERS for determination of the concentration of uric acid and hypoxanthine (p > 0.05). For clinical applications, 3 kDa centrifugal filtration followed by SERS can be used for uric acid and hypoxanthine screening is, which can be used to reveal the subtle abnormalities enhancing the great potential of vibrational spectroscopy as an analytical tool. Our work supports the hypnosis that it is possible to obtain the specific concentration of uric acid and hypoxanthine by comparing the SER signals of serum, saliva and urine. In the future, the analysis of other biofluids can be employed to detect biomarkers for the diagnosis of systemic pathologies.

FTIR spectroscopy as a point of care diagnostic tool for diabetes and periodontitis: A saliva analysis approach.

Diabetes mellitus (DM) is a general term for heterogeneous metabolic disorders whose main characteristic is chronic hyperglycemia. Considering that conventional diagnostic methods are currently unable of early DM detection and the number of diabetic patients has been increasing worldwide, there is a clinical need for novel diagnostic approaches. Fourier-transform infrared (FT-IR) spectroscopy technique an alternative non-invasive diagnostic method for real-time evaluation of biofluids such as saliva. This study aims evaluate the feasibility of diagnosing diabetes and periodontitis through saliva samples based on their FT-IR spectra. Our first collection and spectral analysis of samples was a pilot study and comprised a total of 23 patients, 2 healthy, 9 with diabetes and 12 with diabetes and periodontitis. By using weighted KNN as classifier, we have obtained an area under the Receiver Operating Characteristic curve of 0.92 and 0.95 when considering the diabetes or diabetes + periodontitis groups as positive groups, respectively.

Rapid diagnosis of COVID-19 using FT-IR ATR spectroscopy and machine learning.

Early diagnosis of COVID-19 in suspected patients is essential for contagion control and damage reduction strategies. We investigated the applicability of attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy associated with machine learning in oropharyngeal swab suspension fluid to predict COVID-19 positive samples. The study included samples of 243 patients from two Brazilian States. Samples were transported by using different viral transport mediums (liquid 1 or 2). Clinical COVID-19 diagnosis was performed by the RT-PCR. We built a classification model based on partial least squares (PLS) associated with cosine k-nearest neighbours (KNN). Our analysis led to 84% and 87% sensitivity, 66% and 64% specificity, and 76.9% and 78.4% accuracy for samples of liquids 1 and 2, respectively. Based on this proof-of-concept study, we believe this method could offer a simple, label-free, cost-effective solution for high-throughput screening of suspect patients for COVID-19 in health care centres and emergency departments.

Diagnosis of Systemic Diseases Using Infrared Spectroscopy: Detection of Iron Overload in Plasma-Preliminary Study.

Despite the important role of iron in cellular homeostasis, iron overload (IO) is associated with systemic and tissue deposits which damage several organs. In order to reduce the impact caused by IO, invasive diagnosis exams (e.g., biopsies) and minimally invasive methods were developed including computed tomography and magnetic resonance imaging. However, current diagnostic methods are still time-consuming and expensive. A cost-effective solution is using Fourier-transform infrared spectroscopy (FTIR) for real-time and molecular-sensitive biofluid analysis during conventional laboratory exams. In this study, we performed the first evaluation of the accuracy of FTIR for IO diagnosis. The study was performed by collecting FTIR spectra of plasma samples of five rats intravenously injected with iron-dextran and five control rats. We developed a classification model based on principal component analysis and supervised methods including J48, random forest, multilayer perceptron, and radial basis function network. We achieved 100% accuracy for the classification of the IO status and provided a list of possible biomolecules related to the vibrational modes detected. In this preliminary study, we give a first step towards real-time diagnosis for acute IO or intoxication. Furthermore, we have expanded the literature knowledge regarding the pathophysiological changes induced by iron overload.

Terapia periodontal de suporte em paciente com periodontite agressiva generalizada: acompanhamento clínico e radiográfico de 13 anos / Periodontal maintenance therapy in patient with generalized aggessive periodontitis: clinical and radiographic following by 13 years

A terapia periodontal de suporte (TPS) tem como objetivo principal a manutenção dos resultados obtidos durante o tratamento periodontal ativo, sendo a forma mais previsível de controlar a doença periodontal. Essa extensão do tratamento periodontal, pode ocorrer em intervalos de tempo que variam de acordo com a severidade da doença, condição sistêmica do indivíduo, idade, fatores de risco, entre outros. A TPS contribui para a redução da perda dentária e recorrência da doença periodontal, além de possibilitar o diagnóstico de outras doenças bucais. Durante essa etapa, é possível traçar o perfil do paciente, identificar suas dificuldades e estabelecer condutas educativas, preventivas e terapêuticas necessárias para o controle do biofilme e da doença periodontal. Assim, o periodontista deve conscientizar o paciente sobre a importância da TPS, sendo que, a adesão ao tratamento é fundamental para a manutenção da saúde dos tecidos periodontais a longo prazo. O presente relato de caso clínico, demonstra o sucesso da TPS em paciente jovem acometida por periodontite agressiva generalizada. Após a realização da terapia periodontal não cirúrgica, a paciente foi inserida em um programa de manutenção periodontal, há 13 anos atrás, no qual participa ativamente até o presente momento. (AU)

The main objective of the periodontal maintenance therapy (PMT) is to maintain the results achieved during the active periodontal therapy, being the most predictable way of controlling the periodontal disease. This extension of the periodontal treatment may occur at different times, varying according to the aggressiveness of the disease, general health condition of the subject, age and risk factors, among others. The PMT contributes to the reduction of dental loss and prevents the reoccurrence of the periodontal disease, while also allowing the diagnose of other diseases of the mouth. During this phase it is possible to trace the patient's profile, identifying the difficulties and stablishing educational, preventive and therapeutic practices to control oral biofilm and periodontal disease. Thus, the periodontist must raise the patient's awareness to the importance of the PMT, as the patient compliance to the treatment is essential for the long term preservation of the periodontal tissue health. The clinical case here described demonstrates the success of the PMT performed on a young female patient afflicted with generalized aggressive periodontitis. After having performed the non-surgical periodontal therapy, the patient entered a periodontal maintenance program 13 years ago, in which she has been actively participating until the present time.(AU)

New insights of Raman spectroscopy for oral clinical applications.

Oral injuries are currently diagnosed by histopathological analysis of biopsy, which is an invasive procedure and does not give immediate results. On the other hand, the Raman spectroscopy technique is a real-time and minimally invasive analytical tool with a notable diagnostic capability. At the current stage, researchers are widely aware of the diagnostic potential of the technique and how it is considered promising for providing biochemical information in real time and without damaging the tissue. The problem originates from a lack of relevant studies and clinical trials that could show the actual use of Raman spectroscopy to help patients. Our goal here is to narrow the relationship between physicists, chemists, engineers, computer scientists, and the medical community, and in fact discuss the potential of Raman spectroscopy as a novel clinical analysis method. In the present study, we focused on the use of Raman spectroscopy as a daily clinical practice. In this context, additional studies and in vivo tests should be performed with the same approach as a real application. We want to show the scientific and industrial community what is really necessary for this, starting from a clinical point of view. Using our previous experience publishing different oral pathologies and types of samples, we also aim to discuss the current state and potential of Raman spectroscopy and what is required to implement Raman spectroscopy for oral clinical applications.

Evaluation of inflammatory processes by FTIR spectroscopy.

Fourier transform infrared (FTIR) spectroscopy is a powerful diagnosis technique and has been used to identify patterns of molecular changes based on vibration modes. The objective of this study was to evaluate inflammatory fibrous hyperplasia (IFH) lesions and oral normal mucosa (NM) initially with histopathological exam and then using micro-FTIR spectroscopy to analyse the samples. Eleven IFH and 11 NM samples were analysed at five different points to cover the largest area possible by the micro-FTIR technique. Bands were observed between 970 and 1743 cm-1 which corresponded to different structural components like collagen, lipids, fatty acids, proteins and amino acids. Spectral bands were more intense mostly for IFH lesions, including collagen bands, which are an important component of inflammatory fibrous hyperplasia. This study demonstrated that differentiation in the inflammatory tissue was observed in FTIR spectral differences, in terms of biochemical composition.

Human papillomavirus detection using PCR and ATR-FTIR for cervical cancer screening.

The human papillomavirus (HPV) genital infection is considered one of the most common sexually transmitted diseases worldwide, and has been associated with cervical cancer. The objective of this study was to investigate the efficacy of the diagnostic methods: polymerase chain reaction (PCR) and Fourier transform infrared (FTIR) equipped with an ATR (Attenuated Total Reflectance) unit (Pike Tech) spectroscopy, to diagnose HPV infection in women undergoing gynecological examination. Seventeen patients (41.46%) of the 41 patients analyzed were diagnosed with exophytic/condyloma acuminate lesions by clinical analysis, 29 patients (70.7%) (G1 group) of the 41 patients, showed positive result for HPV cell injury by oncotic colpocitology and 12 patients (29.3%) (G2 group), presented negative result for cellular lesion and absence of clinical HPV lesion. Four samples were obtained per patient, which were submitted oncotic colpocitology analysis (Papanicolau staining, two samples), PCR (one sample) and ATR-FTIR analysis (one sample). L1 gene was amplified by PCR technique with specific GP5+/GP6+ and MY09/MY11 primers. PCR results were uniformly positive for presence of HPV in all analyzed samples. Multivariate analysis of ATR-FTIR spectra suggests no significant biochemical changes between groups and no clustering formed, concurring with results of PCR. This study suggests that PCR and ATR-FTIR are highly sensitive technique for HPV detection.

Molecular model for hydrated biological tissues.

A density-functional microscopic model for soft tissues (STmod) is presented. The model was based on a prototype molecular structure from experimentally resolved type I collagen peptide residues and water clusters treated in periodic boundary conditions. We obtained the optimized geometry, binding and coupling energies, dipole moments, and vibrational frequencies. The results concerning the stability of the confined water clusters, the water-water, and water-collagen interactions were successfully correlated to some important experimental trends of normal and inflammatory tissues.

Bone mimetic for confection of bio inspired ceramic materials: literature review

The loss of bone mass is a very common condition that is affecting people of various ages and causing a declinein quality of life of these people. Currently there is the possibility of using bone grafts to replace this bone loss, whichcan be autogenously, halogen or heterogeneous, with autogenously those get better results, but with disadvantageof providing two surgical sites in patients. In this sense, and also for other reasons related to properties of materials,authors are seeking to mimic natural bone for the production of ceramic biocompatible materials that can retainthe structure and properties of natural bone tissue. Such material should present structure dense/porous structuresimilar to the cortical and cancellous bone. With this, these materials can have good future applications, including thereplacement of lost bone tissue, and then becoming one more option to improve the quality of life of these patients.Thus, the objective of this study was a literature review of the ceramics that mimic the bone tissue, which are thenconsidered bio inspired materials...

Lateral periodontal cyst: a case report and literature review.

BACKGROUND: The lateral periodontal cyst is considered a developmental odontogenic cyst with unusual occurrence. In most cases it is preliminary diagnosed as a radiographic finding, presenting as well circumscribed or as a round or teardrop-shaped radiolucent area. Due to its location it can easily be misdiagnosed as a lesion of endodontic origin. Final diagnosis should be based on histopatological examination. The purpose of this paper is to report a classic case of lateral periodontal cyst located in the anterior region of mandible and to review the relevant literature which describes the clinical, radiological and histopathological features of lateral periodontal cysts. METHODS: A 50 years female patient complained of an asymptomatic gingival swelling in the region between the left mandibular lateral incisor and canine. Radiographic examination revealed a well circumscribed radiolucency with approximately 0.5 cm diameter with a radiopaque margin between the roots of the left mandibular lateral incisor and canine. The adjacent teeth had vital pulp. RESULTS: A total enucleation of the lesion was performed, and intraoperative examination showed a single lesion with no communication between the cyst's cavity and the oral environment. Histological examination revealed that the lesion was "lateral periodontal cyst of developmental origin". There was no recurrence or complications for 24 months follow-up. CONCLUSIONS: The lateral periodontal cyst can be considered in the differential diagnosis when a radioloucent lesion appears adjacent to the roots of vital teeth. The treatment of choice is surgical removal and subsequent histological evaluation to confirm the diagnosis. Relapses are infrequent.

Análise de queilite actínica por espectroscopia micro FT-IR / Analysis of actinic cheilitis by micro spectroscopy FT-IR

A queilite actínica (QA) é uma lesão considerada potencialmente cancerizável, localizada principalmente em lábio inferior e causada pela exposição crônica à radiação UV. A Espectroscopia FT-IR fornece informações moleculares através de fenômenos ópticos observado pela vibração de suas moléculas. Tem sido empregada em estudos biológicos para a caracterização de alterações neoplásicas. No entanto, são escassos os estudos que envolvam processos potencialmente cancerizáveis. Objetivou-se avaliar Q As através da espectroscopia micro FT-IR com relação aos seus aspectos moleculares para região de finger print (900-1800 cm-1) e altos números de onda (2800-3600 cm-1), e ainda verificar a análise dos componentes principais (PCA) e regressão logística binária (RLB) como modelo de diagnóstico. Foram avaliadas 14 amostras de QA e14 amostras de mucosas normal (MN), obtendo-se 5 espectros por amostra, totalizando 140 espectros avaliados (70 de cada grupo). Os resultados demonstrados pela análise dos componentes principais revelaram pelo gráfico de scree plot que os dez primeiros PCs deveriam ser utilizados na análise. As maiores variações observadas pelo gráfico de loading plot relacionaram-se aos modos vibracionais do colágeno, ácidos nucléicos, lipídios e água confinada. O modelode regressão logística binária mostrou 80,6% de pares concordantes para região de finger print e 81,7% de pares concordantes para a região de altos números de onda. Concluiu-se que a espectroscopia micro FT-IR provê características moleculares importantes das19 amostras de QA, evidenciadas tanto na região de finger print como na de altos números de onda.

Actinic cheilitis (AC) is a potentially precancerous lesion, located primarily in lower lip caused by chronic exposure to UV radiation.The FT-IR spectroscopy provides molecular information through optical properties observed by the vibration of its molecules. This technique has been used in biological studies for characterization of neoplastic tissues. However, there are few studies involving potentially cancerous processes. This study aimed to evaluate molecular changes on AC through micro FT-IR spectroscopy infinger print (900-1800 cm-1) and high wave numbers (2800-3600 cm-1) region, and also to verify the principal components analysis (PCA)and binary logistic regression (BLR) as a model of diagnosis. We evaluated 14 samples of AC and 14 samples of normal mucosa (NM),resulting in 5 spectra per sample, totalling 140 spectra analyzed (70from each group). The results demonstrated by PCA revealed byscree plot graph showed that the first ten principal components(PCs) should be used in the analysis. The largest variations observedby loading graph plot related to the vibrational modes of collagen,nucleic acids, lipids and confined water. The BLR model showed80.6% of concordant pairs for the finger print region and 81.7% of concordant pairs of high wave numbers region. It was concluded that the micro FT-IR spectroscopy provides important molecular features of AC samples, evidenced both in the finger print and in thehigh wave numbers region.

Spectral region optimization for Raman-based optical biopsy of inflammatory lesions.

OBJECTIVE: The biochemical alterations between inflammatory fibrous hyperplasia (IFH) and normal tissues of buccal mucosa were probed by using the FT-Raman spectroscopy technique. The aim was to find the minimal set of Raman bands that would furnish the best discrimination. BACKGROUND: Raman-based optical biopsy is a widely recognized potential technique for noninvasive real-time diagnosis. However, few studies had been devoted to the discrimination of very common subtle or early pathologic states as inflammatory processes that are always present on, for example, cancer lesion borders. METHODS: Seventy spectra of IFH from 14 patients were compared with 30 spectra of normal tissues from six patients. The statistical analysis was performed with principal components analysis and soft independent modeling class analogy cross-validated, leave-one-out methods. RESULTS: Bands close to 574, 1,100, 1,250 to 1,350, and 1,500 cm(-1) (mainly amino acids and collagen bands) showed the main intragroup variations that are due to the acanthosis process in the IFH epithelium. The 1,200 (C-C aromatic/DNA), 1,350 (CH(2) bending/collagen 1), and 1,730 cm(-1) (collagen III) regions presented the main intergroup variations. This finding was interpreted as originating in an extracellular matrix-degeneration process occurring in the inflammatory tissues. The statistical analysis results indicated that the best discrimination capability (sensitivity of 95% and specificity of 100%) was found by using the 530-580 cm(-1) spectral region. CONCLUSIONS: The existence of this narrow spectral window enabling normal and inflammatory diagnosis also had useful implications for an in vivo dispersive Raman setup for clinical applications.

Papiloma escamoso bucal e condiloma acuminado: relato de caso clínico / Oral squamous papilloma and condyloma accuminattum: a case report

Objetivos: O presente artigo relata um caso clínico de papiloma em ventre lingual associado à história pregressa de condiloma acuminado em região peniana. Materiais e métodos: Paciente do gênero masculino, leucoderma, 28 anos, foi encaminhado à clínica de Propedêutica Estomatológica. O paciente relatou queixa de "condiloma bucal" (sic). O mesmo informou que havia notado uma "bolinha na base da língua" e que havia cauterizado uma lesão peniana há sete meses, com diagnóstico de condiloma acuminado. Ao exame clínico intrabucal notou-se lesão nodular pediculada, papilomatosa, assintomática, de coloração semelhante à mucosa adjacente, localizada em região de freio lingual, medindo aproximadamente 0,5 cm no maior diâmetro. Foi realizada biópsia excisional e o material enviado para exame histopatológico. Resultados: O exame histológico mostrou lesão proliferativa epitelial benigna, constituída por numerosas projeções papíliferas revestidas por epitélio pavimentoso estratificado, que mostrava áreas de espessura aumentada, exibindo várias células com vacuolização citoplasmática, halos perinucleares e/ou aspecto coilocitótico, recebendo diagnóstico de papiloma escamoso. Conclusão: No caso clínico relatado, o papiloma escamoso bucal sugere inter-relação com a história pregressa de condiloma acuminado em região peniana do paciente. Cabe ao cirurgião dentista minuciosa observação clínica e atenta anamnese visando favorecer o diagnóstico, o tratamento, a orientação, e o esclarecimento ao paciente quanto aos riscos e as medidas profiláticas a serem tomadas.

Objectives: This article reports a case of oral papilloma in the ventral tongue associated to previous penile Condyloma acuminatum. Materiais and methods: A white male, 28 years old, was referred to the Propaedeutic Stomatology University Clinic claiming of a nodule at the base of the tongue. He had a penile lesion removed seven months before, with diagnosis of Condyloma acuminatum. Clinical exarnination showed a 0.5 cm intraoral pedunculated nodular papillomatous asymptomatic lesion, located in the tongue frenulum. Excisional biopsy was performed. Results: Histological examination showed a benign epithelial proliferative lesion, presenting numerous long papillary projections with thinned extremities, lined by stratified epithelium, with areas of increased thickness and severa I coilocytotic cells characterized by cytoplasmic vacuolization and perinuclear halos, receiving the diagnosis of squamous papilloma. Conclusion: The oral squamous papilloma, in this case, suggests inter-relationship with the penile Condyloma acuminatum. Dental professionals must be able to make a good clinical examination and anamnesis in order to promote the patients diagnosis, treatment and orientation about the risks and prophylactic measures regarding this lesion.

Gingival squamous cell carcinoma: a case report.

BACKGROUND: Squamous cell carcinoma is a malignant epithelial neoplasm characterized by variable clinical manifestations. When located in the gingiva, this neoplasm may mimic common inflammatory lesions. The aim of this study was to report a case of atypical squamous cell carcinoma, in which the patient had no risk factors for the development of this neoplasm. METHODS: A 61 year old Caucasian female was seen with a 3 month history of a rapidly growing, painful nodule in the gingiva adjacent to tooth #11. Clinical examination revealed a proliferative lesion in the vestibular marginal gingiva of teeth #11 and #12, presenting with purulent exudation. Thus, in view of the clinical symptoms and differential diagnosis of an infectious granulomatous process and malignant neoplasm, an incisional biopsy was obtained from the lesion. RESULTS: The diagnosis of squamous cell carcinoma was made and fourteen days after incisional biopsy, healing was found to be unsatisfactory. The patient was referred for treatment consisting of surgical excision of the tumour. A removable partial denture was fabricated for rehabilitation, one month after surgery of the maxilla; the patient was submitted to dissection of the regional lymph nodes and radiotherapy for an additional 3 months. Three years after the end of treatment, the patient continues to be followed-up and does not show any sign of recurrence. CONCLUSIONS: Gingival squamous cell carcinoma is a condition which chance of cure is higher when carcinomatous lesions are diagnosed and treated early. In this instance dentists play an important role in early detection of gingival squamous cell carcinoma.

Rational use of antimicrobials in dentistry during pregnancy.

The use of medicines during pregnancy deserves special attention from dentists due to the potential risks to fetal development. The prescription of antimicrobial drugs during this period must be based not only on the etiology of the disease but also on the drug's effect on the embryo, which may be toxic, possibly leading to irreversible lesions. Interest in studies of the teratogenic effects of drugs increased in response to reports of the high incidence of phocomelia in patients treated with thalidomide. Although teratogenicity has long been known, pregnant women today are still exposed to this risk. The effects of drugs depend on the level of susceptibility of the fetus and on the period of exposure during pregnancy. In this context, and considering the paucity of studies on this subject in dentistry, the aim of this review was to offer an up-to-date compilation of data on the antimicrobial drugs most frequently used during pregnancy and the effects of their use.