Chemical preconditioning escalates chondrogenic activity in explant cultured human dental pulp stem cell study model for future temporomandibular joint regeneration.

Context: Human dental pulp stem cells (hDPSC) derived from dental pulp in conducive environment activated by chemicals can enhance chondrogenic cells for future animal model temporomandibular joint model. Aim: The study aims at evaluating the chemicals preconditioning (curcumin and rapamycin) efficacy toward chondrogenic proliferation of human dental pulp stem cells. Settings and Design: The in vitro study model with 10 premolar teeth extirpated pulp was processed under sterile chemical conditions. The cells viability was checked with calorimetric assay for adipogenic and chondrogenic, osteogenic lineages. The viability of the cells and the concentration of curcumin (CU) and rapamycin (RP) required for cell differentiation toward chondrogenic lineage were assessed. Material and Methods: The hDPSC was evaluated after explant long-term cultivation with characterization and chemical conditioning with dimethyl sulfoxide (DMSO) as control. MTT assay was used for cytotoxicity evaluation, cell viability, and proliferation. The dose optimization was observed with RP and CU. Chondrogenic proliferation was assessed with standard staining method of 0.1% Safranin O and 0.1% Alcian blue. Statistical Design: The flow cytometry analysis revealed good results for CD 90 compared to others. The intergroup analysis was done by ANOVA, and intragroup analysis was done by Post hoc Tukey's test. The intragroup analysis showed P value < 0.05 for RP in comparison between the various preconditioning agents CU and RP. The dosage of 10 µg/ml RP was considered statistically significant. Results: The flow cytometer analysis revealed good results for CD 90 compared to other surface markers. The dosage of 10 µg/ml RP was having good chondrogenic cell proliferation. The intragroup analysis showed P value < 0.05 for RP in comparison between the various preconditioning agents CU and RP. The calorimetric assay (MTT) quantitative analysis of the chondrogenic cells with Safranin O stain the standard deviation (SD = 0.017 for rapamycin), Alcian blue (SD = 0.49 for RP) in comparison to DMSO (control) and CU. Conclusion: RP activates mTOR pathway and hence stabilizes the stem cell maintenance of human dental pulp stem cell and the dose quantified can be used for future animal temporomandibular joint animal model.

Antifibrotic Effect of Baicalin on Arecoline Induced Human Oral Fibroblast: An In-Vitro Study.

BACKGROUND: Baicalin is a flavonoid obtained from the Chinese herb Scutellaria baicalensis, which has a wide varieties of health benefits and scope to be studied for its therapeutic potential in oral fibrosis. AIM: The aim of the study was to investigate the antifibrotic effect of a Baicalin in arecoline induced human oral fibroblast in vitro setting. MATERIAL AND METHODS: Arecoline and ethanolic extracts of Baicalin were commercially purchased from Sigma-Aldrich. Human oral fibroblasts were cultured and characterized with specific fibroblast markers, and cells were stimulated with arecoline. An MTT assay (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) was executed to determine the half-maximal inhibitory concentration of arecoline and Baicalin. Arecoline-induced cells (25µg/ml) were treated with a non-toxic dose of Baicalin (proliferative dose of 25µg/ml). Cytokine (CCL2, CXCL-8, IL17, IL-beta, and IL-6) and fibrotic marker genes were studied by reverse transcription-polymerase chain reaction (RT-PCR). The inhibitory effect of Baicalin was studied to prove its antifibrotic properties. RESULTS: Arecoline significantly upregulated all inflammatory and fibrotic markers. On treatment with 25µg/ml of Baicalin, all inflammatory and fibrotic markers were inhibited. Arecoline affects fibroblast morphology, supporting the fact that arecoline is cytotoxic to cells. CONCLUSION: Baicalin can be used as an antifibrotic herb to treat OSMF.

Effects of surface modification techniques on zirconia substrates and their effect on bonding to dual cure resin cement - An in- vitro study.

Aim: This study aims to evaluate the effect of different surface treatments of monolithic zirconia on the bond strength of resin to zirconia and, to explore alternative methods to improve this bonding. Settings and Design: In-Vitro study. Materials and Methods: Fifty rectangular sintered blocks of Yttria-stabilized Tetragonal Zirconia Polycrystal ceramics of dimensions were milled and sintered. These specimens were further divided into five groups (control, air abrasion, etching with primer application, air abrasion with primer application and novel glass infiltrated zirconia surface group), containing 10 samples each. The specimens were analyzed for surface roughness, tensile bond strength to resin cements, and adhesive and cohesive mode of failures. Statistical Analysis Used: ANOVA and Post-Hoc Tukey test was perform to evaluate the significant differences in the mean values of the groups. Results: Air-abraded samples showed the highest surface roughness (4.95 ± 0.65) (P < 0.05). The group with air abrasion followed by primer application showed the highest tensile bond strength (7.12 ± 0.69) (P < 0.05). The lowest surface roughness (0.638 ± 0.8093) and tensile bond strength (2.03 ± 0.58) was seen in samples that were subjected to etchant treatment followed by application of methacryloyloxydecyl di-hydrogen phosphate (MDP) primer. The changes in comparison to the control group were statistically insignificant (P > 0.05). Except Groups A (control) and C (etchant followed by primer), all other groups showed a cohesive failure. Conclusion: Air abrasion of the zirconia surface with 50 µm alumina particles increases the surface roughness without damaging the surface. Air abrasion followed by MDP primer application is the recommended method of surface treatment to achieve superior bonding. Glass infiltration also showed promising results in terms of tensile bond strength.

Comparison of salivary total protein and electrolyte profile in HIV patients with and without antiretroviral therapy.

BACKGROUND: Saliva provides a primary defense mechanism against several infectious diseases through its numerous immunological and non-immunological factors. Alteration in the composition of saliva often compromises its defense mechanisms, predisposing the oral cavity to disease entities. HIV patients under antiretroviral therapy (ART) have shown to exhibit altered salivary composition. These changes are postulated to be a result of the effect of ART on the salivary protein and electrolytes levels. OBJECTIVES: The present study aims to assess the potential difference in the salivary total protein and electrolyte levels in HIV patients with and without ART. METHODS: Patients were divided into 3 groups- Group A (HIV-1 positive patient under ART for at least 6 months)-66, Group B (HIV-1 positive patient not started on ART)-66, Group C (HIV negative patients)-66. Saliva samples were collected and evaluated for total salivary protein and electrolyte levels in all the 3 groups. RESULTS: There was a statistically significant difference in the salivary protein (p = 0.000) and electrolyte (Sodium, p = 0.000; Potassium, p = 0.039; chlorine, p = 0.027; ionized calcium, p = 0.002) levels among the three groups. CONCLUSION: HIV positive individuals with and without ART have alteration in the salivary composition. Some of these alterations (total protein and iCa levels) are due to the HIV infection, while others (Na, K, Cl) could be due to ART or a combined effect of both. Salivary changes in HIV positive individuals could predispose them to oral diseases. Thus, regular oral examination and prophylactic regimen must be formulated to maintain their oral hygiene and quality of life.

Assessment of Antagonist Enamel Wear and Clinical Performance of Full-Contour Monolithic Zirconia Crowns: One-Year Results of a Prospective Study.

PURPOSE: To assess the clinical performance and survival of full-contour monolithic zirconia (MZ) crowns and enamel wear produced over a 1-year period. MATERIALS AND METHODS: 60 patients requiring full-coverage restorations for endodontically treated posterior teeth opposed by healthy unrestored antagonistic teeth were selected. MZ crowns were fabricated. Vinyl polysiloxane impressions of the antagonist teeth were made, and the stone casts were digitized using a 3D laser scanner. Wear of the opposing natural teeth was evaluated at baseline (1 week), 6 months, and 1 year after crown cementation. Superimposition of the follow-up scans on the baseline scans were performed to evaluate wear. Survival and function of the restorations were evaluated by the modified USPHS rating criteria at the same timeframes. RESULTS: Comparison of the baseline and the follow-up wear values was statistically tested using the paired t-test. Statistical significance was noted between the wear values at 6 months (15.5 µm) and at 12 months (16.3 µm) (p < 0.05). The Wilcoxon signed rank sum test was performed to evaluate each parameter of the modified USPHS criteria and to analyze the change in the follow-up scores of the restorations. The survival rate for the crowns was 100%. Results were classified as "excellent" over a 1-year follow up. CONCLUSIONS: MZ crowns showed promising results related to antagonist enamel wear and survival/clinical performance.

Long term explant culture for harvesting homogeneous population of human dental pulp stem cells.

Dental pulp stem cells have emerged as a preferred source of mesenchymal stem cells, because of its easy availability and high stem cell content. Dental pulp is a specific fibrous tissue that contains heterogeneous populations of odontoblasts, fibroblasts, pericytes, progenitors, stem cells, leukocytes and neuronal cells. In this study, we propose sustained explant culture as a simple, economical and efficient process to isolate dental pulp stem cells from human Dental pulp Tissue. Historically explant cultures were used to get fibroblast cells from embryonic chick heart using plasma clot cultures. The subculture was performed by lifting mother explant (original explant) and grafting it in a new plasma clot. We modified this age old technique to suit the modern times. Here we demonstrate for the first time that the mother explant (E0) of human dental pulp tissue could be sub-cultured consecutively seven times (E7) without displacement. This technique is highly reproducible and permits growth and proliferation of dental pulp stem cells yielding an enriched homogeneous mesenchymal stem cells population in the first passage itself as revealed by surface marker expression. These dental pulp stem cells exhibit differentiation into adipogenic, chondrogenic and osteogenic lineage revealing their mesenchymal stem cell nature. We propose that dental pulp stem cells isolated by sustained explant culture are phenotypically and functionally comparable to those obtained by enzymatic method. It is a simple, inexpensive and gentle method, which may be preferred over the conventional techniques for obtaining stem cells from other tissue sources as well especially in cases of limited starting material.

Angiogenesis and Fibrogenesis in Oral Submucous Fibrosis: A Viewpoint.

Oral submucous fibrosis (OSF) is characterized by excessive fibrosis of submucosa. The degree of vascularity in OSF has always been a matter of debate. Angiogenesis is the key mechanism involved in regeneration and repair. It also plays an important role in various pathologic conditions. Angiogenesis may contribute to the progression of fibrosis in fibrotic disorders. Inhibition of pathological angiogenesis is considered to be a new strategy for the treatment of various fibrotic disorders. In OSF, angiogenesis can be related to progression fibrosis. This article briefly describes the role of angiogenesis in pathogenesis of fibrosis in OSF and the importance of inhibition of pathologic angiogenesis in its prevention and treatment. CLINICAL SIGNIFICANCE: Understanding the association between angiogenesis and fibrogenesis can help in developing new therapeutic strategies for treatment of OSF.

Three-Dimensional Evaluation of Alveolar Bone and Soft Tissue Dimensions of Maxillary Central Incisors for Immediate Implant Placement: A Cone-Beam Computed Tomography Assisted Analysis.

INTRODUCTION: This study explored the relationship between the thickness of bone and soft tissue along the labial and palatal aspect of maxillary central incisors. The influence of overall socket width, labiopalatal positioning of the incisor on the bone, and soft tissue thickness were also investigated. MATERIALS AND METHODS: This study used cone-beam computed tomography of 150 patients to determine labial, palatal soft and hard tissue thickness, labiopalatal (B-P) socket width and corelated the same to the labiopalatal positioning of maxillary central incisors. RESULTS: Mean (SD) thicknesses of the labial soft tissue at cervical (C), midroot (M), and apical (A) locations and the corresponding bone thicknesses were 1.07 (0.28), 0.987 (0.27), 1.240 (0.41), and 0.928 (0.39), 0.894 (0.52), 1.57 (0.88), respectively. Similarly, palatal soft tissue and bone thicknesses at locations C, M, A were 1.807 (0.66), 1.557 (0.62), 1.639 (0.66), and 1.679 (0.62), 3.439 (1.28), 6.038 (1.63), respectively. Mean (SD) thicknesses of the B-P socket width at location C was 8.047 (0.963). CONCLUSIONS: There is a positive correlation between the labial and palatal bone and corresponding soft tissue thickness, between thickness of the labial bone and the labiopalatal thickness of the alveolar socket. No correlation was observed between the thickness of the labial cortical bone and the labiopalatal positioning of the tooth.

Evaluating the efficacy of osteopontin expression as a prognostic marker in oral squamous cell carcinoma in the Indian subpopulation.

AIM: This study aimed to correlate the prognostic value of osteopontin (OPN) expression using both tissue and plasma samples from patients with clinically and histologically confirmed oral squamous cell carcinoma (OSCC). METHODS AND MATERIALS: The study group comprised of sixty patients (n = 60), which were clinically and histologically diagnosed for oral squamous cell carcinoma (OSCC). The Control group comprised of ten (n = 10) healthy volunteers. Plasma OPN levels were assayed using a quantitative enzyme-linked immunosorbent assay (OPN ELISA). Expression of OPN was also identified and evaluated by immunohistochemistry in tissue sections. These OPN expressions were then correlated with different parameters like age, sex, site, clinical presentation, tumor node metastasis (TNM) staging, histopathological grading and lymph node metastasis. STATISTICAL ANALYSIS: One-way analysis of variance (ANOVA) was used to evaluate the difference in tissue intensity and plasma OPN levels between the OSCC and the normal control groups. RESULTS: The distribution of the plasma OPN levels and tissue OPN intensity in OSCC cohorts were compared to histopathological grades and analyzed. When evaluated OPN expression in tissue had higher intensity observed in OSCC (95% +ve) cases. And the mean plasma OPN concentration in OSCC cohort was more in comparison to the normal cohort. The results clearly showed that the plasma OPN levels and intensity grading in tissue correlated with tumor grades. CONCLUSION: The study highlights OPN as a biomarker for prognosis in OSCC in both plasma and tissue samples. We would like to emphasize on the evaluation of plasma OPN as a protocol of blood examination for all cancer patient, as it may serve as an indicator for tumor progression and potential risk of metastasis.

The Anatomic Inter Relationship of the Neurovascular Structures Within the Inferior Alveolar Canal: A Cadaveric and Histological Study.

OBJECTIVE: The location and inter relationship of the structures of the inferior alveolar neurovascular bundle within the mandibular canal has not been clearly defined. The knowledge of the same is important while planning surgeries in the posterior mandible. METHODS: Eight cadaveric mandibles were dissected and sections were made at the distal aspect of every tooth. The inferior alveolar neurovascular bundle was identified and examined for the location of the inferior alveolar artery, vein and nerve. Hematoxylin and Eosin sections were made for each specimen to confirm the position of these structures. RESULTS: All the sections in all the specimens confirmed that a blood vessel lies superior to the nerve. This position appeared consistent in all the positions relative to all the posterior teeth. There was a variation in the bucco-lingual positioning of these structures relative to each other for the various mandibles. CONCLUSION: A blood vessel is found to always lie superior to the inferior alveolar nerve within the mandibular canal. Variations in the inter relationship of the structures is present. SIGNIFICANCE: This cadaveric study proves that all along the course of the neurovascular bundle, at various cross-sections studied, the inferior nerve is always inferior to a blood vessel. There can be great variations to the positioning of the structures within the neurovascular bundle in the bucco-lingual dimension and also in the exit of the nerve in various mandibles. Knowledge of the location of the structures is of importance during surgical procedures carried out in the vicinity of these structures.

Osteopontin: a marker for invasive oral squamous cell carcinoma but not for potentially malignant epithelial dysplasias.

This study aimed to evaluate and correlate osteopontin (OPN) expression in oral squamous cell carcinoma (OSCC) and potentially malignant disorders including oral leukoplakia and oral submucous fibrosis (OSMF). Expression of OPN was investigated in 140 samples including OSCC, oral leukoplakia, and OSMF with or without dysplasia and normal oral mucosa. By using immunohistochemistry. Both intercellular and intracellular staining of the keratinocytes was considered to be positive, and intensity grading was assessed. Statistical analysis was done using analysis of variance. OPN positivity was detected in 85% cases of OSCC, 55% cases of oral leukoplakia, 35% cases of OSMF, and 60% cases of normal mucosa. These study highlights OPN as a biomarker for malignancy in the form of invasion but not to study progression from dysplasia to malignant transformation.