Fit, Precision, and Trueness of 3D-Printed Zirconia Crowns Compared to Milled Counterparts

Precise fit of a crown and accurate reproduction of the digital design are paramount for successful treatment outcomes and preservation of clinician and technician time. The study aimed to compare the internal fit, marginal adaptation, precision, and trueness of 3D-printed zirconia crowns compared to their milled counterpart. A total of 20 monolithic 3 mol% yttria stabilized-zirconia crowns (n = 10) were made using computer-assisted design (CAD) followed by additive (3D-printed) and subtractive (milled) manufacturing. Digital scanning of the master die with and without a fit checker followed by image superimposition, and analysis was performed to evaluate internal and marginal adaptation in four areas (occlusal, axial, marginal, and overall). ISO 12836:2015 standard was followed for precision and trueness evaluation. Statistical analysis was achieved using a t-test at α = 0.05. Internal fit and marginal adaptation revealed no significant difference between the two test groups (p > 0.05). The significant difference in trueness (p < 0.05) was found between the two groups in three areas (occlusal, axial, and internal). The best and worst trueness values were seen with 3D-printed crowns at occlusal (8.77 ± 0.89 µm) and Intaglio (23.90 ± 1.60 µm), respectively. The overall precision was statistically better (p < 0.05) in the 3D-printed crowns (9.59 ± 0.75 µm) than the milled (17.31 ± 3.39 µm). 3D-printed and milled zirconia crowns were comparable to each other in terms of internal fit and marginal adaptation. The trueness of the occlusal and axial surfaces of 3D-printed crowns was better, whereas the trueness of fitting surface of milled crowns was better. 3D-printed crowns provided a higher level of precision than milled crowns. Although the internal and marginal fit of both production techniques were comparable, 3D printing of zirconia produced more precise crowns.

Inter‑component immunohistochemical assessment of proliferative markers in uterine carcinosarcoma

In the scientific literature, a selected number of reports have investigated the impact of proliferative activity on the development and progression of uterine carcinosarcomas (UC). The aim of the present retrospective study was to compare the immunohistochemical proliferation markers [Ki67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance complex component 3 (MCM3), and topoisomerase IIα (topoIIα)] assessment in both components of UC. A total of 30 paraffin-embedded slides of UCs, obtained from patients who underwent surgery between January 1, 2006, and December 31, 2020, were analyzed. Medical records and clinicopathological data of patients were reviewed. Formalin-fixed, paraffin-embedded tissue sections were immunostained with monoclonal antibodies against Ki67, PCNA, MCM3 and topoIIα. Ki67-positive nuclear immunoreactivity was reported in 20 (67%) and 16 (53%) UC carcinomatous and sarcomatous components, respectively. In the epithelial component, Ki67 positive staining was related to the International Federation of Gynecology and Obstetrics (FIGO) stage (P=0.025), and histological grade (G1 vs. G2/G3, P=0.031). Nuclear PCNA reactivity was observed in 18 (60%) and 16 (53%) carcinomatous and sarcomatous components, respectively. Notably, all four cases with omental metastases were PCNA-positive, and a relationship between staining pattern and the existence of metastases was of significant value (P=0.018). MCM3-positive nuclear staining was found nearly twice as high in the carcinomatous (n=19; 63%), compared with the sarcomatous (n=11; 37%) component, respectively, and MCM3 expression in the epithelial component was related to clinical stage (P=0.030), and the existence of omental metastasis (P=0.012). In addition, out of the 30 UCs, 17 (57%) and 13 (43%) showed topoIIα positivity in the carcinomatous and sarcomatous UC components, respectively. A significant relationship between protein immunoreactivity and FIGO stage (P=0.049), and omental metastasis (P=0.026) was revealed to exist. However, no significant differences between expression of proliferation markers and clinicopathological features in the sarcomatous UC component were identified. Finally, a significant correlation between each protein immunohistochemical staining was demonstrated, particularly in the sarcomatous UC component. Collectively, a combined analysis of Ki67, PCNA, MCM3, and topoIIα may provide more detailed information of cell-cycle alterations determining the heterogeneity of uterine carcinosarcomas.

Effect of Speed Sintering on Low Temperature Degradation and Biaxial Flexural Strength of 5Y-TZP Zirconia

Translucent zirconia is becoming the material of choice for the esthetic restorative material. We aimed to evaluate the surface structure, phase determination, translucency, and flexural strength of 5Y-TZP Zirconia (Katana STML Block and Disc) between the regular sintering and the speed sintering with and without low-temperature degradation (LTD). A total of 60 zirconia discs (30 per group; regular sintering and speed sintering) were used in this study. A CAM machine was used to mill cylinders out of the zirconia blanks and then cut into smaller discs. For the speed sintering, the zirconia blocks were milled into smaller discs. The zirconia discs were subjected to regular and speed sintering with and without LTD. Scanning electron microscopy was used to characterize the zirconia specimens and the zirconia grain size. Furthermore, the zirconia specimens were analyzed for elemental analysis using energy dispersive spectroscopy and phase identification using X-ray diffraction. The zirconia specimens were subjected to translucency measurements and biaxial flexural strength testing. The results of the zirconia specimens were compared among the groups. Statistical analysis was completed using SPSS version 20.0 to detect the statistically significant differences (p value = 0.05). A one-way ANOVA with multiple comparisons was performed using Scheffe analysis among the groups. The speed sintering presented smaller grain sizes. The zirconia specimens with and without LTD in regular and speed sintering presented a similar surface structure. Regular sintering showed more translucency compared to speed sintering. Multiple comparisons of the translucency parameter were a significant difference (p value < 0.05) between the various groups except for the comparison between speed sintering and speed sintering LTD. The regular sintering showed bigger gain sizes and slightly more translucency compared to speed sintering. The speed sintering showed higher biaxial flexural strengths compared to regular sintering. This shows that speed sintering can be considered a suitable method of sintering zirconia.

Transforming growth factor β1-enriched secretome up-regulate osteogenic differentiation of dental pulp stem cells, and a potential therapeutic for gingival wound healing: A comparative proteomics study

OBJECTIVES

Current study aimed at comparing the human dental pulp-derived stem cell (hDPSC) secretome (Control secretome) and transforming growth factor beta1 (TGF-β1)-transfected hDPSC secretome (TGF-β1 Secretome), which have the potential to be therapeutic in terms of regenerative dentistry, in terms of osteogenesis, adipogenesis and gingival wound healing with proteomic analyses.

MATERIALS AND METHODS

pCMV-TGF-β1 plasmid was transfected into hDPSCs by electroporation. hDPSC and TGF-β1 transfected hDPSC secretomes were collected for LC-MS/MS. Protein contents in control secretome and TGF-β1 secretome were analyzed by tandem mass spectrometry-based shotgun proteomic method. Bioinformatic evaluations for canonical pathways, upstream regulators and networks were completed via Ingenuity Pathway Analysis (IPA, QIAGEN) software. Surface marker expressions between groups, treated secretome were measured by flow cytometry. To support the proteomic data morphologically, we performed osteogenic-adipogenic differentiation in hDPSCs treated with control secretome and TGF-β1 secretome, and scratch wound healing assay in gingival fibroblasts. Statistical analyses were performed by GraphPad Prism 8.02.

RESULTS

Venn diagram classification showed us 174 common proteins were identified from each group. In the control secretome 140 unique proteins were identified and 66 entries were exclusive for TGF-β1 secretome. TGF-β1 secretome was found to have therapeutic effect on MSC-specific immunophenotypes. TGF-β1 secretome was determined to up-regulate osteogenesis-related molecules and pathways while down-regulating adipogenesis-related pathways. Analysis of canonical pathways showed that TGF-β1 secretome is associated with the wound healing pathway.

CONCLUSION

Our study provided the first evidence that proteins identified in TGF-β1-transfected hDPSC secretomes are potential regulators of osteogenic/adipogenic differentiation and fibroblast wound healing.

CLINICAL SIGNIFICANCE

Based on these results, TGF-β1 secretome may have a therapeutic effect in repairing osteoporosis-related bone injuries, wound healing of oral mucosa and gingival tissue. TGF-β1 secretome may be a potential cell-free therapeutic in orthopedics and regenerative dentistry.

The role of Herpes Simplex Virus type 1 in oral diseases in children

Relevance. Herpes virus infections are the most common and poorly controllable viral infections. There are many difficulties in herpetic lesion verification and treatment in dental practice.

Purpose. The study aimed to present the results of a foreign publication investigation on the role of herpes simplex virus type 1 in the development of oral diseases in children.

Material and methods. Foreign scientific articles about the oral HSV-1 infections published from 2018 to 2022 formed the basis for the study. The study searched the publications on PubMed and Google Scholar bases.

Results. The article presents the newest data on the prevalence, clinical characteristics and diagnosis of oral HSV infection in children. Primary herpetic gingivostomatitis (PHGS), chronic recurrent herpetic gingivostomatitis, chronic recurrent herpes labialis are the main clinical presentations of herpes infection diagnosed in a dental practice. Primary herpetic gingivostomatitis is very common in children aged six months to fve years and occurs in newborns from 2 to 43 days of life. Modern virology success can improve diagnosis and treatment of oral herpetic lesions.

Conclusion. Primary herpetic gingivostomatitis is an acute infectious disease that requires the joint attention of a general practitioner and a dentist to ensure comprehensive treatment.

Erosive Effect of Acidic Beverages and Dietary Preservatives on Extracted Human Teeth—An In Vitro Analysis

Objectives Frequent consumption of acidic beverages and dietary preservatives in younger generation, diet-conscious (celebrities), and obese individuals have a rapid impact on demineralization of the teeth. An attempt was made to analyze the erosive potential of various acidic beverages.

Materials and Methods One hundred and ninety extracted human permanent teeth were sectioned longitudinally, pre-weighed, randomly grouped, and placed in nine acidic beverages (200 mL) with predetermined pH, i.e., three commercially available fruit juices, three carbonated drinks, and three dietary preservatives.

Statistical Analysis The sectioned specimens (n = 10) were analyzed at time intervals of 12, 24, 48, and 96 days. Mean weight loss was calculated, and surface changes were assessed under a stereomicroscope. The demineralization pattern and microscopic changes were observed under a compound and polarizing microscope. One-way analysis of variance test followed by Tukey's post-hoc analysis was employed.

Results Overall the maximum demineralizing effect was caused by vinegar and apple cider. In the fruit juices category, lemon juice induced significant changes, while in the carbonated drinks category Coca-Cola induced the maximum changes and in the category of food preservatives vinegar induced the maximum changes. Severe discoloration was seen with respect to Coca-Cola followed by Mountain Dew (carbonated drink).

Conclusion The present study is unique as three different types of microscopes have been employed and both dentin and enamel of permanent teeth have been analyzed. In addition, the effect of dietary preservatives on hard tissues was evaluated. Oral health educators can reinforce important practices such as decreasing the frequency of consumption and time duration of beverage contact with the teeth. Also, the use of mouth rinses and buffering agents after the consumption of dietary beverages can be advocated along with regular fluoride application for those who are regular consumers.

Impact of Smokeless Tobacco on the Color Stability of Zirconia, Zirconia-Reinforced Lithium Silicate and Feldspathic CAD/CAM Restorative Materials: An In-Vitro Study

WHO estimates that the global number of tobacco users exceeds 1.3 billion people. Few studies have examined the effect of locally made smokeless tobacco (ST) products on the color changes of material used in dental prosthetics. Bearing the recent advances in CAD/CAM ceramic restorations material in mind, this study aimed to assess ST influence on mean color change (∆E*) values among selected CAD/CAM ceramic types: multilayer zirconia (Ceramill Zolid PS), zirconia-reinforced lithium silicate ceramic (Vita Suprinity), and feldspathic (Vita TriLuxe) restorative materials. The color changes of the ceramics were compared to VITA classical and VITA 3D-MASTER shade guides. Sixty CAD/CAM ceramic specimens (20 samples each) were fabricated from Ceramill Zolid PS, Vita TriLuxe Forte, and VITA Suprinity. Specimens were prepared and divided into two groups according to the ST type and immersed for two weeks. Basic VITA classical and VITA 3D-MASTER colors were recorded at a baseline of one week and two weeks. The highest ∆E* values were recorded in the black ST for Vita Suprinity (4.77) in the first week, followed by Vita TriLuxe (4.07) in the second week. For white ST, Vita TriLuxe (4.87), and Vita Suprinity (4.42) showed extensive color change after two weeks and one week, respectively. The color change was least in zirconia for black and white ST after one week. CAD/CAM ceramic materials showed no significant difference after 1 and 2 weeks for the tested ST types. The effects of ST on CAD/CAM ceramic material (∆E* values) were high but did not reach clinically unacceptable values. Zirconia showed the least amount of color change among all the tested materials.

Non-surgical treatment as an alternative for the management of central giant cell granuloma: a systematic review

OBJECTIVE

To evaluate the effectiveness of non-surgical treatment as an alternative in the management of central giant cell granuloma (CGCG).

MATERIAL AND METHODS

A literature search was carried out in accordance with the PRISMA statement in order to answer the question "Are non-surgical treatments effective as an alternative in the treatment of CGCG?". Two examiners independently assessed eligibility, risk of bias, and extracted data, which included therapeutic protocol, side effects, and need for surgical supplementation.

RESULTS

Among 1712 studies, 15 were included, totaling 145 patients. Calcitonin, intralesional corticosteroids, and denosumab were the medications used. For calcitonin (n = 61), complete remission was found in 30 cases. For intralesional triamcinolone (n = 68), reduction in size was observed in most cases (n = 39). Four cases received subcutaneous denosumab and showed absence of active bone metabolism in the region, of which three presented ossification. Combination of drug therapies (n = 29) was reported in one study and included subcutaneous interferon and oral imatinib. More and less side effects were found for interferon and corticosteroids, respectively. Forty percent of patients required additional surgical treatment.

CONCLUSION

Despite the side effects presented and the need for additional surgery in some patients, in general, all non-surgical treatments could provide positive results as an alternative for the management of CGCG, especially with regard to reducing the size of the lesion.

CLINICAL RELEVANCE

CGCG is a benign bone lesion that mainly affects young individuals. Although the most common therapy is surgery, its contraindication in some patients, the large extension, and high recurrence rate of the aggressive variant have led the search for non-surgical therapies.

Transplanted neural lineage cells derived from dental pulp stem cells promote peripheral nerve regeneration

Cell therapy for peripheral nerve injury is a promising strategy as regenerative medicine that restores neurological function. However, challenges remain in producing suitable and sufficient amounts of autologous cells for promoting nerve regeneration. This study aimed to identify the characteristics of neural lineage cells (NLCs) differentiated from dental pulp stem cells (DPSCs) and reveal their effect on functional recovery and nerve regeneration after cell transplantation into an immunodeficient rat using a nerve guide conduit. Here we report a protocol of neural induction in monolayer culture and characterize NLCs in vitro. Furthermore, NLCs were transplanted into an immunodeficient rat model with a 10-mm sciatic nerve defect, and cell survival and differentiation were investigated in vivo. Outcomes of nerve regeneration were also assessed using the remyelinated axon numbers, myelin sheath thickness, electrophysiological activities, and gastrocnemius muscle mass. NLCs comprised neuronal, astrocyte, oligodendrocyte, and neural crest lineage cells. NLCs enhanced the activities of endothelial cells, Schwann cells, and neurons in a paracrine-dependent manner in vitro. At 2 weeks post-transplantation, numerous transplanted NLCs differentiated into platelet-derived growth factor receptor alpha (PDGFRα) + oligodendrocyte progenitor cells (OPCs) and a few PDGFRα + /p75 neurotrophin receptor + Schwann cell-like cells derived from OPCs were observed. At 12 weeks post-transplantation, human Schwann cell-like cells survived, and axon growth, remyelination, electrophysiological activities, and muscle atrophy were improved. This study demonstrates the broad application of our protocol of neural induction of DPSCs and portrays the efficacy of transplantation of NLCs derived from human DPSCs as a promising strategy for peripheral nerve regeneration.

Adjunctive techniques and diagnostic aids in the early detection of oral premalignant disorders and cancer: An update for the general dental practitioners

Oral cancer (OC), a potentially fatal disease, is a major health concern across the world. It is reported to be the sixth most common cancer in the world with a disappointingly low 5-year survival rate, despite major advances in onco-medicine in the past three decades. The low 5-year-survival rate is associated with late diagnosis of the disease, while OC diagnosed at early stages enjoy a much higher 5-year-survival rate, comparatively. Although the oral cavity is one of the most easily accessible parts of the body for cancer screening, OC is typically diagnosed at later stages. The delay in diagnosis is one of the factors for the poor 5-year survival rate and high mortality and morbidity among patients. Therefore, an early diagnosis is of utmost importance. Visual and tactile examination and scalpel biopsy are still considered the gold standard for definitive diagnosis of oral potentially malignant disorder (OPMD) and OC. Nevertheless, adjunctive techniques could be employed to increase the ability to distinguish benign abnormalities from dysplastic/malignant changes. These would also aid in identifying areas of dysplasia/early OC that are not visible to the naked eye and tackle the delay in diagnosing OPMD/OC. These adjunctive tools are not a replacement for visual and tactile examination but are supplementary aids. They could be used to screen healthy patients for the presence of any occult cancerous change and evaluate the biological potential of clinically abnormal mucosal lesions, thus enabling early recognition and diagnosis which might increase survival rate and reduce mortality and treatment-associated morbidity.

Color stability of bioactive restorative materials after immersion in various media

Objectives:

The aim of this article is to assess the color stability of the bioactive restorative materials (Activa Bioactive, Beautifil II) compared with the conventional resin composite and resin-modified glass ionomer cement after immersion in different staining solutions overtime.

Materials and Methods:

This is an in-vitro study that investigated four different material groups: (1) bioactive composite (ACTIVA Bioactive-Restorative, Pulpdent, USA), (2) Giomer composite (Beautifil II, SHOFU Dental GmbH, Japan), (3) resin-modified glass ionomer cement (Fuji II, GC Corporation, Japan), and (4) resin composite (Filtek Z350XT, 3M ESPE, USA). One hundred samples (n=25 each group) were fabricated using a custom acrylic mold (1 mm thick × 10 mm diameter) and then immersed in five different staining solution groups: coffee, black tea, cola, mixed berry juice, and saline. Baseline (T0) shade of samples was recorded using two spectrophotometers: VITA Easyshade Digital Advance and a spectrophotometer. Then shade was recorded at the intervals of 7 (T1), 14 (T2), and 28 (T3) days of immersion. Measurements were obtained and then ΔE was calculated for each group at each time point. Three-way analysis of variance tests were used to test the interactions between different variables at the 0.05 significance level.

Results:

All specimens showed a significant color change (P<0.001), following 7, 14, and 28 days of storage. Activa Bioactive and Filtek Z350 showed the highest color stability overtime in different staining solutions, whereas Fuji II and Beautifil II showed the least color stability. The most significant color change was noticed in the coffee group and then in the mixed berry juice group.

Conclusion:

Resin-based restorative materials showed higher color stability than glass ionomer-based restorations. Both spectrophotometers gave comparable results for materials’ color stability.

Photobiomodulation of inflamed dental pulp stem cells under different nutritional conditions

Aim: The present study aimed to investigate photobiomodulation's (PBM) effect on inflamed dental pulp stem cells (IDPSCs) under different nutritional conditions. Methods: Cell proliferation and odontogenic differentiation were evaluated using the MTT assay and real-time quantitative reverse transcription PCR, respectively after laser PBM of cells in 5 or 10% fetal bovine serum (FBS) culture conditions. Results: A significant positive effect of laser irradiation on cell proliferation under both nutritional conditions after 24 and 48 h was observed. DMP-1 gene expression increased in the groups with laser irradiation and 5% FBS. Comparison of gene expression levels in the four groups revealed no statistically significant stimulatory effect. The highest gene expression was observed in the non-laser group with 5% FBS. Conclusion: Further studies are required to obtain an irradiation setup to ideally improve inflamed dental pulp stem cells' proliferation and differentiation.

Characterization and Pathogenic Speculation of Xerostomia Associated with COVID-19: A Narrative Review

Patients with coronavirus disease 2019 (COVID-19) have become known to present with different oral symptoms. However, xerostomia remains poorly recognized compared with taste dysfunction. For better understanding of COVID-19 symptomatology, xerostomia associated withCOVID-19 was characterized and its possible pathogenesis was speculated by a narrative literature review. Scientific articles were retrieved by searching PubMed, LitCovid, ProQuest, Google Scholar, medRxiv and bioRxiv from 1 April 2020 with a cutoff date of 30 September 2021. Results of the literature search indicated that xerostomia is one of prevalent and persistent oral symptoms associated with COVID-19. In contrast to taste dysfunction, the prevalence and persistence of xerostomia do not necessarily depend on ethnicity, age, gender and disease severity of patients. COVID-19 xerostomia is pathogenically related to viral cellular entry-relevant protein expression, renin-angiotensin system disturbance, salivary gland inflammation, zinc deficiency, cranial neuropathy, intercurrent taste dysfunction, comorbidities and medications. Despite a close association with COVID-19, xerostomia, dry mouth and hyposalivation tend to be overlooked unlike ageusia, dysgeusia and hypogeusia. Although mouth dryness per se is not life-threating, it has an impact on the oral health-related quality of life. More attention should be paid to xerostomia in COVID-19 patients and survivors.

Dental Pulp Stem Cell-Derived Secretome and Its Regenerative Potential

The therapeutic potential of the dental pulp stem (DSC) cell-derived secretome, consisting of various biomolecules, is undergoing intense research. Despite promising in vitro and in vivo studies, most DSC secretome-based therapies have not been implemented in human medicine because the paracrine effect of the bioactive factors secreted by human dental pulp stem cells (hDPSCs) and human exfoliated deciduous teeth (SHEDs) is not completely understood. In this review, we outline the current data on the hDPSC- and SHED-derived secretome as a potential candidate in the regeneration of bone, cartilage, and nerve tissue. Published reports demonstrate that the dental MSC-derived secretome/conditional medium may be effective in treating neurodegenerative diseases, neural injuries, cartilage defects, and repairing bone by regulating neuroprotective, anti-inflammatory, antiapoptotic, and angiogenic processes through secretome paracrine mechanisms. Dental MSC-secretomes, similarly to the bone marrow MSC-secretome activate molecular and cellular mechanisms, which determine the effectiveness of cell-free therapy. Many reports emphasize that dental MSC-derived secretomes have potential application in tissue-regenerating therapy due to their multidirectional paracrine effect observed in the therapy of many different injured tissues.

Apical Sealing Ability of Two Calcium Silicate-Based Sealers Using a Radioactive Isotope Method: An In Vitro Apexification Model

The aim of this study was to evaluate and compare the sealing ability of two calcium silicate-based sealers (TotalFill BC RRM Fast Set Putty and White ProRoot MTA) when used as apical plugs in immature teeth through nuclear medicine. Single-rooted extracted teeth (n = 34) had their crowns and root tip sectioned to obtain 14 mm long root segments to simulate an in vitro apexification model. Were created two experimental groups, namely MTA (n = 12) and BC (n = 12), and two control groups, PG (positive group, n = 5) and NG (negative group, n = 5). On the 4th day after placing the respective apical plug, the apical portions of the teeth were submerged in a solution of sodium pertechnetate (^99mTcNaO₄) for 3 h. Statistical analysis showed a significant difference between the MTA group and the controls (p < 0.05). The BC group had a significant difference regarding the negative control (p < 0.001) but showed no statistical significance regarding the positive control (p = 0.168). There was a statistically significant difference (p = 0.009) between the BC group (7335.8 ± 2755.5) and the MTA group (4059.1 ± 1231.1), where the last showed less infiltration. Within the limitations of this study, White ProRoot MTA had a significantly better sealing ability than TotalFill BC RRM Fast Set Putty.

Effect of piper extract mouthwash as postprocedural rinse on levels of Porphyromonas gingivalis in periodontitis patients

Background:

Dental biofilm plays a crucial role in periodontal disease development. Mouth rinse is used to enhance oral hygiene after scaling and root planning (SRP). The aim of the study was to evaluate the clinical and microbiological effectiveness of a piper extract mouthwash against Chlorhexidine (CHX) in periodontitis patients.

Materials and Methods:

Sixty patients with Stage II periodontitis participated in this study and were randomly divided into two groups (Group I – Stage II Grade A periodontitis patients were provided with prepared piper extract mouthwash and Group II – Stage II Grade A periodontitis patients were provided with 0.2% CHX). Plaque index, gingival index, sulcus bleeding index, probing pocket depth, and clinical attachment level were recorded at baseline and 30 days after SRP. Subgingival plaque samples were taken for microbial examination (colony-forming unit), quantification of Porphyromonas gingivalis using the real-time polymerase chain reaction at baseline, and 30 days after SRP.

Results:

Intragroup comparison for the clinical parameters showed statistically significant reduction in both the groups (P < 0.0001). Intergroup comparison for clinical parameters, there was no statistical significance seen after 30 days. Intragroup comparison for microbial analysis showed significant reduction in both the groups after 30 days (P < 0.0001). On intergroup comparison for microbial analysis, both the groups showed reduction after 30 days without significance.

Conclusion:

Piper extract mouthwash (Group I) showed similar antimicrobial activity against P. gingivalis when compared to 0.2% CHX mouthwash (Group II) that could be used as a substitute to CHX.

Evaluation of Efficacy of Foldscope - A Paper Microscope to be Used as a Chairside Diagnostic Tool in Oral Dysplastic Lesions: A Comparative Study

Introduction:

Precancerous lesion of the oral mucosa consists of a group of diseases which sometimes resemble each other leaving the clinician in a diagnostic dilemma. Etiology of these diseases varies geographically with most frequently being tobacco use, alcohol drinking, chewing of betel quid containing areca nut, and solar rays. The long-standing practice of these lifestyle habits causes an alteration in the mucosal barrier level leading to malignant transformation. Earlier, the diagnosis of malignant transformation was confirmed using biopsy, but the advent of exfoliative cytology showed that histological features of a cell undergoing transformation are distinctive during early stages. Early diagnosis can be lifesaving, along with chairside adjunct tools that can facilitate the clinician for better diagnosis and use it as an explanatory tool for patients.

Aim:

The aim of this study was to test the efficacy of foldscope as a chairside diagnostic tool to detect dysplastic changes in potentially malignant lesions affecting the oral cavity.

Materials and Methods:

This was a cross-sectional comparative study of a total of 54 individuals clinically diagnosed with oral premalignant lesions. Exfoliative cytological smears were taken and observed under light microscope and foldscope. After Papanicolaou stain, it was subjected to cytomorphometric analysis.

Results:

Cytological changes in potentially malignant lesions detected using foldscope were appreciable and found to be a mirror image of the routine light microscope.

Conclusion:

Morphological parameters assessed by foldscope proved to be employed in routine practice as well as in the mass screening of oral lesions.

Preliminary Study on the Diagnostic Performance of a Deep Learning System for Submandibular Gland Inflammation Using Ultrasonography Images

This study was performed to evaluate the diagnostic performance of deep learning systems using ultrasonography (USG) images of the submandibular glands (SMGs) in three different conditions: obstructive sialoadenitis, Sjögren’s syndrome (SjS), and normal glands. Fifty USG images with a confirmed diagnosis of obstructive sialoadenitis, 50 USG images with a confirmed diagnosis of SjS, and 50 USG images with no SMG abnormalities were included in the study. The training group comprised 40 obstructive sialoadenitis images, 40 SjS images, and 40 control images, and the test group comprised 10 obstructive sialoadenitis images, 10 SjS images, and 10 control images for deep learning analysis. The performance of the deep learning system was calculated and compared between two experienced radiologists. The sensitivity of the deep learning system in the obstructive sialoadenitis group, SjS group, and control group was 55.0%, 83.0%, and 73.0%, respectively, and the total accuracy was 70.3%. The sensitivity of the two radiologists was 64.0%, 72.0%, and 86.0%, respectively, and the total accuracy was 74.0%. This study revealed that the deep learning system was more sensitive than experienced radiologists in diagnosing SjS in USG images of two case groups and a group of healthy subjects in inflammation of SMGs.

Comparison of Fracture Load of the Four Translucent Zirconia Crowns

Recently, translucent zirconia has become the most prevalent material used as a restorative material. This study aimed to compare the crown fracture load of the four most common different translucent zirconia brands available in the market at 1.5 mm thickness. Standardized tooth preparations for a full ceramic crown were designed digitally with software (AutoCAD) by placing a 1.0 mm chamfer margin and 1.5 mm occluso-cervical curvature for the crown sample manufacturing. Stylized crowns were chosen to control the thickness of the crown. The axial and occlusal thickness were standardized to 1.5 mm thickness except at the central pit, which was 1.3 mm thick. The STL file for the tooth dies was prepared using software (3Shape TRIOS^® Patient Monitoring, Copenhagen, Denmark). The tooth dies were printed with a resin material (NextDent Model 2.0, Vertex-Dental B.V., Soesterberg, The Netherlands) using a 3D printing software (3D Sprint^® Client Version 3.0.0.2494) from a 3D printer (NextDent™ 5100, Vertex-Dental B.V., Soesterberg, The Netherlands). The printing layer thickness was 50 µm. Then, a total of twenty-eight (N = 28) stylized crowns were milled out of AmannGirrbach (Amann Girrbach GmbH, Pforzheim, Germany) (n = 7), Cercon HT (Dentsply Sirona, Bensheim, Germany) (n = 7), Cercon XT (Dentsply Sirona, Bensheim, Germany) (n = 7), and Vita YZ XT (Zahnfabrik, Bäd Sackingen, Germany) (n = 7). Following sintering the crowns, sandblasting was performed and they were bonded to the tooth dies with the resin cement (RelyX U-200, 3M ESPE, Seefeld, Germany) and permitted to self-cure under finger pressure for 6 min. The crowns were loaded on the occlusal surface in a universal testing machine (MTS Centurion) with a stainless-steel ball indenter (7 mm radius) with a loading rate of 1 mm/min to contact the stylized crowns on each of the four cusps until failure. A rubber sheet (1.5 mm thickness) was positioned between the crown and indenter, which helped with the load distribution. Statistical analysis was done using SPSS version 20 (IBM Company, Chicago, USA). The fracture loads were analyzed using Dunnett’s T3 test, and the number of cracks was analyzed using the Mann–Whitney U test among the groups. The significant level was set at p value = 0.05. The mean fracture loads were 3086.54 ± 441.74 N, 4804.94 ± 70.12 N, 3317.76 ± 199.80 N, and 2921.87 ± 349.67 N for AmannGirrbac, Cercon HT, Cercon XT, and Vita YZ XT, respectively. The mean fracture loads for the surfaces with the greatest number of cracks (excluding the occlusal surfaces) were on the lingual surface for AmannGirrbach and Cercon HT, on the distal and mesial for Cercon XT, and on the buccal for Vita YZ XT. We found that the AmannGirrbach had the most overall cracks. Cercon XT had the greatest number of occlusal cracks and appeared to be the most shattered. Cercon HT had the least number of cracks. In conclusion, Cercon HT presented the best strength properties, the highest fracture load, and no visible cracks. AmannGirrbach presented the lowest strength properties.

Surface roughness and color measurements of glazed or polished hybrid, feldspathic, and Zirconia CAD/CAM restorative materials after hot and cold coffee immersion

Background

The purpose of this study evaluates and compares the effect of surface roughness (Ra) and color stability on computer-aided design/computer-aided manufacturing (CAD/CAM) hybrid resin (Vita Enamic), feldspathic (Vitablocs® Mark II), and lithium disilicate Zirconia (Vita Suprinity) glazed or polished ceramics immersed in hot Arabic Qahwa and cold coffee.

Methods

A total of 96 standardized samples were prepared from CAD/CAM restorative materials. Half of the samples were polished as per the manufacturer’s instructions using a porcelain polishing kit, and the other half were glazed. Samples were distributed and immersed in hot Arabian Qahwa and cold coffee followed by thermocycling. Ra measurements and color changes were conducted before and after immersion. SEM images were captured from each type of glazed or polished ceramic. One-way ANOVA paired Student’s t-test, and Bonferroni test were conducted to detect significant difference between the groups. P > 0.05 was a significant level.

Results

Of all the tested samples, Ra increased without any significant difference; however, mean color changes (ΔE*) showed significant differences. An increase in Ra was noted for all the glazed and polished samples after immersion and thermocycling. However, differences were significant only in VM II. In addition, ΔE* was significant only in Vita Suprinity (VS) samples. For immersion groups, significant Ra changes were noticed in glazed samples, only in Vita Enamic (VE) with no ΔE*. In polished samples, mean Ra changes were observed in VM II and VS samples. Significant differences were also noticed in polished VE and VS subgroups of ΔE*.

Conclusions

Ra affects all the tested samples, providing higher values on the polished specimens. The ΔE* caused by hot Arabic Qahwa and cold coffee on glazed or polished CAD/CAM restorative materials were clinically acceptable.

Color stability of 3D-printed denture resins: effect of aging, mechanical brushing and immersion in staining medium

PURPOSE

This in-vitro study evaluated and compared the color stability of 3D-printed and conventional heat-polymerized acrylic resins following aging, mechanical brushing, and immersion in staining medium.

MATERIALS AND METHODS

Forty disc-shaped specimens (10 mm in diameter and 3 mm thick) were prepared from two 3D-printed [DentaBASE (DB) and Denture 3D+ (D3D)] and one conventional polymethylmethacrylate (PMMA) denture materials. The specimens were thermo-cycled, subjected to mechanical brushing, and were immersed in either coffee, lemon juice, coke, or artificial saliva (AS) to simulate one and two years of oral use. Color measurements of the specimens were recorded by a spectrophotometer at baseline (T0), and after one (T1) and two years (T2) of simulation. The color changes (∆E) were determined and also quantified according to the National Bureau of Standards (NBS) units. Descriptive statistics, followed by factorial ANOVA and Bonferroni post-hoc test (α=.05), were applied for data analysis.

RESULTS

The independent factors, namely material, staining medium, and immersion time, and interaction among these factors significantly influenced ∆E (P<.009). Irrespective of the materials, treatments, and time, the highest and the lowest mean ∆Es were observed for PMMA in lemon juice (4.58 ± 1.30) and DB in AS (0.41 ± 0.18), respectively. Regarding the material type, PMMA demonstrated the highest mean ∆E (2.31 ± 1.37), followed by D3D (1.67 ± 0.66), and DB (0.85 ± 0.52), and the difference in ∆E between the materials were statistically significant (P<.001). All the specimens demonstrated a decreased color changes at T2 compared to T1, and this difference in mean ∆E was statistically significant (P<.001).

CONCLUSION

The color changes of 3D-printed denture resins were low compared to conventional heat polymerized PMMA. All the tested materials, irrespective of the staining medium used, demonstrated a significant decrease in ∆E values over time.

2021 Update on Diagnostic Markers and Translocation in Salivary Gland Tumors

Salivary gland tumors are a rare tumor entity within malignant tumors of all tissues. The most common are malignant mucoepidermoid carcinoma, adenoid cystic carcinoma, and acinic cell carcinoma. Pleomorphic adenoma is the most recurrent form of benign salivary gland tumor. Due to their low incidence rates and complex histological patterns, they are difficult to diagnose accurately. Malignant tumors of the salivary glands are challenging in terms of differentiation because of their variability in histochemistry and translocations. Therefore, the primary goal of the study was to review the current literature to identify the recent developments in histochemical diagnostics and translocations for differentiating salivary gland tumors.

Three-Dimensional Zirconia-Based Scaffolds for Load-Bearing Bone-Regeneration Applications: Prospects and Challenges

The design of zirconia-based scaffolds using conventional techniques for bone-regeneration applications has been studied extensively. Similar to dental applications, the use of three-dimensional (3D) zirconia-based ceramics for bone tissue engineering (BTE) has recently attracted considerable attention because of their high mechanical strength and biocompatibility. However, techniques to fabricate zirconia-based scaffolds for bone regeneration are in a stage of infancy. Hence, the biological activities of zirconia-based ceramics for bone-regeneration applications have not been fully investigated, in contrast to the well-established calcium phosphate-based ceramics for bone-regeneration applications. This paper outlines recent research developments and challenges concerning numerous three-dimensional (3D) zirconia-based scaffolds and reviews the associated fundamental fabrication techniques, key 3D fabrication developments and practical encounters to identify the optimal 3D fabrication technique for obtaining 3D zirconia-based scaffolds suitable for real-world applications. This review mainly summarized the articles that focused on in vitro and in vivo studies along with the fundamental mechanical characterizations on the 3D zirconia-based scaffolds.

Electromagnetic field-assisted cell-laden 3D printed poloxamer-407 hydrogel for enhanced osteogenesis

3D bioprinted hydrogel has gained enormous attention, especially in tissue engineering, owing to its attractive structure and excellent biocompatibility. In this study, we demonstrated that 3D bioprinted cell-laden 'thermoresponsive' poloxamer-407 (P407) gels have the potential to stimulate osteogenic differentiation of apical papilla stem cells (SCAPs) under the influence of low voltage-frequency (5 V-1 Hz, 0.62 mT) electromagnetic fields (EMFs). SCAPs were initially used for cell-laden 3D printing to biomimic the apical papilla of human teeth. The developed hydrogel exhibited higher mechanical strength as well as good printability, showing high-quality micro-architecture. Moreover, the as-printed hydrogels (5 mm × 5 mm) were loaded with plasminogen activator inhibitor-1 (PAI-1) for testing the combined effect of PAI-1 and EMFs on SCAP differentiation. Interestingly, the 3D hydrogels showed improved viability and differentiation of SCAPs under EMFs' influence as examined by live/dead assay and alizarin Red-S staining, respectively. Therefore, our results confirmed that P407 hydrogels are non-toxic for encapsulation of SCAPs, yielding high cell viability and accelerate the cell migration potential. The 3D hydrogels with PAI-1 exhibited high mRNA expression levels for osteogenic/odontogenic gene markers (ALP, Col-1, DSPP, and DMP-1) vis-à-vis control after 14 days of in vitro culture. Our findings suggest that 3D bioprinted P407 hydrogels are biocompatible for SCAP encapsulation, and the applied low voltage-frequency EMFs could effectively improve dental tissue regeneration, particularly for oral applications.

Evaluation of temporomandibular disorders among dental students of Saudi Arabia using Diagnostic Criteria for Temporomandibular Disorders (DC/TMD): a cross-sectional study

BACKGROUND

Temporomandibular disorders (TMD) are a broad category of conditions arising from the various components of the temporomandibular joint complex. Bio-psychosocial model is the most accepted theory describing the etiopathogenesis of TMD. Dental students are vulnerable to psychological disorders, including anxiety, depression, and stress. Hence, the aim of the current study was to evaluate the prevalence and possible risk factors of TMD among dental students of various academic levels and explore the association of TMDs with demographic, academic, and psychosocial parameters.

METHODS

A total of 246 students of a Saudi Arabia dental school were chosen for the study. After getting consent, all students were examined according to the Diagnostic Criteria for Temporomandibular Disorders, including Axis I and II components.

RESULTS

The overall cross-sectional prevalence of TMD was found to be 36.99%. Pain arising from the jaw, temple, and the peri-auricular area were the most commonly reported symptoms and elicited signs during examination. Among the pain-related TMD, myalgia was the commonest diagnosed condition, whereas disc displacement with reduction was found prevalent in the intra-articular disorder category. Female (OR = 1.94; P = 0.004), married (OR = 1.74; P = 0.04), and students in clinical academic levels (OR = 1.65; P = 0.03) were found to have significantly increased risk of TMD. Among the psychosocial parameters, anxiety (OR = 1.55; P = 0.04) and parafunctional behaviours (OR = 2.10; P < 0.001) were shown to increase the risk of developing TMD. Students with any TMD reported to have significantly higher pain intensity levels (OR = 1.68; P = 0.01) and jaw functional limitations (OR = 1.45; P = 0.008).

CONCLUSION

Dental students, especially in clinical levels were shown to pose a higher risk of developing TMD, hence strategies such as academic counselling and objective evaluation via rubrics should be planned to modify the administration of the curriculum, training methods and evaluation process.

Translucency of nanoparticle-reinforced PMMA denture base material: An in-vitro comparative study

The aim of this study was to assess the translucency of denture base acrylic resin reinforced with zirconium dioxide (ZrO₂NPs), silicon dioxide (SiO₂NPs), and diamond (DNPs) nanoparticles. A total of 130 heat-polymerized acrylic discs (15×2.5 mm) were fabricated conventionally and divided into control and experimental groups according to nanoparticle type and concentration (0.5, 1, 1.5, and 2.5 wt%). Unmodified acrylic resin specimens served as control. All specimens were thermocycled (5,000 cycles). Translucency was measured using a spectrophotometer. ANOVA and post-hoc Turkeys' test were used for data analysis at α=0.05. The translucency of modified PMMA was significantly lower than control (p<0.05) except 0.5% ZrO₂NPs and SiO₂NPs (p>0.05) which exhibited the highest translucency values among modified groups. As the NPs concentration increased, the translucency decreased and the lowest value was seen with 2.5% DNPs (1.18±0.10). The addition of ZrO₂NPs, SiO₂NPs, and DNPs into denture base resin decreased the translucency.

Automatic text-mining as an unbiased approach to uncover molecular associations between periodontitis and coronary artery disease

The increasing prevalence of periodontal and cardiovascular diseases is the result of a sedentary lifestyle associated with poor diet, obesity, hypercholesterolaemia, smoking habits, alcohol consumption and stress. The present study aims to uncover molecular associations between periodontitis and coronary heart disease using an unbiased strategy of automatic text mining traditionally applied to bibliometric studies. A total of 1590 articles on these diseases were retrieved from the Web of knowledge database and searched using the VOS viewer to create a network of keywords associated with both diseases. These data were supplemented with data from DisGeNET, which stores known associations to either periodontitis or coronary heart disease. Overall, the automated text mining approach presented here highlighted inflammatory molecules as common associations between periodontitis and coronary heart disease. Specifically, this study showed that molecules such as C-reactive protein, interleukins 6 and 1-β, myeloperoxidase, and matrix metalloproteinase 9 are simultaneously associated with periodontitis and coronary artery disease by both text mining and DisGeNET analyses. This association validates the multiplex assessment of salivary inflammatory markers as a tool to assess cardiovascular disease risk and could become an important tool to identify common molecular targets to monitor both diseases simultaneously. In addition, the text mining protocol and subsequent data processing and methods using bioinformatics tools could be useful to uncover links between other diseases.

The Glycoprotein/Cytokine Erythropoietin Promotes Rapid Alveolar Ridge Regeneration In Vivo by Promoting New Bone Extracellular Matrix Deposition in Conjunction with Coupled Angiogenesis/Osteogenesis

The loss of bone following tooth extraction poses a significant clinical problem for maxillofacial esthetics, function, and future implant placement. In the present study, the efficacy of an erythropoietin-impregnated collagen scaffold as an alveolar ridge augmentation material versus a conventional collagen scaffold and a BioOss inorganic bovine bone xenograft was examined. The collagen/Erythropoietin (EPO) scaffold exhibited significantly more rapid and complete osseous regeneration of the alveolar defect when compared to bone xenograft and the collagen membrane alone. The new EPO induced extracellular matrix was rich in Collagen I, Collagen III, Fibronectin (Fn) and E-cadherin, and featured significantly increased levels of the osteogenic transcription factors Runt-related transcription factor 2 (Runx2) and Osterix (Osx). Histomorphometric evaluation revealed a significant two-fold increase in the number of capillaries between the EPO and the BioOss group. Moreover, there was a highly significant 3.5-fold higher level of vascular endothelial growth factor (VEGF) in the collagen/EPO-treated group compared to controls. The significant effect of EPO on VEGF, FN, and RUNX2 upregulation was confirmed in vitro, and VEGF pathway analysis using VEGF inhibitors confirmed that EPO modulated extracellular matrix protein expression through VEGF even in the absence of blood vessels. Together, these data demonstrate the effectiveness of an EPO-impregnated collagen scaffold for bone regeneration as it induces rapid matrix production and osseoinduction adjacent to new capillaries via VEGF.

Identification of secreted factors in dental pulp cell-conditioned medium optimized for neuronal growth

With their potent regenerative and protective capacities, stem cell-derived conditioned media emerged as an effective alternative to cell therapy, and have a prospect to be manufactured as pharmaceutical products for tissue regeneration applications. Our study investigates the neuroregenerative potential of human dental pulp cells (DPCs) conditioned medium (CM) and defines an optimization strategy of DPC-CM for enhanced neuronal outgrowth. Primary sensory neurons from mouse dorsal root ganglia were cultured with or without DPC-CM, and the lengths of βIII-tubulin positive neurites were measured. The impacts of several manufacturing features as the duration of cell conditioning, CM storage, and preconditioning of DPCs with some factors on CM functional activity were assessed on neurite length. We observed that DPC-CM significantly enhanced neurites outgrowth of sensory neurons in a concentration-dependent manner. The frozen storage of DPC-CM had no impact on experimental outcomes and 48 h of DPC conditioning is optimal for an effective activity of CM. To further understand the regenerative feature of DPC-CM, we studied DPC secretome by human growth factor antibody array analysis and revealed the presence of several factors involved in either neurogenesis, neuroprotection, angiogenesis, and osteogenesis. The conditioning of DPCs with the B-27 supplement enhanced significantly the neuroregenerative effect of their secretome by changing its composition in growth factors. Here, we show that DPC-CM significantly stimulate neurite outgrowth in primary sensory neurons. Moreover, we identified secreted protein candidates that can potentially promote this promising regenerative feature of DPC-CM.

Recent Advances in Nano-Bio-Sensing Fabrication Technology for the Detection of Oral Cancer

Nanotechnology-based miniaturized devices have been a breakthrough in the pre-clinical and clinical research areas, e.g. drug delivery, personalized medicine. They have revolutionized the discovery and development of biomarker-based diagnostic devices for detection of various diseases such as tuberculosis, malaria and cancer. Nanomaterials (NMs) hold tremendous diagnostic potential due to their high surface-to-volume ratio and quantum confinement phenomenon, improving the detection limit of clinically relevant biomolecules in bio-fluids. Thus, they are helpful in the translation of bench-on platform to point-of-care (POC) screening device. The nanomaterial-based biosensor fabrication technology has also simplified and improved oral cancer (OC) or oral squamous cell carcinomas (OSCC) diagnosis. The fabrication of nano-bio sensors involves application specific modifications of NMs. The unique properties functionalized NMs have augmented their application on the nano-biosensing platform for the detection of clinically relevant biomolecules in bio-fluids. Therefore, this article summarizes the recent advancements in the process of fabrication of nano-biosensors for detection of OC.

Management of Maxillary Premolar with Pre-eruptive Intracoronal Resorption: A 5-year Follow-up Case

Aim and objective

The present article aims to describe and discuss the preventive clinical management of a pre-eruptive intracoronal resorption (PEIR) defect on a maxillary right second premolar of an 11-year, 5-month-old girl.

Background

Pre-eruptive intracoronal resorption is described as an abnormal, well-circumscribed, radiolucent area, occurring within the coronal dentinal tissue close to the dentinoenamel junction of unerupted teeth and extending into various depths of the dentin. It is a rare anomaly occurring in primary and permanent dentitions. In the past, these defects were misdiagnosed as caries, and were therefore called “pre-eruptive caries” or “hidden caries”. Currently, the most acceptable etiological hypothesis for PEIR is intracoronal resorption by the invasion of resorptive cells into the dentine through breakdowns in the enamel during crown formation. These lesions are often detected accidentally during routine dental radiographic examination.

Case description

A fissure sealant was applied to the affected tooth shortly after its eruption. Clinical and radiographical assessments were scheduled every 6 months for a period of 5 years and 5 months.

Conclusion

The preventive approach proved to be effective in preserving the tooth vital and asymptomatic with normal root development for the entire follow-up period.

Clinical significance

This article raises awareness about misdiagnosed PEIR in primary and permanent dentitions. A close inspection of radiographs, taken during routine visits and orthodontic check-ups, is important for early detection and proper management of such defects.

How to cite this article

Ambriss B, Moukarzel C, Ezzeddine M, et al. Management of Maxillary Premolar with Pre-eruptive Intracoronal Resorption: A 5-year Follow-up Case. Int J Clin Pediatr Dent 2021;14(1):161–166.

Nitrate-rich beetroot juice offsets salivary acidity following carbohydrate ingestion before and after endurance exercise in healthy male runners

There have been recent calls for strategies to improve oral health in athletes. High carbohydrate diets, exercise induced dehydration and transient perturbations to immune function combine to increase oral disease risk in this group. We tested whether a single dose of nitrate (NO₃^-) would offset the reduction in salivary pH following carbohydrate ingestion before and after an exercise bout designed to cause mild dehydration. Eleven trained male runners (V˙O2max 53 ± 9 ml∙kg^-1∙min^-1, age 30 ± 7 years) completed a randomised placebo-controlled study comprising four experimental trials. Participants ingested the following fluids one hour before each trial: (a) 140 ml of water (negative-control), (b) 140 ml of water (positive-control), (c) 140 ml of NO₃^- rich beetroot juice (~12.4 mmol NO₃^-) (NO₃^- trial) or (d) 140 ml NO₃^- depleted beetroot juice (placebo-trial). During the negative-control trial, participants ingested 795 ml of water in three equal aliquots: before, during, and after 90 min of submaximal running. In the other trials they received 795 ml of carbohydrate supplements in the same fashion. Venous blood was collected before and after the exercise bout and saliva was sampled before and repeatedly over the 20 min following carbohydrate or water ingestion. As expected, nitrite (NO₂^-) and NO₃^- were higher in plasma and saliva during the NO₃^- trial than all other trials (all P<0.001). Compared to the negative-control, salivary-pH was significantly reduced following the ingestion of carbohydrate in the positive-control and placebo trials (both P <0.05). Salivary-pH was similar between the negative-control and NO₃^- trials before and after exercise despite ingestion of carbohydrate in the NO₃^- trial (both P≥0.221). Ingesting NO₃^- attenuates the expected reduction in salivary-pH following carbohydrate supplements and exercise-induced dehydration. NO₃^- should be considered by athletes as a novel nutritional strategy to reduce the risk of developing acidity related oral health conditions.

Effect of Endodontic Treatment on Serum Glutathione (GSH) Levels in Patients with Chronic Apical Periodontitis: A Clinical Pilot Study

Aim:

To assess the before- and after-treatment levels of glutathione (GSH) in the serum of patients with chronic apical periodontitis.

Materials and Methods:

The study involved 20 systemically healthy patients with radiographic evidence of chronic apical periodontitis in at least one tooth, of which 11 were finally assessed. 10 mL of the patient’s venous blood was obtained before commencing the endodontic treatment to assess the pre-operative serum GSH levels (T0). The canals cleaned and shaped, and irrigated with 2.5% sodium hypochlorite, and filled with a calcium hydroxide based intracanal medicament. At the subsequent appointment after one week, teeth were obturated. The patients were recalled 30 days after the completion of endodontic therapy, and blood samples were assessed again at time frame T1 for serum GSH. The difference in pre- and post-treatment values for T0 and T1 was statistically analyzed.

Results:

The mean age of the subjects ( N = 11) was 21.09±3.24 years, with 19.50±0.71 years in female group and 21.44±3.50 years in the male group. The mean GSH at T0 was 11.73±8.30 units, which was increased to 14.04±13.96 units at T1. However, no significant change was observed in the GSH level from T0 to T1 (change = –2.30, t-value = –0.49, P = .635).

Conclusion:

The results of this study suggest that endodontic therapy may play a role in restoring the systemic oxidative balance, as seen by the increase in post-treatment serum GSH levels.

Experimental Animal Model Systems for Understanding Salivary Secretory Disorders

Salivary secretory disorders are life-disrupting pathologic conditions with a high prevalence, especially in the geriatric population. Both patients and clinicians frequently feel helpless and get frustrated by the currently available therapeutic strategies, which consist mainly of palliative managements. Accordingly, to unravel the underlying mechanisms and to develop effective and curative strategies, several animal models have been developed and introduced. Experimental findings from these models have contributed to answer biological and biomedical questions. This review aims to provide various methodological considerations used for the examination of pathological fundamentals in salivary disorders using animal models and to summarize the obtained findings. The information provided in this review could provide plausible solutions for overcoming salivary disorders and also suggest purpose-specific experimental animal systems.

Serum and salivary levels of lactate dehydrogenase in oral squamous cell carcinoma, oral lichen planus and oral lichenoid reaction

BACKGROUND

Increased levels of lactate dehydrogenase (LDH) as a tumor marker have been reported in malignant and some premalignant oral lesions such as oral lichen planus (OLP) and oral lichenoid reactions (OLRs). This study aimed to assess the level of total LDH in the saliva and serum of patients with oral squamous cell carcinoma (OSCC), OLP and OLRs.

METHODS

In this case-control study, the participants were divided into four groups (n = 25) of healthy controls, OLP, OLRs, and OSCC. The serum and stimulated/unstimulated salivary levels of LDH were spectrophotometrically measured using standard LDH kits (Pars Azmoun). One-way ANOVA, Chi-square test, Pearson's correlation test, and receiver operating characteristic (ROC) analysis were applied to analyze the data.

RESULTS

The serum and salivary levels of LDH in OSCC patients were significantly higher than that the corresponding values in other groups (P = 0.0001). The serum level of LDH in OLR group was significantly higher than that in the control and OLP groups (P = 0.0001), but the difference in salivary level of LDH was not significant. The ROC analysis showed that both the serum and salivary levels of LDH had significant diagnostic ability for detection of OSCC and OLRs. Significant associations were noted between the serum and salivary levels of LDH.

CONCLUSIONS

Patients with OSCC and OLRs had higher serum levels of LDH than OLP and control groups. Further prospective longitudinal studies are required to assess the tissue level of LDH and monitor the transformation of OLRs because they have low rate of malignant transformation compared with other oral premalignant lesions.

Class II resin composite restorations-tunnel vs. box-only in vitro and in vivo

Purpose

In a combined in vitro/in vivo approach, tunnel vs. box-only resin composite restorations should be evaluated using thermomechanical loading (TML) in vitro and a restrospective clinical trial in vivo.

Materials and methods

For the in vitro part, box-only and tunnel cavities were prepared in 32 extracted human third molars under simulated intraoral conditions in a phantom head. Specimens were randomly assigned to four groups (n = 8; 16 box-only/16 tunnel) and received bonded resin composite restorations with Amelogen Plus (box A/tunnel A) or lining with Ultraseal and Amelogen plus (box B/tunnel B) both bonded using PQ1 (all Ultradent). Specimens were subjected to a standardized aging protocol, 1-year water storage (WS) followed by TML (100,000 × 50 N; 2500 × + 5/+ 55 °C). Initially and after aging, marginal qualities were evaluated using replicas at × 200 magnification (SEM). For the corresponding in vivo observational study, 229 patients received 673 proximal resin composite restorations. From 371 tunnel restorations, 205 cavities were filled without flowable lining (tunnel A), and 166 tunnels were restored using UltraSeal as lining (tunnel B). A total of 302 teeth received conventional box-only fillings. Restorations were examined according to modified USPHS criteria during routine recalls up to 5 years of clinical service.

Results

In vitro, all initial results showed 100% gap-free margins when a flowable lining was used. Tunnels without lining exhibited some proximal shortcomings already before TML and even more pronounced after TML (p < 0.05). After TML, percentages of gap-free margins dropped to 87–90% in enamel with lining and 70–79% without lining (p < 0.05). In vivo, annual failure rates for box-only were 2.2%, for tunnel A 6.1%, and for tunnel B 1.8%, respectively (p < 0.05). Tunnels had significantly more sufficient proximal contact points than box-only restorations (p < 0.05). Flowable lining was highly beneficial for clinical outcome of tunnel-restorations (p < 0.05).

Conclusions

With a flowable lining, tunnel restorations proved to be a good alternative to box-only resin composite restorations.

Clinical relevance

Class II tunnel restorations showed to be a viable alternative for box-only restorations, however, only when flowable resin composite was used as adaptation promotor for areas being difficult to access.

The effect of electromagnetic fields on survival and proliferation rate of dental pulp stem cells

Aims: Extremely low-frequency electromagnetic fields (ELF-EMF) can affect biological systems and alter some cell functions like proliferation rate. Dental pulp tissue is known as a source of multipotent stromal stem cells (MSCs), which can be obtained by a less invasive and more available process compared to bone marrow-derived stem cells (BMSCs). This study aimed to consider the effect of ELF-EMF on proliferation rates of human dental pulp stem cells (hDPSCs).Material and methods: ELF-EMF was generated by a system including autotransformer, multi-meter, solenoid coils, teslameter and its probe. The effect of ELF-EMF with the intensity of 0.5 and 1 mT and 50 Hz on the proliferation rate of hDPSCs was assessed in 20 and 40 min per day for 7 days. MTT assay and DAPI test were used to determine the growth and proliferation of DPSCs.Results: Based on MTT, ELF-EMF has maximum effect with the intensity of 1 mT for 20 min/day on the proliferation of hDPSCs. The survival and proliferation rate in all exposure groups were significantly higher than the control group. Based on the data obtained from MTT and DAPI assay, the number of viable cells in the group exposed to 1 mT for 20 min/day was higher than other groups (p < .05).Conclusions: Regarding to the results of this study, 0.5 and 1 mT ELF-EMF can enhance survival and proliferation rates of hDPSCs.

Comparative evaluation of Platelet Rich Plasma (PRP) versus Platelet Rich Fibrin (PRF) scaffolds in regenerative endodontic treatment of immature necrotic permanent maxillary central incisors: A double blinded randomized controlled trial

OBJECTIVES

The research aims to assess the regenerative potential of Platelet Rich Plasma (PRP) versus Platelet Rich Fibrin (PRF) scaffolds in immature permanent maxillary central incisors with necrotic pulps, clinically and radiographically.

TRIAL DESIGN

Double blinded parallel randomized controlled trial was implemented to identify the results.

SUBJECT & METHODS

The proposed study was conducted among 30 patients with maxillary necrotic permanent immature central incisors but only 26 patients fulfilled the study requirements. Group I was treated with PRP and Group II with PRF scaffolds. Follow up has been done every 3 months for one year. Primary outcomes were measured clinically: Pain, Mobility, Swelling, and Sinus/fistula. Radiographically: increase root length and width. Secondary outcomes were clinically: Discoloration and Sensibility test. Radiographically: increase in bone density measurements and decrease in apical diameter. Standardized radiographs were collected during the follow up period, and radiographic changes were measured by using Image J software. Statistical analysis was performed on 25 patients who had completed the study.

RESULTS

All 25 patients' teeth were survived during the 12-month follow-up period. PRP showed marginal increase in radiographic root length and width, periapical bone density and a decrease in apical diameter. No statistical significant differences were observed when it was compared with PRF. The teeth which were treated did not respond to sensibility test at the end of the study. PRF displayed statistical significant higher amount of crown discoloration when compared to PRP group.

CONCLUSIONS

For necrotic immature teeth, revascularization using PRP is an appropriate alternative to PRF and showed excellent 12-months prognosis.

Microporous Frameworks as Promising Platforms for Antibacterial Strategies Against Oral Diseases

Nowadays, the heavy burden of oral diseases such as dental caries, periodontitis, endodontic infections, etc., and their consequences on the patients' quality of life indicate a strong need for developing effective therapies. Bacterial infections played an important role in the field of oral diseases, in-depth insight of such oral diseases have given rise to the demand for antibacterial therapeutic strategies. Recently, microporous frameworks have attracted tremendous interest in antibacterial application due to their well-defined porous structures for drug delivery. In addition, intensive efforts have been made to enhance the antibacterial performance of microporous frameworks, such as ion doping, photosensitizer incorporation as building blocks, and surface modifications. This review article aims on the major recent developments of microporous frameworks for antibacterial applications against oral diseases. The first part of this paper puts concentration on the cutting-edge researches on the versatile antibacterial strategies of microporous materials via drug delivery, inherent activity, and structural modification. The second part discusses the antibacterial applications of microporous frameworks against oral diseases. The applications of microporous frameworks not only have promising therapeutic potential to inhibit bacterial plaque-initiated oral infectious diseases, but also have a wide applicability to other biomedical applications.

Improvement of oral cancer screening quality and reach: The promise of artificial intelligence

Oral cancer is easily detectable by physical (self) examination. However, many cases of oral cancer are detected late, which causes unnecessary morbidity and mortality. Screening of high-risk populations seems beneficial, but these populations are commonly located in regions with limited access to health care. The advent of information technology and its modern derivative artificial intelligence (AI) promises to improve oral cancer screening but to date, few efforts have been made to apply these techniques and relatively little research has been conducted to retrieve meaningful information from AI data. In this paper, we discuss the promise of AI to improve the quality and reach of oral cancer screening and its potential effect on improving mortality and unequal access to health care around the world.

Potentiometric Solid-Contact Ion-Selective Electrode for Determination of Thiocyanate in Human Saliva

A new solid-contact potentiometric ion-selective electrode for the determination of SCN- (SCN-ISE) has been described. Synthesized phosphonium derivative of calix[4]arene was used as a charged ionophore. The research included selection of the ion-selective membrane composition, determination of the ISEs metrological parameters and SCN-ISE application for thiocyanate determination in human saliva. Preparation of the ISEs included selection of a plasticizer for the ion-selective membrane composition and type of the electrode material. The study was carried out using ISE with liquid internal electrolyte (LE-ISE) and solid-contact electrodes made of glassy carbon (GC-ISE) and gold rods (Au-ISE). The best parameters were found for GC sensors for which the ion-selective membrane contained chloroparaffin as a plasticizer (S = 59.9 mV/dec, LOD = 1.6 ´ 10-6 M). The study of potentiometric selectivity coefficients has shown that the thiocyanate-selective sensor could be applied in biomedical research for determination of SCN- concentration in human saliva. The accuracy of the SCN- determination was verified by testing 59 samples of volunteers' saliva by potentiometric sensors and UV-Vis spectrophotometry as a reference technique. Moreover, SCN- concentrations in the smokers' and non-smokers' saliva were compared. In order to investigate the influence of various factors (sex, health status, taken medications) on the thiocyanate level in the saliva, more extensive studies on a group of 100 volunteers were carried out. Additionally, for a group of 18 volunteers, individual profiles of SCN- concentration in saliva measured on a daily basis for over a month were collected.

Effects of Khat on Surface Roughness and Color of Feldspathic and Zirconia Porcelain Materials under Simulated Oral Cavity Conditions

Background and Objectives: Khat chewing is considered as a daily habit that is practiced by more than five million people globally. The effect of khat chewing on the surface roughness and the color stability of natural teeth and the material used in the fabrication of dental prosthesis remains unknown. This study was conducted to explore and compare the effect of khat homogenate (KH) on the surface roughness (Ra) and the average color changes (ΔE*) amongst natural teeth and selected shades from different porcelain types, namely, feldspathic metal ceramic (MC) VM13, computer-aided design/computer assisted manufacture (CAD/CAM) feldspathic (Vitablocs Mark II), and multilayer zirconia (Ceramill Zolid PS) porcelains. Materials and Methods: Seventy samples were prepared from natural teeth, feldspathic MC, CAD/CAM Vitablocs Mark II, and zirconia porcelain. The Ra values were measured using a profilometer and expressed in micrometers, whereas the ΔE* values were measured using VITA Easyshade® V spectrophotometer for all samples before and after frequent immersion and thermocycling in KH for 30 days. The surface topography was used to assess the materials surfaces (glazed or polished) after KH immersion by using a white light interferometry machine. Results: Results revealed that the Ra and the ΔE* values of the different types of tested porcelain were influenced by KH. The order of surface roughness values was glazed or polished MC > polished Zircon > polished Vitablocs Mark II > natural teeth. The lowest ΔE* values were recorded for glazed Vitablocs Mark II and MC, and the values could be arranged as polished zircon > natural teeth > glazed zircon > polished MC > polished Vitablocs Mark II. P values were significantly varied (< 0.001) among all the tested groups, except the zircon group (>0.05) for both Ra and ΔE*. Conclusion: KH significantly affected both surface parameter and color of glazed or polished porcelain materials and natural teeth.

Plasma rich in growth factors (PRGF) in non-surgical periodontal therapy: a randomized clinical trial

The aim of this split mouth, double blinded, randomized clinical trial was to evaluate the clinical efficacy of use of Plasma rich in growth factors (PRGF) as an adjunct to scaling and root planing (SRP) in the treatment of periodontal pockets. Twenty six patients (15 males, 11 females) diagnosed with generalized periodontitis with Pocket Depth > 5mm and plaque index score < 1.5, were randomly allocated by using computer generated random sequence, into two groups, one treated with intra-pocket application of PRGF adjunct to SRP and other with SRP alone. The clinical outcomes like pocket depth (PD), relative attachment level (RAL) and sulcus bleeding index (SBI) were assessed at baseline, 3 months and 6 months. Twenty two patients (44 sites) were analyzed at the end of 6 month follow-up, using SPSS 20.0v software. There was a significant statistical difference observed between both the groups favouring SRP +PRGF group in terms of PD (p = 0.007) and RAL (p = 0.021) at the end of 6 month follow-up. Also there was a statistical significant difference (< 0.001) at all time points compared to baseline, for all parameters in intra-group comparison. Moreover, the sites with PD>4mm necessitating further treatment after 6-month follow-up were significantly lesser for SRP+PRGF group. The use of PRGF technology in non-surgical periodontal therapy, by single intra-pocket application in to periodontal pockets as an adjunct to SRP, in chronic periodontitis patients, was found to be effective in reduction of pocket depth and gain in clinical attachment level.