Comparative Evaluation of Salivary Parameters in Tobacco Substance Abusers.

BACKGROUND: Tobacco use by youth is ever-demanding, and it is increasingly distributed not only in India but also globally. Saliva is a complex oral bio-fluid, freely available, performing absolute tasks for maintaining oral health and homeostasis. It contains a plethora of significant constituents such as proline-rich proteins (PRPs), immunoglobulins, IgA, enzymes lysozyme, lactoferrin, peroxidases, amylase, etc. The basic ecological balance of the oral cavity is stabilized via salivary clearance by reduced aggregation and adherence of microorganisms by direct microbial activity. This balance of oral activity is also done by indirect mechanisms by immunological as well as non-immunological means and also by effectively regulating salivary pH flow rate. This institutional observational study was planned to assess and compare salivary parameters (pH, salivary flow rate), total proteins, α-amylase, calcium, phosphate, and IgA, of unstimulated whole saliva of both tobacco abusers and tobacco non-users. METHODS: The Study consisted of 270 participants (Tobacco habit) group, n = 135 and Control (Healthy) group, n = 135 and were in the age range of 20-50 years. They were assessed for oral health status, followed by the analysis of salivary pH, flow rate, total proteins, amylase, calcium, phosphates, and IgA of unstimulated whole saliva. RESULTS: Comparative evaluation of salivary parameters among groups found that varying tobacco abusers had increased salivary amylase, protein levels, and phosphate whereas decreased salivary pH, flow rate, IgA, and in the whole unstimulated saliva samples than those of non-tobacco users. This difference among groups was statistically significant. (p < 0.05), and calcium levels were not altered significantly. CONCLUSIONS: This study concludes that salivary parameters are altered in tobacco abusers when compared to those of non-abusers, and it was more significant in smokeless tobacco abusers than in any other form of tobacco abuse.

Efficacy of laser in re-osseointegration of dental implants-a systematic review.

Despite their high success rates, peri-implantitis can affect the stability and function of dental implants. Various treatment modalities have been investigated for the treatment of peri-implantitis to achieve re-osseointegration. An electronic literature search was performed supplemented by a manual search to identify studies published until January 2022. Articles that evaluated re-osseointegration in peri-implantitis sites in animal models following laser therapy or antimicrobial photodynamic therapy (aPDT) were included. Case reports, case series, systematic reviews, and letters to the editor were excluded. Risk of bias and GRADE assessment were followed to evaluate the quality of the evidence. Six studies out of 26 articles identified on electronic search were included in this review. The studies included animal studies conducted on canine models. Four out of six studies reported a higher degree of re-osseointegration following treatment of implants with laser therapy. The findings suggest that laser decontamination shows potential in enhancing re-osseointegration, particularly with the Er: YAG laser, which effectively decontaminated implant surfaces. However, conflicting outcomes and limitations in the evidence quality warrant caution in drawing definitive conclusions. Based on the limited available evidence, laser therapy may show a higher degree of re-osseointegration of implants than mechanical debridement.

Identification of oral immune disorders- A review and a diagnostic algorithm.

Immunological disorders are observed in various clinical presentations in the oral cavity. The pathophysiology of these disorders include but are not limited to primary oral auto-immune disease, systemic disease with oral findings, malignancies, hypersensitivity reactions, drug-induced, and infection-related. Many of these disorders have overlapping oral features, making it difficult for the clinician to diagnose and treat the disorder. There is a need to provide a simple and practical decision-making algorithm to the clinicians and provide them guidance on laboratory investigations. The present review provides a diagnostic algorithm that might minimize outpatient process delays and lead to early management. This is crucial in many cases where oral findings may be the first sign of the disorder, and early treatment can preclude dissemination and complications of the disorder.

Advancement in therapeutic strategies for immune-mediated oral diseases.

BACKGROUND: Immune-mediated diseases are a diverse group of conditions characterized by alteration of cellular homeostasis and inflammation triggered by dysregulation of the normal immune response. Several immune-mediated diseases exhibit oral signs and symptoms. Traditionally, these conditions are treated with corticosteroids or immunosuppressive agents, including azathioprine, cyclophosphamide, and thalidomide. Recent research into the developmental pathways of these diseases has led to the exploration of novel approaches in treatment. This review examines newer treatment modalities for the management of immune-mediated diseases with oral presentations. Topical calcineurin inhibitors (TCIs) such as tacrolimus and pimecrolimus have been employed successfully in managing oral lichen planus and pemphigus vulgaris. Biologic agents, comprising monoclonal antibodies, fusion proteins, and recombinant cytokines, can provide targeted therapy with fewer adverse effects. Neutraceutical agents comprising aloe vera, curcumin, and honey are commonly used in traditional medicine and offer a holistic approach. They may have a place as adjuvants to current standard therapeutic protocols. Photodynamic therapy (PDT) and low-level laser therapy (LLLT) utilize a specific wavelength of light to achieve desired cellular change. While the use of PDT in immune-mediated diseases is contentious, LLLT has shown positive results. Newer therapeutic modalities involve kinase inhibitors, S1P1 receptor modulators, MSCs, and iRNA providing targeted treatment of specific diseases.

CC group of chemokines and associated gene expression of transcription factors: Deciphering immuno-pathogenetic aspect of oral submucous fibrosis.

BACKGROUND: Oral submucous fibrosis (OSMF) is a chronic disease with significantly increasing malignant transformation rate. To date the pathogenesis of OSMF has been considered to be associated with areca nut constituents and their action on fibroblasts. However, fibrosis is also associated with immunological factors such as chemokines. In-depth analysis of such factors is the need of the hour in OSMF to better understand the pathogenesis so that effective therapeutic strategies can be developed in the future. MATERIALS AND METHOD: Clinically diagnosed cases of OSMF (n=21) and healthy individuals (n=10) were enrolled in the present study. Chemokines such as CCL2, CCL3, CCL4, CCL5, CCL11, CCL17, CCL28, CXCL1, CXCL5, CXCL8, CXCL9, CXCL10, and CXCL11 were assessed using the chemokine bead array in conjunction with the flow cytometry, along with real-time PCR (RT-PCR). The transcription factors CREB, NF-κB and NFAT5 were also studied for their expressions. The analysis of pg/ml (picogram/milliliter) values was done by using LEGENDplex™ Data Analysis Software. RESULTS: The results obtained demonstrated early phase transient increase in CXCL-11, CCL20, CXCL9, CCL3, CCL2, CXCL10 and CXCL8. However, the expression of CCL3, CXCL10 and CXCL8 was higher in the late stage as compared to the early stage. The relative gene expression of CREB, NF-κB, NFAT5 were upregulated in the late stage of OSMF when compared to normal. CONCLUSION: Distinctive sets of chemokine expression during the early and late stages of OSMF suggest a unique pattern of disease progression playing an important role in the pathogenesis.

Suppression of Tumorigenicity 2 Pro-Inflammatory Biomarker Linking Diabetes Mellitus and Periodontitis: A Pilot Study.

BACKGROUND Suppression of tumorigenicity 2 (ST2) is a member of the interleukin (IL)-1 family and has 2 isoforms: ST2L, a transmembrane form, and ST2, a soluble form. IL-33 can act as an immune system alarm signal when released by damaged cells, which in turn activates other cells expressing the ST2 receptor. This can cause inflammatory cytokines to be released and produced, as well as trigger osteoclastogenesis. This study aimed to investigate the levels of soluble ST2 in gingival samples. MATERIAL AND METHODS The study population consisted of 30 individuals. The participants were divided into 3 groups: healthy participants, patients with periodontitis, and patients with periodontitis and diabetes mellitus. Periodontitis was determined using probing depth, clinical attachment loss, and gingival index. Patients with stage 2 to 4 periodontitis met the inclusion criteria. Gingival crevicular fluid (GCF) was collected for quantification of samples for ST2 levels by using an enzyme immunoassay. RESULTS The mean±standard deviation of ST2 GCF concentrations was relatively high (558.87±68.99) in the group with periodontitis and diabetes mellitus, compared with that of the periodontitis group (452.06±54.18) and healthy group (252.82±87.9). CONCLUSIONS GCF ST2 values were found to be a marker of inflammatory activities. Thus, GCF ST2 could be a potential biomarker for the diagnosis of periodontitis as well as systemic diseases, such as diabetes mellitus. This pilot study was limited by a small number of participants. To confirm the associations, more large-scale investigations should be conducted.

Assessing the Effect of Curcumin on the Oral Mucosal Cytomorphometry and Candidal Species Specificity in Tobacco Users: A Pilot Study.

OBJECTIVES: Tobacco consumption is of major concern for public health. Compromised oral hygiene accentuated by tobacco leads to alteration in the oral mucosa and microbiome, including Candida, and its species can be identified rapidly using CHROMagar. Curcumin, a naturally available compound possesses antioxidant, anti-inflammatory, anti-microbial, anti-carcinogenic, anti-fungal, and immunomodulatory properties. Hence, a comprehensive study was planned. AIM: To evaluate and compare cytomorphometric analysis and Candida colonization and speciation in tobacco users before and after the use of curcumin gel. MATERIALS AND METHODS: The study comprised a total of 120 participants (the study (tobacco habit) group, n = 60 and control (healthy) group, n = 60). The intervention was the application of curcumin gel over the lesion area three times daily for 2 months. All participants' oral health status was assessed, followed by cytomorphometric analysis and Candida colonization and speciation using CHROMagar. RESULTS: Cytomorphometric analysis showed statistically significant differences in the control and study group for cell diameter (CD), nuclear diameter (ND), CD:ND ratio, and micronuclei (p = 0.0001). Candida colonization had a significantly higher number of colonies in the habit group when compared to the control group. Candida tropicalis was predominant in the study group, whereas Candida albicans was predominant in the control group. In the study group, after intervention with curcumin, a statistically significant difference was seen in nuclear diameter, CD:ND ratio, and micronuclei. There was a reduction in the number of Candida colonies, and Candida albicans was the predominant species observed in the study group after the intervention of curcumin and discontinuation of habit. CONCLUSION: Curcumin was found to reduce the number of micronuclei and also decreased Candida colonization, along with the discontinuation of habit in tobacco users.

Bone Regeneration in Vertical Osseous Defect in Periodontitis Patients using Bovine Colostrum.

Background: The treatment plan for periodontitis may include both nonsurgical and surgical phases. During surgical procedures, bone grafts and barrier membranes were used after degranulation in order to achieve healing. Colostrum is one of the materials that is composed of bioactive components which has either osteoinductive or regenerative potential. Aim: The aim of the present study is to evaluate the effectiveness of bovine colostrum as bone regeneration material in periodontitis. Case Description. Clinical periodontal parameters, including probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI), were evaluated. Patients who were diagnosed with localised periodontitis were selected. Three patients presenting vertical defect at buccal sites were treated with bovine colostrum. Following nonsurgical treatment, flap surgery was performed using bovine colostrum. After 6 months, favourable clinical and radiographical improvements were obtained. Conclusion: All cases showed reduction in PD; these findings suggest that the bovine colostrum could favour periodontal regeneration. The clinical significance is that bovine colostrum is cost effective and easily available and enhances bone regeneration. It can therefore be used as an alternative to bone grafts during periodontal surgery.

Surgical-anatomical evaluation of mandibular premolars by CBCT among the Italian population.

BACKGROUND: The thorough knowledge of the anatomy of mandibular premolars is an essential factor for a correct approach to endodontic treatment, concerning both non-surgical and surgical treatment. OBJECTIVES: Since there is no data on the Italian population in this context, the aim of this study was to evaluate, from a surgical perspective, the anatomy of mandibular premolars among the Italian population through a cone-beam computed tomography (CBCT) analysis, considering the morphology of their root canals according to Vertucci's classification and the prospect of their apices with regard to the vestibular bone plate and the proximity to the inferior alveolar nerve and the mental foramen as well as to evaluate the most appropriate distance from the apex in the radicular resection (3 mm or 5 mm). MATERIAL AND METHODS: At total of 492 CBCT acquisitions (from 246 males and 246 females) were included retrospectively, evaluating 720 mandibular premolars. Age, gender, the tooth position in relation to the vestibular plate, the number of roots, the tooth length and the root length, the number of canals, the configuration of the root canal system according to Vertucci's criteria, C-shaped canals, the distance from the cementoenamel junction (CEJ) to the canal bifurcation, the number of apical foramina, and the distance from the apex to the inferior alveolar nerve or the mental foramen were evaluated. RESULTS: The study highlighted the frequent anatomic variability of the root canal system. It found the presence of 1 root for first and second premolars in 97% and 99% of cases, of 2 roots in 2.7% and 0.7% of cases, and of 3 roots in 0.3% and 0.3% cases, respectively. In 92% of cases, the mental foramen was located below a second premolar, or between a first premolar and a second premolar; only in 8% of cases, it was located close to a first premolar, but never as close as to a second premolar. CONCLUSIONS: Mandibular premolars show a truly surprising anatomical variability, especially for mandibular first premolars, which therefore requires adequate radiographic planning before providing any endodontic treatment, or especially endodontic retreatment or endodontic surgery. Taking into account proximity to the inferior alveolar nerve and the mental foramen, any surgical approach must be carefully planned. Frequently, a two-dimensional (2D) radiographic examination is not sufficient to fully understand the anatomical variability of these teeth.

Artificial Intelligence in the Diagnosis of Oral Diseases: Applications and Pitfalls.

Background: Machine learning (ML) is a key component of artificial intelligence (AI). The terms machine learning, artificial intelligence, and deep learning are erroneously used interchangeably as they appear as monolithic nebulous entities. This technology offers immense possibilities and opportunities to advance diagnostics in the field of medicine and dentistry. This necessitates a deep understanding of AI and its essential components, such as machine learning (ML), artificial neural networks (ANN), and deep learning (DP). Aim: This review aims to enlighten clinicians regarding AI and its applications in the diagnosis of oral diseases, along with the prospects and challenges involved. Review results: AI has been used in the diagnosis of various oral diseases, such as dental caries, maxillary sinus diseases, periodontal diseases, salivary gland diseases, TMJ disorders, and oral cancer through clinical data and diagnostic images. Larger data sets would enable AI to predict the occurrence of precancerous conditions. They can aid in population-wide surveillance and decide on referrals to specialists. AI can efficiently detect microfeatures beyond the human eye and augment its predictive power in critical diagnosis. Conclusion: Although studies have recognized the benefit of AI, the use of artificial intelligence and machine learning has not been integrated into routine dentistry. AI is still in the research phase. The coming decade will see immense changes in diagnosis and healthcare built on the back of this research. Clinical significance: This paper reviews the various applications of AI in dentistry and illuminates the shortcomings faced while dealing with AI research and suggests ways to tackle them. Overcoming these pitfalls will aid in integrating AI seamlessly into dentistry.

Dental Caries and Oral Health Status of Psychoactive Substance Abusers.

Substance-abuse disorders are universally associated with comorbid illness. Tobacco is a widely abused substance across the globe and presents a critical public health problem. The precise correlation between tobacco use and dental caries remains unclear. Thus, the present study aimed to evaluate the correlation between tobacco use and dental caries. METHODOLOGY: Based on selection criteria, a total of 270 (age 20-50 years) participants were included in the study, and were categorized as group A (n = 135), consisting of tobacco users, and group B (n = 135), comprising healthy controls (non-users). The Decayed, Missing, and Filled index (DMFT) was used to measure caries status. The Simplified Oral Hygiene index was used to evaluate oral health. RESULTS: The tobacco group reported the use of cigarettes; smokeless tobacco in indigenous forms, such as gutka (areca nut, tobacco, and slaked lime), betel nut chewing; and a combination. Individuals with tobacco habits had a higher prevalence of dental caries (Mean DMFT 4.73 ± 4.32) compared to the non-habit group (Mean DMFT 3.17 ± 3.11 (p = 0.001). The Oral Hygiene index was significantly higher (indicating bad/poor oral hygiene) in tobacco abusers than those of non-users (p = 0.0001). Duration and frequency of tobacco use were correlated with the levels of moderate and severe caries (p = 0.001). CONCLUSION: Psychoactive substance abuse, such as smoking/smokeless tobacco consumption, is associated with higher prevalence of dental caries.

Impact of Red Complex Bacteria and TNF-α Levels on the Diabetic and Renal Status of Chronic Kidney Disease Patients in the Presence and Absence of Periodontitis.

Scientific evidence shows a positive association in the etiopathogenesis of periodontitis and chronic kidney disease (CKD). Various confounding factors, such as obesity, diabetes, and inflammation, also play a significant role in the progression of CKD, which remains unexplored. We hypothesise the role of red complex bacteria with various confounding factors associated with chronic kidney disease. The study comprised a total of 120 participants categorised into 4 groups: the control group (C), periodontitis subjects without CKD (P), periodontally healthy chronic kidney disease subjects (CKD), and subjects having both periodontitis and CKD (P + CKD), with 30 subjects in each group. Demographic variables, and periodontal, renal, and diabetic parameters were recorded. Tumour necrosis factor (TNF)-α levels and those of red complex bacteria such as Prophyromonas gingivalis (P.g), Treponema denticola (T.d), and Tonerella forsythia (T.f) were assessed, and the obtained results were statistically analysed. Among the various demographic variables, age showed a level of significance. Mean PI, GI, CAL, and PPD (the proportion of sites with PPD ≥ 5 mm and CAL ≥ 3 mm) were elevated in the P + CKD group. Diabetic parameters such as fasting blood sugar (FBS) and HbA1c levels were also greater in the P + CKD group. Renal parameters such as eGFR and serum creatinine levels were greater in CKD patients. The estimation of red complex periodontal pathogens such as Pg, Td and Tf levels were significantly greater in the P and P + CKD groups. Pearson correlation analysis revealed significant correlation of red complex bacteria with all variables. Greater levels of P.g, T.d and T.f were found in the P groups, thus indicating their important role in the initiation and progression of inflammation of periodontitis and CKD, with diabetes as one of the confounding factors. The study also confirmed a log-linear relationship between TNF-α levels and red complex bacteria, thereby demonstrating the role of inflammatory biomarkers in periodontal disease progression that could contribute to the development of systemic inflammation such as CKD.

CD44-positive cancer stem cells from oral squamous cell carcinoma exhibit reduced proliferation and stemness gene expression upon adipogenic induction.

We proposed to assess adipogenic differentiation and its effect on the proliferation and stemness markers in CD44 + OSCC CSCs. D44 + CSCs were sorted by magnetic sorting from the single-cell suspension of the OSCC tumor. Adipogenic differentiation was induced by an adipogenic induction medium. Lipid droplet formation was confirmed by oil red O staining. The expression of the cell surface marker was analyzed by flow cytometry. Real-time qPCR was performed to examine the gene expression activity. CD44 + OSCC CSCs can differentiate into adipocytes and adipogenesis in these cells decrease their proliferation and stemness gene expression. Adipogenic induction can make the cancer stem cells from OSCC tumors lose their stemness potential. Oral cancer, especially OSCC, is a huge burden worldwide. Similar to other stem cells, cancer stem cells can differentiate into other lineage cells. Our study shows that the proliferation and stemness gene expression in the CSCs from OSCC tumors can be thwarted by inducing them to differentiate into adipocytes, which could be advantageous to find out new clinical approaches in the treatment of cancers, like OSCC.

Treatment Prognosis of Restored Teeth with Crown Lengthening vs. Deep Margin Elevation: A Systematic Review.

Crown lengthening surgery and deep margin elevation are two distinct approaches used to manage decayed teeth. This systematic review examined the survival rate of badly decayed teeth when restored using the crown lengthening technique and compared it to the deep margin elevation technique. The search was conducted during July 2020 and then again updated at the end of July 2021, and no restriction concerning publication status and time was applied during the search. Cochrane Database, EBSCO, Scopus, and Medline databases were searched electronically for relevant literature. Google Scholar was used as a secondary source. Predefined inclusion and exclusion criteria were used to select the relevant articles. PRISMA guidelines were followed. The focused PICO question was: 'Does the crown lengthening technique (I) provide a better survival rate (O) than deep margin elevation technique (C) following the restoration of badly decayed teeth (P).' A total of six articles were included after performing screening based on the eligibility criteria. Four studies focused on crown lengthening while two focused on deep margin elevation technique. A majority of the studies showed a high risk of bias owing to methodological insufficiencies. Crown lengthening (CL) treated cases showed a change in the free gingival margin at six months post-surgery. A tissue rebound was seen that was correlated to the periodontal biotype. Teeth treated with the deep margin elevation (DME) technique showed high survivability. There is a lack of high-quality trials examining surgical comparisons between CL and DME with long-term follow-up. Patient- and dentist-reported outcomes have not been given adequate consideration in the literature. Based on the limited evidence, it can be concluded that for restorative purposes, crown lengthening surgery can be successful in long-term retention of restored teeth. However, the deep margin elevation technique has a better survival ratio. Future well-designed and executed research will have an effect on the evidence and level of certainty for the best approach to treating severely decayed teeth.

Allicin May Promote Reversal of T-Cell Dysfunction in Periodontitis via the PD-1 Pathway.

We evaluated the role of allicin in periodontitis using an in silico and in vitro design. An in silico docking analysis was performed to assess the plausible interactions between allicin and PD-L1. The cytokine profile of gingival crevicular fluid (GCF) samples obtained from periodontitis patients was estimated by cytometric bead array. CD3+ lymphocytes isolated from the peripheral blood were sorted and characterized using immunomagnetic techniques. Cultured and expanded lymphocytes were treated with the GCF samples to induce T-cell exhaustion. Optimum concentrations of allicin were added to exhausted lymphocytes to compare the expression of TIM-3 and LAG-3 gene expression at baseline and post-treatment. Allicin was found to bind to the PD-L1 molecule as revealed by the in-silico experiment, which is possibly an inhibitory interaction although not proven. GCF from periodontitis patients had significantly higher concentrations of TNF-α, CCL2, IL-6, IFN-γ, and CXCL8 than controls. GCF treatment of CD3+ lymphocytes from the periodontitis patients significantly increased expression of T-cell exhaustion markers TIM-3 and LAG-3. Allicin administration with GCF treatment resulted in significant lowering of the expression of exhaustion markers. Allicin may exert an immunostimulatory role and reverse immune-destructive mechanisms such as T-cell exhaustion.

The Growth Factors and Cytokines of Dental Pulp Mesenchymal Stem Cell Secretome May Potentially Aid in Oral Cancer Proliferation.

BACKGROUND: Growth factors and cytokines responsible for the regenerative potential of the dental pulp mesenchymal stem cell secretome (DPMSC-S) are implicated in oral carcinogenesis. The impact and effects of these secretory factors on cancer cells must be understood in order to ensure their safe application in cancer patients. OBJECTIVE: We aimed to quantify the growth factors and cytokines in DPMSC-S and assess their effect on oral cancer cell proliferation. MATERIALS AND METHODS: DPMSCs were isolated from patients with healthy teeth (n = 5) that were indicated for extraction for orthodontic reasons. The cells were characterized using flow cytometry and conditioned medium (DPMSC-CM) was prepared. DPMSC-CM was subjected to a bead-based array to quantify the growth factors and cytokines that may affect oral carcinogenesis. The effect of DPMSC-CM (20%, 50%, 100%) on the proliferation of oral cancer cells (AW123516) was evaluated using a Ki-67-based assay at 48 h. AW13516 cultured in the standard growth medium acted as the control. RESULTS: VEGF, HCF, Ang-2, TGF-α, EPO, SCF, FGF, and PDGF-BB were the growth factors with the highest levels in the DPMSC-CM. The highest measured pro-inflammatory cytokine was TNF-α, followed by CXCL8. The most prevalent anti-inflammatory cytokine in the DPMSC-CM was IL-10, followed by TGF-ß1 and IL-4. Concentrations of 50% and 100% DPMSC-CM inhibited Ki-67 expression in AW13516, although the effect was non-significant. Moreover, 20% DPMSC-CM significantly increased Ki-67 expression compared to the control. CONCLUSIONS: The increased Ki-67 expression of oral cancer cells in response to 20% DPMSC-CM indicates the potential for cancer progression. Further research is needed to identify their effects on other carcinogenic properties, including apoptosis, stemness, migration, invasion, adhesion, and therapeutic resistance.

Nickel-Titanium Rotary Instruments: An In Vitro Comparison (Torsional Resistance of Two Heat-treated Reciprocating Files).

AIM AND OBJECTIVE: The present study aims to evaluate the difference in torsional resistance of two reciprocating nickel-titanium (Ni-Ti) rotary files: WaveOne Gold and EdgeOne Fire. MATERIALS AND METHODS: A total of 40 nickel-titanium rotary instruments (n = 40): 20 WaveOne Gold Small (WOGS) and 20 EdgeOne Fire Small (EOFS) were divided into two groups. Each instrument was tested using a torsional resistance device already validated in previous studies to evaluate and compare torsional resistance. The static torsional test was implemented by blocking each instrument at 3 mm from the tip and rotating it until fracture with a reciprocating motion. Torque to fracture (TtF) and fragment length (FL) were measured and statistically analyzed. RESULTS: Statistical analysis of TtF found significant differences between the two groups (p<0.05). The EOFS showed higher TtF if compared to WOGS, with a mean value and a standard deviation of 3.05 ± 0.07 (N cm) against 2.97 ± 0.08 (N cm). Data for FL showed no significant differences (p>0.05) between the two groups. CONCLUSION: According to the results of this study, it is reasonable to assert that EOFS instruments showed a higher torsional resistance if compared to the WOGS. CLINICAL SIGNIFICANCE: As evidenced by this study, EOFS should be considered as a safer solution, in terms of torsional resistance, if compared to WOGS, reducing the risk of intracanal separation due to excessive torsional load.

Incidence of Different Types of Intracanal Fracture of Nickel-Titanium Rotary Instruments: A Systematic Review.

AIM: The aim of this systemic review is to investigate these parameters by analyzing the characteristics of fractured instruments to determine which is the most relevant mechanical stress that induces intracanal separation in vivo. BACKGROUND: The fracture of nickel-titanium (Ni-Ti) instruments is a result of flexural fatigue and torsional fatigue. An electronic search was conducted in MEDLINE database, Web of Science, and Cochrane following preferred reporting items for systematic reviews and meta-analyses guidelines. Data were collected and the key features from the included studies were extracted. Overview quality assessment questionnaire scoring assessed the quality of the articles. A total of 12 articles were selected, where the lowest score was 13. REVIEW RESULTS: Considering Ni-Ti rotary instruments, this overall evaluation comprehends 939 broken instruments with an incidence of fracture of 5%. Out of the 12 selected articles, 10 studies revealed that flexural failure was the predominant mode (range of 62-92%). It appears that motion plays an important role when it comes to mechanisms of fracture. The majority of defects found in hand-operated instruments were in the form of torsional failure. Although the major cause of separation of rotary instruments is flexural fatigue, smaller instruments show more torsional fracture than the larger instruments. The average fragment length was found to be 2.5 mm and 3.35 mm, respectively, for torsional failure and flexural failure. The risk of bias depends on fractographic analysis. CONCLUSION: Flexural fatigue is the predominant mode of fracture in rotary Ni-Ti instruments. The type of motion and size of the instrument seem to affect the mechanism of fracture. Fragment length may show a strong association with the type of fracture mechanism. CLINICAL SIGNIFICANCE: This systemic review found that flexural fatigue is the most relevant mechanical stress that induces intracanal separation in vivo. Moreover, in clinical practice, the fragment length might be an excellent indicator of the type of fracture.

Developments, application, and performance of artificial intelligence in dentistry - A systematic review.

BACKGROUND/PURPOSE: Artificial intelligence (AI) has made deep inroads into dentistry in the last few years. The aim of this systematic review was to identify the development of AI applications that are widely employed in dentistry and evaluate their performance in terms of diagnosis, clinical decision-making, and predicting the prognosis of the treatment. MATERIALS AND METHODS: The literature for this paper was identified and selected by performing a thorough search in the electronic data bases like PubMed, Medline, Embase, Cochrane, Google scholar, Scopus, Web of science, and Saudi digital library published over the past two decades (January 2000-March 15, 2020).After applying inclusion and exclusion criteria, 43 articles were read in full and critically analyzed. Quality analysis was performed using QUADAS-2. RESULTS: AI technologies are widely implemented in a wide range of dentistry specialties. Most of the documented work is focused on AI models that rely on convolutional neural networks (CNNs) and artificial neural networks (ANNs). These AI models have been used in detection and diagnosis of dental caries, vertical root fractures, apical lesions, salivary gland diseases, maxillary sinusitis, maxillofacial cysts, cervical lymph nodes metastasis, osteoporosis, cancerous lesions, alveolar bone loss, predicting orthodontic extractions, need for orthodontic treatments, cephalometric analysis, age and gender determination. CONCLUSION: These studies indicate that the performance of an AI based automated system is excellent. They mimic the precision and accuracy of trained specialists, in some studies it was found that these systems were even able to outmatch dental specialists in terms of performance and accuracy.

An Update of Possible Radiation-free Imaging Techniques in Dentistry.

Cone-beam computed tomography (CBCT) represents today the most widespread and most used 3D examination in dentistry. It is precise because of its usefulness in orthodontics and orthognathic surgery with large field of view (FOVs); in oral surgery and implantology for the 3D evaluation of bone volumes and proximity to noble structures; and in endodontics for the understanding of the often difficult root canal system anatomy with reduced FOV and greater resolution that this imaging technique, also considering the wide diffusion and availability in dental offices, in addition to the short examination execution times, allows its wide use.1-4.