Now showing items 1-20 of 238

    • Novel Bioactive Low-Shrinkage-Stress Composite with Antibacterial and Remineralization Properties

      ALHUSSEIN, ABDULLAH; Xu, Huakun H. (2023)
      Methacrylate-based resin composites are frequently employed in dentistry for their aesthetic qualities, durability, and adhesive properties. Nevertheless, these restorations generally exhibit a lifespan of 5 to 10 years, with recurrent caries and tooth fractures being primary failure factors. Marginal integrity and the absence of bioactivity at the tooth-restoration junction contribute to recurrent caries development. Consequently, this dissertation endeavors to introduce a novel bioactive low-shrinkage-stress nanocomposite, featuring dimethylaminododecyl methacrylate (DMADDM) as an antibacterial agent, as well as remineralization nanoparticles of calcium fluoride (nCaF2) and nanoparticles of amorphous calcium phosphate (NACP), with the potential of increase the longevity of dental restoration and protect tooth structure. All novel formulations of low-shrinkage-stress composite were subjected to a series of mechanical, antibacterial, cytocompatibility, and ion release assessments. First, we investigated the optimum concentration of DMADDM that can be incorporated with a low-shrinkage-stress composite without compromising mechanical properties. We found that incorporation of up to 5% DMADDM into a low-shrinkage stress composite efficiently inhibited Streptococcus mutans (S. mutans) biofilm commonly associated with secondary caries. This potent antibacterial effect is achieved while maintaining excellent mechanical properties and minimizing polymerization shrinkage stress, potentially improving the long-term success of dental restorations. Next, we investigated the antibacterial and cytocompatibility of the incorporation of 3% DMADDM with 20% nCaF2 or 20% NCAP into a low-shrinkage-stress nanocomposite. We found that incorporating DMADDM with either nCaF2 or NACP into a low-shrinkage-stress nanocomposite provides a potent antibacterial effect against S. mutans biofilm while maintaining excellent mechanical properties. In addition, the novel formulations demonstrated excellent biocompatibility against human gingival fibroblasts and dental pulp stem cells. Lastly, we investigated the ions release and antibacterial properties against a salivary biofilm for our innovative formulations. The innovative mixture of DMADDM, NACP, and nCaF2 demonstrated strong antibiofilm effects on salivary biofilm, while concomitantly releasing a significant amount of remineralizing ions. This nanocomposite is a promising dental material with antibiofilm and remineralization capacities, with the potential to reduce polymerization-related microleakage and recurrent caries.
    • The quality of information on oral hygiene instructions for orthodontic patients in TikTok videos

      Dorfmann, Sabrina; Schneider, Monica, D.D.S., M.S. (2023)
      Objective: The study aimed to assess the reliability, content, quality, and overall usefulness of orthodontic oral hygiene instructions in TikTok videos. Methods: The final videos were evaluated for content, reliability, quality, and usefulness by using a content domain checklist, DISCERN questionnaire, and Global Quality Scale (GQS). Descriptive video characteristics were also recorded. Results: Dental professionals uploaded 70.00% of the TikTok videos, with orthodontists responsible for 39%. The videos had average scores of 2.19 for DISCERN, 3.96 for content, 2.14 for GQS, and 6.10 for usefulness. Video length was significantly associated with content scores (r = 0.3553, P = 0.0003), usefulness (r=0.3553, P = 0.0003), and quality (GQS) (r=0.2620, P=0.0085). Conclusion: Most TikTok videos on orthodontic oral hygiene were uploaded by dental professionals. Reliability, content, and quality of the videos were all poor. Videos were considered slightly useful. Longer videos were significantly correlated with higher content, higher quality, and increased usefulness.
    • Perception of lip attractiveness: a survey of orthodontists, general dentists, and laypersons

      McCormack, Katie; Copello, Flavio (2023)
      We aim to investigate the proposed standards of ideal lip proportions and compare those standards to what different people view as most attractive. A 16-question survey was distributed via Qualtrics to orthodontists, general dentists, and laypersons asking demographics as well as opinion-based questions regarding a series of facial photographs. Photographs were digitally altered using Adobe Photoshop to produce different dimensions of the lips from both profile and frontal views. Participants were asked to rate the perceived attractiveness of the lips shown. Regardless of occupation, individuals preferred the appearance of slightly protrusive or thicker lips. Retrusive and thin lip varieties had the lowest median attractiveness scores. Average values for lip projection and thickness were not found to be mutually agreed upon across occupation types (p<0.05) and average lip thickness was not mutually agreed upon between age groups of orthodontists (p=0.004). Based on the results of this study, care should be taken not to produce retrusive or thin lips during orthodontic treatment. Acceptance of a slightly thick or protrusive lip profile may be a more esthetic or well-accepted patient outcome.
    • Three-Dimensional Assessment of Virtual Clear Aligner Attachment Removal: A Prospective Clinical Study

      Dock, Jeremy; Bosio, Jose A. (2023)
      Virtual attachment removal (VAR) is a process used in digital dentistry to prefabricate retainers by removing attachments from a digital scan before the removal of clear aligner attachments. This study aims to evaluate the accuracy of VAR in the maxillary arch. 110 teeth were analyzed from a sample of 54 maxillary scans from 25 subjects. Models with attachments were virtually debonded using Meshmixer® and superimposed over the control group in MeshLab. Vector Analysis Module was used to calculate 3D distances on the buccal surfaces between the superimposed models. The VAR protocol showed no statistical differences in the root mean square between different tooth segments with an overall tendency for inadequate attachment removal. No difference between the groups were found when regarding the number of attachments was used as a main factor. The VAR technique is precise enough for the fabrication of retainers from printed dental models in a clinical setting.
    • Effect of Polydopamine-RGD Peptide Coating on the Adhesion of Cultured Fibroblasts on Polymethylmethacrylate Provisional Custom Abutment Materials

      Mui, Philip; Saito, Hanae (2023)
      Cellular attachment properties of the temporary and prosthetic abutment is one of the important factors for creating optimal peri-implant soft tissue around the implant. Surface modifications appear to play an important role in promoting early healing of the soft tissue around the dental implant, affecting primarily the epithelium, fibroblast, and osteoblast cell behavior. Another strategy to better manage peri-implant and abutment soft tissue integration is to coat the surface with bioactive agents to enhance biocompatibility. Among the most commonly utilized are proteins and peptides. The proposed in-vitro study will provide better insights of surface characteristics for implant-abutment interface by application of the peptide RGD for optimized attachment of peri-implant soft tissue cells. The hypothesis is that application of polydopamine and the peptide RGD on the implant-abutment surface can improve fibroblast early attachment, migration and proliferation, thereby advancing early wound healing and establishing peri-implant soft tissue attachment.
    • The Etiology of Peri-implantitis: Microbiological Profile Within and Around Dental Implants and the Associated Human Immune Response

      Kensara, Anmar; Masri, Radi, 1975- (2023)
      Objectives: To characterize the microbiome composition within and around dental implants of peri-implantitis subjects and within and around healthy implants using 16S rRNA gene sequencing, and to profile salivary inflammatory mediators associated with peri-implantitis compared to healthy controls from the same subjects. Methods: A total of 24 subjects (peri-implantitis n=14, healthy n=10) were enrolled in the study. From the 24 subjects, 24 endosseous implants from affected (peri-implantitis) and 14 healthy controls were included in this cross-sectional study. Samples for microbiological analysis were obtained from the internal surfaces of dental implants and peri-implant sulcus using sterile paper points. DNA was extracted and 16S rRNA gene was amplified using universal primers targeting the V3-V4 regions. Amplicons were sequenced using Illumina MiSeq platform. Alpha and beta diversity, core microbiome, and taxa differential abundance were assessed. Saliva was collected from the same subjects for immunology-based assays. Salivary inflammatory mediators in peri-implantitis and healthy implant subjects were profiled using antibody arrays. Results: A significant increase in microbial diversity was observed in the internal implant surface of healthy implants compared with the internal surfaces of peri-implantitis (Shannon P= 0.02), and no significant differences in microbial diversity between healthy implants sulci and peri-implantitis pockets (Shannon P= 0.82). Bacterial community structure was significantly different within implant in both healthy and peri-implantitis groups (P= 0.012) but not significantly different around implants in both healthy and peri-implantitis (P= 0.18). Enterococci is the predominant bacteria within peri-implantitis (LD >2.0, P< 0.05). Abundant species in peri-implantitis were C. leadbetteri, T. maltophilum, Peptostreptococcus, Neisseria, P. gingivalis, and P. endodontali, L. lactis and F. alocis (P < 0.05). Gram-positive bacteria such as S. salivaris, P. melaninogenica, L. wadei, and Actinomyces spp were more abundant in the peri-implant healthy sulcus. Around 48% of detected bacteria were cultivable in general media. In addition, out of 105 analytes examined in saliva, we found that 29 mediators were upregulated in subjects with peri-implantitis (P < 0.001). Conclusions: Our results indicate that microbial colonization of the internal implant surface may act as a major contributor to the etiology of peri-implant disease. Multiple inflammatory mediators were significantly elevated in the saliva of peri-implantitis patients compared to healthy implant patients.
    • Effect of Contact Type on Caries Experience in Primary Dentition

      Jaafar, Ameena; Dhar, Vineet VD (2023)
      Purpose: The aim is to evaluate effect of contact type and other caries risk factors (diet, plaque, and fluoride) on caries experience in primary dentation. Secondly, to assess prevalence of OXIS contacts among 3-10 years old children enrolled in the study. Methods: Clinical examination was completed on healthy children 3 to 10 years of age. Contact type of primary molars was recorded based on OXIS classification. Information on other caries risk factors were collected (plaque, fluoride, and diet habits). The outcomes assessed included clinical caries (presence/absence), decayed, missing, and filled primary teeth (dmft), decayed teeth (dt), and decayed surfaces (ds). Results: A total of 277 contacts were examined in 107 children ( 51 females and 56 males). Moderate plaque was found to be associated with dmft and dt for contacts S, I, and X. High diet frequency was associated with high dmft and dt scores for contacts S, I, and X. Contact type I showed significant association with dmft compared to other contacts in multivariable analysis. Conclusion: Both high diet frequency and moderate plaque index were linked to higher caries experience in children with contact types S,I, and X. Contact type I found to be associated with higher dmft scores compared to other contacts (X and S).
    • Comparison of Shear-bond Strength of Orthodontic Brackets on Enamel with use of Pro Seal with Assure Plus

      Greene, David; Sanchez, Dina (2023)
      Title of Thesis: Comparison of Shear-bond Strength of Orthodontic Brackets on Enamel with use of Pro Seal with Assure Plus David Greene, Master of Biomedical Sciences, 2023 Thesis directed by: Dr. Dina Sanchez, Director of Predoctoral Orthodontics, Clinical Assistant Professor, Department of Orthodontics and Pediatric Dentistry We aim to investigate the shear bond strength of orthodontic brackets bonded with Assure Plus alone and in combination with Pro Seal, following the manufacturer's recommended bonding protocol. Forty-two (42) extracted premolar human teeth were randomly assigned to two bonding groups, the control group (Assure Plus) and the test group (Assure Plus and Pro Seal). After bonding, the teeth were stored at 37°C for 24 hours. Next, the shear bond strength test was completed. The results of the Mann- Whitney test showed there was not a statistical difference of shear bond strength between the two groups for the variables, Peak Load and Shear Bond Strength. The use of Pro Seal with Assure Plus as a preventive measure for white spot lesions during orthodontic treatment does not negatively impact the shear bond strength of orthodontic brackets during treatment.
    • Novel Bioactive Low-shrinkage-stress Nanocomposite with Antibacterial and Remineralization Properties and Thermal-cycling and Aging Resistance.

      FILEMBAN, HANAN; Xu, Huakun H.; Weir, Michael D. (2022)
      Dental composites continue to be the material of choice in daily dental practice for several reasons, including their good mechanical properties, conservative cavity design, and superior esthetics. However, the longevity of current resin composite restorations ranges only 5-10 years. Recurrent caries and tooth fracture are the most common types of failure during the first 6 years of clinical service. These failures are often caused by the polymerization shrinkage stress of the dental composite materials. Thus, there is an increased need to develop a new generation of bioactive dental composite with the ability to reduce polymerization shrinkage stress, long-term antibacterial, remineralization abilities, and excellent mechanical properties. Therefore, this dissertation aims to develop a new bioactive low-shrinkage-stress dental composite containing dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP) which could be a promising approach to increase the chances of success of composite restorations and strengthen tooth structures. First, we found that the new bioactive low-shrinkage-stress resin composite significantly reduced the polymerization shrinkage stress, without compromising their mechanical properties. Increasing the DMAHDM mass fraction increased the antibacterial effect in a dose-dependent manner. Next, we investigated the low-shrinkage-stress composite mechanical stability and antibacterial durability in thermal cycling for 20,000 cycles, equivalent to two years of clinical life. We found that the bioactive low-shrinkage-stress composite possessed good mechanical properties that matched commercial composite both before and after thermal cycling. The new composite had potent antibacterial activity, which was maintained and did not decrease after thermal cycling. Lastly, we further examined the mechanical and antibacterial durability of a bioactive low-shrinkage-stress after 50,000 and 100,000 thermal cycles which corresponds to 5 and 10 years respectively of in vivo function. We found that the bioactive low-shrinkage-stress composite maintained its antibacterial potency after thermal cycling, indicating long-term antibacterial durability. In addition, it possessed good mechanical properties that were comparable to commercial composite both before and after thermal cycling. The triple benefits of antibacterial, remineralization, and lower shrinkage stress have a great potential to inhibit recurrent caries and increase restoration longevity.
    • Soluble Immune Biomarkers as a Diagnostic Tool of Head and Neck Squamous Cell Carcinoma Histological Inflammatory Subtypes

      Ghita, Ioana; Younis, Rania H. (2022)
      Head and neck squamous cell carcinoma (HNSCC) is a devastating malignancy that occurs in close proximity to vital structures. Despite all advances in diagnostic and therapeutic measures, the overall 5-year survival rate stays at ~65% and can be dismal for recurrent and advanced stages. There is accumulating evidence indicating the immune suppressive potential of HNSCC by which it can escape and/ or suppress the immune system. The recent advent of immunotherapy showed unprecedented improvement in overall response of advanced stage HNSCC. Yet, the overall response rate of HNSCC to immunotherapy remains at ~ 15%. Hence, further understanding of HNSCC tumor inflammation is warranted. The hypothesis of the current work is that the histological inflammatory subtype (HIS) of HNSCC can provide the basis for patient stratification that can be distinguished from the cytokine profile in peripheral blood, therefore better treatment strategies and patient outcomes. Paired tumor tissue and plasma of 104 HNSCC cases were collected according to UMB IRB protocol. Scoring of the HIS subtype was carried out using immunohistochemistry (IHC) of the emerging immune biomarker Semaphorin 4D (Sema4D). Our cohort showed 52% HIS inflamed (HIS-INF), 40% immune excluded (HIS-IE) and 8% deserted (HIS-ID). Differential gene expression (DGE) analysis of 10 HNSCC tumor tissues using NanoString immune-oncologic (human IO-360) 700 genes set showed that tumors with HIS-IE clustered as IFN-γ negative/ low immune signature compared to HIS-INF and were higher in hypoxia gene expression and the myeloid cellular compartment, while the HIS-INF demonstrated higher lymphoid component. DGE revealed a novel association between the high soluble Sema4D in plasma (HsS4D) and higher transcriptional level of Osteopontin (OPN) in the tumor tissue, that we also demonstrated in vitro. Furthermore, using ELISA-Luminex™ system, HIS-IE tumor tissue was significantly distinguished from the HIS-INF, in almost 40 traditional cytokines detected in the paired plasma samples. In conclusion, our work demonstrated a stratification model of HNSCC based on the underlying HIS profile that can be detected via the soluble cytokine panel in blood. These findings can open new avenues for patient stratification and enhance personalized clinical care in the field of HNSCC.
    • The Trueness of additive and Subtractive Zirconia Crowns

      Almutairi, Eman Sager; Masri, Radi, 1975- (2021)
      Purpose: To assess the trueness of ceramic crowns fabricated using additive technology compared to crowns fabricated using subtractive technology. Material and methods: single crown was designed using Dental Designer Software. 3D design was used to fabricate milled and printed crowns. All crowns were scanned. Geomagic software was used for analysis. Best Fit and Marginal Fit Alignment used to analyze the 3D accuracy of the crowns. One Way ANOVA used to analyze the data, and p<0.05 was considered significant. Result: Significant differences found between the additively and subtractive manufactured crowns [p=0.003,F=11.172]. Additively manufactured crowns exhibited better trueness than subtractive crowns. For the additively manufactured crowns, the Best fit Alignment showed 42.81±40.8μm deviation, and the Marginal Alignment showed a 43.11 ±38.05μm deviation. For Subtractive manufactured crowns, the deviation in Best Fit Alignment was 62.67 ±50.79μm and in Marginal Alignment was 55.35±48.69μm. Conclusion: Additive technology fulfills surface trueness criteria.
    • Novel Bio-interactive Fixed Dental Restoration Cement with Potent Antibacterial and Remineralization Properties

      AlSahafi, Rashed A.; Weir, Michael D.; Xu, Huakun H. (2022)
      Resin-based cement is increasingly used in clinical practice due to its excellent mechanical and physical properties. The cementation and accurate placement of fixed dental restorations with an ideal marginal adaptation to the tooth structure remains a challenging laboratory and clinical task. The marginal gap of fixed dental restoration increases the opportunity for microleakage, plaque accumulation, and tooth demineralization by increasing the potential for food buildup around the margin and exposing the tooth-cement interface to the oral cavity. Thus, there is an increased need to develop a new generation of bio-interactive dental cement with antibacterial, long-term remineralization abilities, and excellent mechanical properties. Therefore, this dissertation aims to invent new bio-interactive resin-based cement containing dimethylaminohexadecyl methacrylate (DMAHDM), nanoparticles of amorphous calcium phosphate (NACP), and nanoparticles of calcium fluoride (nCaF2), which could be a promising approach to increase the chances of success of fixed dental restoration and strengthen tooth structures. All new cement formulations were subjected to a series of mechanical, antibacterial, and ion release assessments. In the first manuscript, we found that the new NACP+DMAHDM cement has excellent potential for fixed restoration cementation, as it efficiently inhibited S. mutans biofilm commonly associated with secondary caries and maintained an excellent mechanical property with high levels of Ca and P ions released. In the second manuscript, we found that incorporating DMAHDM and NACP into resin-based cement provides strong antibacterial action against saliva microcosm biofilm and presents a high level of Ca and P ion recharge abilities. In the third manuscript, we found that the new cement with both NACP and nCaF2 demonstrated the advantages of both types of bio-interactive fillers as it could release a higher level of ions than the resin cement with only nCAF2 and exhibits a better rechargeability compared to the resin cement with only NACP. Lastly, in the fourth manuscript, we found that the novel antibacterial low-shrinkage-stress resin-based cement provided strong antibacterial action and maintained excellent mechanical properties with reduced polymerization shrinkage stress, which could improve the long-term success of the fixed dental restoration.
    • Caries Experience Based on A Simulated Epidemiological Screening and Routine Examination with Radiographs

      Kuchari, Abrar; Dhar, Vineet (2022)
      Purpose: To assess and compare caries experience based on an epidemiological “screening” examination and a routine examination with radiographs. Methods: 128 patients ages 5 to 10 years were included. An initial examination was done by a pediatric dentist in conditions simulating an epidemiological screening assessment. A second evaluation was done by eight postgraduate pediatric dental resident who conducted a routine clinical exam of the patient in the dental chair including radiographs. Results: By the epidemiological screening, the prevalence of untreated dental caries (Y/N) in primary and/or permanent teeth was 50% and the caries experience was 77%. After the routine examination with radiographs, the prevalence of untreated dental caries was 74.22% and caries experience was 90%. The severity of untreated dental caries was 2.0 and 3.9, and the severity of caries experience was 3.2 and 5.6 by the simulated epidemiological screening and routine examination with radiographs, respectively.
    • Generational Perspectives of Orthodontists in the U.S. and Canada– A Survey Study

      Hussain, Syed Rassal; Bosio, Jose A. (2022)
      Objective: To identify differences between generations of orthodontists in the U.S. and Canada and to evaluate the perspective of each generation on widely debated topics in orthodontics. Materials and Methods: A 22-item IRB approved survey was distributed to orthodontists in the U.S. and Canada. Participants were asked questions about the use of technology, future of clear aligner therapy (CAT), orthodontic education, student debt, marketing, and corporate orthodontics among other topics. Results: Significant increase in female orthodontists over generations and a decrease in orthodontic educators was found (P<0.001). Among generations, differences were found in regard to their amount of student debt, use of specific diagnostic tools, marketing preferences, and their opinion on the future of CAT. Conclusions: Clear distinctions exist between different generations of orthodontists. Issues such as increasing student debt load and a decrease in orthodontic educators over generations should be addressed to preserve the future of the orthodontic profession.
    • The role of Angiopoietin-like 4 in head and neck squamous cell carcinoma progression and dissemination

      Hefni, Eman; Montaner, Silvia (2022)
      Dysregulation of cellular signaling is instrumental in the promotion of tumor cell metabolism, proliferation, tissue invasion and metastasis. Molecular-based therapies for neoplastic diseases are designed to modulate or interact with cell surface receptors, intracellular cascades, or microenvironment components related to the extracellular matrix, tumor vasculature and immune response. To design these therapies, an improved understanding of the molecular underpinnings leading to tumor growth is essential. The overall aim of our investigation is identification of the molecular mechanisms associated with the induction of tumor cell migration and proliferation induced by Angiopoietin-like 4 (ANGPTL4), a pro-tumorigenic and pro-angiogenic factor, in head and neck cancer squamous cell carcinoma (HNSCC). HNSCC accounts for around 54,000 new cases and 11,000 deaths per year in the United States. Unfortunately, the clinical management of this tumor remains challenging. Our studies, divided into two research aims, use in vitro cell-based models together with signal transduction and cell and molecular biology methods. Our results demonstrate that: 1) ANGPTL4 is upregulated in human-derived dysplastic oral keratinocytes (DOKs) and HNSCC cell lines, but not in normal oral keratinocytes (NOKs), suggesting an early and sustained role for ANGPTL4 in disease progression. ANGPTL4 is a molecular marker in biopsies from patients with mild-moderate or moderate oral epithelial dysplasia, primary HNSCC and metastatic HNSCC. ANGPTL4 is necessary and sufficient to promote cell migration in DOKs and HNSCCs lines. Binding of ANGPTL4 to neuropilin-1 (NRP1) leads to paxillin (PXN) phosphorylation and cell migration in an ABL1-dependent manner, exposing the ANGPTL4/NRP1/ABL1/PXN cascade as a vulnerable target for HNSCC treatment. 2) Epidermal Growth Factor (EGF)- and Hypoxia-inducible Factor-1 (HIF-1)-mediated pathways cooperate in the upregulation of ANGPTL4 in normal and dysplastic oral keratinocytes and HNSCC cells. Besides EGF, the EGF ligand amphiregulin leads to an increase in ANGPTL4 and is upregulated in HNSCC lesions. ANGPTL4 activates the HNSCC molecular markers p38 MAPK, AKT and mTOR in NOKs; these kinases may act as potential intracellular regulators of the autocrine signals and paracrine secretions that ANGPTL4 activates to promote HNSCC tumorigenesis. Collectively, our findings suggest that ANGPTL4 and its associated signaling molecules are potential therapeutic targets in HNSCC clinical management.
    • Global Temporary Anchorage Device (TAD) Usage: A Survey of Orthodontists

      Ashton, Kelsea; Bosio, Jose A.; 0000-0002-8045-3370 (2022)
      Objective: We aim to determine how often TADs are used worldwide and establish guidelines for implementing TADs in everyday practice. Methods: A 19 question survey was sent to orthodontists around the world asking opinion based, case-specific, and placement technique questions regarding TADs. The country of practice and length of time practicing orthodontics were the independent variables. Results: Most orthodontists use TADs rarely/sporadically. There were significant findings for how TADs are being used, sizes, and placement techniques amongst different continents. There was a significant difference in how many TADs orthodontists placed in residency according to how long they have been practicing, but it did not greatly affect frequency of use, mechanics, or placement technique. Conclusion: The frequency of TAD use is similar worldwide and amongst different age groups. Although significant data was found in this study, there is such variability in regard to TADs that clear guidelines were not established.
    • Optimal Antero-Posterior Position of the Maxillary Central Incisors and its Relationship to the Forehead in Adult African American Males

      Endres, Elise Tigani; Sanchez, Dina (2022)
      Objective: To determine an optimal antero-posterior (AP) position of the maxillary central incisors (CI) and its relationship to the forehead in African American males. Methods: 95 smiling profile photographs were taken, evaluated by orthodontists and laypersons, and categorized in Group B, R or F. The CI position and forehead inclination (FI) were measured relative to glabella vertical (GV). Statistical analysis evaluated the relationship between CI position and FI, differences between groups, and differences between orthodontists and laypersons. Results: Optimal CI position was -2.1mm behind GV. There were no significant differences between orthodontists and laypersons. All group comparisons were significantly different, except Group B v Group R. The optimal CI position relative to GV and FI were not significantly correlated. Conclusions: The AP position of the CI relative to the forehead in African American males can be evaluated to determine the optimal AP position of the CI and optimal esthetics.
    • The Perspectives of Middle Atlantic Society Orthodontists on COVID-19

      Vumback, Matthew; Schneider, Monica, D.D.S., M.S. (2022)
      Purpose: This study aims to survey Middle Atlantic Society Orthodontists on how COVID-19 has impacted and altered their practices and outlook on the profession. Methods: This cross-sectional study was designed using Qualtrics XM and consisted of 20 questions focusing on the licensed orthodontists in the MASO regions. Results: Responders had split feelings regarding the length of time out of practice due to regulations. Nearly 48% felt that it was too long, while about 49% felt that it was appropriate. During this time, over 32% have offered more aligner therapy but roughly 51% have seen a reduction in patients. Regardless, over 61% do not believe retirement plans have been affected. Conclusion: A meaningful difference in perspectives exists amongst MASO orthodontists regarding COVID-19 regulations and infection control. Treatment philosophy appears to be shifting towards clear aligner therapy and tele-dentistry. Despite the disruption to the profession, most orthodontists feel hopeful for the future.
    • A Novel Magnetic Nanoparticle Containing Adhesive to Enhance Microtensile Bond Strength of Composite Resin to Dentin: An in vivo Study.

      Bulloch, Brandon; Masri, Radi, 1975- (2022)
      Purpose: An in vivo study to compare microtensile bond strength and resin tag density of a novel adhesive that relies on magnetic force. Materials and Methods: Twenty-five teeth were obtained from subjects. In the experimental group, teeth were restored with a novel nanoparticle adhesive and magnetic force (n=16). In the control group (n=9), no nanoparticle or magnetic force was used. Teeth were extracted and cut into beams. Microtensile bond strength and resin tag density were measured. A two tailed student t test was used to compare groups. P<0.05 was considered significant. Results: There was a significant increase of microtensile bond strength of the experimental group compared to controls (P= 0.025). The SEM images showed resin tag density was increased by a magnitude of two with the experimental group. Conclusion: Magnetic force improves the microtensile bond strength and resin tag density of resin adhesive when used in vivo.
    • The effect of silver diamine fluoride on the surface roughness of dental ceramics

      Chandy, Tintu Sara; Masri, Radi, 1975- (2022)
      Purpose: This study compared the effect of silver diamine fluoride, acidulated phosphate fluoride and distilled water on the surface roughness of dental ceramics. Materials and Methods: Rectangles of zirconia, lithium disilicate and feldspathic porcelain were treated with 38% SDF, 1.23% APF and distilled water. The surface roughness of each rectangle was measured using a profilometer before and after treatment with the solutions. Multiple comparison of the means among the ceramics and testing solutions was done using 2-Way ANOVA followed by Tukey’s test. P<0.05 was considered significant. Results: APF created the greatest surface roughness compared to SDF and water. Zirconia was unaffected by all solutions. SDF increased the roughness of lithium disilicate and felspathic porcelain, however the results were not statistically significant compared to the control group. Conclusions: With many topical fluoride preparations available, dentists should be aware of their effect on different ceramic systems to prevent surface roughening of restorations.