Prosthodontics and Prosthodontology Commons^™

Impacts Of A Duf2207 Family Protein On Streptococcus Mutans Stress Tolerance Responses And Biofilm Formation, Xiaochang Huang, Camile G. Laird, Paul P. Riley, Zezhang Tom Wen

School of Dentistry Faculty Publications

Locus SMU.243 in Streptococcus mutans was annotated as a member of the DUF2207 family proteins highly conserved in all bacteria but with unknown function. To investigate its role in S. mutans physiology, a SMU.243-deficient mutant was constructed using allelic exchange mutagenesis, and the impacts of SMU.243 deletion on bacterial growth, stress tolerance response, and biofilm formation were analyzed. Compared to the wild-type UA159, S. mutans lacking SMU.243 displayed a reduced growth rate and a reduced overnight culture density (p < 0.01) when grown at low pH and in the presence of methyl viologen. Relative to the parent strain, the deficient mutant also had a reduced survival rate following incubation in a buffer of pH 2.8 (p < 0.01) and in a buffer containing hydrogen peroxide at 58 mM after 60 min (p < 0.001) and had a reduced capacity in biofilm formation especially in the presence of sucrose (p < 0.01). To study any ensuing functional/phenotypical links between SMU.243 and uppP, which is located immediately downstream of SMU.243 and encodes an undecaprenyl pyrophosphate phosphatase involved in recycling of carrier lipid undecaprenyl phosphate, a uppP deficient mutant was generated using allelic exchange mutagenesis. Unlike the SMU.243 mutant, deletion of uppP affected cell envelope biogenesis and caused major increases in susceptibility to bacitracin. In addition, two variant morphological mutants, one forming rough colonies and the other forming mucoid, smooth colonies, also emerged following the deletion of uppP. The results suggest that the SMU.243-encoded protein of the DUF2207 family in S. mutans plays an important role in stress tolerance response and biofilm formation, but unlike the downstream uppP, does not seem to be involved in cell envelope biogenesis, although the exact roles in S. mutans’ physiology awaits further investigation.

Accuracy And Trueness Of Exporting Computer Aided Designs Of 3-Unit Fixed Dental Prosthesis By 3 Cad Systems, Ezzat Abou-Alnaga, Ashraf Hussein, Ahmed Naguib, Shereen Ahmed Nossair

Future Dental Journal

Objectives: Computer-aided design (CAD) software programs offer the option to export 3D scans and designs across different CADCAM systems, commonly referred to as open CADCAM technology. However, there is insufficient evidence of whether this exporting procedure has an impact on the accuracy of digital designs.This study aimed to investigate the accuracy of exporting of computer aided designs (CAD) of three-unit fixed dental prosthesis using 3 CAD systems. Materials and Methods: Three CAD softwares (inLab 17™, CeraMill Mind™, Dental System 2017™) were used to generate designs of a three-unit fixed partial denture. The designs generated by each CAD software were exported …

Current Oral Hygiene And Recreational Behavioral Trends In Hiv Disease, Donald E. Mercante, Emily Guarisco, Elizabeth A. Lilly, Arni Rao, Kelly Treas, Clifford J. Beall, Zach Thompson, Ann L. Griffen, Eugene J. Leys, Jose A. Vazquez, Michael E. Hagensee, Paul L. Fidel

School of Dentistry Faculty Publications

Objective: HIV disease is evolving with more HIV+ persons experiencing a high quality of life with well-controlled viremia. We recently enrolled a large cohort of HIV+ and clinically relevant HIV− persons for oral microbiome analyses that included a questionnaire related to oral hygiene and recreational behaviors. Here, the questionnaire responses were analyzed for behavioral trends within the cohort, together with trends over time by comparison to a previous geographically centered HIV+ cohort. Methods: Data were collected by questionnaire at baseline visits as cross-sectional assessments. Multivariable analyses were conducted for associations of HIV status as well as age, race, and sex, …

The Effect Of Two Sintering Cycles And Aging On Biaxial Flexural Strength Of Strength Gradient Multi-Layered Zirconia (An Vitro Study), Passent Hm El Galab, Maged Zohdy, Fatma Makkeyah, Mustafa Noor

Dentistry

No abstract provided.

Assessment Of The Effect Of Two Different Digital Fabrication Techniques On Marginal And Internal Fit Of Interim Fixed Dental Prothesis, Mohamed A. Shalaby, Mennatallah M. Wahba, Hisham I. Al-Ansari, Ahmed N. Mohamed

Future Dental Journal

Aim: The aim of that study was to evaluate the marginal and internal fit of a 3-unit, and 6-unit interim fixed dental prosthesis manufactured through milling and 3D printing technologies. Materials and Methods: Forty-eight interim fixed dental prostheses (FDP) were equally divided into two groups according to the fabrication technique. In group (MT), specimens were fabricated through milling technology while in group (PT), specimens were obtained by 3D printing. Each group was subdivided equally according to the FDP span length into 3-unit FDP (SFDP), and 6-unit FDP (LFDP). Marginal and internal fit were measured through the superimposition of the digital …

Digital Fabrication Of Attachment For Implant-Anchored Auricular Prosthesis (Case Report)., Hussein El Charkawi Proffesor

Future Dental Journal

Aim: This novel technique, has adopted digital technology to fabricate a customized precision attachment for a patient who has lost his attachment which anchor his implant retained auricular prosthesis. A scanner was used to acquire the ball abutment’ geometry of craniofacial implant in the mastoid area. CAD/CAM technology and special software was used to fabricate a customized small PEEK precision attachment that was no longer available in the market. This attachment was picked-up by an auricular prosthesis. The retention qualities of the auricular prosthesis with this attachment was satisfactory for both the patient and the dentist. This novel approach will …

Computer Guided Versus Conventional Maxillary Sinus Augmentation Using Allogenic Bone Blocks With Simultaneous Implant Placement In Severely Pneumatized Sinuses, Hisham G. Zulhemma Department Of Oral And Maxillofacial Surgery, Future University In Egypt, Egypt. [email protected], Waleed Ragab El-Beialy Professor Of Oral And Maxillofacial Surgery -Cairo University, Egypt. [email protected], Ahmed Abd Elsamad Associate Professor Of Oral And Maxillofacial Radiology– Cairo University, Egypt. [email protected], Ahmed Abozekry Lecturer Of Oral And Maxillofacial Surgery –Future University In Egypt, Egypt. [email protected]

Future Dental Journal

Background: Maxillary sinus lifting is a complex procedure with reported complications in the literature where the presence of sinus septa further complicates the procedure, they including membrane perforation, bleeding. Aim: The aim of this study is to decrease the incidence of membrane perforation which is the most common reported complication, and to determine whether the use of surgical guides could decrease the incidence of membrane perforation. Materials and methods: A total of 12 cases where blindly divided into 2 groups; Group (A) computer guided maxillary sinus lifting and Group (B) conventional sinus lifting, both groups received allogenic bone blocks for …

Defining Success In Healthcare Education: Us Dental Student And Faculty Perspectives., David Alexandre Cruz Walma, Mathieu Alexander Cruz Walma, Shirin Khoynezhad, Sang E. Park, Carly Timmons Mckenzie, Et Al

School of Dentistry Faculty Publications

Purpose/objectives Academic metrics and clinical performance are necessary but alone insufficient in describing success in dental education. This paper identifies themes critical for dental student success as commonly cited by both dental students and faculty. Methods Dental faculty interviews and pre-doctoral D2/D3/D4 student focus groups at two dental institutions generated data for thematic analysis. Themes were individually identified then merged, compared, and contrasted to establish a definitive list of key themes reflected in student and faculty comments. Results Twenty-five pre-doctoral students participated in one of four focus groups (two focus groups at each dental institution). Thirteen dental education faculty across …

Acceptability Of Fully Guided Virtual Implant Planning Software Among Dental Undergraduate Students, Shishir Ram Shetty, Colin Murray, Sausan Al Kawas, Sara Jaser, Wael Talaat, Medhini Madi, Vinayak Kamath, Nisha Manila, Raghavendra Shetty, Vidya Ajila

School of Dentistry Faculty Publications

Background: Fully guided implant surgery as a technique is gaining popularity. It has been observed that use of surgical guides improves precision and predictability for dental implant placement. However, like any other newer technology, the acceptance of fully guided dental implant technology among users is based upon its perceived usability. This study aimed at evaluating the perception about using Virtual Implant Planning Software (VIPS) among undergraduate dental students at the university of Sharjah. Methods: Ninety-Six dental surgery students from the University of Sharjah were included in the study. One week after the Virtual Implant Planning Software (Planmeca Romexis version 6.2 …

Analysis Of Changes In Gingiva-Occlusal Parameters As Perceived By Three Middle-East Populations, Nadine Nachabeh, Tony Daher, Elie Maalouf, Khalil Kharma, Eliane Kaydouh, Carina Mehanna

International Arab Journal of Dentistry

Purpose. This study aims to compare the effect of various smile parameters (buccal corridor, gummy smile, midline to face discrepancy, with and without upper lip filling) on the perception of smile attractiveness by applying the digital modification of images judged by one hundred and eighty laypersons from different Middle East populations.

Materials and Methods. A frontal photo of a woman’s smile is manipulated with Photoshop to modify each smile parameter gradually into 3 grades. The total number of smiles to be assessed is 18. One hundred and eighty participants divided into 3 groups (n=60: 30 men and 30 women): …

Distal Cantilever Length Comparison In Esthetic Materials For Hybrid Implant Prostheses: An In Vitro Study, Sana Shams Eddin, Elie Jasser, Mohammad Chams Eddin, Carole Abi Ghosn Yared, Joseph Makzoumi, Paul Boulos

International Arab Journal of Dentistry

Objective: the assessment of distal cantilever length in implant supported prothesis (Hybrid prosthesis) by comparing the load to fracture in two different esthetic framework materials (Zirconia and Polyetheretherketone (PEEK)) with two different cantilevers loading distances (10mm, 15mm).

Material and methods: 20 frameworks were fabricated and divided into 4 groups (n=5): according to the material type, Peek, zirconia, and according to the cantilever loading distance (10), or (15) mm and a load-to-fracture test was used until complete fracture of specimens occurs.

Results: The effect of material type and cantilever loading distance were statistically significant for the mean load-to-fracture …

Evaluation Of Heated Cure Acrylic Immersed In Ozonated Water, Shawq Azmi Tawfeeq, Aseel Mohammed Al-Khafaji

Maaen Journal for Medical Sciences

Background: Denture cleansing is an important step that can prevent the spread of infection and improve a patient's health, the durability of the dentures, and the overall quality of life; therefore, it is necessary to choose a suitable cleanser that, in addition to being effective, does not have an unfavorable effect on the qualities of the denture base resin itself when used for an extended period.

Aim: This research aims to assess the effects of ozonated water on the surface roughness and hardness of heat-cured acrylic resin by immersion technique.

Materials: Sixty bars shape made of heat-cured acrylic were manufactured. …

Independent Effects Of Hiv And Antiretroviral Therapy On The Oral Microbiome Identified By Multivariate Analyses, Clifford J. Beall, Elizabeth A. Lilly, Carolina Granada, Kelly Treas, Kenneth R. Dubois, Shahr B. Hashmi, Jose A. Vazquez, Michael E. Hagensee, Ann L. Griffen, Eugene J. Leys, Paul L. Fidel

School of Dentistry Faculty Publications

The oral microbiome is an important predictor of health and disease. We recently reported significant yet modest effects of HIV under highly active antiretroviral therapy (ART) on the oral microbiome (bacterial and fungal) in a large cohort of HIV-positive (HIV+) and matched HIV-negative (HIV-) individuals. As it was unclear whether ART added to or masked further effects of HIV on the oral microbiome, the present study aimed to analyze the effects of HIV and ART independently, which also included HIV- subjects on preexposure prophylaxis (PrEP) therapy. Cross-sectional analyses of the effect of HIV devoid of ART (HIV+ ART- versus matched …

Enhanced Periodontal Ligament Stem Cell Viability And Osteogenic Differentiation On Two Implant Materials: An Experimental In Vitro Study, Sara Fikry, Shereen Nader Dr, Engy Farag Dr

Dentistry

Background: Surface roughness of dental implants impacts the survival of adult periodontal stem cells and rate of differentiation. This research was conducted to test how human periodontal ligament stem cells behaved on yttria stabilized tetragonal zirconia polycrystals and polyetheretherketone (PEEK) discs with different surface topographies. Methods: Discs roughening was prepared by sandblasting. Stem cells were cultivated on zirconia discs with a polished surface, PEEK discs with a polished surface, sandblasted zirconia discs and sandblasted PEEK discs. Cells viability was assessed after 24, 48, 72 hours. Scanning electron microscopy was used to examine the adherence and attachment of cells. Osteoblastic differentiation …

Effect Of Different Span Lengths With Different Total Occlusal Convergences On The Accuracy Of Intraoral Scanners, Omar Elsergany

Dentistry

Purpose: The aim was to assess the effect of span lengths and total occlusal

convergence (TOC) on the accuracy of intraoral scanners .

Materials and methods: Two typodont acrylic teeth models were prepared to receive

fixed dental prostheses with three different span lengths. Span 1: between maxillary

canines; span 2: between maxillary second premolars; and span 3: between maxillary

In recent years, the employment of digital techniques in

1–4

(CAD–CAM). Obtaining a digital scan using an intrao-

ral scanner (IOS) is the first step of this digital workflow.

This technique, when compared to traditional impression

techniques, has shown exceptional accuracy …

Fit Assessment Of Soft Milled Co-Cr And Zirconia Fixed Dental Prosthesis Compared To Cast Co-Cr., Elie E. Daou Prof

Annual Research Symposium

No abstract provided.

Evaluation Of Color Difference And Translucency Of Modified Peek Restorations Veneered With Different Veneering Materials Before And After Thermal Cycling, Mohamed Hamdy Abdulmaguied, Tarek Salah Morsi, Mennatallah M. Wahba, Hesham Katamish

Future Dental Journal

Objective: The aim of this study was to investigate the effect of different PEEK veneering materials, as well as thermocycling on the color difference (ΔE) and the translucency parameter (TP) of modified PEEK veneered restorations.

Materials and Methods: Thirty disc shaped specimens of veneered BioHPP (1.5 mm X 12 mm) were randomly divided into three groups (n=10) based on the type of the veneering material. Group (A): Discs veneered with CAD milled Lithium Disilicate, group (B): Discs veneered with pre-cured milled composite, and group (C): Discs veneered with conventional light cured composite. CIELab values were calculated for all specimens over …

Effect Of Chromium Metal Alloy Fabrication Techniques On Enamel Wear, Pattrapond Eopsirisuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

This in vitro study aimed to investigate the effect of different chromium metal alloys on enamel wear through longitudinal observation across various simulated chewing cycles. Four groups of alloys were studied (n=10 per group): casting Ni-Cr alloys (NC), casting Co-Cr alloys (CC), SLM Co-Cr alloys (CS), and heat-treated SLM Co-Cr alloys (CS-H). The test simulated chewing of enamel cusps against the alloys in distilled water under specific conditions (49 N load, 0.7 mm sliding movement, and 1.6 Hz frequency). Enamel wear was measured at 60,000, 120,000, and 240,000 cycles by using intraoral scanner matching with open-source 3D software. Enamel wear …

ผลของการปรับสภาพพื้นผิวต่อกำลังแรงยึดเฉือนระหว่างวัสดุครอบฟันชั่วคราวกับแบร็กเกตจัดฟันโลหะ, มนนภัส เลาหะอัญญา

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยมีวัตถุประสงค์เพื่อเปรียบเทียบกําลังแรงยึดเฉือนระหว่างแบร็กเกตจัดฟันโลหะกับครอบฟันชั่วคราวชนิดต่าง ๆ ที่ใช้การปรับสภาพพื้นผิวที่แตกต่างกัน เตรียมวัสดุบูรณะครอบฟันชั่วคราว 3 ชนิด ได้แก่ พอลิเมทิลเมทาคริเลตชนิดบ่มด้วยตัวเอง (Unifast™ Trad) พอลิเมทิลเมทาคริเลตชนิดแคดแคม (CADCAM VIPI Block) และเรซินคอมโพสิตชนิดบิสเอคริล (Protemp™ 4) จำนวน 4 กลุ่ม กลุ่มละ 11 ชิ้น นำวัสดุปรับสภาพพื้นผิวด้วยการทามอนอเมอร์เมทิลเมทาคริเลต การเป่าผงอะลูมินัมออกไซด์ การใช้เข็มกรอกากเพชร และกลุ่มที่ไม่ได้ถูกปรับสภาพพื้นผิวเป็นกลุ่มควบคุม นำชิ้นงานตรวจความหยาบของพื้นผิวและส่องด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องกราด ทำการยึดติดแบร็กเกตจัดฟันโลหะด้วยเรซินแอดฮีซีฟทรานสบอนด์ เอ็กซ์ที นำไปทดสอบค่ากำลังแรงยึดเฉือนด้วยเครื่องทดสอบอเนกประสงค์โดยใช้ความเร็วในการทดสอบที่ 1 มิลลิเมตรต่อนาที ศึกษาดัชนีส่วนเหลือของสารยึดติดด้วยกล้องจุลทรรศน์ชนิดสเตอริโอ วิเคราะห์ด้วยสถิติการวิเคราะห์ความแปรปรวนแบบสองทางที่ระดับนัยสําคัญ 0.05 และเปรียบเทียบแต่ละกลุ่มโดยใช้สถิติ Games-Howell test ผลการศึกษาพบว่าวัสดุบิสเอคริลการเป่าผงอะลูมินัมออกไซด์มีค่ากำลังแรงยึดเฉือนสูงที่สุด ตามมาด้วยการใช้เข็มกรอกากเพชร และการทามอนอเมอร์ ตามลำดับ วัสดุพอลิเมทิลเมทาคริเลตชนิดแคดแคมการเป่าผงอะลูมินัมออกไซด์มีค่ากำลังแรงยึดเฉือนสูงที่สุด ตามด้วยการทามอนอเมอร์ และการใช้เข็มกรอกากเพชร ตามลำดับ และวัสดุพอลิเมทิลเมทาคริเลตชนิดบ่มด้วยตัวเองการทามอนอเมอร์และการเป่าผงอะลูมินัมออกไซด์ มีค่ากำลังแรงยึดเฉือนสูงที่สุดโดยไม่แตกต่างกันอย่างมีนัยสำคัญทางสถิติ ตามด้วยการใช้เข็มกรอกากเพชร ดังนั้นการปรับสภาพพื้นผิวด้วยการเป่าผงอะลูมินัมออกไซด์มีประสิทธิภาพในการเพิ่มแรงยึดติดแบร็กเกตจัดฟันมากที่สุด ในพอลิเมทิลเมทาคริเลตชนิดบ่มด้วยตัวเองควรทามอนอเมอร์เมทิลเมทาคริเลตเพิ่มเติม และวัสดุบิสเอคริลมีแรงยึดติดกับแบร็กเกตจัดฟันมากที่สุดหลังปรับสภาพพื้นผิวเชิงกล

Effect Of Aprotic Solvents On The Microtensile Bond Strength Of Composite Core And Fiber-Reinforced Composite Posts, Wisarut Prawatvatchara

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objective: The purpose of this study was to examine the effect of aprotic solvents, which were tetrahydrofuran, pyridine, and morpholine, compared to hydrogen peroxide on surface roughness of fiber-reinforced composite post and microtensile bond strength between fiber-reinforced composite post surfaces and the composite core. Material and methods: A total of 75 FRC posts plus, and 75 D.T. light posts were divided into 3 groups (non-thermocycling, 5,000-cycle and 10,000cycle thermocycling groups). Each group was divided into five subgroups according to the post-surface treatment: C: non-treatment group; H2O2: immersing with 35% hydrogen peroxide; THF: immersing with tetrahydrofuran; PY: immersing with pyridine; MP: …