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1.
Nanomaterials (Basel) ; 12(21)2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36364508

RESUMO

Experimental adhesives with functional nitrogen-doped titanium dioxide nanoparticles (N_TiO2) have been shown to display improved properties. However, these materials have not been characterized regarding their degree of conversion (DC), biaxial flexure strength (BFS), surface roughness (SR), elastic modulus (EM), and long-term antibacterial functionalities. Experimental adhesives were synthesized by dispersing N_TiO2 (10%, 20%, or 30%, v/v%) into OptiBond Solo Plus (OPTB, Kerr Corp., USA). Unpolymerized adhesives (volume = 50 µL/drop, n = 3/group) were individually placed onto a heated (37 °C) attenuated total reflectance (ATR) monolithic diamond crystal (Golden Gate, Specac). The spectra of composites were obtained with a Fourier-transform infrared (FTIR) spectrometer (Nicolet IS50; 500-4500 cm-1; resolution = 4 cm-1, 10 internal scans/spectrum) before and after polymerization. Disk-shaped specimens (diameter = 6.0 mm, thickness = 0.5 mm) for BFS (n = 12/group), SR and EM (n = 3/group), and for antibacterial testing (n = 18/group/time-point) were fabricated and photopolymerized (1 min each; 385-515 nm, 1000 mW/cm2; VALO). DC values (%) were calculated from pre- and post-polymerization spectra using the two-frequency method and tangent-baseline technique. BFS was assessed using a universal testing machine (Instron 68TM-5, crosshead speed = 1.27 mm/min, 25 °C). SR and EM were investigated using an atomic force microscope (Multimode 8) with aluminum-coated silicon probes (8 nm pyramidal tip, spring constant 40 N/m, Bruker). Antibacterial testing was performed by growing Streptococcus mutans biofilms (UA159-ldh, 37 °C, microaerophilic) on the surfaces of specimens for 24 h and then measuring the relative luminescence units (RLU) with a Biotek Synergy HT multi-well plate reader. Results demonstrate that experimental materials containing 10%, 20%, and 30% of N_TiO2 displayed higher levels of DC, had better mechanical properties, and were able to exert strong and durable antibacterial properties without visible light irradiation and after extended periods of simulated shelf-life and aging in PBS. The reported experimental materials are expected to increase the service lives of polymer-based bonded restorations by decreasing the incidence of secondary caries.

2.
Nanomaterials (Basel) ; 12(17)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36080033

RESUMO

The present study reports on the development and testing of novel bleaching agents containing co-doped metaloxide nanoparticles (NP; 0%, 5%, 10% v/w) and hydrogen peroxide (HP, 0%, 6%, 15%, and 35%). Bovine blocks (n = 200, A = 36 mm2) were obtained and randomly distributed into experimental groups (n = 10/group). NPs were incorporated into gels before bleaching (3 sessions, 7 days apart, 30 min/session, irradiated with violet light-LT). Color changes (ΔE00, ΔWID), mineral content (CO32−, PO43−), and topography were assessed (spectrophotometer, ATR-FTIR, and AFM) before and after bleaching procedures (14 days). Metabolic status and three-dimensional components of non-disrupted Streptococcus mutans biofilms were investigated using a multimode reader and confocal microscopy. The results indicate that ΔE00 and ΔWID significantly increased with NPs' concentrations and LT. The enamel's mineral ratio was adversely impacted by HP, but alterations were less pronounced when using NP-containing gels. The enamel's topography was not damaged by the bleaching protocols tested. The bioluminescence results show that bleaching protocols do not render latent antibacterial properties to enamel, and the confocal microscopy results demonstrate that the 3-dimensional distribution of the components was affected by the protocols. The proposed nanotechnology improved the bleaching efficacy of experimental materials independent of hydrogen peroxide or irradiation and did not adversely impact the enamel's surface properties or its chemical content.

4.
J Am Dent Assoc ; 153(1): 86-87.e2, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34996534

RESUMO

BACKGROUND: With many states in the United States permitting dentists to administer the COVID-19 vaccine, there is much discussion about their scope of practice in relation to delivering other vaccines. METHODS: Survey questions were developed to assess dentists' awareness about their vaccine administration scope of practice and attitudes and barriers if choosing to incorporate vaccine delivery into their practice scope. The survey was deployed electronically to members of the American Dental Association Clinical Evaluators (ACE) Panel (N = 989) on September 2, 2021, and remained open for 2 weeks. Data were summarized descriptively in Qualtrics and SAS Version 9.4. RESULTS: Of the 330 ACE Panel members who responded to the survey, 42% were not aware of which vaccines their state permits them to deliver. More than one-half (55%) would be willing to administer influenza or COVID-19 vaccines in their practice setting, but at present only 2% of respondents administer vaccines. To overcome vaccine administration barriers, the top 3 resources respondents want access to are the following: training or education, financial support, and access to protocols. Of all the respondents, 91% indicated the dental hygienist should be involved in certain capacities. CONCLUSIONS: Few dentists are administering vaccines, possibly owing to a number of challenges. Dental hygienists may play an integral role in the administration of vaccines in the dental clinic, but few dentists are educating their patients about vaccines. PRACTICAL IMPLICATIONS: Although dentists wishing to administer vaccines in their practice may encounter barriers, support at the state, federal, and organizational levels could help them overcome these challenges.


Assuntos
COVID-19 , Vacinas , American Dental Association , Atitude do Pessoal de Saúde , Vacinas contra COVID-19 , Higienistas Dentários , Odontólogos , Humanos , SARS-CoV-2 , Inquéritos e Questionários , Estados Unidos
5.
Sci Rep ; 11(1): 23800, 2021 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-34893687

RESUMO

The aim of this study was to evaluate the antimicrobial efficacy of non-thermal atmospheric plasma (NTAP) against Streptococcus mutans biofilms. Resin discs were fabricated, wet-polished, UV sterilized, and immersed in water for monomer extraction (37 °C, 24 h). Biofilms of bioluminescent S. mutans strain JM10 was grown on resin discs in anaerobic conditions for (37 °C, 24 h). Discs were divided into seven groups: control (CON), 2% chlorhexidine (CHX), only argon gas 150 s (ARG) and four NTAP treatments (30 s, 90 s, 120 s, 150 s). NTAP was applied using a plasma jet device. After treatment, biofilms were analyzed through the counting of viable colonies (CFU), bioluminescence assay (BL), scanning electron microscopy (SEM), and polymerase chain reaction (PCR). All NTAP-treated biofilm yielded a significant CFU reduction when compared to ARG and CON. BL values showed that NTAP treatment for 90 s, 120 s or 150 s resulted in statistically significantly lower metabolic activity when compared to the other groups. CHX displayed the lowest means of CFU and BL. SEM showed significant morphological changes in NTAP-treated biofilm. PCR indicated damage to the DNA structure after NTAP treatment. NTAP treatment was effective in lowering the viability and metabolism of S. mutans in a time-dependent manner, suggesting its use as an intraoral surface-decontamination strategy.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Resinas Compostas , Gases em Plasma/farmacologia , Streptococcus mutans/efeitos dos fármacos , Medições Luminescentes/métodos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Streptococcus mutans/ultraestrutura , Propriedades de Superfície , Fatores de Tempo
6.
J Am Dent Assoc ; 152(10): 872-873.e2, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34579811

RESUMO

BACKGROUND: Given the oral health implications of smoking, vaping, and using smokeless tobacco products (STPs), the dental office can be an effective setting for clinicians to offer smoking cessation counseling and treatment (SCCT). METHODS: A survey tool was developed to assess dentists' approach and experience with SCCT. This survey was deployed electronically on May 21, 2021, to the American Dental Association Clinical Evaluators (ACE) Panel (N = 982), and 1 week later, nonresponders were sent reminders. Results were summarized in SAS Version 9.4. RESULTS: Of the 283 survey responders, one-half offered SCCT to their patients. Of those who offered SCCT, 69% would be willing to prescribe pharmacologic agents to help with cessation. Nine of 10 times, SCCT conversations included the dentist. Of the 49% of respondents who did not offer SCCT, one-quarter were current or past smokers, vapers, or STP users. Out of all of the survey respondents, 40% were aware that SCCT is part of most medical benefits. Most respondents (82%) perform surgeries on patients who smoke, vape, or use STPs. CONCLUSIONS: Implementation of SCCT in the dental office was split among ACE panelists, but when it was offered, the dentist was almost always involved. Awareness about SCCT medical benefits and surgical protocols for current smokers, vapers, and STP users differed among this sample. PRACTICAL IMPLICATIONS: Dentists can benefit from more formal training and resources around SCCT and access to reimbursement for having these crucial conversations with their patients.


Assuntos
Abandono do Hábito de Fumar , Tabaco sem Fumaça , American Dental Association , Aconselhamento , Humanos , Inquéritos e Questionários , Estados Unidos
7.
Phys Fluids (1994) ; 33(8): 085102, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34471340

RESUMO

The coronavirus disease 2019 pandemic has imposed unprecedented occupational challenges for healthcare professionals. In dentistry, handheld instruments such as air and electric handpieces, ultrasonic scalers, and air/water syringes are capable of generating aerosols, droplets, and splatter, thereby exposing dental professionals to airborne contaminants such as viruses, bacteria, and fungi. The objective of the present study was to determine the spatial distribution of aerosols by size (0.30 to 20.00 µm) and the efficacy of a novel aerosol containment device (ACD) in a large operatory room with 12 dental chairs. Real-time portable laser aerosol spectrometers were used to measure the size-resolved number concentration of aerosols generated by a collision nebulizer. Results reported demonstrate that aerosol number concentrations significantly decreased as a function of distance with or without the utilization of the ACD. The ACD was able to efficiently decrease (up to 8.56-fold) the number and size distribution of particles in a large dental clinic. The novel device demonstrated higher efficiency for particles shown to contain the highest levels of severe acute respiratory syndrome coronavirus 2 in Chinese hospitals, thereby showing great promise to potentially decrease the spreading of nosocomial pathogens in dental settings.

8.
J Am Dent Assoc ; 152(8): 669-670.e2, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34325781

RESUMO

BACKGROUND: Dentists may choose to integrate intraoral scanners (IOSs) into their practices, but there are many different IOS technologies and system generations to choose from, posing a challenge for dentists who want to invest in them. METHODS: A survey of IOS use rates, advantages, satisfaction, and training was developed and deployed through Qualtrics to the 968 members of the American Dental Association Clinical Evaluators (ACE) Panel on February 19, 2021. Nonrespondents were sent reminders, and data were analyzed in SAS Version 9.4 (SAS). RESULTS: A total of 369 panelists responded to the survey. IOS use was split among the ACE Panel; 53% indicated they use one in their practice. The top reason respondents began using IOSs was to improve clinical efficiency (70%). Ninety percent of respondents use IOSs for single tooth-supported crowns, and 58% began using IOSs less than 4 years ago. Most users are at least mostly satisfied (91%) with the results. Among nonusers, the top reason for not using an IOS was the high level of financial investment (66%); 34% and 40% of nonusers are thinking of buying or training with IOSs in 2021, respectively. CONCLUSIONS: Uptake of IOSs is split; most users are satisfied with their results, and nonusers cited financial barriers as the most common reason for not investing in one. PRACTICAL IMPLICATIONS: As IOSs continue to penetrate the market and dentists are faced with a decision whether to invest in one, they will need guidance on how to choose the most appropriate device for their patients.


Assuntos
American Dental Association , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Humanos , Inquéritos e Questionários , Estados Unidos
9.
Am J Orthod Dentofacial Orthop ; 160(1): 50-57, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34090735

RESUMO

INTRODUCTION: The purpose of this study was to compare the metabolism of Streptococcus mutans biofilms after 1-7 days of growth on different orthodontic adhesives. METHODS: Specimens of 6 commercial orthodontic adhesives were fabricated in custom-made molds and polymerized using a light-emitting diode light-curing unit. Bioluminescent S mutans (UA159:JM10) biofilms were grown on ultraviolet-sterilized specimens for 1, 3, 5, and 7 days (n = 18 biofilms/d/product) in anaerobic conditions at 37°C. The metabolism of biofilms (relative luminescence unit [RLU]) was measured 0, 2, 4, and 6 minutes after exposure to D-luciferin solution using a microplate reader. A linear mixed-effects model was used to analyze the logarithm of RLU (log RLU). The model included fixed effects of products, days, and minutes. Tukey-Kramer post-hoc tests were then performed on the significant predictors of log RLU (α = 0.05). RESULTS: Days (P <0.0001) and minutes (P <0.0001) were independent predictors of log RLU, but the products were not (P = 0.5869). After adjusting for minutes, the log RLU was analyzed with a post-hoc test, and all differences between days were significant with the exceptions of day 3 from day 5 (P = 0.0731) and day 5 from day 7 (P = 0.8802). After adjusting for day, log RLU was analyzed with a post-hoc test and all differences in minutes were significant. CONCLUSIONS: No significant differences in the metabolism of S mutans biofilms were observed among the 6 orthodontic adhesives. Biofilms that were grown for 3 days demonstrated the highest levels of biofilm metabolism as evidenced by higher mean log RLU values relative to 1, 5, and 7-day growth durations.


Assuntos
Cimentos Dentários , Streptococcus mutans , Biofilmes , Humanos
10.
J Am Dent Assoc ; 152(4): 329-330.e2, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33775289

RESUMO

BACKGROUND: Clinicians often encounter defective restorations and are faced with the difficult decision of whether to repair the existing restoration or replace it. METHODS: An electronic survey on repairing or replacing defective restorations was developed to assess how clinicians are making these decisions and the technical aspects considered when making a repair. E-mails containing the survey link were sent to the American Dental Association Clinical Evaluators (ACE) Panel on August 14, 2019, and the survey remained open for 2 weeks. Nonrespondents were sent reminders 1 week after deployment. RESULTS: Approximately 4 of every 5 respondents repair defective restorations. The top 3 conditions for making these repairs were noncarious marginal defects (87%), partial loss or fracture of the restoration (79%), and crown margin repair due to carious lesions (73%). Among respondents who repair defective restorations, almost all repair direct resin composite (98%), whereas approximately one-third do not repair the other restorative materials (that is, amalgam, glass ionomer, and fractured indirect all-ceramic crowns). Resin composite is used most often to repair resin direct composite restorations, and likewise, glass ionomer is used most often to repair glass ionomer restorations. Only 54% of respondents use amalgam to repair amalgam restorations. Surface treatments varied among the 3 available restorations types. CONCLUSIONS: Many dentists are actively making restoration repairs, but choosing clinical scenarios to make these repairs is material dependent. PRACTICAL IMPLICATIONS: The repair of defective restorations is an acceptable and more conservative alternative than restoration replacement, and its success depends on proper case selection, material, and technique.


Assuntos
Cárie Dentária , Reparação de Restauração Dentária , American Dental Association , Resinas Compostas , Amálgama Dentário , Falha de Restauração Dentária , Restauração Dentária Permanente , Humanos , Inquéritos e Questionários , Estados Unidos
11.
J Am Dent Assoc ; 152(1): 80-81.e2, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33250170

RESUMO

BACKGROUND: Zirconia is a relatively new dental material used for indirect dental restorations. Little is known about how dental practitioners are using this material in their practice. METHODS: A survey on zirconia restorations was developed and administered electronically through e-mail communications to the American Dental Association Clinical Evaluators (ACE) Panel on August 31, 2020. Reminders were sent to nonrespondents, and the survey closed 2 weeks after the launch date. RESULTS: When using zirconia for a restoration, respondents choose it to restore natural teeth (99%) more often than implants (76%). Almost all respondents (98%) use it for posterior crowns, whereas approximately two-thirds (61%) use it for anterior crowns. Restoration removal or replacement and shade matching and translucency were the top 2 cited disadvantages of zirconia, whereas most of the respondents (57%) cited flexural strength or fracture resistance as the biggest advantage. Fine diamonds and ceramic polishers are used most often to polish and adjust zirconia restorations, whereas coarse diamond rotary instruments and those made specifically for zirconia are most frequently used for removing these restorations. Compared with metal ceramic restorations, more than 50% of respondents experience debonding more often with zirconia restorations. CONCLUSIONS: Dentists recognize the favorable fracture resistance and flexural strength properties of zirconia, and most use similar techniques when adjusting and removing this material. Removing these restorations and shade matching are a struggle for many. PRACTICAL IMPLICATIONS: Dentists may benefit from tips on the best methods to remove, shade match, and adhesively bond zirconia restorations.


Assuntos
American Dental Association , Odontólogos , Cerâmica , Coroas , Materiais Dentários , Porcelana Dentária , Planejamento de Prótese Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário , Humanos , Papel Profissional , Inquéritos e Questionários , Estados Unidos , Zircônio
12.
Heliyon ; 6(10): e05226, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33102851

RESUMO

Previous reports demonstrated the utility of systemic application of growth hormone (GH) in the treatment of bone defects. Very few studies correlated bone repair efficacy with hepatic and renal side effects promoted by locally-delivered GH. The objectives of this study were to assess the bone repair properties along with hepatic and renal adverse effects promoted by local application of GH in a rat model. Thirty-two rats were randomly divided (4 groups; n = 8/group), as follows: (i) AB (autogenous bone + local application of saline solution [SS]), (ii) AB+ (autogenous bone + SS local application + SS irrigation), (iii) AB/GH+ (autogenous bone + SS local application + GH irrigation) and (iv) AB/GHL+ (autogenous bone + GH local application + GH irrigation). Critical-sized defects (diameter = 5.0 mm) were surgically created by a single operator in the calvaria of rats. Defects were filled with ground autogenous bone. Defects pertaining to AB+ and AB/GH+ received a mixture of autogenous bone and a SS-saturated (0.02 mL) collagen sponge covered with bovine cortical membrane. Defects in group AB/GHL+, were filled with the same biomaterials saturated with GH (0.02 mL). SS (0.1 mL) or GH (0.1 mL, equivalent to 0.4 IU) were applied locally on alternate days (8 weeks) in animals in groups AB, AB+ and AB/GH+ or AB/GHL+, respectively. Bone repair properties was determined in hematoxylin/eosin-stained slices using traditional histologic and histomorphometric techniques along with optical microscopy and digital image analysis. Statistical differences among groups was determined using Kruskal-Wallis and Tukey post hoc tests (α = 0.05). Histology results indicated that AB and AB+ displayed greater presence of autogenous bone as compared to AB/GH+ and AB/GHL+. Histomorphometric results indicated significantly higher osteoid matrix formation in AB and AB+ when compared to AB/GHL+ (p = 0.009). Kidneys and livers were found to have their glomeruli preserved in AB and AB+. Strong glomeruli necrosis and large areas of protein deposition were found in AB/GH+. Abnormal small-sized glomeruli were found in AB/GHL+. The utilization of autogenous bone graft associated with local application and irrigation with GH was shown to not improve the bone repair in calvarial critical-sized defects in a rat model.

13.
J Am Dent Assoc ; 151(10): 796-797.e2, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32979959

RESUMO

BACKGROUND: Bonding crowns and bridges with resin cement can improve retention and reinforcement of the restoration. However, there is variation in the steps taken by different practitioners to achieve this goal. METHODS: The authors developed a survey on bonding dental crowns and bridges with resin cement and distributed it electronically to the American Dental Association Clinical Evaluators (ACE) Panel on May 22, 2020. The survey remained open for 2 weeks. Descriptive data analysis was conducted using SAS Version 9.4. RESULTS: A total of 326 panelists responded to the survey, and 86% of respondents who place crowns or bridges use resin cements for bonding. When placing a lithium disilicate restoration, an almost equal proportion of respondents etch it with hydrofluoric acid in their office or asked the laboratory to do it for them, and more than two-thirds use a silane primer before bonding. For zirconia restorations, 70% reported their restorations are sandblasted in the laboratory, and 39% use a primer containing 10-methacryloyloxydecyl dihydrogen phosphate. One-half of respondents clean their lithium disilicate or zirconia restorations with a cleaning solution. Resin cements used with a primer in the etch-and-rinse mode are the most widely used. The technique used to cure and clean excess resin cement varies among respondents. CONCLUSIONS: The types of resin cements used, tooth preparation, crown or bridge preparation, and bonding technique vary among this sample. PRACTICAL IMPLICATIONS: Although many dentists bond crowns and bridges on the basis of best practices, improvement in the process may be achieved by dentists communicating with their laboratory to confirm the steps performed there, ensuring an effective cleaning technique is used after try-in and verifying that the correct primer is used with their chosen restorative material.


Assuntos
Colagem Dentária , Cimentos de Resina , American Dental Association , Coroas , Cimentos Dentários , Materiais Dentários , Porcelana Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Propriedades de Superfície , Inquéritos e Questionários , Estados Unidos
14.
Sci Rep ; 10(1): 13503, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782299

RESUMO

Dental adhesives hydrolyze in the mouth. This study investigated the water sorption (SOR), solubility (SOL) and cytotoxicity (CYTO) of experimental adhesives containing nitrogen-doped titanium dioxide nanoparticles (N_TiO2). Specimens (n = 15/group [SOR, SOL]; n = 10/group [CYTO]) of unaltered Clearfil SE Protect (CSP), OptiBond Solo Plus (OSP), Adper Scotchbond (ASB) and experimental adhesives (OSP + 25% or 30% of N_TiO2) were fabricated, desiccated (37 °C) and tested for SOR and SOL according to ISO Specification 4049 (2009). CYTO specimens were UV-sterilized (8 J/cm2) and monomer extracted in growth medium (1, 3 or 7 days). Human pulp cells were isolated and seeded (0.5 × 104) for MTT assay. SOR and SOL data was analyzed using GLM and SNK (α = 0.05) and CYTO data was analyzed with Kruskal-Wallis and SNK tests (α = 0.05). SOR and SOL values ranged from 25.80 µg/mm3 (30% N_TiO2) to 28.01 µg/mm3 (OSP) and 23.88 µg/mm3 (30% N_TiO2) to 25.39 µg/mm3 (25% N_TiO2). CYTO results indicated that pulp cells exposed to experimental materials displayed comparable viabilities (p > 0.05) to those of OSP. Experimental materials displayed comparable SOR, SOL and CYTO values (p > 0.05) when compared to unaltered materials. N_TiO2 incorporation have not adversely impacted SOR, SOL and CYTO properties of unaltered adhesives.


Assuntos
Antibacterianos/química , Antibacterianos/toxicidade , Nanoestruturas/química , Resinas Sintéticas/química , Resinas Sintéticas/toxicidade , Adesividade , Sobrevivência Celular/efeitos dos fármacos , Polpa Dentária/citologia , Humanos , Solubilidade , Água/química
15.
J World Fed Orthod ; 9(2): 68-74, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32672657

RESUMO

OBJECTIVES: The purpose of this study was to identify the combination of orthodontic adhesive resins and light-emitting diode (LED) light-curing units (LCUs) that result in the highest degree of resin conversion (DC). The hypothesis tested was that pairing orthodontic resins with LCUs from the same manufacturer produces higher DC versus unpaired resins and LCUs. METHODS: Pre-polymerization spectra of adhesive resins (Transbond XT [3M Unitek], BracePaste [American Orthodontics] or Opal Bond MV [Opal by Ultradent]) were obtained at oral temperature (37°C) using an attenuated total reflectance (ATR) diamond crystal (Golden Gate, Specac) in a Fourier-transform infrared (FTIR) spectrometer (Nicolet IS50). Resin specimens were polymerized using various LCUs (Ortholux Luminous [3M Unitek], Blue Ray 3 [American Orthodontics], or VALO Ortho Cordless [Ultradent Products, Inc.]) before obtaining post-polymerization infrared (IR); spectra. Twelve LCU-resin combinations were tested (n = 20/combination), half with a bracket present (Mini Diamond Twin, Ormco) and half without. DC values (%) were calculated using the two-frequency method and tangent-baseline technique. Data for each resin were statistically analyzed using General Linear Models and Student-Newman-Keuls post hoc tests (α = 0.05). RESULTS: Statistically significant differences were found within each resin for the groups without brackets present (P < 0.0001), the groups with brackets present (P < 0.0001), and the groups with brackets when compared with the manufacturer-paired group without a bracket (P < 0.0001). CONCLUSIONS: Adhesive resins and LCUs from the same manufacturer did not consistently result in statistically higher mean DC values than unpaired combinations. Metal brackets do not uniformly reduce the degree of conversion of adhesive resins when assessed using IR spectrometry.


Assuntos
Resinas Compostas , Lâmpadas de Polimerização Dentária , Cura Luminosa de Adesivos Dentários , Teste de Materiais , Ortodontia/instrumentação , Resinas Compostas/química , Humanos , Braquetes Ortodônticos , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Sci Rep ; 10(1): 9811, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32555360

RESUMO

Nanotechnology can improve the performance of dental polymers. The objective of this study was to modify the surfaces of nanoparticles with silanes and proteins, characterize nanoparticles' agglomeration levels and interfaces between nanoparticles and the polymeric matrix. Undoped (n-TiO2), nitrogen-doped (N_TiO2) and nitrogen-fluorine co-doped titanium dioxide nanoparticles (NF_TiO2) were synthesized and subjected to surface modification procedures in preparation for Small-Angle X-Ray Scattering (SAXS) and Small-Angle Neutron Scattering (SANS) characterizations. Experimental adhesives were manually synthesized by incorporating 20% (v/v) of n-TiO2, N_TiO2 or NF_TiO2 (as-synthesized or surface-modified) into OptiBond Solo Plus (OPTB). Specimens (n = 15/group; d = 6.0 mm, t = 0.5 mm) of OPTB and experimental adhesives were characterized using Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS), 2-D ToF-SIMS chemical imaging and SANS. SAXS results indicated that surface-modified nanoparticles displayed higher scattering intensities in a particle-size dependent manner. ToF-SIMS results demonstrated that nanoparticles' incorporation did not adversely impact the parental polymer. 2-D ToF-SIMS chemical imaging demonstrated the distribution of Ti+ and confirmed nitrogen-doping levels. SANS results confirmed nanoparticles' functionalization and revealed the interfaces between nanoparticles and the polymer matrix. Metaloxide nanoparticles were successfully fabricated, incorporated and covalently functionalized in a commercial dental adhesive resin, thereby supporting the utilization of nanotechnology in dentistry.

17.
Nanomaterials (Basel) ; 10(6)2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32498241

RESUMO

In this study, six solvents (water, diiodomethane, bromonaphthalene, formamide, ethanol and ethylene glycol) were examined for three nanoparticle substrates, zinc oxide and titanium dioxide (21 nm and 100 nm), with the goal of assessing the suitability of a modified drop penetration method (DPM) for orders of magnitude smaller particles. Nanoparticles were compressed into flat discs and the solvent dropped on the surface while the image with time was recorded. Contact angles were in reasonable agreement with literature over the range of 20-80°, but failed to provide acceptable results for surface energy components. It was necessary to eliminate certain solvents and substrates not meeting the selection criteria.

18.
J Am Dent Assoc ; 151(7): 544-545.e2, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32498964

RESUMO

BACKGROUND: The ability to polymerize light-activated dental materials with dental light-curing units (DLCUs) has revolutionized dentistry. However, proper DLCU use is essential for ensuring the effectiveness and performance of these materials. METHODS: The authors developed an electronic cross-sectional survey in the American Dental Association Qualtrics Research Core platform. The survey included questions about DLCU use, unit type and selection, training, maintenance, technique, and safety measures. The authors deployed the survey to 809 American Dental Association Clinical Evaluators (ACE) panelists on October 9, 2019, and sent reminder links to nonrespondents 1 week later. They conducted exploratory and descriptive analyses using SAS software Version 9.4. RESULTS: Of the 353 ACE panelists who completed the survey, most used a DLCU in their practices (99%), and light-emitting diode multiwave units were the most common type of DLCU units (55%). Dentists use DLCUs for over one-half of their appointments each day (mean [standard deviation], 59% [22%]). Regarding technique, respondents reported that they modify their curing technique on the basis of material thickness (79%) and material type or light tip-to-target distances (59%). Maintenance practices varied, with two-thirds of respondents reporting that they periodically check their DLCUs' light output. CONCLUSIONS: DLCUs are an integral part of a general dentist's daily practice, but maintenance, ocular safety, and technique varied widely among this sample. PRACTICAL IMPLICATIONS: Because clinical effectiveness requires delivery of an adequate amount of light energy at the appropriate wavelength, variation in DLCU maintenance, safety, and techniques suggest that dentists could benefit from additional guidance and training on DLCU operation.


Assuntos
Resinas Compostas , Lâmpadas de Polimerização Dentária , American Dental Association , Estudos Transversais , Inquéritos e Questionários , Estados Unidos
19.
Biomed Res Int ; 2020: 2925879, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32149098

RESUMO

Novel biomaterials capable of accelerating the healing process of skeletal tissues are urgently needed in dentistry. The present in vivo study assessed the osteoconductive and osteoinductive properties of experimental biphasic bioceramics (HA-TCP) modified or not by a nacre extract (marine organic extract, MOE) in a sheep model. Fabrication of MOE involved mixing ground nacre (0.05 g, particle sizes < 0.1 mm) with glacial ethanoic acid (5 mL, pH 7) for 72 hours using external magnetic stirring (25°C). Nonreactive carriers (sterile polythene tubes; 3/animal, radius: 2.5 mm, length: 10.0 mm) pertaining to the control (empty) or experimental groups (HA-TCP or MOE-modified HA-TCP) were implanted intramuscularly into the abdominal segment of the torso in sheep (n = 8, age: 2 years, weight: 45 kg). Euthanization of animals was performed at 3 and 6 months after surgery. Tissues harvested were subjected to macroscopic and radiographic assessments. Specimens were then stained for histological analysis. Both control and experimental animals were capable of inducing the neoformation of fibrous connective tissue at both time points where superior amounts of tissue formation and mineralization were detected for experimental groups (unaltered (at 3 and 6 mos) and MOE-modified HA-TCP (at 3 mos)). Histological results, however, revealed that mature bone formation was only observed for specimens fabricated with MOE-modified HA-TCP in a time-dependent manner. The present study has successfully demonstrated the in vivo utility of experimental biphasic bioceramics modified by MOE in an ectopic grafting sheep model. Promising osteoconductive and osteoinductive properties must be further developed and confirmed by subsequent research.


Assuntos
Materiais Biocompatíveis , Regeneração Óssea/efeitos dos fármacos , Nácar , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Cerâmica/química , Feminino , Hidroxiapatitas/química , Nácar/química , Nácar/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Projetos Piloto , Ovinos
20.
J Am Dent Assoc ; 151(4): 303-304.e2, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32222178

RESUMO

BACKGROUND: Human papillomavirus (HPV) is a sexually transmitted oncovirus associated with several malignancies, including oropharyngeal squamous cell carcinoma. The 9-valent HPV vaccine can help protect against the high-risk HPV strains most commonly associated with HPV-related cancers. METHODS: The authors used an electronic survey to assess the roles of dentists and their team members in discussing the HPV vaccine, as well as administering the vaccine in a dental setting. On December 6, 2019, the authors e-mailed a survey link to the American Dental Association Clinical Evaluators (ACE) Panel (n = 813), a sample of American Dental Association member dentists. After 1 e-mail reminder, the survey closed on December 19, 2019, and the authors conducted exploratory and descriptive data analyses using SAS Version 9.4 (SAS). RESULTS: A total of 329 dentists responded to the survey, and 83 (25%) of them reported that they or their team members discuss the implications of the HPV vaccine with age-eligible patients or their parents or guardians. Dentists lead two-thirds (n = 218) of the discussions, and the clinical examination is the most frequent moment during the patient visit in which HPV-related topics are discussed. Some of the top reasons respondents mentioned for not discussing the vaccine in their practice were the perception that these discussions are best left to other health care professionals and not knowing how to address the topic with patients. If the scope of dental practice is expanded to include administering the vaccine, 125 (38%) of respondents would feel uncomfortable administering the vaccine. The most common potential barriers to administering the vaccine in a dental setting include obtaining reimbursement and vaccine management and preservation. CONCLUSIONS: The survey results suggest that dentists' comfort levels and perceived roles in discussing and administering the HPV vaccine vary. PRACTICAL IMPLICATIONS: There is a need to further define the role of dentists and their team members in the promotion and administration of the HPV vaccine. Resources for dentists and dental team members may be helpful to support professional education and communication about the HPV vaccine.


Assuntos
Infecções por Papillomavirus , Vacinas contra Papillomavirus , American Dental Association , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Inquéritos e Questionários , Estados Unidos
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