The Surface Deterioration of Prefabricated Zirconia Crowns on Exposure to Acidulated Phosphate Fluoride Gel: An In Vitro Study.

Introduction Zirconia is a widely used restorative material in dentistry due to its superior aesthetic and mechanical properties. The oral cavity is a complex ecosystem with various components, which affect the teeth, as well as artificial restorative materials. Various personal and professional interventions carried out can severely affect the properties of restorative materials, thus altering the longevity of the prosthesis; 1.23% acidulated phosphate fluoride (APF) gel is one such professionally applied topical fluoride agent used to prevent caries. The interaction of this APF gel with highly aesthetic restorative material such as zirconia crowns is unknown. Objective The objective of this study is the evaluation of the surface deterioration of prefabricated zirconia crowns on exposure to deionised water and 1.23% acidulated phosphate fluoride (APF) gel with field emission scanning electron microscope (FE-SEM) and mass loss analysis. Material and method Sixty prefabricated paediatric zirconia crowns were taken, 10 samples were immersed in deionised water, 40 samples were immersed in 1.23% APF gel and 10 samples were used as control. Surface morphology and mass loss analysis were carried out at time intervals of four minutes, 24 hours, 48 hours and 72 hours using FE-SEM and digital weighing machine. Results No visual change was observed in the samples immersed in deionised water at the time interval of 72 hours. There was a marked visual change in samples immersed in 1.23% APF gel at the time interval of four minutes to 72 hours; this change involved a loss of gloss to the appearance of chalkiness. FE-SEM analysis for the control group and samples immersed in deionised water showed a smooth, continuous, undisrupted top layer, while samples immersed in 1.23% APF gel showed changes ranging from surface etching, to pinhole porosities, to crack formation and disruption of the surface depending upon the exposure time. Conclusions On the immersion of zirconia crowns in an aqueous acidic medium of 1.23% APF gel, the crowns showed flaws, imperfections and uneven superficial layers. It has been observed that surface grains are disrupted and micropores have been formed. This degraded superficial surface when undergoes cyclic mechanical loading can accelerate the ageing phenomenon of zirconia. Mechanical forces along with a dynamic electrochemical environment can degrade the material properties of zirconia.

Voice Acoustics and Vocal Effort in Mask-Wearing Healthcare Professionals: A Comparison Pre- and Post-Workday.

OBJECTIVE: We evaluated voice acoustics and self-perceptual ratings in healthcare workers required to wear face masks throughout their workday. METHODS: Eighteen subjects (11 cisgender female, 7 cisgender male; M = 33.72 years, SD = 8.30) completed self-perceptual ratings and acoustic recordings before and after a typical workday. Chosen measures were specific to vocal effort, dysphonia, and laryngeal tension. Mixed effects models were calculated to determine the impact of session, mask type, sex, and their interactions on the set of perceptual and acoustic measures. RESULTS: The subjects self-reported a significant increase in vocal effort following the workday. These perceptual changes coincided with an increase in vocal intensity and harmonics-to-noise ratio, but decrease in relative fundamental frequency offset 10. As expected, men and women differed in measures related to fundamental frequency and vocal tract length. CONCLUSION: Healthcare professionals wearing masks reported greater vocal symptoms post-workday compared to pre-workday. These symptoms coincided with acoustic changes previously related to vocal effort; however, the degree of change was considered mild. Further research is needed to determine whether vocal hygiene strategies may reduce vocal symptoms in mask-wearing workers.

Factors Related to Treatment Attendance for Patients Seeking Gender-Affirming Voice Therapy.

OBJECTIVE: The purpose of this study was to investigate factors related to treatment attendance for patients seeking gender-affirming voice therapy (GAVT). METHOD: We completed retrospective chart reviews of 50 patients (43 transgender women, three transgender men, four nonbinary patients; aged 18-67 years, M = 34.92 years, SD = 12.32 years) referred for GAVT at a Midwest outpatient center from 2016 to 2021. Data extraction included patient demographics, therapy visit specifics (e.g., number of sessions attended, treatment completion status, and in-person vs. virtual visits) and treatment timing (in relation to the onset of the COVID-19 pandemic), and psychosocial and socioeconomic information. RESULTS: There was no impact of treatment-timing relative to the onset of the pandemic on any attendance measure; however, patients were 1.9 times more likely to complete therapy with each virtual telehealth session attended. Individual factors of outside social support and hormone replacement therapy were positively related to the number of therapy sessions attended, whereas insurance provider and employment status were related to therapy completion. CONCLUSIONS: Telehealth attendance during the COVID-19 pandemic was positively associated with GAVT completion. Future research should investigate psychosocial and socioeconomic factors to understand how to identify patients at risk for poor treatment adherence and facilitate access to clinical care.

Impact of Face Masks on Speech Acoustics and Vocal Effort in Healthcare Professionals.

OBJECTIVES/HYPOTHESIS: We investigated speech acoustics and self-reported vocal symptoms in mask-wearing healthcare professionals. We hypothesized that there would be an attenuation of spectral energies and increase in vocal effort during masked speech compared to unmasked speech. STUDY DESIGN: Within and between subject quasi-experimental design. METHODS: We prospectively enrolled 21 healthcare providers (13 cisgender female, 8 cisgender male; M = 32.9 years; SD = 7.9 years) and assessed acoustics and perceptual measures with and without a face mask in place. Measurements included: 1) acoustic Vowel Articulation Index (VAI); 2) cepstral and spectral acoustic measures; 3) traditional vocal measures (e.g., fundamental frequency, intensity); 4) relative fundamental frequency (RFF); and 5) self-reported ratings of vocal effort and dyspnea. RESULTS: During masked speech, there was a significant reduction in VAI, high-frequency information (>4 kHz), and RFF offset 10, as well as a significant increase in cepstral peak prominence and perceived vocal effort. Further analysis showed that high-frequency attenuation was more pronounced when wearing an N95 mask compared to a simple mask. CONCLUSIONS: Face masks pose an additional barrier to effective communication that primarily impacts spectral characteristics, vowel space measures, and vocal effort. Future work should evaluate how long-term mask use impacts vocal health and may contribute to vocal problems. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:391-397, 2022.

Developing Educational Health Modules to Improve Vocal Wellness in Mask-Wearing Occupational Voice Users.

OBJECTIVE: To develop educational modules to improve vocal wellness and optimize communication in mask-wearing occupational voice users. METHODS: Module development focused on identifying accurate, understandable, and actionable steps to improve vocal wellness in the workplace. We i) interviewed eight voice-specialized speech-language pathologists and researchers on current speech and voice recommendations for mask-wearers, ii) developed educational content using the standardized Patient Education Materials Assessment Tool (PEMAT), iii) assessed the ability of nine mask-wearing community members to learn educational content, and iv) compared behavioral, acoustical, and perceptual changes in four mask-wearing healthcare professionals following educational training. RESULTS: We created three educational modules that described key vocal health and communication strategies, including microphone amplification, postural alignment, clear speech, hydration, vocal naps, and vocal warm-ups. PEMAT scores were 96% and 93% on understandability and actionability, respectively. Mask-wearing healthcare professionals increased use of 4 out of the 6 strategies following educational training and were able to retain information at rates >90% at 1-week follow-up. CONCLUSIONS: We developed a set of free-to-use educational modules to promote vocal wellness among mask-wearing occupational voice users (see VSMechLab.com). Future work should examine the impact of these strategies on voice measures in a larger group of mask-wearing community members.