Comparative evaluation of treatment of noncarious cervical hypersensitivity b...DR.AJAY BABU GUTTI M.D.S
Comparative evaluation of treatment of noncarious
cervical hypersensitivity by a fluoride varnish, a
dentin bonding agent, and Er, Cr:YSGG laser: An
in vivo study JCD 2020
Comparative evaluation of treatment of noncarious cervical hypersensitivity b...DR.AJAY BABU GUTTI M.D.S
Comparative evaluation of treatment of noncarious
cervical hypersensitivity by a fluoride varnish, a
dentin bonding agent, and Er, Cr:YSGG laser: An
in vivo study JCD 2020
Valuable clinical guide for soft tissue diode laser users with pre & post operative pics , useful , fully informative with tips helps my beloved coleagues to enjoy & profession the use of soft tissue dental laser #clinical_dental_laser #dental_laser #soft_tissue_laser
Application of laser in cosmetic dentistry / Dr.Sarah alkhateeb / Supervised ...Dr.Sarah Al-khateeb
Laser become an important part in cosmetic dentistry it provide predictable healing and reduce postoperative pain and swelling
All information also in my youtube account
https://www.youtube.com/watch?v=YqbWfA9jhWE&t=428s
Lasers in orthodontics /certified fixed orthodontic courses by Indian dental ...Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Comparative evaluation of the etching patter of er.cr and acid etching on ext...Mireya Ramírez
Etching of enamel and dentin surfaces increases the surface area of the substrate for better bonding of the tooth colored restorative materials. Acid etching is the most commonly used method. Recently, hard tissue lasers have been used for this purpose.
Diode laser applications in periodonticsMinkle Gulati
Periodontics extensively deals with soft tissue surgeries. However, pain, trauma, bleeding, postoperative
edema and scarring are often associated with conventional methods of surgery which are
problematic for both the patient and the clinician. Hence, to overcome these drawbacks, 940nm Diode
laser was used to perform various surgical procedures including frenectomy, gingivectomy,
vestibuloplasty, depigmentation and second stage implant surgery. The intra-operative and postoperative
advantages i.e. lack of swelling, bleeding, pain or scar tissue formation, and good wound
healing were observed in all the cases, verifying diode laser as an appropriate and beneficial device for
soft tissue surgeries.
Valuable clinical guide for soft tissue diode laser users with pre & post operative pics , useful , fully informative with tips helps my beloved coleagues to enjoy & profession the use of soft tissue dental laser #clinical_dental_laser #dental_laser #soft_tissue_laser
Application of laser in cosmetic dentistry / Dr.Sarah alkhateeb / Supervised ...Dr.Sarah Al-khateeb
Laser become an important part in cosmetic dentistry it provide predictable healing and reduce postoperative pain and swelling
All information also in my youtube account
https://www.youtube.com/watch?v=YqbWfA9jhWE&t=428s
Lasers in orthodontics /certified fixed orthodontic courses by Indian dental ...Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Comparative evaluation of the etching patter of er.cr and acid etching on ext...Mireya Ramírez
Etching of enamel and dentin surfaces increases the surface area of the substrate for better bonding of the tooth colored restorative materials. Acid etching is the most commonly used method. Recently, hard tissue lasers have been used for this purpose.
Diode laser applications in periodonticsMinkle Gulati
Periodontics extensively deals with soft tissue surgeries. However, pain, trauma, bleeding, postoperative
edema and scarring are often associated with conventional methods of surgery which are
problematic for both the patient and the clinician. Hence, to overcome these drawbacks, 940nm Diode
laser was used to perform various surgical procedures including frenectomy, gingivectomy,
vestibuloplasty, depigmentation and second stage implant surgery. The intra-operative and postoperative
advantages i.e. lack of swelling, bleeding, pain or scar tissue formation, and good wound
healing were observed in all the cases, verifying diode laser as an appropriate and beneficial device for
soft tissue surgeries.
The effect of the non thermal plasma needle on pseudomonas aeruginosa bacteriaIbrahim Karim
The reduction of the use of antibiotics and dependence on devices and tools that link between physics and modern therapeutic medicine led to a modern leap in the treatment of patients. In this research was designed nonthermal
plasma needle system at the normal atmosphere pressure and working on argon gas, the system was applied to gram positive Staphylococcus aureus bacteria isolated from patients with burns from Yarmouk Teaching Hospital, wounds and Burns Division. The bacteria were exposed to non-thermal plasma generated at different time intervals and at two values of voltages (4.9, 8). The killing percentage depends on the non-thermal plasma needle system operating
conditions such as gas flow, applied voltage on bacteria and distance between tip needle and isolates (Staphylococcus
aureus) bacteria, the perfect and partial killing percentage increase with the applied voltage increasing. The result showed various killing percentage were obtained for the bacteria. A perfect killing percentage of these bacteria was obtained at time (6 min) and the applied voltage were (8 kV) and gas flow (5 l/min).
The Invention of the Mid-Infrared Generating Atomizer and its Human and Veter...semualkaira
In the current scenario, there
are different therapies for different diseases of human and animals. The existed therapies are associated with hurdles like drug
resistance, less sensitivity, side effects, uneconomical, etc. However, none of the therapies provide multi-disease management on
a molecular basis. Every disease originates due to inter and/or intra-molecular (cell/ tissue) changes, which changes their respective chemical bonds. Therapies focusing to rectify the molecular
changes (molecular medicine) are growing slowly, which could
act as a single remedy, but needs extensive multi-faculty research.
The Invention of the Mid-Infrared Generating Atomizer and its Human and Veter...semualkaira
In the current scenario, there
are different therapies for different diseases of human and animals. The existed therapies are associated with hurdles like drug
resistance, less sensitivity, side effects, uneconomical, etc. However, none of the therapies provide multi-disease management on
a molecular basis. Every disease originates due to inter and/or intra-molecular (cell/ tissue) changes, which changes their respective chemical bonds. Therapies focusing to rectify the molecular
changes (molecular medicine) are growing slowly, which could
act as a single remedy, but needs extensive multi-faculty research.
The Invention of the Mid-Infrared Generating Atomizer and its Human and Veter...semualkaira
In the current scenario, there
are different therapies for different diseases of human and animals. The existed therapies are associated with hurdles like drug
resistance, less sensitivity, side effects, uneconomical, etc. However, none of the therapies provide multi-disease management on
a molecular basis. Every disease originates due to inter and/or intra-molecular (cell/ tissue) changes, which changes their respective chemical bonds. Therapies focusing to rectify the molecular
changes (molecular medicine) are growing slowly, which could
act as a single remedy, but needs extensive multi-faculty research.
EFFECT OF NANO SiO2 ON SOME MECHANICAL PROPERTIES OF BIODEGRADABLE POLYLACTIC...IAEME Publication
Effect of nano SiO2(13.69nm)with different weight percentage (1, 3, 5wt %)on some mechanical properties of polylactic acid (PLA) is investigated .PLA film with thickness 100µm was
prepared by solution casting method .Chemical and crystal structure of PLA and its composites with 5% nano SiO2 are characterized by FTIR and X-ray diffraction techniques .
Atmospheric Exposure to Cr III Powder Causes Genotoxicity in Rattus Norvegicus.inventionjournals
Several chemical elements are responsible for altering the genetic integrity of living beings. The metal Cr stands out in this regard. It exists in two oxidation states, Cr VI and Cr III, and has been investigated as an important environmental and occupational contaminant. Although the former is considered carcinogenic, the latter is classified as safe, even for human use in food supplementation. However, most studies with Cr( III) have been carried out by different routes to how it is occupationally found – in the atmosphere. This study evaluated the genotoxicity of Cr(III) inhaled during 8 hours of exposure to the maximum concentration permitted by ATSDR. Fifteen male Rattus norvegicus were used in this study. There were 3 groups (n=5 per group); these were - group exposed to Cr (III) powder (S), the negative control group (NC) and the positive control group (PC). The animals were exposed to Cr aerosol particles at a flow rate of 9L/min and atmospheric concentration of 500μg/m3 for only 8 hours in this study. An increase in genotoxicity and mutagenicity in the group exposed to the metal powder was observed. These findings suggest that further studies should be carried out in order to establish safe levels of exposure to Cr III in work environments
EDSP 360
Lesson Component
Criterion
Points Possible
Points Earned
Subject and Grade Level
Subject and grade level are identified.
1
Topic
Topic is identified.
1
Standards
State and national standards are written out. Standards relate to the lesson.
2
Objective
Objective is written in the proper condition, performance, criteria format. Performance is written in a measureable term.
5
Diversity/
Differentiated Instruction
Class description is briefly described including students with disabilities. Teacher candidate describes what portions of the lesson is differentiated for each subgroup. Five differentiations are noted, each based on a disability represented.
15
Materials
Complete list of materials are given.
1
Technology Connection
Specific technology connection is identified, including web address and/or name of computer program to be used.
1
Character Education
Principle
Scripture and reference are provided. Description of how the principle is taught in the lesson.
5
Procedures:
Set
Introduces the lesson and provides a creative way to engage students in the lesson.
5
Procedures:
Instruction
Detailed description of how the teacher candidate plans to teach the skill. How the skill will be modeled is fully explained. All components of objective are addressed.
15
Procedures:
Guided Practice
A practice activity where the teacher guides the class is provided. All components of objective are addressed.
7.5
Procedures:
Independent Practice
A practice activity where the teacher allows students to work independently is provided. All components of objective are addressed.
7.5
Closure
Closure recaps the main point of the lesson.
4
Evaluation
A tool to assess the objective is provided. Expected mastery level is stated. Matches the objective.
5
Total Points
75
Instructor Comments:
Project 3: Lesson Plan Grading Rubric
The Journal of Emergency Medicine, Vol. 52, No. 1, pp. 8–15, 2017
� 2016 Elsevier Inc. All rights reserved.
0736-4679/$ - see front matter
http://dx.doi.org/10.1016/j.jemermed.2016.07.108
RECEIVED: 26 Se
ACCEPTED: 26 Ju
Brief
Reports
COMPARISON OF METAL AND PLASTIC DISPOSABLE LARYNGOSCOPE BLADE
WITH REUSABLE MACINTOSH BLADE IN DIFFICULT AND INHALATION INJURY
AIRWAY SCENARIO: A MANIKIN STUDY
Andreas Moritz, MD, Sebastian Heinrich, MD, Andrea Irouschek, MD, Torsten Birkholz, MD,
Johannes Prottengeier, MD, and Joachim Schmidt, MD
Department of Anesthesia, University Hospital of Erlangen, Erlangen, Germany
Reprint Address: Andreas Moritz, MD, Department of Anesthesia, University Hospital of Erlangen, Krankenhausstr. 12, 91054 Erlangen,
Germany
, Abstract—Background: Single-use plastic blades
(SUPB) and single-use metal blades (SUMB) for direct
laryngoscopy and tracheal intubation have not yet been
compared with reusable metal blades (RUMB) in difficult
airway scenarios. Objective: The purpose of our manikin
study was to compare the effectiveness of these different
laryngoscope blades in a difficult airway ...
Survey of emf emitted by lab equipments in pharmacy labs of southeast univers...eSAT Journals
Abstract The aim of this survey is to investigate whether the Electromagnetic Fields (EMF) emitted by various lab equipments affects the students. There is a standard threshold value recommended by WHO for both electric and magnetic fields. Electro-Magnetic Fields commonly known as Non Ionizing Radiation is emitted from high power transmission lines, computer monitor/video display unit, radio waves of different frequencies (extremely low frequency to microwaves), telecommunication, satellite, radar etc. which causes health hazards to living system and environment. The WHO/ International Agency for Research in Cancer (IARC) has classified radio frequency electromagnetic field as possibly carcinogenic to humans. There has been no such study performed in Bangladesh. The data were collected from various labs of department of pharmacy at Southeast University in Dhaka, Bangladesh. These labs are Pharmaceutical, Cosmetology and Biopharmaceutical Lab, Pharmacology Lab, Organic Pharmacy and Pharmacognosy Lab, Inorganic Pharmacy Lab and Microbiology Research Lab. Both threshold values of Electric and Magnetic fields were measured for various electronic equipments. Also the maximum value of the magnetic field results showed that in many cases the magnetic field radiated from the different sources are greater than the threshold limit which are the main point of our findings. As a result of the long time efforts of world scientist community WHO formed ICNIRP in 1969. Key Words: EMF, NIR, DNA, EMC, AML and ICNIRP
Similar to Aerosols generation using Er,Cr:YSGG laser compared to rotary instruments in conservative dentistry: A preliminary study (20)
Micro-computed tomographic assessment of dentinal microcrack formation in str...DR.AJAY BABU GUTTI M.D.S
Micro-computed tomographic assessment of
dentinal microcrack formation in straight and
curved root canals in extracted teeth prepared
with hand, rotary and reciprocating instruments IEJ 2021
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
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APVP powder
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Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
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Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
3. ◦ The pandemic triggered by the novel coronavirus causing Severe Acute Respiratory Syndrome (SARS-CoV-2) started in December
2019 in Wuhan, China, affecting 195 countries around the world. Its high transmission rate (R0 of 3.58) has generated great concern
in the field of dentistry.
◦ The main symptoms of the disease include fever, dry cough, dyspnea, respiratory distress and fatigue or myalgia, as well as headache,
diarrhea, hyposmia and dysgeusia. Recently, dermatological lesions have been reported predominantly on hands and feet, which
appear mainly in children and adolescents.
◦ Routes of transmission are either direct contact with oral, nasal or eye mucous membranes and via respiratory tract (coughing,
sneezing and droplet inhalation) or indirect via contaminated surfaces. From the analysis of conjunctival samples of confirmed cases
of SARS-Cov-2, eye exposure has also been demonstrated to be an effective way for the virus to enter and infect the host.
◦ Most restorative and surgical procedures in dentistry require the use of rotary instruments which have been demonstrated to generate
considerable amount of splatter and aerosols. The highest amount of aerosol emission usually occurs during dental prophylaxis with
ultrasonic equipment and in tooth preparation using the high-speed dental handpiece. Aerosols are suspensions of solid or liquid
particles, which may contain saliva, blood elements, organic tooth particles, bacteria or viruses. The particle size can vary from 0.001
to >100 μm.
◦ Van Doremalen et al. describe the half-life of SARS-CoV-2 in aerosols being 1.2 hours (range 0.64 to 2.64 hours), 7 hours on plastic
surfaces and 6 hours on stainless steel. Apart from disinfecting material and work areas, dentists must wear protective equipment.
3
4. ◦ Use of special respirators like European standard Filtering Face Piece 2 (EU FFP2) and maintain a minimal distance from the
patient of 35-40 cm to limit the transmission of airborne diseases, especially in procedures involving aerosols generation.
◦ The use of hard tissue lasers may be an alternative technique in many dental procedures traditionally performed by rotary
instruments to reduce the amount of aerosols. Their introduction in dentistry started in the late 1980’s with advantages such as
the absence of smear layer, bactericidal nature and tissue selectivity depending on the wavelength of the laser. For example, in
restorative dentistry the Erbium Chromium: Yttrium Scandium Gallium Garnet laser (Er,Cr:YSGG) with wavelength in the
mid-infrared range of the electromagnetic spectrum (2780 nm) is characterized by its energy being highly absorbed by water
molecules. For cavity preparations in natural teeth, the incremental pulpal temperature rise with this laser is less than 4ºC due
to the low thermal side-effect production. However, a rotatory instrument generates higher thermal side-effect because of the
direct contact and friction during cutting. Therefore, higher amounts of water cooling is mandatory, leading to more aerosols
generation, depending on the flow rate of the coolant.
◦ The laser parameters with higher percentage of water/air allow the use of higher peak energy per pulse and lower repetition
rate for faster ablation, while avoiding significant temperature increase. However, lower water percentage could possibly be
used for similar indications.
4
6. Objective
The objective of this study is to describe the quantity of aerosols generated during class I cavity preparation
performed with three different techniques: using a rotatory instrument (high-speed turbine) and
Er,Cr:YSGG laser with two different parameters.
6
8. ◦ A descriptive study was carried out. Human teeth were used in each group with the following inclusion criteria: permanent
lower molars extracted due to periodontal problems without structural alterations of the dentin or enamel.
◦ This study was approved by the Ethical Committe for Clinical Research (CEIC) of the Dental Hospital of the University of
Barcelona (Spain) (30/2020) and complied with the Helsinki Declaration. All patients signed the in formed consent for the
use of their teeth. These specimens were stored in saline solution and then refrigerated at 4ºC until mounted in a typodont.
◦ In order to collect the aerosol particles produced by the turbine and the laser, we used fourty eight cotton cellulose discs of
grade I, qualitative filters of 11 cm diameter and 0.2 mm thickness; fluorescein sodium (C20H10Na2O5), an odorless,
orangered powder that is commonly used in microscopy, ophthalmology and forensic medicine.
◦ For class I cavity preparation the following materials were used: A-DEC performer dental chair (A-DEC, Oregon United
States). This chair has a refillable self contained 2-liter water bottle for the coolant spray and a conventional high-speed air
turbine NSK S-Max M600L (NSK Company, Tochiji Japan) with diamond access cavity bur F0137 (Maillefer. Ballaigues
Switzerland).
◦ An Er,Cr:YSGG 2780 nm wavelength laser Express model (Biolase Technology, Irvine, CA, USA) with 600 microns
Sapphire tip (MGG6. Biolase Technology, Irvine, CA, USA). An Ultraviolet light of 395 nm wavelength, was used to easily
detect the flourescence material in aerosols that were collected on the filters.
8
9. ◦ The procedures were performed in a closed transparent plastic box (80 cm long x60 cm wide x 33 cm high). Two holes
were made in the anterior area to insert the instruments. The typodont was placed in the centre of the box and one of the
lower molar was isolated with a rubber dam and a molar clamp to simulate the clinical situation. A total of 16 filters were
placed : 5 filters on the right and left lateral sides, 4 filters on the posterior side and 2 filters on the anterior side. The
distance from the typodont to the anterior and posterior sides of the box was 30 cm and the distance to the lateral sides was
40 cm.
◦ Through the left hole we introduced a disposable saliva ejector for aspiration of the excess water and through the right hole
a turbine or laser handpiece. We prepared the fluorescent dye placing it in the water (coolant reservoir), with the ratio 1
gram dye powder to one liter of distilled water.
◦ A class I cavity was made in the tooth during 5 minutes in each group. We analyzed and took pictures with a digital camera
of the fluorescent material with the help of an ultraviolet light in a dark room. With a computer program a grid template of
1x1cm2 was calibrated and super-imposed over the photo of each filter , allowing us to measure the stained area
(quantitative variable measured in cm2). A square was considered contaminated with a minimum stain on it.
◦ The three experimental groups were: Group 1, high speed rotary handpiece at 330,000 rpm, with water coolant at flow rate
of 25 ml/min (intermediate rate). Groups 2 and 3, using Er,Cr:YSGG laser in a non contact mode at a distance of 1.5-2 mm
by the parameters with water percentages of 80% and 40% respectively.
9
13. ◦ The variable analyzed was the contaminated area in cm2 in each filter of the 3 groups. A total of 1744 cm2
correspond to the surface of the 16 filters.
◦ 1349 cm2 (77,3%) was detected with fluorescein in group 1, 128 cm2 (7,3%) in group 2 and 68 cm2 (3,8%) in the
third group.
◦ The high speed turbine contaminated 70% and 73%,5% more surface area of the filters compared to the Laser with
80% and 40% of water respectively.
◦ The difference between the use of different laser parameters resulted in 3.5% less contamination of the total of all
filters.
◦ We noted that the mean contamination on the left side of the box was more than on the right side in all groups. In
group 1 using air turbine, we measured a mean of 102.6[±7.5 SD] cm2 on the left side compared to 70.6[±32.3 SD]
cm2 on the right side. In laser groups 2 and 3, a mean of 12.8[±14.9 SD]cm2 and 6.8 [±5.7SD] cm2 respectively
was described on the left side and 0 cm2 of surface contamination on right side.
13
14. Example of a contaminated filters illuminated with UV light and
gridded for area measurment, in different positions for the 3
groups.
14
17. ◦ Splatter and aerosols are differentiated by the particle size, splatter contains fragments larger than 50 μm which
rapidly fall down due to the effect of gravity leaving droplet nuclei which can be suspended in air for many hours
and can be inhaled into the lungs causing respiratory infection. “Bioaerosols” is a more precise term in a clinical
setting, as it is always contaminated with blood, tooth and organic particles, bacteria from oral flora or dental plaque
and restorative materials.
◦ Miller S et al. in a retrospective analysis for SARS-CoV-2 suggested that airborne transmission is the most likely
mechanism rather than only direct or indirect contact with contaminated surfaces. Furthermore, viral RNA in
droplets smaller than 5 μm can still be infective. Rotary instruments during tooth cutting generate considerable
amount of aerosols and the use of abundant water coolant is obligatory.
◦ Serdar Toroglu et al. using the high-speed air-turbine, found a significant increase in enviromental aerosols after five
minutes of removing excessive adhesive material after brackets debonding.
◦ Several measures can be taken to reduce the enviromental contamination during these procedures such as pre-
procedural mouth wash with 0.2% chlorhexidine which showed significant bacterial reduction in aerosols during
ultrasonic scaling. The use of rubber dam during tooth preparation and high volume evacuator (HVE) can reduce
spread of microorganisms by 90%. These strategies can be used together or individually.
17
18. ◦ In recent years, Er,Cr:YSGG laser has become an accepted alternative method for cavity preparation, but we
didn´t find reports concerning the generation of aerosols using laser cutting compared to conventional high-
speed air turbine. Hard tissue laser provides low cutting pressure, less vibration compared to bur cutting and
minimal or no need for local anesthesia.
◦ The laser ablation mechanism is achieved through photothermal effect, due to the absorption of laser photons
by the water molecule present in the tissue to be cut, producing micro-explosions and surface disruption. Higher
water and air ratios reduce the thermal effect.
◦ In the present study we used two different water percentages to see if it affect the amount of aerosols produced.
To avoid an increase in the thermal effect with lower water percentage, we increased the pulse repetition rate
and decreased the power, while maintaining air percentage to decrease variables that can affect the
dissemination of aerosols. However this reduction in power per pulse for group 3 with the double reduction of
aerosol may be also due to five times lower energy per pulse, further experimenting in future studies having the
same pulse energy but 40% water can be considered, to eliminate possible variables that can alter amount of
aerosols.
18
19. ◦ Conventional air driven handpiece, on the contrary, requires specific air pressure range to function, and
air percentage is not a modifiable variable.
◦ Electric handpiece has been introduced to overcome disadvantages of air turbine in terms of maintaining
the cutting torque, but there are no studies that describe the aerosols generated. However, it still requires
abundant water irrigation due to the heat production.
◦ In the present study we observed that higher amount of water can attribute to more splatter and aerosols
production. In conventional rotary cavity preparation with air turbine we need more water spray as a
coolant than in laser groups to decrease thermal pulp damage. We observed more contamination in the
filters located on the left side of the box [1, 2, 3, 4, 5, 6, 7, 16] than those on the right side [8, 9, 10, 11,
12, 13, 14, 15]. This can be attributed to the fact that the operator was right handed orienting the
handpiece towards the left side, also the right arm may have blocked the aerosols from reaching the filters
located in the right side.
19
22. ◦ The contaminated area during the procedure of class I cavity preparation, is reduced by 70% using
Er,Cr:YSGG laser compared to high-speed turbine. A slightly higher contamination was observed in 80%
versus 40% water laser groups. Further studies are needed with more trials to determine a statistical
significant difference between laser and conventional technique, as the use of Er,Cr:YSGG laser could be
considered as a safe alternative for aerosols and splatter reduction in daily clinical practice for prevention
of airborne diseases transmission in the current pandemic.
22
23. ◦ The study investigated the influence of varying amounts of air/water spray and the energy used by an
erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) 2,780 nm laser when treating dental
tissues. The morphological effects produced by the laser interaction on healthy human enamel were
evaluated by scanning electron microscopy (SEM). The vestibular and lingual surfaces of ten molars
were treated with laser at different power settings; each surface was subdivided into cervical, median,
and occlusal parts and treated with different proportions of water spray; the series contained 60 tooth
portions. Treatment differed in terms of power setting and air/water percentage. All specimens were
then subjected to dehydration and metallisation. At SEM evaluation, the classic aspect of laser-treated
enamel was visible: grooves, flakes, shelves and sharp edges, indicative of micro-explosion rather than
melting. Vaporisation of the tissue created a clear delimitation from surrounding healthy tissue, with
partial respect to the prismatic structure of the treated enamel. The aspect of the enamel was rarely
type 1 Silverstone but more frequently type 2 or 3, with prismatic structure not respected and/or
completely disordered. These morphological differences appeared to be correlated with the inclination
of the laser beam aimed at the enamel prisms and with the percentage of air/water used. The laser
system analyzed showed itself to be effective at removing human dental enamel. The results
appeared to be closely correlated with the variation of the percentage of the laser's water-air spray. 23
Use of the erbium, chromium: yttrium-scandium-
gallium-garnet laser on human enamel tissues.
Influence of the air-water spray on the laser-tissue
interaction: scanning electron microscope
evaluations
24. Atmospheric contamination during
dental procedures
P Legnani, L Checchi, G A Pelliccioni, C D'Achille
◦ The aim of this study was to evaluate the level of aerosol pollution following dental procedures
performed in 15 sessions with an ultrasound scaler and a bicarbonate cleaner. The air contamination was
measured by means of the Surface Air System method and the "plate" method (Air Microbial Index).
Each colony-forming unit per cubic meter of air was allotted a unit value for statistical analysis. The data
were then compared with the hygienic assessments made in previous studies. The results showed that the
initial environmental conditions in a dental office initiated at the level of mediocre, then became very bad
during dental procedures, and fell between mediocre and very bad at the end of the procedures.
24