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Download ALD LASER Test - 11 May 2025 Exam | Questions With Verified & 100% Correct Answers and more Exams Dentistry in PDF only on Docsity!
Who theorized the concept of stimulated emission? - Correct Answer Einstein Who theorized that an excited electron will spontaneously return to its ground state? - Correct Answer Bohr The first ruby laser was created in by . - Correct Answer 1960, Ted Maiman reported in 1965 that a ruby laser could vaporize enamel. - Correct Answer Stern and Sognnaes First pulsed Nd:YAG laser released in and cuts tissue. - Correct Answer 1990, soft tissue In the first dental hard tissue was FDA cleared and is called . And the laser a year later. - Correct Answer 1997 Er: YAG laser Er, Cr: YSGG The word LASER is an acronym standing for . - Correct Answer Light Amplification by Stimulated Emission of Radiation Laser parameters include what 3 things? - Correct Answer 1)Duration of exposure 2)Fiber Diameter 3)Wavelength Lasers are: chromatic? ____ directional? coherent or noncoherent? emitted from a stimulated . - Correct Answer monochromatic: made of a single wavelength (visible or infrared) unidirectional coherent (all peaks and valleys of each wave travel in unison) active medium What states can the active medium be in? - Correct Answer solid, gas, semiconductor Energy is measured in - Correct Answer Joules (millijoules) Power is and is measured in - Correct Answer rate of doing work, or energy used over a period of time and is measured in Watts (J/sec) Frequency is measured in . - Correct Answer Hertz ( laser pulses/sec) What is the most important variable dictating how the laser beam will interact with the target tissue? - Correct Answer Peak Power Define Peak Power: - Correct Answer power level in each individual laser pulse, however it is not visible to the operator Describe Peak Power in the 3 types: 1) Continuous 2) Gated 3) Free running pulsed - Correct Answer 1) the peak power equals the average power displayed 2) Average power is half of peak power 3) Low Average power, very high peak power What are the two basic forms of pulsed laser modes? - Correct Answer Gated wave Free running pulsed How is the gated wave pulse created? - Correct Answer created with a shutter that blocks the laser beam from reaching the handpiece and target tissue at varying speeds: the laser is on constantly but the shutter device blocks the light from transmitting. (example: flashlight moving hand in front of it) How is the Free running pulse created? - Correct Answer Not on constantly, but emit photons in powerful bursts of energy measured in millionths of seconds. (example: turning flashlight on and off) Which lasers operate in continuous mode? (can be mechanically turned into a gated mode when a shutter is used) - Correct Answer CO2, Diode Which lasers operate in free running pulsed mode? - Correct Answer Nd:YAG, Erbium lasers Shorter pulses peak power (increase or decrease?) Which laser uses shorter pulses? - Correct Answer increases Hard tissue lasers Describe the 4 types of interactions the laser has with the target - Correct Answer 1) Absorption: chromophores absorb the photons, the light energy is then converted into thermal or mechanical energy to perform work (Preferred) 2) Reflection: The laser beam bounces off the surface with no penetration or interaction. (usually NOT preferred) 3) Transmission: laser can pass through superficial tissues to interact with deeper areas. (Nd:YAG and diode lasers) 4) Scattering: laser energy enters the target tissue will scatter in various directions. Define Chromophore: - Correct Answer Light-Absorbing compounds or molecules normally occurring in tissues that are attractors of specific wavelengths What are absorbed by Nd: YAGs and Diodes? - Correct Answer pigments: hemoglobin and melanin What part of the eye can diodes and Nd:YAGs cause damage to? - Correct Answer Retina (because it has pigment) What are absorbed by Erbium and CO2? - Correct Answer Water and erbium also does hydroxyappetite Which lasers penetrate tissue deeply? - Correct Answer Nd: YAG ( shorter near infrared wavelengths) penetrate tissue deeper than the longer mid infrared wavelengths like Erbium and CO2 Which lasers are soft tissue cutting? - Correct Answer Nd:YAG, Diode lasers,CO2, and Erbium (all 4) Which lasers are hard tissue cutting? - Correct Answer Er: YAG, Er,Cr:YSGG (all erbium) What are the five types of biological effects that can occur once the laser photons enter the tissue? - Correct Answer Fluorescence, photothermal, photodisruptive/photoacoustic, photochemical, photobiomodulation Define Fluorescence: - Correct Answer Determines the size of the carious lesion to diagnose and manage early carious lesions What types of interactions predominate in hard tissue procedures? - Correct Answer Photoacoustic/Photodisruptive interactions What temperature do the following things happen? 1) Hyperthermia 2) Coagulation and protein denaturation 3) Vaporization 4) Carbonization - Correct Answer 1) Below 50 degree C 2) 60+ degree C 3) 100 + degree C 4) 200 + degree C Which two of the above are irreversible? - Correct Answer Denaturation and carbonization: results in inflammation, pain and edema What are the wavelengths of the following? 1) Er-YAG 2) ER,Cr:YSGG 3) Nd:YAG 4) Diode 5) Diagnodent 6) CO2 - Correct Answer 1) 2940 nm (mid infrared range) 2) 2780 nm (mid infrared range) 3) 1064 nm (near infrared range) 4) 805-1064 nm (invisible near infrared wavelength) 5) 655nm (visible red wavelength) 6) 10,600 nm (infrared wavelength) (1nm=104-9 m) **Halket said they might have meters so make sure to look at units** What are the visible light wavelengths? - Correct Answer 400-750nm Describe the absorption of Er:YAG vs ER,Cr:YSGG - Correct Answer Er: YAG: peak of water absorption in infrared spectrum ER,Cr:YSGG: less absorption Describe the difference in thermal penetration between Er:YAG vs ER, Cr:YSGG - Correct Answer Er, Cr: YSGG has deeper thermal penetration in tooth structure, (the smaller the wavelength= the deeper the penetration) Are Erium lasers used in soft or hard tissue? - Correct Answer Both soft and hard tissue What type of interaction does Nd:YAG use? - Correct Answer Photothermal Describe the different functions of Nd:YAG - Correct Answer -primarily used for periodontal treatment: debridement of periodontal pockets -bacterial decontamination -seals the treated pockets by stimulating fibrin formation, acts as a scaffold for reattachment -forms clots in extraction sites via fibrin formation -gingivectomy, frenectomy, impression troughing, biopsy Are Diode lasers soft or hard tissue? - Correct Answer soft tissue What type of interactions occur in diode lasers? - Correct Answer Photothermal What type of procedures can Diode lasers do? - Correct Answer -Intraoral soft tissue procedures: gingivectomy, biopsy, impression troughing, and frenectomy. -Bactericidal -Laser assisted tooth whitening -Photobiomodulation When preparing to use a diode laser, the practitioner's first step should be to: - Correct Answer Check for PATENCY of transmission How do CO2 lasers work? - Correct Answer Articulated arms or hollow waveguides transmit CO2 laser beams. CO2 gas is in a chamber with nitrogen and helium and the active medium is pumped with an electrical current. What are CO2 lasers mainly used for? - Correct Answer HEMOSTASIS Are CO2 lasers used for hard or soft tissue? - Correct Answer Soft tissue What type of modes do CO2 lasers use? - Correct Answer Continuous wave, gated wave modes (superpulsed mode) What procedures can CO2 lasers be used for? - Correct Answer -Incisional and excisional biopsies, frenectomy, gingivectomy, pre prosthetic procedures, HEMOSTASIS -ablation and vaporization of leukoplakia and dysplasia Describe safety procedures that must be implemented for use of lasers: -eye protection -plume control -occlusal lesions above 30: -occlusal lesions 10-30: - Correct Answer -above 30= need restoration -10-30= potentially reversible What types of caries is diagnodent good at detecting? - Correct Answer Class I, Class V, Incisal caries , (permanent class Ill and primary class II lesions when paired with transillumination) What are the advantages of using erbium lasers for operative dentistry? - Correct Answer -precise ablation= minimally invasive preps -smear layer removed -disinfection -eliminates noise, hear, and vibration of high speed hand piece -reduced need for anesthetic -selective caries removal due to carious dentin's higher water content and softer consistency Between diode lasers, Nd:YAG, and erbium, which have the highest tissue penetration? which have the greatest potential for tissue damage? - Correct Answer -Diode and Nd:YAG have higher tissue penetration and greater potential for tissue damage why do Nd:YAG lasers and diodes have greater tissue damage than erbium? - Correct Answer -Nd:YAG and erbium can both run on free running pulses however, Nd:YAG has high absorption by pigment and deeper penetration of the tissue. -Diodes: run in continuous or gated wave mode so they have much less thermal relaxation capabilities and also have high absorption by pigments Which two lasers can be used to decontaminate the implant surface without damaging the titanium to treat peri-implantitis? - Correct Answer Erbium and CcO2 Which lasers are used for treating periodontal disease? - Correct Answer Erbium, Co2, Diodes, and Nd-YAG (all of them) *“Nd-YAG and erbium are the most used however Describe how Nd-YAG treats periodontal disease - Correct Answer -affinity for pigment allows for selective debridement of diseased sulcular epithelium -bactericidal -biostimulative -fibrin stimuation -Frenectomies -Tuberosity reductions -Vestibuloplasty -Tori Removal Which laser helps create a more durable clot in extraction sockets? - Correct Answer Nd:YAG (due to fibrin stimulation) (also has bone healing: good when treating bisphosphonate induced osteonecrosis) Lasers and pediatrics? - Correct Answer -good for many restorative procedures without LA -good for pulpotomies -good for orthodontic surgical needs Which lasers can be used in endodontics? - Correct Answer Nd:YAG, Erbium lasers and diodes What are the advantages of using lasers for endo? - Correct Answer -improved smear layer removal -disinfection in the apical third of the tooth Describe PIPS - Correct Answer -photon induced photoacoustic streaming -extremely high peak power and affinity for water of the Er:YAG laser with specially shaped radial firing tips are placed in irrigant solutions sends a powerful wave of ACOUSTIC energy throughout the root canal system. -little thermal effect Which lasers are capable of photobiomodulation? What is it also known as? - Correct Answer -All four -LLLT (low level laser therapy) what is LLLT used for? - Correct Answer -Treatment of apthous stomatitis and traumatic ulcers -Reduction of oral edema -Post-operative analgesia following periodontal, oral surgery, and endodontic procedures -Treatment of recurrent intraoral and labial herpies -management of lichen planus -reduce pain of orthodontics -management of TMJ disorders in LLLT, the Arndt-Shultz law states: - Correct Answer Doses between 0.1- 10J/cm are stimulating the wound healing but higher doses are inhibitory 
