Exam 2 Flashcards
What are the goals for surgical procedures with lasers?
- Minimize all photobiotic effects without causing unwanted collateral damage.
- Use of laser with power well below surgical thresholds for biostimulation.
- Use of minimal energy in performace of laser therapeutic procedures.
What lasers would you use for Soft Tissue and Hard Tissue?
- Soft Tissue
- CO2
- Erbium
- Diode
- Nd-YAG
- Hard Tissue
- Erbium
What are the indications for laser use with intra and extra oral soft tissue?
- Ablating
- Incising
- Excising
- Coagulation
What are the indications for laser use intra-oral hard tissue surgery?
- Cutting
- Shaping
- Contouring
- Wavelength tissue penetration
What’s the difference between laser surgery and conventional surgery?
- Laser
- Decreased internal tissue damage
- Less traumatic (depth control)
- Few myofibroblasts - less scaring
- Healing rate 2-3 weeks
- Secondary intention healing
- Hemostasis
- Contraction of vascular wall collagen
- Reduction in surgical time
- Blade
- Healing rate 7-10 days
What is the scaring mechanism?
- With lasers - fewer myofibroblasts = less scaring
- Less contraction and smoother healing
What is the healing mechanism with lasers?
It is prolonged for laser surgery
- Due to sealing of blood vessels and lymphatics
- Time for neovasuclarization
- New blood vessels where circulation has been impaired
- Secondary intention healing
What is the clotting mechanism with lasers?
- Photocoagulation results as denaturation of proteins occur (60-100C range)
- Hemostasis achieved by
- Contraction of vascular wall collagen
- Constriction of vessel opening
What lasers has the FDA approved/
- CO2 laser
- Argon laser
- Nd-YAG laser
- Diode laser
- Er-YAG laser
What are the characteristics of the “non-contact” application mode?
CO2 Laser
- Focused - cutting
- Defocused - surface vaporization
- Articulated arm, mirror - delivery system of choice wavelength 9000-11000 nm
What are the procedures indicated for non contact application mode?
- Removal of fibroma, lipoma, papilloma, veruca, haemangioma, frenulectomy, epulis fissuraturm
- Uncovering implants
- Gingivectomy, gingivoplasty, troughing, vestibulo-extensions (with grafting)
What are the procedures indicated for the Defocused Mode?
- Apthous ulcer coagulation
- Hemostasis
- Hyperlasia (palatal, medication induced)
- White lesions
What is the indication and applications for the Nd-YAG and Diode in oral surgery?
- Incision and Excision
- Removal of fibroma, lipoma, papilloma, frenulum - contact
- Uncovering implants - contact
- Apthous ulcers, herpetic lesions - non contact
- Venous lake syndrome - non contact
What is the indication and applications for the Erbium Laser in oral surgery?
- Water absorption - non contact
- Short pulses
- Lower thermal diffusion, no carbonization, low coagulation characteristics
- Clinical applications
- Small lesions, leukoplakia, gingevectomy, gingivoplasty
- Bone surgery
- Short high peak power pulses, water and air coolant, high H2O absorption
Which lasers are in contact and which are not?
- Contact
- Nd-YAG laser
- Diode laser
- Non-Contact
- CO2 laser
- Erbium laser
- Nd-YAG laser (gingivectomy, uncovering implants)
- Diode laser (gingivectomy, uncovering implants)
Why is a diode tip activated?
Tip activation is necessary for cutting, diode becomes a hot blade, this increase in fluence is necessary for quick, efficient cutting. When used for perio therapy, tip is not activated and it works as a true optical laser.
What is the need for controlling lateral thermal damage?
- It could extend up to 500 um from target - scaring
- Lateral thermal damage is controlled by:
- Speed of application
- Faster pulse, less time available for conduction into tissues
- Mid and Long IR = 100% absorption in epithelium - minimal collateral damage
What are the 3 basic parameters for successful surgery?
- Power
- Time on Target
- Spot size of the beam
Adjusting these parameters allows you to create:
- Deep thin cuts for incision and excision
- Wide superficial surface vaporization for tissue ablation
- Crucial to prevent scaring
What are the surgical techniques for ablation and vaporization?
- To increase depth, increase power
- Slower movement = bad!
- To decrease depth, decrease power, move faster, widen spot size
- Remove char after each pass
- Surface of hundreds of microns to 1-2mms
What are the surgical techniques for incision and excision?
- Make thin, deep cuts when trying to simulate a scalpel blade
- High power density
- Small spot size 0.1-0.5mm
- Gated mode, low fluence, minimize depth of penetration
- Connect dots, rapid controlled movement
How does laser energy affect specifc perio pathogens?
- Lowers bacterial levels in red and orange and complexes without antibiotic regimens (which just cover biofilm)
- Orange Complex
- F nucleatum, F periodontium, P micros, P intermedia, P nigrescens, S constellatus, E nodatum, C showar, C gracilis, C rectus
- Red Complex
- P gingivalis, T denticola, B forsythius, E nodatum
- Orange Complex
How do you minimize potential adverse outcomes?
- Adverse Outcomes
- Excessive temperature elevation
- Excessive dehydration of tissues
- Laterla thermal conduction (excessive)
- Pain
- To do so:
- Use lowest possible energy
- Shortest amount of time
What are the visual tissue changes that occur at specific temperatures?
- 37-60˚C - Shrinkage of tissue
- 60-65˚C - Blanching
- 65-90˚C - White, gray
- 90-100˚C - Puckering
- 100˚C - Smoke plume
What are the photobiologic effects?
- Lower bacterial levels in the red and orange complexes without antibiotic regimens
- Ablation and vaporization of inflammed tissue
- Redeveloping proper gingival architechture
- Using energy to affect the process of biostimulation
- Enhance mesenchymal activity
