Pilot in vivo animal study of bone regeneration by fractional YAG: Er laser

Altshuler G.B.1, Belikov A.V.2, Shatilova K.V.2, Yaremenko A.I.3, Zernitskiy A.Y.3, Zernitckaia E.A.3

1Dental Photonics, Inc., Walpole, MA, USA2ITMO University, SaintPetersburg, Russian Federation, kshatilova@mail.ru3Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russian Federation

COLLABORATION

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Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russian Federation

ITMO University, SaintPetersburg, Russian Federation

PROBLEMDEGRADATION OR LACK OF BONE AMOUNT

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Mandible after traumatic tooth extraction. Installation of implants is impossible due to lack of bone tissue.

The defect was formed in the maxilla after the removal of tumor. Implantation is impossible. Restoration of bone tissue volume by bone transplantation.

With the development of dental implantology the problem of insufficiency jaw bone is becoming increasingly important. In 25-30% of cases, you must first make a buildup of bone in jaws, before installation the implant and restore a person's ability to chew. If the implant installation is a routine procedure at the moment, the transplantation of bone is traumatic and requires a highly skilled surgeon.

BASIC BONE AUGMENTATION METHODS

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• Bone block grafting1

• Guided tissue regeneration2

• Bone reconstruction proposed by Khoury F3

Wide separating of alveolar bone and additional incision in donor area

Disadvantages:• Pain• Significant period of treatment• Specific requirements for doctor qualification

Tasks:• Pain reduction• Shortening of treatment period• Simplifying of medical manipulation

1. Khoury, F., and Khoury, C. "Mandibular bone blocks grafts: instrumentation, harvesting technique and application," Journal de Parodontologie & d’Implantologie Orale 25(1), 15–34 (2006).2. Nyman, S., Lang, N. P., Buser, D., and Bragger, U. "Bone regeneration adjacent to titanium dental implants using guided tissue regeneration: a report of two cases," Int. J. Oral Maxillofac. Implant. 5(1), 9–14 (1990).3. Khoury, F. "Augmentation osseuse et chirurgie implantaire:facteurs de prognostic," Implant 5, 221–237 (1999).

Step of harvesting the bone tissue from the donor area. Mandible is

uncovered on large area. Operation is traumatic. Healing is painful.

FRACTIONAL LASER TECHNOLOGIESAND BONE REGENERATION

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FRACTIONAL LASER TECHNOLOGIESFOR BONE REGENERATION

BONE REGENERATION AFTERLASER TREATMENT

Erbium laser excision:• effective hemostasis;• minimal delay before the healing;• bone healing at a faster pace than CO2-

treated wounds;• all of the bone defects are completely

replaced by new bone;• stimulate the secretion of PDGF in

osteotomy sites;• improves the healing of osteotomy

sites;• successful pocket reduction and bone

regeneration.

(see refs. in note to slide)

Bone tissue has successfully restoredafter erbium laser treatment

FRACTIONAL LASER TECHNOLOGIESFOR SKIN PHOTO-REJUVENATION

Grunewald, S., Bodendorf, M. O., Simon, J. C., and Paasch, U. "Update dermatologic laser therapy," JDDG 9(2), 146-159 (2011).

Fractional photothermolysis Specifics of post-fractional wound healing

before after

LASER TECHNOLOGIES FOR ALVEOLAR BONE TREATMENT

6Karabut, М. М., Belikov, А. V., Skripnik, А. V., Strunina, Т. V., Kuznetsov, S. S., Kiseleva, Е. B., Gubarkova Е. V., Senina-Volzhskaya, I. V., Feldchtein, F. I., Altshuler, G. B., and Gladkova, N. D. "Laser microablative tunnel formation to initiate alveolar bone regeneration. Pilot ex vivo study," Sovremennye tehnologii v medicine 5(4), 6-18 (2013).

Paramerets of laser treatment- Er:YAG laser, λ=2.94 μm- TEM00

- Ø=200 μm- τp=105-125 μs- Ep=5, 10, 30 mJ- Np=5, 7, 10, 50

Ability to create ablative microchannels in the porcine jaw bone through gingival mucosa by YAG: Er-laser radiation (λ=2.94 µm)

tooth8 mm

Laserradiation

Gum

Tooth cementum

Alveolar bone

Periodontium

Laseraction

Ep=30 mJ, Np=5

STUDY PROTOCOL

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two Angora rabbits Anesthesia

Mechanical excision Suturing

Xyla-ject (xylazin)

Soft tissue cutting

Staining (H&E)

Laser treatment

C-area and Tx-area

C-area – controlTx-area – laser treated

Er: YAG-laser, λ=2.94 μm

Lux2940 fractional handpiece(Palomar, USA)

• 4 mm output diaphragm• 22 parallel microbeams• distance of 1.0±0.1 mm• Dmb=100 μm (e-2 level)• τp=140±10 μs (FWHM)• Emb=5.40.1 mJ• ΣE=1181 mJ

48 days after operation100 days after operation

Nikon D80

OPERATION AREA PREPERETION - SHAVING

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CUTTING OF SOFT TISSUEAND PERIOSTEUM

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C-area

Tx-area

LASER TREATMENT OF PARIETAL BONE OF RABBIT SKULL

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traces of laser treatment

1 mm

SUTURING OF SOFT TISSUEAND PERIOSTEUM

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MECHANICAL EXCISION OF PARIETAL BONE WITH Tx- AND C-AREAS

1248 days after operation100 days after operation

HISTOLOGICAL IMAGE OF C-SAMPLE IN 48 DAYS AFTER OPERATION

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Nucleus of osteocytes

Osteocyte in lacunae

Empty lacunae

Haversian canals (HC)

Bone matrix

Osteoblasts at the edges of HC

Osteoid(not calcified bone)

Magnification 100×

Staining with H&E

HISTOLOGICAL IMAGE OF Tx-SAMPLE IN 48 DAYS AFTER OPERATION

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Blood-formingbone marrow

Detritus(coagulated protein, amorphous

acellular mass, debris of destroyed tissue)

Foreign objects

Necrosis

Necrosis

Bone capsules

Magnification 100×

Staining with H&E

HISTOLOGICAL IMAGE OF Tx-SAMPLE IN 100 DAYS AFTER OPERATION

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Blood-formingbone marrow

Fatty bone marrow

Resorption of "laser necrosis"

Сalcifieddetritus

Magnification 100×

Staining with H&E

CONCLUSION

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The pilot in vivo animal study of bone regeneration by fractional YAG: Er-laser was done. The histological structure of the rabbit parietal bone during its regeneration after fractional Er: YAG-laser (l=2.94 μm) treatment was investigated by hematoxylin and eosin (H&E) stain. Laser impact of single laser pulse consisted from 22 microbeams with diameter of each microbeam of approximately 100 μm on the e-2 level, pulse duration (FWHM) of 140±10 μs and energy of 5.40.1 mJ leads to formation in rabbit parietal bone the isolated from each other microcenters of necrosis with greater transverse dimension than diameter of laser microbeam. Microcenters of necrosis caused by the laser action are clear visible in 48 and 100 days after laser treatment. Partial filling of microcavities edges by fibrous tissue with presence of osteoblasts on their inner surface was observed in 100 days also, that indicates regenerative processes in the bone.

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Fundamentals of Laser-Assisted Micro- and Nanotechnologies (FLAMN-16), St Petersburg, Russia

Main Topics:Laser-Assisted Micro- and Nanotechnologies

Laser-Matter InteractionIntensive Laser Actions and Applications

Intensive laser actions in biology and medicine (Workshop)

27 June – 1 July 2016

The International Congress "Lasers and Photonics"

lpc.ifmo.ru

http://lpc.ifmo.ru/en/page/4/

Thanks for attention

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